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The Future of Mold Making and Plastics

Mold Making and Plastics is injection molding process which is a simplistic and efficient manufacturing process that involves injecting heated material into a plastic injection mold to shape plastics or rubber.

Currently, plastic injection molding is used in several industries such as aerospace, packaging, and injection molding toys. The injection molding and plastics industry is consistently evolving owing to technological breakthroughs, market disruptions, and certain economic and social factors.

Significant Breakthroughs

Tool formation, sharpening, heat treating, metal machining, and drilling out the design were carried out by hand, requiring an enormous time commitment. Since humans performed almost the entire process manually, conformity issues became inevitable, with no two molds exhibiting similar properties.

However, with the advancement of technology, two mold-making techniques contributed immensely to the shift from manual to computer-assisted machining –

CNC Milling Machines

These machines initially assumed the form of 2D Bridgeport milling machines, which were integrated with CNC attachments. These machines took the market by storm and transformed the way toolmakers created parts since they offered swift processing speeds paired with greater accuracy and minimal manual oversight.

Modern-day CNC milling machines offer expeditious processing speeds while achieving high accuracy even when working with complex molds.

injection molding cost

CAD Programs

CAD programs have had a crucial impact on the evolution of the mold-making industry by streamlining the process of mold designing. These programs enabled industry professionals to form 2D and later 3D renderings, which could be quickly and easily edited, tested, and altered.

The Future Scope of Injection Mold Making and Plastics

The injection molding industry has continued to thrive over the years and has exhibited massive potential for enhancements in terms of efficiency, such as creating direct-to-metal molds at a faster pace while staying within budget.

Here are some crucial industry trends that can potentially define the path of evolution of plastic mold making and plastics, injection molding, and plastics for years to come –

Composite Materials

Since 2020, composite materials have gained momentum as one of the leading trends in the aerospace and automotive industries. A composite substance is a heterogeneous blend of two or more materials performed to obtain a stronger end product. 

Composites are considerably stronger despite being lightweight than high-performance substances such as steel. Such properties make them an ideal choice for aerospace, automotive, and construction industries.

Composites are flexible, durable, and cost-efficient substitutes for the materials used for injection molding and mold making. In the upcoming years, composite materials will make their way into the medical sector and manufacturing military-grade equipment.

Increased Automation

Implementing automation and software, advanced analytics, and machine learning in manufacturing processes is surging rapidly with the latest technological breakthroughs. Programming has become considerably simpler, which has led to minimized downtime, sped-up production cycles, and efficient maintenance.

Automation enables manufacturers and engineers to exercise a higher degree of control of the injection molding process. It can also help designers and product developers maintain a competitive edge in the market.

A form of automation called mold flow analysis is gaining traction in the manufacturing sector. It uses software to simulate the injection molding cycle and provide insights into the mold filling process. This simulation is notably effective when making alterations to the product design in the design phase. Mold flow analysis can also test for warpage, shrinkage, improper fill patterns, and more before prototyping.

If you run a small business and are operating on a budget, invest in a vertical mill as it is relatively cost-effective and offers decent levels of accuracy.

Sustainable Development

Manufacturing industries are shifting toward sustainability, and consequently, the plastics industry must also make a move in this direction. Eco-conscious buyers have grown in numbers, which has inspired manufacturing firms to make their operations more efficient and significantly trim down wastage.

The mold-making industry has devised ways of operating injection molding machines with greater efficiency to curtail power consumption, switch to sustainable power sources, use recycled raw materials, minimize material wastage, and more.

While sustainability is rapidly advancing, manufacturing firms must meet critical project specifications to ensure optimum quality parameters. This is because recycled products often fail to satisfy the physical and mechanical specifications of the final commodity.

Bioplastics

Bioplastics are a direct derivative of sustainable development as several manufacturers have begun exploring its benefits and implementation in injection molding and mold making.

Bioplastics are petroleum-based plastic substitutes derived from biomasses like sugarcane, corn, seaweed, and others. Bioplastics are unique since they exhibit biodegradability and carbon neutrality.

Manufacturing and packaging products using bioplastics can push mold-making firms towards being more eco-friendly and minimizing negative environmental impacts.

However, it is vital to note that bioplastics are not entirely pollution-free. Bioplastics often get mixed with non-recyclable polymers as a means to improve upon their strength. If these hybrid bioplastics end up in a conventional landfill, they can take about 100 years to decompose, which can be toxic to the environment.

PA6 injection molding shop

Lightweight Alternatives 

Manufacturers and consumers are on the lookout for lightweight products. In the aerospace and automotive sectors, lighter components lead to more mileage throughout the journey and efficient consumption of charge in batteries.

For medical device manufacturing, stents and joint replacements made using lightweight materials can significantly boost the patient’s recovery. Lightweight materials also cost less during transportation.

Final Words

The above-mentioned trends can help engineers and manufacturers achieve better results by minimizing the scope of error and time consumption. Besides the two breakthroughs, namely the CNC milling machines and the CAD programs, there has been a significant advancement in the plastic molding sector with the latest technology.

Some promising future trends include lightweight material substitutes, automation, and a commitment to sustainable manufacturing that will jolt up the mold-making industry.

About the Author:

Peter Jacobs is the Senior Director of Marketing at CNC Masters. He is actively involved in manufacturing processes and regularly contributes his insights to various blogs on CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general.

If you are looking for mould suppliers to make your plastic injection molding project, welcome to contact us. We are one of the top 10 plastic injection molding companies in China that offers custom plastic injection mold and moldings, die casting, CNC machining, part design, testing, prototyping, assembly, and delivery, all in one service here.

Injection Mold

In modern industrial production, mold is an important technology used in shaping products (including metal products and nonmetal products) for all of the industries. Meanwhile, it is the ‘magnifying glass of efficiency and profit’ to the raw material and equipment, because the value of the final product made in the mold is often tens of, even hundreds of times as valuable as that of the mold itself.

The mold industry is the basic industry of the national economy, and it is called ‘the mother of industry’. Every aspect of human life such as clothes, food, housing, and transportation is closely connected with the mold industry. Therefore, the level of injection mold technology has been a significant symbol to measure a country’s developing level of mechanical industry.

And mold can be divided into two kinds of them: mold for metal products and nonmetal products.
The metal products mold include cold-press mold, pressing mold, forging mold, press casting mold, precise casting mold, stamping tool, punch tool, and dust metallurgy mold, etc. These kinds of mold have extensive apply-cation in electrode-cranial products, automobiles, aviation instruments, and other metal products.
The nonmetal products include plastic injection mold, ceramic mold, rubber mold, glass mold, food mold, and ornament mold. These kinds of molds have extensive apply cation in our lives, at this page we are talking about injection mold. this is the most papular modern technology which used in our life everywhere.

An injection mold used to form a plastic product using the injection molding process. A standard injection mould is made of a stationary or injection side containing one or more cavities and a moving or ejection side.

The resin, or raw material for injection moulding, is usually in pellet form and is melted by heat and shearing forces shortly before being injected into the mould. The channels through which the plastic flows toward the chamber will also solidify, forming an attached frame. This frame is composed of the sprue, which is the main channel from the reservoir of molten resin, parallel with the direction of the nozzle, and runners, which are perpendicular to the direction of the nozzle and are used to convey molten resin to the gate(s), or point(s) of the gate and feeding the molten material into the mold cavity. The sprue and runner system can be cut off and recycled after molding. Some moulds are designed such that it is automatically stripped from the part through the action of the mould. For example, the submarine gate or banana gate, if using hot runner systems then there will be no runners.

The quality of the injection molded part depends on the quality of the mould, the care taken during the moulding process, and upon details of the design of the part itself. It is essential that the molten resin is at just the right pressure and temperature so that it flows easily to all parts of the mold. The parts of the injection mold must also come together extremely precisely, otherwise small leakages of molten plastic can form, a phenomenon known as flash. When filling a new or unfamiliar mould for the first time, where shot size for that particular mould is unknown, a technician should reduce the nozzle pressure so that the mold fills, but does not flash. Then, using that now-known shot volume, pressure can be raised without fear of damaging the mould. Sometimes factors such as venting, temperature, and resin moisture content, can affect the formation of flash as well.

Injection Mold Material

Traditionally, molds have been very expensive to manufacture therefore they were usually only used in mass production where thousands of parts are being produced. Injection Molds are typically constructed from hardened steel or aluminum. The choice of material to build a mold is primarily one of economics. Steel molds generally cost more to construct, but their longer lifespan will offset the higher initial cost over a higher number of parts made in the mold before wearing out. Aluminum molds can cost substantially less, and when designed and machined with modern computerized equipment, can be economical for moulding hundreds or even tens of parts.

Requirements for the injection mold

ejection system

An ejection system is needed to eject the molded part from the cavity at the end of the molding cycle. Ejector pins built into the moving half of the mold usually accomplish this function. The cavity is divided between the two mold halves in such a way that the natural shrinkage of the molding causes the part to stick to the moving half. When the mold opens, the ejector pins push the part out of the mold cavity.

cooling system

A cooling system is required for the mold. This consists of an external pump connected to passageways in the mold, through which water is circulated to remove heat from the hot plastic. Air must be evacuated from the mold cavity as the polymer rushes in. Much of the air passes through the small ejector pin clearances in the mold. In addition, narrow air vents are often machined into the parting surface; only about 0.03 mm (0.001 in.) deep and 12 to 25 mm (0.5 to 1.0 in.) wide, these channels permit air to escape to the outside but are too small for the viscous polymer melt to flow through.

Use of plastic injection molding

Plastic injection molding is the most common and widely used method for the mass production of plastic products around the world because of its convenience and ease of use. Plastic products made using this method include plastic chairs and tables, electronic product covers, disposable spoons and knives, and other cutlery products.

History of injection molding

Plastic injection molding was started by European and American chemists who were experimenting with plastics. Originally done manually and pushed into the mold using Parkesine, it turned out to be too brittle and flammable. John Wesley Hyatt is the official inventor of plastic injection molding, and this process has a rich history with a brilliant spirit.

Injection molding was originally invented to solve the problems that billiard players face abundantly. The 19th-century billiard balls were made of ivory derived from tusks taken from elephants. Celluloid was one of the first plastics used to make billiard balls.

Plastic Injection Molding

Plastic Injection Molding

Instructions for the procedure

The scientific procedure used to produce plastic products by applying injection molding is very simple. Your plastic melts and is put into a huge syringe. It is then placed in a suitably shaped mold depending on the product being manufactured and allowed to cool for a sufficient amount of time to reach the desired shape. However, the actual process of actual injection molding is not so simple and can be broadly divided into three subdivisions: injection unit, molding section and finally clamp. The plastic pellets are gradually liquefied and gradually injected into the injection unit through a tunnel that is completely melted until it reaches the front of the barrel. When it reaches the mold, it cools and hardens to the desired fixed shape. The mold will then return to the original machine position.

All injection molded parts start with plastic pellets with a diameter of a few millimeters. They can be mixed with certain limited amounts of pigments called “colorants” or up to 15% recycled material. The mixture is then fed into an injection molding machine. Early molding units used a plunger to push down from above. However, the outer area was hot or cold and the melting process did not work properly. The solution to this was a reciprocating screw. This was often seen as the most important contribution that was none other than a revolution in the plastic product manufacturing industry. The screws cause the shear stress necessary to melt the plastic, and the rest of the heat comes from the traditional heater band that surrounds the machine. When molten plastic is injected into the mold, the air is released through the sideways vents. The honey viscosity plastic is so thick that it cannot be released from these vents, which are only a few microns wide.

Engraving witness marks on plastic products is also an important part of marketing. This is because we need to be able to authenticate and verify the authenticity of the product by looking for a line separate from the witness mark. These are created using removable inserts and can prove very helpful in tracking defects.

If you are looking for injection mould and injection molding parts?

You are welcome to send us your requirement for quote, you will have our competitive price within two working days.

If you have injection mold technical question?

You are welcome to contact our technical Manager to solve your technical issue by steve@sinceretechs.com.

We have over 15 year working experience with 15 years skilled technical English communication.

Your project will be successful with our supporting, we guarantee your satisfaction.

What are you waiting for? Contact with us you will not lose anything buy have your technical issue solved.

Injection Mould China for your market

When it comes to injection mold manufacturers china, there are a number of misconceptions that people typically have. One of the biggest misconceptions is the sense that an operation that is being conducted in China is one that is largely unreliable. This cannot be further from the truth. In fact, this is an extremely reliable operation that is based in China and is turning out products that are of high quality. In order to fully understand this, it is equally important to understand the history of this type of operation as well as its current status.

Injection mold china

Injection mold china

What makes this particular operation better than those that have come before it? In the past, the the hallmark of operations of this type were that quality was sometimes not consistent and sometimes quality barely existed at all. This is especially true of some of the operations that were conducted in China. As a result, people started to have their fair share of doubts about whether or not plastic mould injection operations within the country of China could produce products of reasonable quality. Fast forward to today and those questions have been answered.

In truth, today’s operation is quite reliable and very successful. The reliability issues have been successfully put aside and any questions about quality have them put to rest long ago. Today’s operation distributes products to multiple international customers and is able to produce virtually any type of moulded plastic product for any use. The entire system utilizes a state of the art process, using the latest software to design the products that are ordered and then mass produce them as quickly and efficiently as possible. All of this is done without compromising quality in any way, shape or form.

The best part about it all is that the mistakes that were made throughout the early history of such operations has been taken into account in order to ensure that those types of issues do not happen when products are produced today. In fact, there are more than 15 years worth of operations from which to gain experience and perfect the way that everything is handled ranging from the way that orders are taken to the way that they are produced and shipped out. The fact that software is used to create virtually any type of product minimizes the chances for errors and allows everything to move along very rapidly. The end result is that the only limitation on the types of products that can be produced is the imagination of the individual who is ordering the product in the first place.

In addition, each product gets its own project manager and everything can be produced at a cost that is more than reasonable. This helps to proliferate these types of operations and even though the system is based in China, high quality products are produced each and every day which are then shipped out to locations all over the world. Imagine virtually any plastic mold part such as those parts used for calculators, DVD players or printers, and they can probably be traced directly back to operations of this type. Without them, it would be virtually impossible to operate in the world the way it is understood today.

Why Choose China Plastic Injection Molding Service?

China is well known as a manufacturing center and as an exporter of plastic products. Chinese plastic injection molding manufacturers guarantee high-quality products that are reliable and long-lasting, there are many plastic molding companies in China, it is a headache for you to find a right China mold maker from that huge resource, Sincere Tech is one of the top ten best plastic mold and molding companies in China, we offer you the 100% satisfied quality and service, go to our home page by https://www.plasticmold.net/ to know more.

All of the information we referred from Wikipedia, but we sort out together for easy to read, if you want to know more, please go to injection mold Wikipedia.

If you want to know more information about products made from injection mold china company? You are welcome go to our home page to know more, or send us email,we will reply you with 24 hours.

 

liquid silicone rubber molding

We are Silicone Injection Molding China company that offers plastic mold/molding service, rubber molds, Silicone Injection Molding, liquid silicone injection molding parts to the world, send us your drawing and we will quote you in 24 hours.

What is Silicone Injection molding

Silicone is a kind of environmentally friendly raw material, silicone material is loved by people with its various perfect properties. silicone injection molding part has the softness and poison-free properties so that widely used in industrial sealing and medical devices. Especially its working temperature: between minus 60 to 250 degrees no plastics company compare its advantages. Using silicone to seal metal or plastic parts to form some new properties and makes the product soft and hard. For example, the silicone overmolding kitchen Spatula is environmentally friendly and is loved by consumers. Silicone injection molding parts & plastics parts have very similar but have different processing.

silicone injection molding machines

silicone injection molding machines

To work with us is so easy, you only need to send us your drawing and your requirement, then your seat back and wait for the parts for testing until you approve the parts or molds, we will take all of the jobs for your from mold design, mold manufacturing, sampling, massive production, assembly, and delivery to gods directly to your storage housing, we have the best shipment agency that could save up 30% of shipment cost than others,

Silicone Injection molding services produce molded components made from silicone. Silicone rubber is a two-component, synthetic, flexible rubber-like material made from silicone elastomers that can be cured at room temperature into a solid elastomer used in molding. It is heat resistant, durable, and free of allergens or leaches able chemicals. Liquid silicone is similar to normal silicone but has different processing characteristics.

It is purchased as a two-part raw material with a grease-like viscosity.
Nowadays injection molding of liquid silicon rubber is becoming increasingly important. One reason for this is the increased performance requirements of the finished articles. In addition, more and more producers of rubber parts are seeing benefits in the high level of automation and productivity.

Various ways of liquid silicone injection molding

Molding processes used by providers of silicon molding services include cast molding, compression molding, dip molding, injection molding, reaction injection molding, rotational molding, and transfer molding.

Whereas in the cast molding process, the liquid material is poured into an open mold, in compression molding a slug of silicone is pressed between 2-heated mold halves. On the other hand dip molding is a process similar to hot-dip coating, in which the finished product is the fused plastisol stripped from the dipped mold. However, in injection molding, liquid silicone is forced into a cooled mold under tremendous pressure. In the Reaction Injection Molding (RIM) process two or more reactive chemicals are mixed at high speed as they are being injected into a mold. In rotational molding hollow molds filled with silicone material are secured to pipe-like spokes that extend from a central hub. In transfer molding, the two mold halves are clamped together and silicone is forced by pressure into the mold.

Why the preferred use of silicone rubber in injection molding

Silastic silicon rubber is a sheer material and so its viscosity depends on shear rate. As the shear rate rises the product becomes lower in viscosity. It is this effect that is very favorable for the injection molding process. At the beginning of the injection process, the injection speed profile should be programmed in such a way that the volume flow is high enough for the liquid silicon rubber-not to begin to vulcanize before the cavity is filled, in order to avoid the scorch of the material. Thus liquid silicon rubber is widely used for the process of injection molding due to its following characteristics:

  1. Solventless with low and versatile viscosity.
  2. Easy mixing and pigmentation
  3. Rapid processing compared to solvent dispersion and usually allows a complete coating to be applied in a single pass
  4. Prime less adhesion to glass and some other substrates.
  5. Meter mixed plastic liquid silicon rubber can be dip-coated or fed to a crosshead for supported extrusion coating.

Vulcanized silicone rubber products have the following characteristics:

(1) the property resistant to high and low temperature: with long-term use at 200 ℃and flexibility at -60 ℃;
(2) Electrical insulation property: silicone rubber affords excellent dielectric property which is much higher than the general organic especially under high temperature with dielectric strength almost independent of temperature in the range of 20-200 ℃.
(3) Excellent performances of weather resistance, ozone resistance and resistance to ultraviolet radiation without crack even after long-term outdoor use. It’s generally believed that the silicone rubber can be used outdoors for more than 20 years.
(4) Excellent property of permanent deformation under high-temperature compression.
(5) Excellences include good processing performance, easy to shape, etc.; a variety of products can be made by squeezing out hot air with methods of vulcanization molding, pattern molding, extending molding and so on.

With excellent performance and good technical and economic effect, silicone rubber products have a wide range of applications in various areas of aviation, aerospace, atomic energy, electrical implements, electronics, instrumentation, automobile, machinery, metallurgy, chemical industry, medical health, and daily life.

The application and characteristics of injection molded liquid silicone products:
They have excellent transparency, excellent tear strength, good elasticity, excellent thermal stability and weather resistance, yellowing resistance, heat aging resistance and is mainly used in the cake mold, infant pacifiers, medical catheters, injection molding craft and so on.

Advantages working with silicone injection molding China

Silicon rubber molding has come a long way over the past two decades. From its roots in a few specialty applications where premium physical properties counted more than the premium price, this thermoset carved out a small but solid niche in the medical and automotive fields. Now, among the proliferation of new applications, that niche has begun to burst at the seams.

If you are going to running your business with silicone injection molding or rubber molding? Of any or your new project that needs silicone injection molding parts, we suggest you find a silicone injection molding china company to cooperate your business, when you work with a Chinese company, you will have some advantages for your new model and your business.

Number one,

When you work with silicone injection molding china suppliers, you will have a very competitive price, so you could save your budget on your new model, especially if you are the first time running your one business, this will be one the most important thing to decide if your business will be going smoothly or not.

The advantages number two,

If you choose an injection mold china supplier for your plastic molding parts, silicone rubber molding parts, you will be moving faster than your local supplier, all of the Chinese silicone molding companies are hardworking, fast delivery time, this will save your time and work your project faster on the market, when you put some money into the project, faster will be faster to gain some profits from your project.

Of course, there are some disadvantages when you work with a Chinese silicone molding company, for example, the language. But here you do not need to worry anymore, in our factory we have a professional technical manager who speaks fluent English that will solve all of your issues, you could contact us by email or phone.

Automotive mold

Automotive Plastic Mold from Chia

We know there are many a fashion contracted car parts, it need different parts of the rich also surprises people; And a lot of auto parts in the production of also need certain mold, so the market is need a variety of automobile plastic molds; At the same time due to the use of the car performance is most in need of various parts of the precision of coordinate, so they need auto mold is adherence to specifications.

For car production is a complex process, and that this complexity is the specific performance for the parts of the production process, but if you use the high quality of auto mold is very good, you don’t need to trouble! PURROS can not only provide people with a variety of high quality automotive mold, also can do professional production in the mold.

What is Automotive Plastic Molding?

Automotive plastic molding refers to the process of shaping plastic materials into desired parts and components for use in the automotive industry. This process involves the use of specialized molds, called dies, which are created using computer-aided design (CAD) software. The plastic, typically in pellet form, is then heated and injected into the mold under high pressure. Once the plastic has cooled and solidified, the mold is opened and the finished part is ejected.

There are several different types of plastic molding techniques used in the automotive industry, including injection molding, blow molding, and rotational molding. Injection molding is the most common method, accounting for around 75% of all plastic molding in the automotive industry. It is suitable for producing high volumes of parts with tight tolerances and fine details. Blow molding is used to create hollow parts, such as fuel tanks, and is suitable for low to medium production volumes. Rotational molding is used to create large, complex parts with a seamless, one-piece design and is suitable for low volume production.

Applications of Automotive Plastic Molding

Automotive plastic molding has a wide range of applications, from exterior body panels and trim pieces to interior parts such as dashboards and door panels. It is also used to manufacture a variety of under-the-hood components such as air intake manifolds, engine covers, and transmission parts.

One of the most significant benefits of using plastic molding in the automotive industry is the ability to create complex shapes and designs that would be difficult or impossible to achieve with traditional manufacturing techniques. Plastic molding also allows for the creation of parts with varying thicknesses and strength levels, which can be tailored to meet the specific needs of each application.

In addition to its design flexibility, automotive plastic molding has several other advantages over traditional manufacturing methods. It is lighter in weight, which helps to reduce the overall weight of the vehicle and improve fuel efficiency. Plastic parts are also more resistant to corrosion and can withstand extreme temperatures, making them ideal for use in harsh environments.

Plastic molding also has a lower carbon footprint compared to metal manufacturing techniques, as it requires less energy to produce and produces fewer emissions. This makes it an attractive option for automakers looking to reduce their environmental impact.

Challenges of Automotive Plastic Molding

While plastic molding offers many benefits for the automotive industry, it also presents some challenges. One of the main challenges is the high initial cost of tooling, as the creation of specialized molds can be expensive. Additionally, plastic parts are not as strong as metal parts, and they may not be suitable for certain high-stress applications.

Another challenge of automotive plastic molding is the potential for quality issues. Ensuring that the plastic is properly heated and injected into the mold is crucial for producing parts with consistent quality. Any defects or variations in the process can result in faulty parts that may need to be scrapped.

Finally, there is a growing demand for recycled and sustainable materials in the automotive industry. While plastic can be recycled, the recycled plastic may not have the same properties as virgin plastic and may not be suitable for use in certain applications.

This is the introduction for auto mold, so the rich variety of mold, at the same time to ensure the quality.

For China’s manufacturing industry, a lot of people very bullish on the manufacture of auto mold, because the automotive industry level has very good play to their strength, and now it seems that this is a industry can bring people a lot of people can’t imagine.

Among the many Automotive Plastic Mold maker in what is now the competition is very intense, therefore also make a lot of people are very like this kind of phenomenon can more arouse the vigour of the industry, in now, it seems, mold has such an environment is more and more towards an international standard.

And among manufacturers also have a lot of services, such as car modification industry need some custom of auto mold, as the sample can be custom through such manufacturers, so also can save a lot of need to go abroad for custom-made cost, if you have a automotive parts project then you need Automotive Plastic Injection Molding Companies to finish this project for you, contact us to get price for your automotive project.

TPE injection moulding

Plastic injection molding is a widely used manufacturing process. In today’s world, this method has become essential for producing large-scale plastic parts. Its popularity is due to its fast, accurate, and highly efficient operation.

Plastic injection molding typically allows you to create countless plastic items. Most of these plastic parts are your daily items, from your smartphone casting to the handle on your toothbrush.

Plastic injection molding allows you to make thousands, even millions, of identical parts. Of course, these plastic parts come with tight tolerances up to 0.01mm. This level of precision creates accurate designs and products that make the product effective and look good. Injection-molded products are widely used in the car, consumer goods, and electronics industries. 

Plastic injection molding involves several key stages. Each stage here is critical. In this article, we’ll dive into these stages so you can see how products go from raw plastic to ready-to-use parts. Moreover, you’ll learn about the plastic injection molding services offered in a factory. This article will be a comprehensive guide, so let’s get started.

What Is Plastic Injection Molding?

Injection molding is a prevalent manufacturing method. The term is divided into “injection” and “molding.” As the name indicates, this process entails injecting material into a mold. Plastic injection molding refers to the use of plastic.

This method shapes parts of various designs by injecting the molten material into the plastic injection mold. It is widely used to make plastic parts quickly and accurately. Once the mold is ready, you can create hundreds or millions of plastic parts. The process is highly efficient and offers consistent quality. As a result, people prefer this method to create complex shapes and precise details.

This procedure is not limited to plastic toy pieces or containers. Plastic injection molding is critical to numerous industries. Take the auto industry, for example. Almost every vehicle on the road today features injection-molded components, such as dashboards.

Electronics such as laptops, smartphones, and more depend significantly on this process. Most of their internal components, casings, and joints are injection molded.

In the medical industry, accuracy is essential, and injection molding delivers just that. The process yields precise tolerances for surgical tools, syringes, and other medical items.

Then there’s the consumer goods industry. Injection molding mostly makes our everyday items. Typical examples are kitchen utensils, plastic jars, bottles, furniture, food containers, and more.

plastic injection molding company

Benefits of Plastic Injection Molding Compared to Other Methods

There are various types of plastic-forming methods. Some popular ones are extrusion molding, compression molding, blow molding, and rotational molding. Now, what are the benefits you can get from the plastic injection molding method?

Precision and Complexity

One of the best things about plastic injection molding is precision and complexity. Extrusion molding or compression molding typically deals with simpler shapes. Therefore, these methods are not suitable for complex shapes.

Plastic injection molding, on the other hand, can handle more complex geometries with related mold structure. This method also allows you to work with thin walls, tight tolerances, and small and fine details. You can get the highest quality plastic products compared to any other methods.

High Production Speed

Time is valuable, especially in manufacturing. Plastic injection molding is built for speed. Once the injection mold is set up, it can produce parts rapidly, much faster than traditional or blow molding. This speed makes plastic injection molding process a go-to option for high-volume production. It’s one of the fastest methods out there.

You will be surprised to learn that plastic injection molding can make thousands of plastic parts in an hour. This method can save time and money simultaneously.

Minimal Waste

Plastic injection molding is efficient in material use. If you can make the mold correctly and precisely inject the plastic, you can minimize excess plastic—extrusion molding, where continuous material flow often leads to scraps.

In plastic injection molding, the extra plastics can be used further, reducing injection molding costs and contributing to a green environment.

Consistent Quality

Plastic injection molding also ensures uniform products. One plastic injection mold can produce millions of plastic products with the same shape and properties. It’s tough to achieve exact uniformity with compression and blow molding, but you can do it precisely with injection molding. It reduces the cost and meets the demand for high-quality products.

Versatile Material Choice

There are many types of plastics out there that are widely used in many applications. They are not all the same, and each type has its unique application. Injection molding can easily accommodate a wide range of materials. This flexibility allows you to meet a specific need. This means you can meet exact strength, durability, and flexibility properties.

Superior Finish

Injection molding creates parts with smooth surfaces and a clean finish. This method eliminates or reduces the need for post-processing. Rotational molding, on the other hand, is pretty tricky and requires extra finishing.

plastic injection molding

What is an Injection Molding Machine?

A plastic injection molding machine is a simple piece of equipment. It has several vital components that work together to produce plastic parts. In general, there are three central units in a plastic injection molding machine. Each element plays a crucial role in the plastic injection molding process.

Clamping Unit

The clamping unit holds the mold tightly in place during the injection process. It acts as a grip so the mold doesn’t slip, allowing you to change it based on the final product design.

When the machine begins, the clamping unit closes the mold halves. It uses high pressure, primarily hydraulic pressure, to prevent plastic from leaking during injection.

After the part cools, the clamping unit opens the mold to release the finished product. Without this unit, the process would be a mess.

Injection Unit

The injection unit, on the other hand, is the heart of the machine. It melts the plastic granules and injects them into the mold. The injection unit has a hopper that feeds the plastic into a heated barrel. The material is melted inside the barrel until it reaches a liquid state. Then, a screw or plunger pushes the molten plastic into the mold.

Control Unit

Note that this whole process must be appropriately controlled. Otherwise, the final product might get messy. For example, temperature control is critical in this process. You must set the temperature at the right level so that your final product doesn’t have defects. On the other hand, injection time, ejection time, and pushing force should also be adequately controlled.

What is Injection Mold?

As mentioned in the previous section, the clamping unit typically holds the injection mold. The injection mold is part of the clamping unit and shapes molten plastic into specific forms.

Injection molds are commonly made of tool steel. A variety of tool steels can be used to make injection molds. P-20 28-30 RC, S-7 pre-hardened tool steel 56 RC, H-13, and 420 are noteworthy. These tool steels are strong and durable, and the material must be strong enough to withstand millions of plastic products.

An injection mold comprises two essential parts: the cavity and the core. The cavity is the hollow space that the plastic occupies. It determines the outward form of the component. The core, on the other hand, determines the interior details. Together, they create a complete part.

You can realize the importance of a high-quality mold in making plastic injection-molded parts. The quality of the injection mold also determines the quality of the final parts. Therefore, you must first ensure the quality of the injection mold.

A well-designed mold leads to fewer defects and reduces production time and costs. Poor design may result in warping and inconsistent quality. So, seeking professional help when designing your first injection mold is wise. 

what is plastic injection mold

How Does Injection Molding Work?

You have already gone through a comprehensive study of injection molding. You are also familiar with the various components of an injection molding machine. In this section, you will learn how injection molding works.

Clamping

The first step in the injection molding process is clamping. Here, the two halves of the mold are brought together. This is the crucial stage. If the mold isn’t clamped tightly, molten plastic can escape, which may create defects in your final parts.

The clamping unit holds the mold halves together with significant force. The force or pressure must be strong enough to withstand the pressure of the injected material. If it’s too weak, the mold will open during injection, causing a mess. Too much force can damage the mold.

So, how do you determine the correct clamping force? Consider aspects such as the part’s size and the plastic utilized. For example, bigger pieces need more force. The goal is to get a tight fit without overdoing it. Once the mold is firmly closed, we proceed to the next step.

Injection

The plastic material is fed into the injection molding machine at this stage. The raw plastic, usually in pellet form, is heated until it melts into a thick, gooey substance.

It is pouring syrup into a mold. The molten plastic is poured into the mold cavity under high pressure, ensuring that it fills every nook and corner. If the pressure is too low, the mold cannot fill. It is important to note that improper pressure might result in weak or incomplete portions.

Speed is also critical during injection. The faster the material is injected, the less time it has to cool before filling the mold. But there’s a problem. Doing it quickly can create turbulence, the main cause of a few defects. Therefore, you must carefully balance speed and pressure.

Dwelling

The dwelling phase is also critical in the plastic injection molding method. As you know, you must maintain appropriate pressure while filling the mold. When the plastic is injected, it doesn’t always fill the mold evenly. There might be air pockets or gaps. To avoid this issue, you must hold the pressure steady. This way, you can ensure no trapped air inside. This is where the dwelling phase comes in.

The dwelling time can vary depending on the material and part design. Too short a dwelling time can lead to incomplete parts, while too long can waste time and energy.

Cooling

Once the dwelling phase is complete, it’s time for cooling. This is where the real transformation happens. The molten plastic begins to solidify as it cools. The cooling stage must be maintained properly to set the shape of the part.

This stage usually takes longer than the dwelling stage. In this case, the mold’s temperature generally plays the leading role. You could use an air or water cooling system. Warping might happen if the mold is too cold, so be careful!

Mold cooling system

Mold Opening and Removal of Products

After cooling, it’s time to release the final part. Usually, the ejector pin does this. The clamping unit releases the pressure, generally allowing the two halves to separate. If you do it incorrectly, it can damage the mold or the finished part.

Once the mold is open, you can remove it using tools or hand. Once removed, the part is inspected again. It might undergo further processing, such as trimming or surface finishing.

Plastic Injection Molding Materials

One of the best benefits of plastic injection molding is its versatility. You can generally work with various plastic injection molding materials in injection molding manufacturing. Selecting the suitable material from this diverse list depends on your project needs. Remember, each material here has its unique strengths and weaknesses. Do you need flexibility? Go for PE or PP. Want Toughness? Try ABS or PC.

injection molding material

Polyethylene (PE)

This plastic is incredibly lightweight and flexible. It is also very resistant to chemicals and moisture, making it a popular choice for containers and bottles.

Polyethylene is one of the most widely used plastics globally due to its incredibly lightweight, flexible and cost-effectiveness. It is also very resistant to chemicals and moisture, making it a popular choice for containers and bottles.

There are various type of PE materials, including Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), and Ultra-High Molecular Weight Polyethylene (UHMWPE), each one uses to different applications but very similar.

Properties: Lightweight, flexible, moisture-resistant, and resistant to many chemicals. PE is relatively soft but has good impact resistance. It can handle low temperatures but has limited resistance to high temperatures.

Types of PE materials:

  • LDPE: Known for its flexibility, commonly used in film applications like plastic bags.
  • HDPE: Stronger and more rigid, used in items like milk jugs, detergent bottles, and pipes.
  • UHMWPE: Extremely tough with excellent wear resistance, often used in industrial applications, such as conveyor belts and bulletproof vests.

Applications: Due to its variety, PE is used across industries for containers, piping, and even high-wear applications. In the food industry, it’s ideal for food containers, food packaging due to its moisture resistance. Go to PE injection modling and HDPE injection molding page to know more about this PE material.

what is TPE material

Polypropylene (PP)

Polypropylene is another popular choice. It is prevalent for being strong and very resistant to fatigue, it provides excellent temperature resistance.It’s available in homopolymer and copolymer forms, with each variation suitable for specific applications.

Properties: Strong, durable, fatigue-resistant, and excellent temperature resistance. PP can endure repetitive bending, making it suitable for applications like living hinges.

Advantages: PP offers high chemical resistance and is lightweight, yet stronger than PE. It’s also resistant to absorbing moisture, making it ideal for long-lasting products.

Applications:

  • Automotive: Frequently used in automotive parts like bumpers, dashboards, and battery cases.
  • Consumer Goods: Found in reusable containers, furniture, textiles, and packaging. Its fatigue resistance makes it useful for hinges in household products and storage containers.
  • Medical: Sterilizable and resistant to bacteria, PP plastic material is also common in medical syringes and vials. Go to polypropylene injection molding page to know more.
PP injection molding

Acrylonitrile Butadiene Styrene (ABS)

ABS is a plastic used for injection molding. It is known for its toughness, making it great for parts that need to endure impact. It has a glossy finish, so it’s often used in electronics and toys. ABS might be your best bet if you want something that looks good and lasts.

Properties: ABS is tough, impact-resistant, and lightweight with a glossy finish. It’s also relatively affordable, combining strength and visual appeal.

Advantages: Known for excellent impact resistance, making it ideal for products that must withstand rough handling. ABS is also highly machinable and easy to paint, providing aesthetic and functional versatility.

Applications of ABS plastic products:

Electronics: Used for casings, keyboards, and monitor housings due to its aesthetic finish and durability.

Automotive: Instrument panels, wheel covers, and mirror housings.

Toys and Consumer Products: Especially popular for toys (such as building blocks) that require durability and a pleasing appearance. Go to ABS injection molding and what is ABS material page to know more about this material.

ABS materials

Polycarbonate (PC)

This plastic material is relatively heavier than other plastics. This material could be your best choice when you need a durable solution. It is virtually unbreakable and highly transparent. This material is used in safety glasses and light fixtures. It’s a strong option when transparency and resilience are needed.

Properties: Polycarbonate is heavier than most plastics but is virtually unbreakable and highly transparent. It can withstand high impact and heat, making it suitable for safety applications.

Advantages: It’s one of the strongest transparent plastics available, with excellent heat resistance. It’s also easily molded, allowing for intricate designs in parts and components.

Applications:

Safety Equipment: Used for safety glasses, helmets, and shields due to its shatter-resistant quality.

Optical Media: Common in lenses and DVDs because of its clarity.

Construction and Lighting: Used in skylights, lighting fixtures, and bulletproof glass for durability and transparency. Go to polycarbonate injection molding and Polycarbonate vs Acrylic pages to know more about this PC plastic material.

Polycarbonate Injection Molding

Nylon (PA)

Nylon is a plastic material with excellent strength and flexibility. It is also very resistance to wear and abrasion. Available in different grades (Nylon 6, Nylon 6/6, etc.), each with specific properties, it is widely used in industrial applications requiring toughness. It can also handle high temperatures.

Properties: Excellent strength, flexibility, abrasion resistance, and wear resistance. Nylon can withstand high temperatures and provides good chemical resistance.

Advantages: Nylon’s high durability and heat resistance make it a top choice for mechanical parts, while its low friction makes it suitable for gears and bearings.

Applications:

Mechanical Components: Often used in gears, bearings, bushings, and other wear-prone parts due to its strength and durability.

Textiles: Common in fabrics due to its strength and resilience, often used in outdoor gear and apparel.

Automotive: Used in engine components, fuel tanks, and under-the-hood parts due to its heat resistance. Go to nylon injection molding page to know more.

Every single plastic provides specific advantages that make it ideal for particular applications. Selection depends on factors like strength requirements, environmental conditions, aesthetic preferences, and manufacturing costs. This guide helps in understanding which plastic might be best suited for various product requirements across different industries, from consumer goods to industrial components.

PA66-GF30 plastic

Plastic Injection Molding services

A typical plastic injection molding factory can offer you unique services. Each of these services might benefit you in your business. This section will familiarize you with a few plastic injection molding services.

plastic injection molding service

Service #1 Design and Engineering Support

Designing and engineering support are crucial parts of mold and product design. A perfect injection mold can ensure effective injection and the highest quality of the products. Every mold manufacturing company specializes in this to meet specific customer demands. The engineering team collaborates with clients to optimize part designs.

This way, they can ensure good manufacturability and the efficiency of the whole process. They also evaluate the initial design and suggest changes to save time and reduce costs.

DFM is a term used to manufacture plastic injection molds. Design for manufacturability focuses on how easy or difficult a design is to manufacture. It helps identify potential issues early in the process. By implementing DFM principles, designers can reduce production hiccups. You will know this when you deal with the actual injection mold design process.

Service #2 Custom Mold Making

Custom mold making is another primary service of an injection molding company. To launch new plastic products, you must start by creating a custom plastic injection mold.

The mold-making process starts with the design and engineering steps. What shape do you need? How thick should the walls be? These questions guide the mold design steps.

Several other factors also play a crucial role here. First is the material choice. As mentioned already, injection molds are typically made of high-quality tool steels. When making the molds, tolerance is the most critical parameter. Therefore, the manufacturing method must be wisely chosen.

The two most popular injection mold-making methods are CNC machining and casting. CNC machining can be of various types. Based on your design, the CNC method varies. Sometimes, you may need multiple CNC machining methods. For instance, CNC milling creates grooves, holes, and inner shapes. Other CNC methods include CNC turning, boring, drilling, and more.

Metal casting is another method of making injection mold cavity or core, this is specially used in plastic doll toys related products. It is pretty complex and requires careful consideration to make any type of plastic injection molds. CNC machining and EDM (electric discharge machining) are two popular manufacturing process of creating plastic injection molds.

Service #3 Custom Plastic Parts

You might not have the facility to install custom molds. On the other hand, making such facilities might need high costs. Because of this, most injection molding manufacturers also offer to make various custom plastic parts. This way, you can save a lot of investment costs and make money faster, you only need to buy the injectino molds and send your molds to your plastic injection molding supplier, they will make all of custom palstic products base on your customized injection mold.

This process also starts with a clear design. Once the mold is ready, plastic is injected at high pressure into the mold. As the plastic cools and solidifies, the part takes shape. You already know the benefits and detailed manufacturing process.

Service #4 Quality Control and Testing

A plastic injection molding company offers testing and quality control services in addition to the above three services.

Quality control is crucial in injection molding. It’s the safety net that catches upcoming issues when they happen. Various quality control processes might be needed depending on the mold and its products.

Dimensional checks are one of the first lines of testing. This process measures parts against specified tolerances. Are they the right size? Do they fit together as they should? If not, the engineers make necessary adjustments before mass production. Strength testing is the next testing method. This testing method ensures that parts can withstand their intended use. Besides, there are other tests like surface finishing, pressure testing, spur testing, defects testing, and many more.

Frequently Asked Question

How Much Does Injection Molding Cost?

The cost of injection molding generally varies based on design and size—the average ranges from $1000 to $5000. If you need larger molds, the cost might be higher. The cost of injection-molded plastic parts, on the other hand, depends on the type of material. PC plastic is generally more expensive than PVC or ABS. 

What Is The Problem With The Injection Molding Process?

Every process has its hiccups, and injection molding is no exception. Common problems include warping, which occurs when the part cools unevenly.

Flash is another problem with the injection molding process. It is the excess material that seeps out of the mold. Have you seen unwanted edges on your plastic parts? If yes, then it’s a sign of flash. In contrast, shorts happen when the mold doesn’t fill completely.

How Long Does It Take to Make A Plastic Mold?

The time it takes to create a plastic mold can range from a few weeks to several months. The specific time is not fixed. It all depends on the complexity and the specifics of your project.

How Do I Add Texture to The Mold?

Adding texture to a mold can improve your product’s look. It’s all about aesthetics and function. There are several methods to do it. One of the popular ways is etching, which creates patterns on the mold’s surface before it’s used. Another option is laser engraving.

Electronic Product Design And Manufacturing

Final Words

Plastic injection molding is one of the most popular plastic manufacturing processes. It is an efficient way to make complex, high-precision plastic parts. Throughout this article, we talked about this process, especially plastic injection molding.

We are among the top 10 plastic injection molding companies in China, specializing in plastic injection mold and injection molding manufacturing, and we export plastic parts from China to various contries of the world. Over 40 happy customers have provided us with the best quality, and they are fully satisfied by our quality and service. You are welcome if you need our support. We sincerely hope we could service you in the near future, and you will be surely happy as well as our other happy customers.

The production of thermoplastic plastic products involves a variety of commercial methods. Each has its own specific design requirements as well as limitations. Usually, part design, size, and shape clearly determine the best process. Occasionally, the part concept lends itself to more than one process. Because product development differs depending upon the process, your design team must decide which process to pursue early in product development.

This section briefly explains the common processes used for thermoplastics from Bayer Corporation. Today, many companies purchase injection-molded parts from injection molding companies in China. If you need injection molded parts for your business, you need to really think about this.

The above-described injection molding process uses an injection molding machine to manufacture plastic products. There are two main parts to the machines: the injection unit and the clamping unit. Please visit our injection molding section for further information.

Are you in need of injection molding, or are you seeking a China-based injection mold partner to create plastic molds and manufacture your plastic molded parts? Send us an email, and we will reply to you within two working days.

Injection molding company

We are one of the top 10 plastic injection molding companies in China that provides custom injection mould and injection moulding manufacturing services for a variety of plastic products around the world. We offer part design, mold design, PCB design, prototypes,  mold making, massive production, testing, certificates, painting, plating, silkscreening, printing, assembly, and delivery, all in one-stop services.

Do you know the name of the process by which most plastic-solid materials are produced? It is called injection moulding. It is one of the best molding processes to make millions of injection-molded parts in a very short time. However, the initial injection mold tooling cost is pretty high compared to other machining methods, but this injection tooling cost will be recovered by the large production later, and this process has a low or even no waste rate.

injection molding factory

What is injection molding

Injection molding (or injection moulding) is a manufacturing technology for producing products from plastics. Injecting the molten plastic resin at high pressure into an injection mould, which the mold is made according to the desired part shape, which was created by a designer using some CAD design software (such as UG, Solidworks, etc.).

The mould is made by a mold company (or mold maker) from metal material or aluminum and precision-machined to form the features of the desired part by some high-tech machines like CNC machines, EDM machines, lather machines, grinding machines, wire-cutting machines, etc., step by step to make the final mould cavity base on exactly the desired part shape and size, which we called an injection mold.

The injection moulding process is widely used for producing a variety of plastic products, from the smallest component to the big bumpers of cars. It is the most common technology to produce molding products in the world today, with some commonly made products including food containers, buckets, storage bins, house cooking equipment, outdoor furniture, automotive components, medical components, molding toys, and more.

Injection moulding

Types of Injection Moulding – Basically 7 types of injection molding process as below

Injection moulding equipment

Injection molding machine

Injection molding machines,  normally called injection presses, fasten our custom-made injection mold in the machine. The injection machine is rated by tonnage, which indicates the amount of clamping force that the press can generate. This clamping force keeps the mold closed during the injection molding process. There are various specifications for injection molding machines, from less than 5 tons to 6,000 tons or even bigger.

In general, the basic injection molding machine consists of a mold system, control system, injection system, hydraulic system, and Pinpin system. The tonnage clamp and shot size are used to identify the dimensions of a thermoplastic injection molding machine, which is a major factor in the overall process. Another consideration is the thickness of the mold, pressure, injection rate, the distance between the binding rod, and the screw design.

Injection molding service

Horizontal Injection-molding-machine

Horizontal or vertical machines

There are normally two types of injection molding machines: horizontal and vertical molding machines.

This means molding machines fasten the mold in either a horizontal or vertical position. The majority are horizontal injection molding machines, but vertical machines are used in some niche applications such as cable insert molding, filter injection moldinginsert molding, or some special molding process requirements.Some injection machines can produce two, three, or four colored molded parts at one step; we call them double-shot injection molding machines or 2K injection molding machines (more color will be 3K or 4K molding machines).

Clamping unit

Machines are classified primarily by the type of driving systems they use: hydraulic, electric, or hybrid. Hydraulic presses have historically been the only option available to molders until Nissei introduced the first all-electric machine in 1983. The electric press, also known as Electric Machine Technology (EMT), reduces operation costs by cutting energy consumption and also addresses some of the environmental concerns surrounding the hydraulic press.

Electric injectino molding presses have been shown to be quieter, faster, and have higher accuracy; however, the machines are more expensive. Hybrid injection molding machines take advantage of the best features of both hydraulic and electric systems. Hydraulic machines are the predominant type in most of the world, with the exception of Japan.

Final sumrize for injection molding machine: Injection molding machine converts raw plastic granules or granules into final mold parts using thermoplastic smelting, injection, conditioning, and cooling cycles.

Injection Mold- Types of injection molds

Simply explain that the injection mold is custom made of the desired part shape by cutting the steel or aluminum and producing the mold that can be used in the injection molding machine, which we called injection mold or plastic injection mold. Go to our plastic molding section to learn more about plastic injection mold manufacturing. But making injection mould actually not easy; you need to have a professional team (a mold maker, a mold designer) and mold manufacturing equipment like CNC machines, EDM machines, wire-cutting machines, etc.

There are two main types of injection moldscold runner mold (two plate and three plate designs) and hot runner molds (the more common of the runner-less molds). The significant difference is the presence of sprue and runner with every molded part in the cold runner type. This extra molded component must be separated from the desired molded par;, the hot runner basically does not have any runner wasteore small runner waste.

Cold runner mold

Developed to provide for injection of thermoset material either directly into the cavity or through sprue and a small sub-runner and gate into the mold cavity, there are basically two types of the cold runner which mostly used in the mold industry, two plate mold and Three plate mold.

 

Two plate mold

The conventional two-plate mold consists of two halves fastened to the two platens of the molding machine’s clamping unit. When the clamping unit is opened, the two mold halves open, as shown in (b). The most obvious feature of the mold is the cavity, which is usually formed by removing metal from the mating surfaces of the two halves. Molds can contain a single cavity or multiple cavities to produce more than one part in a single shot. The figure shows a mold with two cavities. The parting surfaces (or parting line in a cross-sectional view of the mold) are where the mold opens to remove the part(s).

In addition to the cavity, there are other features of the mold that serve indispensable functions during the molding cycle. The mold must have a distribution channel through which the polymer melt flows from the nozzle of the injection barrel into the mold cavity. The distribution channel consists of (1) a sprue, which leads from the nozzle into the mold; (2) runners, which lead from the sprue to the cavity (or cavities); and (3) gates that constrict the flow of plastic into the cavity. There are one or more gates for each cavity in the mold.

two-plate cold runner mold

Three plate mold

The two-plate mold is the most common mold in injection molding. An alternative is a three-plate injection mold. There are advantages to this mold design. First, the flow of molten plastic is through a gate located at the base of the cup-shaped part rather than at the side. This allows for a for a more even distribution of melt along the sides of the cup. In the side gate design of the two-plate, the plastic must flow around the core and join on the opposite side, possibly creating a weakness at the weld line.

Second, the three-plate mold allows more automatic operation of the molding machine. As the mold opens, it divides into three plates with two openings between them. This forces the disconnection of runners and parts, which drop by gravity (with possible assistance from blown air or a robotic arm) into different containers beneath the mold.

Three-plate cold runner mold

Hot Runner Mold

Hot-runner molding has parts that are physically heated. These types of molding help transfer the molten plastic quickly from the machine, directly feeding it into the mold cavity. It can also be known as the runner-less mold. The hot runner system is very useful for some of the high volumes of products that will save huge production costs by using the hot runner mold system. The sprue and runner in a conventional two-plate or three-plate mold represent waste material.

In many instances, they can be ground and reused; however, in some cases, the product must be made of “virgin” plastic (original raw plastic material) or there is multiple cavity mold (such as 24 cavities or 48 cavities, 96 cavities, 128 cavities, or even more cavities). The hot-runner mold eliminates the solidification of the sprue and runner by locating heaters around the corresponding runner channels. While the plastic in the mold cavity solidifies, the material in the sprue and runner channels remains molten, ready to be injected into the cavity in the next cycle.

Type of hot runner system.

Basically, there are two types of hot runner systems: one called hot sprue mold (without the manifold plate and hot runner plate), and one called hot runner mold (with the manifold plate and hot runner plate).

Hot sprue mold (without the manifold plate and hot runner plate) uses the hot nozzle (sprue) to feed the material into the mold cavity, either directly or indirectly.

The hot runner mold (with the manifold plate and hot runner plate) means the hot runner system has the hot runner plate, manifold plate, and sub-hot runner sprue. The below pictures are simple explanations for two types of hot runner systems.

Hot runner system

Advantages and Disadvantages of Cold Runner Molding

There are a few amazing advantages to cold-runner molding, such as:

  1. Cold-runner molding is cheaper and easier to maintain.
  2. You are able to quickly change colors.
  3. It has a faster cycle time.
  4. It is more flexible than hot-runner molding.
  5. The gate locations can easily be changed or fixed.

Although there are many advantages, there are also some disadvantages. The disadvantages of cold-runner molding are:

  1. You have to have thicker dimensions compared to the hot runner mold.
  2. You can only use certain types of nozzles, fittings, and manifolds.
  3. Cold-runner molding can result in slower production time when you remove sprues and runners.
  4. You must manually separate the runners and parts after molding.
  5. You may waste the plastic materials if you do not reset after each run.

If you want to know more information, please go to the cold runner mold page to check out more details.

Advantages and Disadvantages of Hot Runner Molding

Hot-runner molding has a few advantages, such as:

  1. Hot-runner molding has a very quick cycle time.
  2. You can save production costs by using hot-runner molding.
  3. Less pressure is needed to inject the molding.
  4. You have more control over the hot-runner molding.
  5. Hot-runner molding can fit a wide variety of gates.
  6. Multiple cavities of mold can be easily filled by using the hot runner system.

The disadvantages of using hot-runner moldings are:

  1. It is more expensive to make the hot runner mold than the cold runner mold.
  2. It is difficult to maintain and fix the hot runner mold.
  3. You are not able to use hot-runner molding on materials that are thermally sensitive.
  4. You will need to get your machines inspected more often than cold-runner molding machines.
  5. It is hard to change the colors in the hot runner mold system.

Want to know more information? Welcome to the hot runner mold section.

Injection Moulding Processing?

Injection molding

Injection molding

Injection moulding is one of the best ways to shape plastic products by injecting a thermoplastic material. During the process of injection molding, the plastic material is placed in the injection molding machine and the melt system of the injection unit is used to melt the plastic into the liquid. The liquid material is then high-pressure-injected into a mold (a custom manufacturing mold) that is assembled in that injection molding machine. The mold is made of any metal, such as steel or aluminum. The molten form is then allowed to cool down and set into a solid form.

The plastic material thus formed is then ejected out of the plastic mold. The actual process of plastic molding is just an expansion of this basic mechanism. The plastic is let into a barrel or chamber under gravity or is force-fed. As it moves down, the increasing temperature melts the plastic resin. Then, the molten plastic is forcibly injected into the mold under the barrel with an appropriate volume. As the plastic cools, it solidifies. The injection-molded parts like this have a reverse shape from the mold. A variety of shapes, both 2D and 3D, can be produced by the process.

The process of plastic molding is cheap due to the simplicity involved, and the quality of the plastic material is modifiable by changing the factors involved in the custom injection molding process. The pressure of injection can be changed to change the hardness of the final product. The thickness of the mold also governs the quality of the article produced.

The temperature for melting and cooling determines the quality of the plastic formed. ADVANTAGES The major advantage of injection molding is that it is very cost-effective and fast. Apart from this, unlike the cutting processes, this process rules out any undesired sharp edges. Also, this process produces smooth and finished products that require no further finishing. Check below for the detailed advantages and disadvantages.

Advantages of injection moulding

Although injection molding is used by many different companies, and there is no doubt this is one of the most popular methods to produce injection molding products, there are some advantages to using it, such as:

  • Precision and aesthetics—because in this injection molding process you can make your plastic part with any shape and surface finish (texture and high gloss finishing), some of the special surface finishing can still be met by the secondary surface finishing process. The injection molding part is the repeatability of their shapes and dimensions.
  • Efficiency and speed: a single production process, even for the most complex products, lasts from a few to several dozen seconds.
    The possibility of full automation of the production process, which in the case of companies dealing with the production of plastic components translates into low production effort and the possibility of mass production,.
  • Ecology: because, compared to metalworking, we are dealing with a significant reduction in the number of technological operations, less direct energy and water consumption, and low emissions of compounds harmful to the environment.

Plastics are materials that, although known relatively recently, have even become indispensable in our lives, and thanks to increasingly modern production processes from year to year, they will contribute even more to saving energy and other natural resources.

Disadvantages of injection molding

  • The high cost of injection molding machines and often the cost of tooling (molds) that equals it result in extended depreciation time and high costs of starting production.
  • Due to the above, injection technology is only cost-effective for mass production.
  • The need for high-qualification technical supervision employees who must know the specifics of injection molding processing.
  • The need for high technical requirements for injection mold making
  • The need to maintain narrow tolerances for processing parameters.
  • A long time of preparation for the production due to the labor-intensive implementation of the injection molds.

Injection molding cycle time

The basic injection cycle time includes mold close, injection carriage forward, plastics filling time, metering, carriage retracts, holding pressure, cooling time, mold open, and eject part(s).

The mold is closed shut by the injection molding machine, and the melted plastic is forced by the pressure of the injection screw to inject into the mold. The cooling channels then assist in cooling the mold, and the liquid plastics become solid into the desired plastic part. The cooling system is one of the most important parts of the mold; inappropriate cooling can result in distorted molding products, and the cycle time will be increased, which will increase the injection molding cost as well.

Molding Trial

When the injection plastic mold has been made by the mold maker, the first thing we need to do is do the mold trial. This is the only way to check the mold quality to see if it was made according to the custom requirement or not. To test the mold, we normally fill the plastics with the molding step by step, using short-shot filling at first, and increasing the material weight little by little until the mold is 95 to 99% full.

After meeting this status, a small amount of holding pressure will be added and holding time increased until the gate freeze-off has occurred. Holding pressure is then increased until the molding part is free of sink marks and the part weight has been stable. Once the part is good enough and has passed any specific technical tests, a machine parameter sheet needs to be recorded for massive production in the future.

Plastic injection molding defects

Injection molding is a complex technology, and problems may happen every time. A new custom made of an injection mold has some issues, which is very normal. To solve the mold issue, we need to fix and test the mold several times. Normally,  two or three trials can completely solve all the issues, but in some cases, only a one-time mold trial can approve the samples. And finally, all of the issues are solved completely. Below are most of the injection molding defects and the troubleshooting skills to solve those issues.

Issue No. I: Short shot defects- What is a short shot issue?

When injecting material into the cavity, molten material does not completely fill the cavity, resulting in the product lacking material. This is called short molding or short shot, as shown in the picture. There are lots of reasons to cause short shot issues.

short shot

Fault Analysis and Method for Correction the defects

  1. Improper selection of injection molding machine: When choosing plastic injection machines, the maximum shot weight of the plastic injection machine must be greater than the weight of the product. During verification, the total injection volume (including the plastic product, runner, and trimming) shall not be more than 85% of the plasticizing capacity of the machine.
  2. Insufficient supply of material: the bottom of the feed position might have “bridging the hole” phenomena. The shot stroke of the injection plunger should be added to increase the supply of material.
  3. Poor flow factor of raw material: improve mold injection system, for example, by proper design of runner location, by enlarging gates, runner, and feeder size, and by using a bigger nozzle, etc. In the meantime, the additive can be added to the raw material to improve the flow rate of the resin or change the material to have a better flow rate.
  4. Overdose of using the lubricant: reduce the lubricant and adjust the gap between the barrel and injection plunger to recover the machine, or fix the mold so that there is no need for any lubricant during the molding process.
  5. Cold foreign substances blocked the runner. This issue normally happens with hot-runner systems. Dismount and clear the nozzle of the hot runner tip, or enlarge the cold material cavity and runner cross-section area.
  6. Improper design of injection feeding system: When designing the injection system, pay attention to gate balance; the product weight of each cavity should be in proportion to the gate size, so that each cavity can be fully filled simultaneously, and gates should be positioned in thick walls. A balanced separate runners scheme can also be adopted. If the gate or runner is small, thin, or long, the molten material pressure will be reduced too much during feeding, and the flow rate will be blocked, which will result in poor filling. To solve this problem, the cross-sections of the gate and runner should be enlarged, and multiple gates should be used when necessary.
  7. Lack of venting: check if there is a cold-slug well or if the position of the cold-slug well is correct. For mold with a deep cavity or deep ribs, venting slots or venting grooves should be added at positions of short molding (end of feeding area). Basically, there are always venting grooves on the parting line; the size of the venting grooves can be 0.02-0.04mm and 5-10mm in width, 3mm close to the sealing area, and the venting opening should be at the end of filling the position.
    When using raw materials with excessive moisture and volatile content, a large amount of gas (air) will also be generated, causing air trap issues in the mold cavity. In this case, raw materials should be dried and cleared of volatile substances. In addition, during the injection process operation, poor venting can be addressed through increasing mold temperature, low injection speed, reducing injection system obstruction and mold clamping force, and enlarging gaps between molds. But the short shot issue happens to the deep rib area. To release the air out, you need to add a venting insert to solve this air trap and short shot issues.
  8. The mold temperature is too low. Before starting molding production, the mold should be heated up to the required temperature. In the beginning, you should connect all of the cooling channels and check if the cooling line is working well, especially for some special materials like PC, PA66, PA66+GF, PPS, etc. The perfect cooling design is a must for those special plastic materials.
  9. Molten material temperature is too low. In a proper molding process window, the temperature of the material is in proportion to the filling length. Low-temperature molten material is poor in fluidity, and the filling length is shortened. It should be noted that after the feed barrel is heated to the required temperature, it should stay constant for a while before starting molding production.
    In the event that low-temperature injection must be used to prevent molten material from being resolved, the injection cycle time can be prolonged to overcome the short shot. If you have a professional molding operator, he should know this very well.
  10. Nozzle temperature is too low. When open mold, the nozzle should be part away from the mold spure to reduce the influence of mold temperature on the nozzle temperature and keep the nozzle temperature within the range of what the molding process requires.
  11. Insufficient injection pressure or holding pressure: injection pressure is close to a positive proportion to the filling distance. The injection pressure is too low, the filling distance is short, and the cavity cannot be fully filled. Increasing the injection pressure and holding pressure can improve this issue.
  12. Injection speed is too slow. Mold filling speed is directly related to injection speed. If injection speed is too low, filling of molten material is slow while slow-flowing molten is easy to cool, hence the flow properties further decrease and result in a short injection. For this reason, the injection speed should be enhanced properly.
  13. Plastic product design is not reasonable. If the wall thickness is out of proportion to the length of the plastic product, the product shape is very complex, and the forming area is large, melt material is easily blocked at the thin wall of the product, leading to insufficient filling. Therefore, when designing the shape and structure of the plastic products, note that wall thickness is directly related to melting limit filling length. During injection molding, product thickness should range between 1-3 mm and 3-6 mm for large products. Generally, it is not good for injection molding if the wall thickness is over 8 mm or less than 0.4 mm, so this kind of thickness should be avoided in design.

Issue No. II: Trimming (Flashing or burrs) Defects

I. What is the flashing or Burrs?

When extra plastic melt material is forced out of the mold cavity from the mold joint and forms a thin sheet, trimming is generated. If the thin sheet is large, it is called flashing.

Molding Flash or burrs

Molding Flash or burrs

II. Fault Analysis and Method for Correction

  1. Mold clamping force is not sufficient. Check whether the booster is overpressurizing and verify whether the product of the projected area of the plastic part and the forming pressure exceed the clamping force of the equipment. Forming pressure is the average pressure in the mold; normally, it is 40 MPa. If the calculation product is larger than the mold clamping force, it indicates that the clamping force is insufficient or the injection positioning pressure is too high. In this case, the injection pressure or section area of the injection gate should be reduced; pressure keeping and pressurization time can also be shortened; injection plunger strokes can be reduced; the number of injection cavities can be reduced; or a mold injection machine with a larger tonnage can be used.
  2. The material temperature is too high. The temperature of the feed barrel, nozzle, and mold should be decreased properly to reduce the injection cycle. For melts of low viscosity, like polyamide, it is difficult to solve overflow flashing defects by simply changing injection molding parameters. To solve this issue completely, fixing the mold is the best way, like doing better mold fitting and making the parting line and shot-off area more precise.
  3. Mold defect. Mold defects are the main reason for overflow flashing. The mold must be carefully examined and the mold parting line re-verified to ensure the pre-centering of the mold. Check whether the parting line fits well, whether the gap between sliding parts in the cavity and core is out of tolerance, whether there is adhesion of foreign matter on the parting line, whether the mold plates are flat and whether there is bending or deformation, whether the distance between mold pate is adjusted to fit the thickness of the mold, whether the surface mold block is damaged, whether the pull rod is deformed unevenly, and whether the venting slot or grooves is too large or too deep.
  4. Improperness of the molding process. If injection speed is too high, injection time is too long, injection pressure in the mold cavity is unbalanced, mold filling speed is not constant, or there is overfeeding of material, an overdose of lubricant can lead to flashing; therefore, corresponding measures should be taken according to the specific situation during operation.

Issue No. III. Welding Line (Joint Line) Defects

I. What is the welding line defect?

Welding line

Welding line

When filling the mold cavity with molten plastic material, if two or more flows of molten material have cooled down in advance before confluence t the joint area, the flows will not be able to totally integrate and a liner is produced at the confluence, thereby a welding line is formed, also called joint line

II. Fault Analysis and Method for Correction

  1. The material temperature is too low. Low-temperature molten material flows have poor confluence performance, and the welding line is easily formed. If welding marks appear at the same position on both the interior and exterior of a plastic product, it is usually inappropriate welding caused by the low temperature of the material. To address this problem, the feeding barrel and nozzle temperatures can be properly increased, or the injection cycle can be prolonged to increase the material temperature. In the meantime, the coolant flow inside the mold should be regulated to properly increase the mold temperature.
    Generally, the strength of the plastic product welding line is relatively low. If the position of the mold with the welding line can be partially heated to partially increase the temperature at the welding position, the strength at the welding line can be enhanced. When a low-temperature injection molding process is used for special needs, injection speed and injection pressure can be increased to improve confluence performance. A small dosage of lubricant can also be added to the raw material formula to increase molten flow performance.
  2. Mold Defect. The fewer numbers of the gate should be adopted, and the position of the gate should be reasonable to avoid inconsistent filling speed and interruption of molten flow. Where possible, a one-point gate should be adopted. To prevent low-temperature molten material from generating a welding mark after being injected into the mold cavity, lower the mold temperature and add more cold water to the mold.
  3. Poor mold venting solution. Check whether the venting slot is blocked by solidified plastic or another substance at first (especially some glass fiber material), and check whether there is a foreign substance at the gate. If there are still carbonation spots after removing the extra blocks, add a venting groove at the flow convergence in the mold or change the gate location. Reduce the mold clamping force and increase venting intervals to speed up the convergence of material flows. In terms of the molding process, reducing material temperature and mold temperature, shortening high-pressure injection time, and decreasing injection pressure can be taken.
  4. Improper use of release agents. In injection molding, usually, a small quantity of release agent is evenly applied at the thread and other positions that are not easy to demold. In principle, the use of the release agent should be reduced as much as possible. In massive production, you should never use a release agent.
  5. The structure of plastic products is not reasonably designed. If the wall of the plastic product is too thin, the thickness differs greatly, or there are too many inserts, it will cause poor welding. When designing a plastic product, it shall be ensured that the thinnest part of the product must be greater than the minimum wall thickness allowed during forming. In addition, reduce the number of inserts and make the wall thickness as uniform as possible.
  6. The welding angle is too small. Each kind of plastic has its own unique welding angle. When two flows of molten plastic converge, the welding mark will appear if the converging angle is smaller than the limit welding angle and will disappear if the converging angle is bigger than the limit welding angle. Usually, the limit welding angle is around 135 degrees.
  7. Other causes. Different degrees of poor welding can be caused by the use of raw materials with excessive moisture and volatile content, oil stains in the mold that are not cleaned up, cold material in the mold cavity or uneven distribution of fiber filler in the molten material, an unreasonable design of the mold cooling system, fast solidification of the melt, a low temperature of the insert, a small nozzle hole, an insufficient plasticizing capacity of the injection machine, or a large pressure loss in the plunger or barrel of the machine.
    To solve these problems, different measures, such as pre-drying of raw materials, regular cleaning of mold, changing the design of mold cooling channels, controlling the flow of cooling water, increasing the temperature of inserts, replacing nozzles with larger apertures, and using injection machines with larger specifications, can be taken in the process of operation.

Issue No. IV: Warp Distortion – What is warp distortion?

Due to internal shrinkage of the product is inconsistent, the internal stress is different and distortion occurs.

Warp Distortion

Warp Distortion

Fault Analysis and Method for Correction

1. The molecular orientation is unbalanced. In order to minimize warp distortion caused by diversification of molecular orientation, create conditions to reduce flow orientation and relax orientation stress. The most effective method is to reduce molten material temperature and mold temperature. When this method is used, it is better to combine it with heat treatment of the plastic parts; otherwise, the effect of reducing molecular orientation diversification is often of short duration. The method of heat treatment is: after demoulding, keep the plastic product at a high temperature for some time and then cool to room temperature gradually. In this way, the orientation stress in the plastic product can be largely eliminated.

2. Improper cooling. When designing a plastic product structure, the cross-section of each position should be consistent. Plastic must be kept in the mold for a sufficient time for cooling and forming. For the design of a mold cooling system, cooling pipelines should be at positions where the temperature is easy to rise and the heat is relatively concentrated. As for the positions that easily cool down, gradual cooling should be adopted to ensure balanced cooling of each position of the product.

Warpage issue

Warpage issue

3. The gating system of mold is not properly designed. When determining the gate position, be aware that the molten material will not directly impact the core, and be sure the stress on both sides of the core is the same. For large flat rectangular plastic parts, a membrane gate or multi-point gate shall be used for resin raw materials with wide molecular orientation and shrinkage, and a side gate shall not be used; for ring parts, a disk gate or wheel gate shall be used, and a side gate or pinpoint gate shall not be used; for housing parts, a straight gate shall be used, and a side gate shall not be used as far as possible.

4. The demolding and venting system is not properly designed. In-mold design, draft angle, position, and the number of ejectors should be reasonably designed to improve mold strength and positioning accuracy. For small and medium-sized molds, anti-warping molds can be designed and made according to their warping behavior. In respect of mold operation, ejection speed or ejection stroke should be properly reduced.

5. Improper operation process. The process parameter shall be adjusted according to the actual situation.

Issue No. V: Sink Mark Defects – What is the sink mark?

Sink marks are unevenly shrinking of the surface caused by the inconsistent wall thickness of the plastic product.

Sink marks

Sink marks

Fault Analysis and Method for Correction

  1. The injection molding condition is not properly controlled. Properly increase injection pressure and speed, increase molten material compression density, prolong injection and pressure-keeping time, compensate for the sinking of the molten, and increase the buffering capacity of injection. However, the pressure should not be too high; otherwise, the convex mark will appear. If sink marks are around the gate, prolonging the pressure keeping time can eliminate the sink marks; if sink marks are at the thick wall, prolonging the cooling time of the plastic product in the mold; if sink marks around the insert are caused by partial shrinkage of molten, the main reason is that the temperature of the insert is too low; try to increase the temperature of the insert to eliminate the sink marks; if sink marks are caused by insufficient material feeding, increase the material. Besides all of this, the plastic product must be fully cooled in the mold.
  2. Mold defects. According to the actual situation, properly enlarge the gate and runner cross-section, and the gate should be in a symmetrical position. The feed inlet should be in the thick wall. If sink marks appear away from the gate, the cause usually is that the flow of molten material is not smooth at some position of the mold, which hampers the transmission of pressure. To solve this problem, enlarge the injection system to allow the runner to extend to the position of the sink marks. For products with thick walls, a wing-type gate is preferred.
  3. Raw materials cannot meet molding requirements. For plastic products with high finish standards, resin with low shrinkage shall be used, or the appropriate dosage of lubricant can also be added to the raw material.
  4. Improper design of product structure. The wall thickness of the product shall be uniform; if the wall thickness differs a lot, the structure parameter of the injection system or the wall thickness shall be adjusted.
  5. sink marks defects

    sink marks defects

Issue No. VI: Flow Mark-What is Flow Mark?

Flow mark is a linear trace on the surface of a molding product that shows the flow direction of molten material.

Flow mark

Flow mark

Fault Analysis and Method for Correction

  1. Ring-shaped flow marks on the surface of the plastic part with the gate as the center are caused by poor flow motion. To address this kind of flow mark, increase the temperature of the mold and nozzle, increase the injection rate and filling speed, prolong the pressure-keeping time, or add a heater at the gate to raise the temperature around the gate. Appropriately expanding the gate and runner area can also work, while the gate and runner section is preferably circular, which can guarantee the best filling. However, if the gate is in the weak area of the plastic part, it will be square. In addition, a large cold-slug well should be set at the bottom of the injection port and at the end of the runner; the greater the influence of material temperature on the flow performance of the melt, the more attention should be paid to the size of the cold-slug well. The cold-slug well must be set at the end of the melt flow direction from the injection port.
  2. Whirl flow marks on the surface of the plastic part are caused by the unsmooth flow of molten material in the runner. When the molten material flows from the runner with a narrow section to the cavity with a larger section or the mold runner is narrow and the finish is poor, the material flow is easy to form turbulence, resulting in a whirl flow mark on the surface of the plastic part. To address this kind of flow mark, reduce injection speed appropriately or control the injection speed in slow-fast-slow mode. The mold gate shall be in the thick wall and preferably in the form of a handle type, a fan type, or a film type. The runner and gate can be enlarged to reduce material flow resistance.
  3. Cloud-like flow marks on the surface of the plastic part are caused by volatile gas. When ABS or other copolymerized resins are used, if the processing temperature is high, the volatile gas produced by the resin and lubricant will form cloud-like ripple marks on the surface of the product. In order to solve this problem, it is necessary to reduce the temperature of the mold and barrel, improve the venting of the mold, reduce the material temperature and filling speed, enlarge the gate section properly, and consider changing the type of lubricant or reducing the use of lubricant.

Issue No. VII: Glass fiber streaks – What is Glass fiber streaks

Surface Appearance: Plastic molding products with glass fiber have various surface defects, such as dim and dreary in color, coarse in texture, and metal bright spots, etc. These are especially obvious in the convex part of the material flow area, close to the joint line where the fluid meets again.

Physical cause

If the injection temperature and the mold temperature are too low, the material containing glass fiber tends to solidify fast on the mold surface, and the glass fiber will not melt in the material again. When two flows meet, the orientation of glass fiber is in the direction of each flow, which will lead to irregular surface texture at the intersection, resulting in the formation of joint seams or flow lines.

This type of defect is more obvious if the molted material is not fully mixed in the barrel. For example, if the stroke of the screw is too long, it will cause the undermixed material to also be injected.

Causes related to process parameters and improvements can be identified:

  1. The injection speed is too low. To increase injection speed, consider using a multi-step injection method like slow-fast mode.
  2. The temperature of the mold is low; increasing the mold temperature could improve the glass fiber streaks.
  3. Molten material temperature is too low; increase barrel temperature and screw back pressure to improve.
  4. The temperature of molten material varies a lot: if the molten material is not fully mixed, increase screw back pressure, reduce screw speed, and use the longer barrel to shorten stroke.

Issue No. VIII: Ejector Marks: What are ejector marks?

Surface Appearance: Stress whitening and stress rising phenomena are found on the side of the product that is facing the nozzle, i.e., where the ejector rod is located on the ejector side of the mold.

Physical cause

If the demoulding force is too high or the surface of the ejector rod is relatively small, the surface pressure here will be very high, causing deformation and eventually whitening at the ejection area.

Causes related to process parameters and improvements can be applied:

  1. Holding pressure is too high; decrease pressure while keeping pressure.
  2. Holding pressure time is too long; shorten holding pressure time.
  3. Holding pressure switch time is too late. advance the pressure-keeping switch
  4. The cooling time is too short; increasing the cooling time

Causes related to mold design and improvements can be applied:

  1. The draft angle is not enough; increase the draft angle according to specification, especially in the area of the ejector mark.
  2. The surface finish is too rough; the mold shall be well polished in the demolding direction.
  3. A vacuum is formed on the ejection side. Install an air valve in the cor

Conclusion

Due to the specific properties of plastics, injection molding is a very complex technological process; unlike the seemingly related process of metal die casting, it is not a mechanical process but a mechanical-physical one. In the injection molding process, a molded piece is obtained. It is characterized not only by a specific shape but also by a specific structure resulting from the flow of the plasticized material in the mold and the course of its solidification.

Because these processes occur in the form of injection, the designer of this tool must take into account, in addition to typically mechanical issues, issues related to the physical nature of the material transformation. Constructing a rationally working form requires, at the same time, from the designer a thorough knowledge of the technical capabilities of the injection molding machine, because it is a machine with extremely rich possibilities provided by its equipment and numerous work programs.

If you want to know more, please go to our other plastic mold page. If you are looking for injection molding services, you are welcome to send us your requirements for a quotation.

If you have a new project or current project that needs a China injection molding company to support you, we are happy to help. Please call us or send us an email.

glass filled PA injection molding

What is Plastic Moulding

Plastic moulding is the plastic work through the Injection moulding machine, The melted plastic will automatically molten after erupting out in all of the plastic moulding methods, injection plastic moulding has been the most widely used. The method comprises the following steps: getting the thermoplastic plastic or the thermosetting plastic imported into the heating cylinder of the injection moulding machine, and when it is completely melted, it will produce heat and frictional heat by the pressure of the plunger or the screw, and is injected into the mould cavity of the closed mould, after curing, and then open the mould and take out the finished product.

Plastic moulding is the principal method of forming thermoplastic materials. Modifications of the plastic injection molding process are sometimes used for thermosetting plastics.

The problem with plastic moulding of thermosetting materials is that, under heat, these plastics will first soften, then harden to an infusible state. Thus it is essential that no softened thermosetting material in the heating chamber be allowed to remain there long enough to set. Jet molding, offset molding and molding using a screw-type machine overcome this problem by liquefying the thermosetting plastic material just as it goes through the injection nozzle into the plastic mold, but not before.

plastic mold technology

Type of plastic molding

There are many type of plastic moulding process, below we will briefly explain each type of plastic mouldings.

Blow Molding

Blow molding is a method of forming hollow articles out of thermoplastic materials.

Blow molding is a process of forming a molten tube of thermoplastic material, then with the use of compressed air, blowing up the tube to conform to the interior of a chilled blow mold. The most common methods are extrusion, injection, and injection-stretch blow molding.

The continuous-extrusion method uses a continuously running extruder with a tuned die head that forms the molten plastic tube. The tube is then pinched between two mold halves. A blow pin or needle is inserted into the tube and compressed air is used to blow up the part to conform to the chilled mold interior. Accumulator-extrusion is similar, however, the molten plastic material is accumulated in a chamber prior to being forced through a die to form the tube.

Injection molding

Injection blow molding is a process of injection molding a preform (similar to a test tube), then taking the tempered preform to a blow mold to be filled with compressed air to conform to the interior of the blow mold. Injection-stretch blow molding can be a single-stage process similar to standard injection blow molding, by adding the element of stretch prior to blow forming. Also, a two-step process is possible, where a preform is made in an injection molding machine, then taken to a reheat-stretch blow molding machine for preform reheating and final blow forming in a blow mold.

Thermoforming molding

plastic moulding

plastic molding company, injection molding machines from 60 Ton to 2000 Ton

Thermoforming of plastic sheet has developed rapidly in recent years. This process consists of heating thermoplastic sheet to a formable plastic state and then applying air and/or mechanical assists to shape it to the contours of a mold.

Air pressure may range from almost zero to several hundred psi. Up to approximately 14 psi (atmospheric pressure), the pressure is obtained by evacuating the space between the sheet and the mold in order to utilize this atmospheric pressure. This range, known as vacuum forming, will give satisfactory reproduction of the mold configuration in the majority of forming applications.

Themoset Transfer Molding

Themoset Transfer molding is most generally used for thermosetting plastics. This method is like compression molding in that the plastic is cured into an infusible state in a mold under heat and pressure. It differs from compression molding in that the plastic is heated to a point of plasticity before it reaches the mold and is forced into a closed mold by means of a hydraulically operated plunger.

Themoset Transfer molding was developed to facilitate the molding of intricate products with small deep holes or numerous metal inserts. The dry mold compound used in compression molding sometimes disturbs the position of the metal inserts and the pins which form the holes. The liquefied plastic material in transfer molding flows around these metal parts without causing them to shift position.

Reaction Injection Molding

Reaction injection molding (RIM) is a relatively new processing technique that has rapidly taken its place alongside more traditional methods. Unlike liquid casting, the two liquid components, polyols and isocyanates, are mixed in a chamber at relatively low temperatures (75° – 140° F) before being injected into a closed mold. An exothermic reaction occurs, and consequently RIM requires far less energy usage than any other injection molding system.

The three major types of polyurethane RIM systems are rigid structural foam, low-modulus elastomers, and high-modulus elastomers.

Reinforced RIM (R-RIM) consists of the addition of such materials as chopped or milled glass fiber to the polyurethane to enhance stiffness and to increase modulus, thus expanding the range of applications.

Compression Molding

Compression molding is the most common method of forming thermosetting materials. It is not generally used for thermoplastics.

Compression molding is simply the squeezing of a material into a desired shape by application of heat and pressure to the material in a mold.

Plastic molding powder, mixed with such materials or fillers as woodflour and cellulose to strengthen or give other added qualities to the finished product, is put directly into the open mold cavity. The mold is then closed, pressing down on the plastic and causing it to flow throughout the mold. It is while the heated mold is closed that the thermosetting material undergoes a chemical change which permanently hardens it into the shape of the mold. The three compression molding factors — pressure, temperature and time the mold is closed — vary with the design of the finished article and the material being molded.

Extrusion Molding

Extrusion molding is the method employed to form thermoplastic materials into continuous sheeting, film, tubes, rods, profile shapes, and filaments, and to coat wire, cable and cord.

In extrusion, dry plastic material is first loaded into a hopper, then fed into a long heating chamber through which it is moved by the action of a continuously revolving screw. At the end of the heating chamber the molten plastic is forced out through a small opening or die with the shape desired in the finished product. As the plastic extrusion comes from the die, it is fed onto a conveyor belt where it is cooled, most frequently by blowers or by immersion in water.

In the case of wire and cable coating, the thermoplastic is extruded around a continuing length of wire or cable which, like the plastic, passes through the extruder die. The coated wire is wound on drums after cooling.

In the production of wide film or sheeting, the plastic is extruded in the form of a tube. This tube may be split as it comes from the die and then stretched and thinned to the dimensions desired in the finished film.

In a different process, the extruded tubing is inflated as it comes from the die, the degree of inflation of the tubing regulating the thickness of the final film.

plastic injection mold tooling

Plastic Moulding Knowledge Guidance

1 The basic knowledge of plastic molding.
1.1 The characteristics and composition of plastic injection moulding.

Plastic Injection moulding is to fill the molten moulding material in a closed mould with high pressure. The pressure that the plastic molding cavity needs to be subjected to about 400 KGF / CM2, approximately 400 atmospheres. With such a high pressure to make a product is its characteristic which is not the only an advantage but also disadvantages. In other words, the mold always has to be made stable, therefore its’ price is always high. So must be mass-produced in order to buckle with high-priced mould costs. For example, the production of each batch must be more than 10000PCS to be reasonable. In other words, plastic molding work surely has to be a mass-production.

A few steps of the plastic molding process :
1.1.1 Closing
Close the security and then start moulding
1.1.2 Clamping mold
Moving forward the moving board in order to get the mould closed. When the mould is closed which means is also locked.

1.1.3 Injecting (including holding press)
The screw is quickly pushing forward, injecting the molten formed plastic material into the mould cavity to full fill it. Keeping the press at the same time after full filling it, this action is particularly named “holding press.” The pressing that the mold has to bear when it just gets full filled, generally called ‘Injection Press’ or ‘one press’.

1.1.4 Cooling off (and the next step of the plasticization project)

The process of waiting for the material getting cool formed in the mould cavity is called “cooling off”, At this time the injection device is also ready for the next step, this process is called “plasticization process. The moulded material is placed in the hopper, inflow into the heated tube to heat, it is based on the rotation of the screw turning the raw material into the molten status.

1.1.5 Opening the mould

Move the moving board to the backward and the mould will be opened.

1.1.6 Opening the security door

Opening the security door, then the machine will be in the standby status.

1.1.7 Picking up

Taking out the product, checking carefully if there is anything left in the mould cavity, and this whole forming operation is called moulding cycle time. The finished product is shaped by the shape of the mould. The mold is composed of the left mould and the right mould, These two sides of moulds are left with voids, and the material would flow into the voids and get compressed to finish the product. There are three main lines of the path of the molding material before it flows into the left side and right side, sprue, runner, gate, and so on.

1.2 Injection molding machine

Injection moulding machine is distinguished from two large projects, they are divided into two, clamping device and injection device.

1.2.2 clamping device

Closing the mould, the molding material would be cooled off and solidified in the mould cavity. Opening the mould cavity and take out the finished product is the action of the clamping device

1.2.3 Injection Device

Injecting the plastic material into the mould cavity called ‘Injection device’

The following describes the ability of the injection moulding machine, there are three provisions to distinguish the ability of it.

A. Clamping force

When the injection is made, the mould won’t be opened by the maximum clamping force, expressed as the number of TON.

B. Injection volume

The weight of a shot is generally expressed in terms of grams.

C. Plasticizing capacity

A certain amount of time able to melt the amount of resin, this is generally expressed in terms of grams. The most important part is the clamping force, the area of the moulded article is referring the mould perpendicular to the shadow of the opening and closing direction (basically the moud’s area). The average pressure within the mold added to the projection area is called the clamping force. If the mold “projection area × average pressure” is greater than the “clamping force” then the left and the right side moulds will be pushed out.

Clamping force = projection area × average pressure within the mold In general, the mold can withstand the pressure of 400KGF / Cm2, so base on this figure to calculate the clamping force, but the clamping force often based on the shape of forming materials and the shape of the product’s vary, the difference between the larger parameters such as PE, PP, PS, ABS materials, these raw materials are used to make the shallow box, the parameter is 300KGF / CM2.

If the depth of the box is deeper then the parameter is 400 KGF / CM2, If it is the small but high precision products. The projection area is about 10CM2 or less, its parameters are 600KGF / CM2. The smaller parameters such as PVC, PC, POM, AS materials, these materials are also used to make a shallow box, the parameters of 400KGF / CM2, if it is a deep box of its parameters is 500KGF / CM2, if it is a small and high precision products, projection area of about 10CM2 below, its parameter is 800KGF / CM2.

To working with Plastic Moulding is not easy, if you have a project that needs plastic molding service you need to find a professional plastic molding company to support you, to reduce your plastic mold and Injection moulding cost, find a Chinese molding company to support you will be one of the best options, plastic mould and moulding parts from China mold company has inexpensive price and short lead time, this is no reason that you do not choose your plastic molding supplier from China, on the world, over 80% or overseas companies that buy products from China, China is the biggest manufacturer country on the world, this is no doubt about this,

Plastic box mold

We are A Plastic Molding Parts Manufacturing Company

Finding the right source for all your injection molded thermoplastic parts is as easy as selecting DONGGUAN SINCERE TECH CO.LTD (SINCER ETECH). If you need quality injected-molded parts from an ISO 9001:2000 Certified supplier, and you need them on time, ACM is the answer.

Plastic Mold & Plastic Molding Parts Service: Your One-Stop Solution

Sincere Tech is a top 10 injection mold companies in China, offer injection mould, plastic moulding service to the world, 90% of our mold and parts are export to American, Europe, and the world, SINCERE TECH is a “one-stop, one-responsibility” company. our skilled, quality-minded thermoplastics professionals are committed to superior service, providing solutions to customers’ needs from concept to finished product. At our modern plastic molding facility you will be guaranteed:

  • Top quality products
  • The latest in technological equipment
  • Cost-effective manufacturing processes
  • Quality assurance procedures

We are capable of producing a wide variety of plastic parts and components, for industries of all types, including:

  • A / C Vents
  • Actuators
  • Bezels
  • Blood Testers
  • Boat Parts
  • Bobbins
  • Bottle Ties
  • Boxes
  • Brackets
  • Buckles
  • Cases
  • Clips
  • Component Boxes
  • Computer Peripherals
  • Connectors
  • Cosmetic Packaging
  • DVD / VCR Faceplates
  • Faucet Extrusions
  • Flower Pot Bases
  • Fuse Blocks
  • Gear Shift
  • Knobs
  • Gears
  • Housings
  • Junction Boxes
  • Key Fobs
  • Knobs
  • Lenses
  • Light Pipes
  • Motor Housings
  • Name Plates
  • Phone Parts
  • Push Buttons
  • Radiator Tops
  • Seat Belt Parts
  • Shields
  • Spacers
  • Spools
  • Switches
  • Tail Lamp Sockets
  • Toys
  • Trim Plates
  • Typewriter Parts
  • Vents
  • Vials
  • Wedges
  • Window Lift Parts
  • Wire Shields

SINCERE TECH’s Capabilitiesplastic mold manufacturing company

SINCERE TECH’s molding machines range from 60-ton to 2000-ton. We are equipped to mold products from many varieties and grades of resin, each with different properties, including:

  • Thermoplastic commodity resins
  • Engineering grade resins (filled and unfilled)
  • Elastomeric materials

Read more details about our Production Facility and Equipment.

Additionally, our facilities can provide a number of secondary operations, such as:

  • Assembly
  • Pad Printing
  • Painting
  • Drilling
  • Ultrasonic Welding
  • Milling
  • Ultrasonic Insertion

Read more details about our Production Facility and Equipment.

You are welcome to send us your new project, we will quote you with 24 hours, we will offer you the best solution for your new project to save you price, not only the injection molding process, but rubber molding, metal parts etc.

 

Injection mold manufacturer in China

What is plastic injection mold press

Plastic injection mold pressPlastic injection mold press is simple called press. Plastic injection mold press holds the plastic mold in which the components are shaped. Mold press is rated by tonnage, which expresses the amount of clamping force that the machine can generate. This pressure keeps the mold closed during the injection process. Tonnage can vary from less than 5 tons and big than 5000 tons, with the higher figures used in comparatively few manufacturing operations.

Plastic injection mold press can fasten the plastic molds in either a horizontal or vertical position. The majority is horizontally oriented, but vertical machines are used in some niche applications such as insert molding ( click here to know more about insert molding) allowing the machine to take advantage of gravity.

Plastic injection mold press is used to create many things such as milk cartons, packaging, bottle caps, automotive dashboards, pocket combs, and most other plastic products available today. It is known that injection molding is the most common method of part manufacturing. It is ideal for producing high volumes of the same object. Go to injection molding page to know more about injection moulding.

Basic Components of a Plastic Injection Mold Press

The basic components of a Plastic Injection Mold Press are integral to its functionality, contributing to the precision and efficiency of the injection molding process. Sincere Tech China Mold Maker, a prominent player in the industry, understands the significance of each component in delivering top-notch manufacturing solutions. Let’s delve into the essential elements that constitute a Plastic Injection Mold Press:

1. Injection Unit:

  • Hopper:
    • The hopper serves as the reservoir for raw plastic material. Sincere Tech ensures that the hopper design facilitates efficient material loading and prevents contamination.
  • Barrel:
    • Within the barrel, the plastic material is subjected to controlled heating and pressurization. Sincere Tech’s barrels are designed for optimal heat transfer and durability, ensuring uniform melting of the plastic.
  • Screw or Plunger:
    • The screw or plunger is responsible for conveying the molten plastic material from the barrel to the mold. Sincere Tech’s precision-engineered screws and plungers ensure a consistent and reliable injection process.

2. Clamping Unit:

  • Mold:
    • The mold defines the shape and features of the final product. Sincere Tech specializes in custom mold designs, tailored to the specific requirements of clients across diverse industries.
  • Clamping Mechanism:
    • The clamping mechanism ensures that the mold remains securely closed during the injection process. Sincere Tech’s robust clamping systems guarantee stability and accuracy in the molding process.
  • Cooling System:
    • Efficient temperature control is critical for the solidification of the plastic within the mold. Sincere Tech integrates advanced cooling systems to maintain precise temperature levels, contributing to the overall quality of the molded products.

These components work seamlessly together during the injection molding process, reflecting Sincere Tech’s commitment to excellence in every facet of Plastic Injection Mold Press technology. Their attention to detail in the design and manufacturing of these components ensures that clients receive reliable and high-performance machinery for their production needs.

Advantages of Plastic Injection Mold Press

Sincere Tech China Mold Maker’s Plastic Injection Mold Press technology comes with a multitude of advantages, positioning it as a preferred choice for manufacturers seeking precision, efficiency, and versatility. Here are the key advantages associated with Plastic Injection Mold Press:

1. High Precision and Accuracy:

  • Sincere Tech’s Plastic Injection Mold Press technology excels in producing intricate and complex designs with exceptional precision. The advanced control systems and precise engineering contribute to the consistent replication of detailed molds, meeting the strictest quality standards.

2. Efficient Production Rates:

  • The efficiency of Sincere Tech’s Plastic Injection Mold Press technology translates into high production rates. Rapid injection cycles, coupled with reliable and durable components, ensure that manufacturers can meet demanding production schedules and reduce time-to-market for their products.

3. Versatility in Material Usage:

  • Sincere Tech understands the importance of material flexibility in manufacturing. Their Plastic Injection Mold Press technology accommodates a wide range of materials, from traditional polymers to advanced engineering plastics. This versatility enables clients to choose the most suitable material for their specific application.

4. Reduced Material Waste:

  • Precision control over the injection process minimizes material waste. Sincere Tech’s technology ensures that the right amount of material is injected into the mold, reducing excess and optimizing resource utilization. This commitment to sustainability aligns with global environmental goals.

5. Cost-Effectiveness:

  • The efficiency and accuracy of Sincere Tech’s Plastic Injection Mold Press technology contribute to cost-effectiveness in manufacturing. Reduced waste, faster production cycles, and reliable operation result in overall cost savings for clients.

6. Scalability:

  • Whether dealing with small-scale production or large-volume manufacturing, Sincere Tech’s Plastic Injection Mold Press technology is scalable to meet varying production needs. This scalability is crucial for adapting to market demands and business growth.

7. Consistent Quality Control:

  • Sincere Tech places a strong emphasis on quality control throughout the manufacturing process. The precise control mechanisms in their Plastic Injection Mold Press technology ensure consistent product quality, minimizing defects and rejections.

8. Tailored Solutions for Diverse Industries:

  • Sincere Tech’s expertise allows them to provide tailored solutions for diverse industries, including automotive, consumer goods, medical devices, and packaging. Their understanding of industry-specific requirements ensures that clients receive customized solutions that align with their unique needs.

In essence, Sincere Tech China Mold Maker’s Plastic Injection Mold Press technology offers a comprehensive package of advantages, making it a reliable and efficient choice for manufacturers seeking excellence in plastic injection molding processes.

Types of Plastic Injection Mold Press

Sincere Tech China Mold Maker offers a range of Plastic Injection Mold Press technologies, each catering to specific needs and preferences. Here are the primary types of Plastic Injection Mold Press provided by Sincere Tech:

1. Hydraulic Injection Mold Press:

  • Description: Hydraulic injection mold presses utilize hydraulic systems to power the various components of the machine. These systems provide high force and are known for their robustness.
  • Advantages:
    • High clamping force suitable for large molds.
    • Versatility in handling a variety of materials.
    • Reliable and durable, with lower maintenance requirements.

2. Electric Injection Mold Press:

  • Description: Electric injection mold presses rely on electric servo motors to drive the machine’s components. This type is appreciated for its precision, energy efficiency, and accuracy.
  • Advantages:
    • Higher energy efficiency and reduced operating costs.
    • Enhanced precision and control over the injection process.
    • Quieter operation compared to hydraulic counterparts.

3. Hybrid Injection Mold Press:

  • Description: Hybrid injection mold presses combine hydraulic and electric systems to optimize performance. They often use electric motors for plasticizing and hydraulic systems for clamping.
  • Advantages:
    • Balances the energy efficiency of electric systems with the power of hydraulic systems.
    • Provides flexibility in adapting to different production requirements.
    • Offers improved precision in injection molding processes.

Sincere Tech China Mold Maker excels in delivering these types of Plastic Injection Mold Press machines, ensuring that clients have the flexibility to choose the technology that best suits their specific production needs. The company’s commitment to innovation and customization enables them to stay at the forefront of the industry, meeting the evolving demands of various manufacturing sectors.

If you are a plastic mold manufacturing company that produces anything from plastic molding toys to car parts and you are not using Plastic injection mold press to produce your parts, you will spend too much money.  Indeed, using Plastic injection mold press provides additional savings to manufacturers because plastic is less expensive than metal and manufacturers pay for fewer parts. As a result, they are widely used because of the high quality of the end product.

One of Plastic injection mold press you can choose in the market is Plastic Injection Molder (YS-1180). This machine has moving platen featuring box type bridge structure and full-connected rear high-rigidity mold platen. Through finite element analysis, it can prevent deforming of mold platen, resist against fatigue, have high repetition accuracy, distribute mold closing force uniformly, greatly increase mold’s service life and reduce injection molding cost.

Another option of Plastic injection mold press is HDT-200 200ton plastic injection molder. This machine comes in two series; HDT series and HDF series. The HDT machines’ clamping force is from 80 tons to 2200 tons and the shot weight is from 80g to 2kg. These machines have strong locking force and a very good injection precise also a stable performance etc.

Meanwhile, the HDF machines are a type of high-speed Plastic injection mold press. The machine’s cycle time is very short (2.6 seconds-3.6 seconds) with a high injection pressure (to be possible to reach 240MPA) and a high-speed injection (to be possible to reach 600MM/S). This machine can be used to produce the thin-wall products, especially the thin-wall snack boxes and containers (with the wall thickness of 0.4mm).Plastic mold

Or you can choose another option among other Plastic injection mold press available in the market. Just choose the one based on your needs and budget, and you will surely find the one you are looking for.

Related Info to Plastic injection mold press

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Is your project ready for molding? Send us your requirement for quotation, we will send you the price in 24 hours, you will not lose anything but have our competitive price for reference.

plastic injection mold

Looking for plastic injection molding service?

Contact us to get quote, we are A Custom injection mold maker in China that offers plastic injection molding services.

The excellent quality of our plastic molds and molded parts, coupled with our experience and the performance of our services give us today a high international recognition.  Indeed, the company is specialized in International Business and has customers all over the world. SINCERE TECH has very high standards of quality control and always runs long tests to make sure that our Plastic Injection Molding Service reaches all the expectations of our customers. We believe that the quality of a company and its products are seen through time and this is why we like to build strong long-term partnerships with our customer

What is plastic injection molding process?

Plastic injection molding is a manufacturing process in which melted plastic is injected into a mold and then cooled to form a solid part. The mold is created from a metal or plastic tool (1.2344, H13, NDK80, etc.) and is typically made in two halves that are clamped together. The plastic material is heated in a barrel and then forced into the mold under high pressure where it cools and solidifies into the desired shape. This process is used to produce large quantities of identical parts with high precision and repeatability.

When do you need plastic injection molding service?

You may need plastic injection molding service when you require mass production of plastic parts with consistent quality and high precision. This process is ideal for producing large quantities of the same part, as the mold can be used multiple times to produce identical pieces. Additionally, plastic injection molding is well-suited for producing complex and intricate shapes that would be difficult or impossible to achieve with other manufacturing methods. This process is often used in various industries such as automotive, consumer goods, medical devices, and electronics.

plastic injection molding service

plastic molding services

Benefits of plastic injection molding service

The benefits of plastic injection molding service include:

  1. High volume production: Plastic injection molding is ideal for high volume production of identical parts, as the mold can be used multiple times.
  2. Consistent quality: The process is highly repeatable, which leads to consistent quality of parts produced.
  3. Complex shapes: Plastic injection molding can produce complex and intricate shapes that would be difficult or impossible to achieve with other manufacturing methods.
  4. Material flexibility: A wide variety of plastic materials can be used in the injection molding process, including thermoplastics, thermosets, and elastomers.
  5. Cost-effective: The process is efficient and cost-effective for producing large quantities of parts, as the cost of the mold can be spread over many parts.
  6. Precision: The process can produce parts with high dimensional accuracy and minimal tolerance variation.
  7. Automation: Plastic injection molding machines can be automated for increased productivity and reduced labor costs.

Plastic injection molding is a versatile and reliable manufacturing process that can provide significant benefits for producing large quantities of complex and high-precision plastic parts.

Plastic Injection Molding Service in China


We are the manufacturer of our own moulds (toolmaker or plastic injection tooling) and support the production of Injection molded parts allowing reducing your numbers of suppliers. Our injection machines have clamping forces going from 60 to 1050 Tons (2000 Tons outside). Plastic injection molding is the process of producing parts from thermosetting and thermoplastic materials.

Our qualified teams of Designers, Quality controllers and our Research and Development Department allow us to complete our policy: achieving Customer Satisfaction through Improvement and Innovation. The quality of our products and organization permits us to obtain quality certifications (ISO 9001, ) and be awarded numerous times of “Quality Supplier” from different customers. We integrate constantly new resources into our process in order to anticipate any future need of the plastic injection molds market and we became one of the most innovative companies in the sector. The modernity and the organization of our facilities allow us to adapt very quickly to the customer’s needs.

SINCERE TECH has always the objective to stay one of the innovative leaders of the sector and play an important role in our customer’s development. The firm can now propose a total solution from mould design to the semi-finished product (All in-house). SINCERE TECH is always willing to integrate new processes to the solution proposed by staying aware of new technologies. If a customer has a special requirement, we will do everything to fulfill its needs.

Plastic Materials /Commodities

We are used to working with all the classic and less classic plastic materials except PVC (PP, PE, PC, ABS, PC+ABS, PA 6, PA 6.6, PBT, PMMA, TPU, PC+GF, AS, PTFE, POM, PEHD, PEEK…). Our main suppliers are Sabic, Bayer, and Chimei.
About the steel used for our moulds, for export plastic molds we work only with the best steel suppliers like Assab (Sweden), Buderus (Germany), Daido Steel (Japan) LKM( the biggest one in China). For our standard component suppliers, we work with Hasco and DME.

We are used to working with our suppliers the same way we work with our customers. It means good long-term relationships with high-quality policy.

Complex moulds: SINCERE TECH has a rich experience in difficult plastic mould and parts, complex moulds and is an expert in finding solutions to your issues. SINCERE TECH is a real specialist in difficult tooling. To give a classic example: many design companies create plastic products without thinking about mould construction. Then, when the designs are sent to toolmakers, it can be hard for them to make the exact parts (Difficult design, many sliders, many lifters, double injection with materials non-bonding well together, many details in awkward places…).

Most of the classic toolmakers will accept the parts and say that they are able to do it. And then, they will have problems with the plastic injection mould construction, the lead time will be extended and the quality of the tool will not be as expected. Often, these companies have to contact SINCERE TECH to help them to resolve their problems. If you are not sure about the complexity of your part, be sure about your mould maker’s professionalism. SINCERE TECH works closely with its customers in order to resolve any issues.Plastic Injection Molding Service

Thin Wall injection molding: it permits a precise, very accurate molding of plastics and gives better details to the product. This is the name referring to products with a wall thickness lower than 2mm. Usually, the flow is quick, permits a short cycle time and a cost-saving.

Hot runner mold: the special process of injection of plastics where the plastic is kept hot when going through cavities of the mould while the rest of the mould is getting cold to solidify the plastic part and create the molded part: this permits to save plastic material. This is mainly used for parts with medium or large sizes. We are used to working with all popular companies like Yudo, INCOE, Synventive, Husky, HRS… We also have the technology to make our own hot runner systems if the production of the parts (Molding) is made in-house. This again allows our customers to save costs.

Optical Lens Molding: precision molding for glass plastic. This is the technique to produce transparent plastic molded parts (For example Security cameras parts such as the dome cover or also phone frames).

Gas-assist Injection Molding: the plastic parts are gas-assisted molded which means that gas (Most often is nitrogen) is injected at the final stage of the part creation process. It permits to reduce the cycle time, the product weight, the risk of deformation and also the pressure tons injection needed. Moreover, it makes the part’s structure stronger with a better look.

LED/LCD frame molding: injection of plastics used for example to manufacture television screen monitors, computer back-light modules, GPS frames…

IMD, IMF, IML, IMR Molding: In-mold decoration. The decoration of the part is made inside the mould through a film. The film is printed before the molding with the designs wanted. It permits better productivity and extends the decoration’s lifetime. If the customer wants to change the design/decoration of the part, it is not necessary to make another mould but only to change the film. SINCERE TECH is experienced with In-mould forming, in-mold-labeling, and in-mold by roller.

Overmolding: this technique permits to join several components together with a thermoplastic material. This reduces assembly and labor costs. Because the parts are made together, this allows less risk of improper termination or misalignment and increases the design flexibility. Moreover, thermoplastic provides better resistance to vibration or shocks. This technique permits to increase resistance, reduce costs and weights.

Insert Molding: this is a technique where a small part (Stamping part, optical part…) is added or inserted to the Injection molded part.two shot molding

Two-Shot Molding: 2 independent injection units using 2 different materials and/or colors. The first material is injected; then, the mould rotates and the second material is injected to make 1 part. It permits a 2-colour-molding or also called double injection, 2 shot molding, two-shot injection, overmolding, 2K injection, two colour injection, bi-injection, dual shot molding or multi-component molding.

CNC Technology. CNC is an abbreviation for Computer Numerical Control. This is a machine extremely accurately controlled by computer programs permitting a CAM (Computer-aided Manufacturing) through a CAD (Computer-Aided Design). Any plastic injection tool manufacturer uses it but the value-added of SINCERE TECH is the experience, professionalism, and training of the staff.

FMMS Molding or can be called RHCM (Rapid Heat Cycle Molding): excellence surface appearance: permits to take off the welding line. This process is integrated into the molding to save time. It is used for example for clear plastic parts.

US Welding: Ultrasonic Welding: process to weld/ join/ assemble plastic parts thanks to ultra-sounds.

Silk-Screen Printing:  this is to print logos or designs on parts.

Dip-Coating: this is the process of putting the component inside a liquid solution to apply a thin film on it. It permits to manage, change the hardness, the strength of the part by protecting it and expanding the lifetime of the product. Then, the excess liquid has to be drained and evaporation of the solvent is done to create the thin layer.

Laser Etching: this process is made for cutting a shape, a pattern, an image on the plastic part. It is also called laser graving.

Sputtering coating: this is the process of creating a very thin layer of conducting material on the component. It is also called Plasma Enhanced Chemical Vapor Deposition (PECVD) and can be done with most metals like aluminum, stainless steel, copper…

EMI shielding: protect parts from electromagnetic interferences. It is used to protect electrical signals from the outside world. For instance, we use it with marine radars for Garmin.

Waterproof technology: SINCERE TECH has the experience to make water-resistant parts and is able to ensure in-house tests thanks to the IP68 tests.

Sub-assembly: this is the pre-assembly of a component who will be later on being assembled in a larger product.

R&D: SINCERE TECH has its own Research and Development department in order to work with the customers on their projects, advise them on designs, resolve issues and study the feasibility of those.

Quality Control: We have very high standards of quality control in order to respect any requirements from our customers. We have a 100% quality control on our plastic molded parts, it means we control any part coming out of our production.

At Sincere Tech China mold maker, our unwavering commitment to staying at the forefront of the plastic mold industry drives us to embrace advancements and anticipate future trends. We continuously explore innovative materials and composites that offer enhanced performance and promote sustainability. By investing in ongoing research and development, we consistently deliver cutting-edge solutions that meet the evolving needs of our valued customers. As a trusted injection mold supplier in China, we take pride in our unwavering dedication to excellence.

Aligned with our sustainability goals, we place a high priority on environmentally friendly practices. We actively seek out sustainable alternatives, such as biodegradable polymers, and implement recycling initiatives to minimize the environmental impact of our manufacturing processes. By choosing our custom injection molding services, you can align your brand with sustainable manufacturing practices and contribute to a greener future.

Ensuring quality is our topmost priority, and we maintain rigorous quality control measures throughout the entire manufacturing process. Equipped with state-of-the-art facilities and staffed by skilled technicians, we subject each product to thorough inspection and testing. This guarantees exceptional performance, reliability, and customer satisfaction.

When you choose Sincere Tech as plastic injection molding service partner in China, you can expect the highest level of professionalism, expertise, and innovation. Our dedicated team is committed to helping you bring your ideas to life, delivering superior products that excel in performance, durability, and cost-effectiveness.

Partner with Sincere Tech Mould suppliers for your custom plastic injection molding service, and benefit from our comprehensive capabilities, unwavering commitment to quality and sustainability, and our drive to exceed your expectations at every step of the process. Together, let’s bring your innovative ideas to life.