plastic box mould

Polyoxymethylene (POM)

Polyoxymethylene (POM) is a semi-crystalline thermoplastic that is known for its high strength, rigidity, and low friction properties. It is commonly used in the production of gears, bearings, and other mechanical parts that require these characteristics. POM is also known by the trade name “Acetal” and is chemically resistant and has a low coefficient of friction, making it suitable for use in a wide range of applications.

POM injection molding process is commonly used in the production of parts for the automotive, electronic, and consumer goods industries. It is also used in the production of medical devices and in the construction of aircraft and other transportation vehicles.

POM has several advantages over other polymers. It has a high strength-to-weight ratio, making it suitable for use in lightweight parts. It also has a low coefficient of friction, which makes it suitable for use in bearing and gear applications. POM also has good dimensional stability, which means that it maintains its dimensions over time and has a low shrinkage rate.

POM injection molding

POM injection molding

There are two main types of POM: homopolymer acetal and copolymer acetal. Homopolymer acetal has a higher tensile strength and is more resistant to wear, making it suitable for use in applications that require these properties. Copolymer acetal, on the other hand, has a lower melting point and is more resistant to moisture absorption, making it suitable for use in applications where these properties are important.

In POM injection molding process, POM is melted and injected under high pressure into a mold cavity, where it cools and solidifies to form a part with precise dimensions and detailed features. The process begins by heating the POM resin to a molten state, after which it is injected into a mold tool that consists of two halves: a stationary half and a moving half. The mold cavity is formed by the space between the two halves of the mold tool, and the shape of the final part is determined by the shape of the mold cavity.

One of the key considerations in the design of POM injection molded parts is the inclusion of draft angles. These are slight tapers that are included on the sides of the part to allow for easier removal from the mold. Without these draft angles, the part may become stuck in the mold and be difficult to remove. It is important to include draft angles that are sufficient to allow for easy removal, but not so large that they compromise the strength or functionality of the part.

The condition of the mold is also important for the production of high-quality POM injection molded parts. Molds that are worn or damaged can result in parts with poor surface finish or dimensional accuracy. It is important to regularly maintain and repair molds to ensure that they are in good condition.

Finally, the processing conditions, such as the temperature and pressure of the injection process, can also affect the quality of POM injection molded parts. It is important to carefully control these parameters to ensure that the parts have the desired properties.

POM injection molding is a versatile and efficient process for the production of high-strength, precise plastic parts. By considering the design of the part, the condition of the mold, and the processing conditions, it is possible to produce high-quality POM injection molded parts that meet the desired specifications.

Additionally. POM has low melting point, good flow characteristics, and a high resistance to wear and abrasion. It also has a low coefficient of friction, which makes it suitable for applications that require low-friction sliding or rotating surfaces.

If you want to know more POM injection molding process you to go to our other POM injection molding page, there are all detail information there.

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mold manufacturer china

How to find Mould Suppliers in China

Today most of companies buy things from China, specially the plastic molds, the reason is the plastic injection mold requires high technology and equipment, but how to find a good mould suppliers will be a hard task. Below there are several steps you can take to find good mould suppliers in China:

  1. Research potential mould suppliers: Look for suppliers that have a good reputation and a track record of delivering high-quality products. You can ask for references from other companies or search online for reviews and ratings.
  2. Evaluate the mould supplier’s capabilities: Make sure the supplier has the necessary equipment and expertise to produce the type of mold you need. Ask about their design and engineering capabilities, as well as their production capacity.
  3. Request quotes and samples: Contact several mould suppliers and ask for quotes and samples of their work. This will allow you to compare prices and evaluate the quality of the supplier’s products.
  4. Consider the mould supplier’s location: Consider the location of the supplier in relation to your business. If you need to frequently visit the supplier or have products shipped back and forth, it may be more convenient to work with a supplier located closer to your business.
  5. Negotiate terms: Once you have identified a potential supplier, it is important to negotiate terms such as price, payment terms, delivery schedule, and any other relevant conditions. Make sure to get these terms in writing to protect your interests.

It is also a good idea to visit the supplier’s facility in person to see their operation and meet the team. This will give you a better understanding of their capabilities and allow you to build a personal relationship with them.

Why should work with China mould supplier?

There are several reasons why you may want to work with a Chinese mold supplier:

  1. Cost: China is known for its low labor and production costs, which can make it an attractive option for companies looking to reduce their manufacturing expenses.
  2. Quality: Many Chinese suppliers have invested in modern equipment and technology, which allows them to produce high-quality products at competitive prices.
  3. Expertise: China is home to a large and skilled workforce, and many Chinese suppliers have extensive experience in mold manufacturing.
  4. Convenience: Many Chinese suppliers offer a range of services, including design, engineering, and production, which can make the manufacturing process more convenient for companies.
  5. Access to a large market: China is the world’s largest market, and working with a Chinese supplier can provide companies with access to this vast market.

It is important to thoroughly research and evaluate potential Chinese mold suppliers to ensure that you are working with a reputable and capable partner.

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Plastic Moulding

plastic mouldingPlastic molding is the plastic working through the Injection moulding machine, The melted plastic will automatically molten by the molding machine after erupting out in all of the plastic moulding methods, injection moulding technology has been the most widely used on the word today.
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.

If you are looking for plastic moulding service, you are welcome to contact us, we are a professional plastic moulding company in China that offer custom plastic moulding service to the wordwide.


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 door of injection molding machine and then start moulding
1.1.2 Clamping mold
Moving forward the moving half 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 barrel 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 x 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.Chinese molding company

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,

Sincere Tech is an injection mold company 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.

If you want to know more information about service, you are welcome to send us an email, if you need price for your project, please send us your requirement for quotation, we will offer you the best price and service. Hope to work together in the near future.

 

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Injection Molding China
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Injection Molding China

Injection Molding ChinaSincere Tech, funded in 2005, located in Dongguan city, Guangdong province, China, is a professional injection molding china manufacturer, specializes in making injection Mould & moulding service to the oversea customer,

If you have a project that needs an injection molding China manufacturer to support, you are welcome to send us your requirement for quotation, you will not lose anything but have our competitive price for your reference,

Worry about your project data being shared by others, no worry, we can sign an NDA document to protect your project.

If you work with us. You will be fully satisfied with our excellent service, quality and reasonable price.

Injection Molding in briefly explaining is a method that mold is gotten by cooling and solidifying the heated and melted material injected into the cavity via high pressure. The method is suitable for the mass production of parts with complex shape and is one of the important processing methods. The injection molding process can be broadly divided into the following six stages of “combining mold – injection – packing – cooling – opening mold – product removal “, and once the above process is repeated, products can be continuously produced.

Asia’s biggest and world’s second, the “12th China intercontinental Injection Molding technology and products Exhibition” in Shanghai ended, in the getting together with was informed that China’s complete producing injection molding & molds have been graded 3rd while in the world, commencing by means of the importer using the mold exporter, import and export ratio from $659.8 billion in total goods trade during 2018. Goods exports totaled $120.3 billion; goods imports totaled $539.5 billion

Injection molding Tooling market because 2000 with an yearly progress amount of twenty percent, “Eleventh Five-Year” period, producing and sales, production, decent quality and level to even more improve, especially while in the automotive market also it market development, producing the mold-end improve, superior producing products for mold tooling to further improve the specialized level to provide a guarantee. Injection Molding China market Association executive vice president and secretary-general, stated Cao Yanan, China’s mold & molding market is undergoing a “golden development period”, the time period forward will hold on to sustain sustained and quick growth.Injection Moulding China

In latest a few years, mold market to pace up adjustment of product or services structure, to large, sophisticated, complex, long-life die since the representative of the high-tech mold progress amount compared to standard market progress rate, accounting for about 35% belonging using the complete mold. Mold progress amount of exports in 2017 reached 60.76%, an even more decline while in the deficit, import and export mold framework even more reasonable, the domestic choice to imported mold has turned in to a climate.

From the marketplace structure, the quick development of individual enterprises, improve the vitality belonging using the state-owned enterprises, market-oriented specialized injection mold makers amount and ability elevated rapidly, to adapt using the qualities belonging using the mold producing industry, producing belonging using the playground have been gathering mold development, mold collectively with other industrial sectors in much less produced middle and western regions higher progress.

To narrow the gap, we should increase R & D, centered on innovation, improve the decent quality of financial operation. At present, China’s injection molding market is entering an extremely important time period of development. producing industries, especially car producing industry, to promote the domestic market developing mold/molding, overseas customers to purchase the quantity of China’s developing intercontinental mold producing to China’s gradual shift tendency is clear. China injection molding market Association predicted that domestic and intercontinental market remains to mold, Injection molding in China will sustain a progress amount of about 20%.

In addition, China Mold market Association that China’s mold & molding market in latest many years can be sustained and quick growth, showed the subsequent characteristics: companies hold on toward even more large-scale, sophisticated, superior and quick financial direction, specialized composed content will hold on to increase, shortening the producing cycle , mold will hold on to proceed in particulars technology, digital, fine, high-speed and automation development, the company will, even more, improve all components belonging using the standard power and key competitiveness.

If you are project ready for injection molding? If so you really need an injection molding China company to help your business. Contact us to get a price.

 

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Plastic Moulding

plastic mouldingPlastic 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 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 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.Chinese molding company

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,

Sincere Tech is an injection mold company 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, if you want to know more information about service, you are welcome to send us an email, if you need price for your project, please send us your requirement for quotation, we will offer you the best price and service. Hope to work together in the near future.

 

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China plastic injection mold company
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China Plastic Injection Mold Company

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Residual Stress

A culprit in shrinkage and warpage problems

Residual stress is process-induced stress, frozen in molded plastic parts. It can be either flow-induced or thermal-induced. Residual stresses affect a part similarly to externally applied stresses. If they are strong enough to overcome the structural integrity of the part, the part will warp upon ejection, or later crack, when external service load is applied. Residual stresses are the main cause of part shrinkage and warpage. The process conditions and design elements that reduce shear stress during cavity filling will help to reduce flow-induced residual stress. Likewise, those that promote sufficient packing and uniform mold cooling will reduce thermal-induced residual stress. For fibre-filled materials, those process conditions that promote uniform mechanical properties will reduce thermal-induced residual stress. China mold supplier

Flow-induced residual stress

Unstressed, long-chain polymer molecules tend to conform to a random-coil state of equilibrium at temperatures higher than the melt temperature (i.e., in a molten state). During processing the molecules orient in the direction of flow, as the polymer is sheared and elongated. If solidification occurs before the polymer molecules are fully relaxed to their state of equilibrium, molecular orientation is locked within the molded plastic part. This type of frozen-in stressed state is often referred to as flow-induced residual stress. Because of the stretched molecular orientation in the direction of flow, it introduces anisotropic, non-uniform shrinkage and mechanical properties in the directions parallel and perpendicular to the direction of flow.

Frozen-in molecular orientation

Due to a combination of high shear stress and a high cooling rate adjacent to the mold wall, there is a highly oriented layer frozen immediately below the part surface. This is illustrated in Figure 1. Subsequent exposure of a part with high residual flow stresses (or frozen-in orientation) to high temperature may allow some of the stresses to relieve. This typically results in part shrinkage and warpage. Due to the thermal insulating effect of the frozen layers, polymer melt in the hot core is able to relax to a higher degree, leading to a low molecular orientation zone. China mold supplier

FIGURE 1. The development of residual flow stresses due to frozen-in molecular orientation during the filling and packing stages.
(1) High cooling, shear, and orientation zone

(2) Low cooling, shear, and orientation zone

Reducing flow-induced residual stress

Process conditions that reduce the shear stress in the melt will reduce the level of flow-induced residual stresses. In general, flow-induced residual stress is one order of magnitude smaller than the thermal-induced residual stress.

  • higher melt temperature
  • higher mold-wall temperature
  • longer fill time (lower melt velocity)
  • decreased packing pressure
  • shorter flow path.

 Thermal-induced residual stress

Thermal-induced residual stress occurs due to the following reasons:

  • The material shrinks as the temperature drops from the process settings to the ambient conditions reached when the process is complete.
  • The material elements experience different thermal-mechanical histories (e.g., different cooling rates and packing pressures) as the material solidifies from the mold wall to the center.
  • Changing pressure, temperature, and molecular and fiber orientation result in variable density and mechanical properties.
  • Certain mold constraints prevent the molded part from shrinking in the planar directions.

Free quenching example

Material shrinkage during injection molding can be conveniently demonstrated with a free quenching example, in which a part of the uniform temperature is suddenly sandwiched by cold runner mold walls. During early cooling stages, when the external surface layers cool and start to shrink, the bulk of the polymer at the hot core is still molten and free to contract. However, as the internal core cools, local thermal contraction is constrained by the already-rigid external layers. This results in a typical state of stress distribution with tension in the core balanced by compression in the outer layers, as illustrated in Figure 2 below.

FIGURE 2. The development of residual thermal stress in a “free-quenching” part due to variations in cooling across the molded part and the material’s response to the temperature history.

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