Tag Archive for: TPE overmolding

2k molding

Brief summary difference between overmolding and 2k molding

While injection overmolding and 2K injection molding (also known as 2-shot injection moulding) share many similarities, they also have some key differences. See below for the difference between those two molding processes.

Injection overmolding is using a normal single-nozzle injection molding machine to produce the two different types of materials in one solid part. The overmolding process means moving the first part (substrate part) or metal inserts (insert molding) to the subsequent mold (overmold) to create the final part. You can use the overmold to add a soft-touch grip to a tool handle or to create a product with multiple colors or textures.

2K injection molding, also referred to as multi-shot injection molding, 2-shot injection molding, or dual-injection moulding, involves using a specialized 2K injection machine to simultaneously inject two or three materials (colors) into the same mold. In fact, the 2K molding machine actually has two installed moulds. Unlike overmolding, the 2K moulding machine simultaneously injects both materials, fully bonding them together once the molding process is complete. The 2k molding process, while complex, is characterized by its speed, efficiency, and high quality.

Compared to over molding and 2K injection molding, 2K injection tooling offers superior quality and production efficiency. However, due to the high cost of the 2K injection moulding machine, overmoulding sometimes serves as a substitute. On the other hand, the cost of an overmolded part is higher than that of a 2K injection-molded part. However, for low volumes of 2-color moulding parts, injection overmoulding can utilize any standard injection-moulding machine to produce the overmoulded parts.

TPU Overmolding

When designing multi-material or two-colored plastic parts, it’s crucial to choose the right moulding process based on your part’s design and production needs. Both overmolding and 2K injection molding have their own advantages and disadvantages. Some of the injection moulded parts can only be molded with the overmolding process, while some of the injection molded parts can only be molded with the 2K injection molding process; this is depending on the plastic part geometry design. If both moulding processes can produce the plastic parts, the 2K molding process will be the most effective for high-volume production.

Both overmolding and 2K injection moulding can be used to create products with multiple materials or layers, but the key difference is that in over molding, two materials are formed separately (preloading the substrate to the second mold), while in 2K injection molding, two materials are formed together in the same process (of course, a specialized machine is needed).

What is overmolding (over mold)?

Overmolding or over mold is a molding process that is molding one plastic over another matreial to be merged to form a single end-molded product. Plastic overmolding needs to make two separate molds: one is the substrate (the first mold), and the second mould is called the overmold, usually a TPE material is used for the second mold, but not always. If the substrate is machined metal or brass components, this type of overmolding is normally called insert molding, and insert molding only needs one mould (over mould) to finish the overmolding process.

The materials most commonly used for plastic over-molding are thermoplastics (TPE), rubber, or the same material as the substrate but in different colors. Today, we will primarily focus on the overmolding technology that utilizes TPE materials, which are widely used in various industries. The rigid substrates can be made of a wide range of materials, including polyethylene (PE), polypropylene (PP), polycarbonate (PC), nylon (PA6 or PA66), acrylonitrile butadiene styrene (ABS), polymethylmethacrylate (PMMA), polystyrene (PS), high-impact polystyrene (HIPS), polyphenylene oxide (PPO), acrylonitrile butadiene styrene (ABS), or any other special-purpose material that can be used as substrates.

Over-Molding utilizes the injection moulding process to inject one plastic material (Over-Mold) over another material (Substrate). The over-molded plastic material normally use TPE, rubber, TPU or same material like substrate but different colors. Overmolded materials will make a strong bond with their substrates, ensuring long-term durability and optimal performance in their intended environments. The use of over-molding removes the need for adhesives when connecting thermoplastic elastomers (TPEs) to hard substrates. Overmolding technique simplifies the molding manufacturing process, lowers costs, and allows for more design flexibility.

TPE overmolding

metal insert overmolding

The types of overmolding

Types of over-molding include two-shot sequential overmolding, insert molding, and multi-shot injection molding (2K injection moulding, 3K injection moulding, or more).

Two shot sequential overmolding

In two-shot sequential plastic injection overmoulding, the molding machine injects the first plastic resin into the first mold cavity (substrate mould); after the material cools and forms the first plastic shape, and then opens the tool, all of those molding processes are the same as the traditional injection moulding process.

Once the first substrates are completely finished and cooled, insert the substrate into the second mold (overmold), close the tool, and then inject the second material. The molding process is also the same as the traditional molding process; the difference is preloading the substrate into the mold before the molding process begins.

All of those moulding process will be done with tradional injection machine.

Inert overmolding

Insert over-molding uses pre-formed inserts or metal inserts placed into the mold before injecting the second material; if the inserts are metal or brass, then we call it metal insert molding. This over-molding process, which we used a lot, for example, metal cwrew insert molding, filter insert molding, this type of over-molding uses a traditional injection moulding machine to proceed, which puts the metal inserts into the mold cavity during the single injection molding cycle.

Like the below picture is showing the insert overmolding with metal inert. This type of overmoulding only requires one injection mold; however, if the first insert is made of a plastic part, we will need an additional mold for the first plastic insert part.

Multi-shot injection molding or 2k injection molding

Multi-shot injection molding, sometimes called 2-shot injection moulding, is also a type of overmolding. This molding technology requires specialized injection molding machines, which have two injection units. The injection barrels can be parallel or perpendicular to each other. There will be two injection molds assembled in this machine; one mold makes the substrate, and the other one is for the overmolding process.

The molding machine injects the first plastic resin into the first mold cavity, also known as the substrate mold. Once the material cools and forms the first plastic shape, it opens the tool. This process is identical to the traditional injection tooling process. Once the molds are open, the movable half rotates 180° without ejecting the substrate. Next, it closes the molds and initiates the second injection, also known as the overmold. Simultaneously, it injects the first shot. Once the second mold completes its molding process, it opens the tools again and ejects the overmolded product from the overmold. During this process, a new substrate is generated for the second cycle.

This is a completely molding cycle for the 2k injection moulding process.

overmolding

insert molding with metal screw, metal insert tooling is a type of over-moldings

TPE overmolding

TPE (thermoplastic elastomer) plastic matrials are used a lots in the injection molding field, specially for the overmolded parts, on the overmolding market, over 80% of overmolded parts made by TPE over molding,

TPE Over molding is the injection molding process where TPE (thermoplastic elastomer) is formed onto a rigid material (for example PC, PA66, ABS material) according to the specific requirement, the overmolded TPE will strong bond with the first plastic and maintain in the final using purpose. To prevent the TPE material strip off from the second material, material selection and part design is very important.

A TPE overmolding manufacturer will consider all relevant factors when selecting the optimal moulding manufacturing method for a plastic injection molding part, choosing between 2K molding and the overmolding process. Critical factors include production capacity, material selection, available equipment, and labor costs.

Normally, the overmolding process is the most popular choice when total production volumes are less than 50K. This number is only a reference and not a definitive one because it depends on the size and complexity of the part design. For higher volume production requirements (total volume over 200,000 units), a 2-shot injection moulding process will be a better option; of course, this is still dependent on the part design because some parts can only be molded with an overmoulding process, foe example like below part can only be create with overmolding process.

TPE overmolding

In every TPE overmolding or 2K injection molding process, the number one issue is to achieve maximum adhesion between the TPE and the substrate. Some TPE overmolding may have significantly different bond strengths between multi-shot and overmolding. Even if an excellent bond is produced with two-shot molding, the same material may have a low bond strength when using overmolding. Thus, to make high-quality finished overmolding and 2K molding products, a thorough understanding of TPEs, part design, engineering plastics, and the specifics of the molding process is important.

TPE Overmolding materials seletion tips

As we know to make high quality TPE overmolded product, both TPE and substrate materials are most important, the number one factor to define the quality of overmolded part is how good the mergeration between two matreials, if the TPE is easy to strip off from the substrate then the material will be issues, below there are some tips for meterials selestion, following thsi tips you will find the best suitable material for overmolded part.

Thickness of TPE overmolded part

Designers frequently request the softest TPE. They don’t realize that a TPE’s soft durometer doesn’t provide much to “cushion” below a particular thickness (usually less than 0.1mm). Thinner TPE overmolded part feel harder—the hardness impact depends on thickness. Multiple closely spaced ribs can produce the illusion of thickness without utilizing much material. Many kitchen utensil handle use this method.

Hardness of TPE plastic material,

There is a softness of TPE material that you need to select when you make TPE overmolding, especially TPE thickless, which is more than 0.5 mm. To have a good touch feel, you may need to test different types of TPE shore A material, unless special function requirements, normally we use in the market will range from TPE Shore A 40 to 60; if too little, that may eash to strip off from the substrate; if hardness is too high, the touch feel may not be good enough.

Substrate material selection tips

Compared to TPE material, substrate materials will be easier to choose; most materials can be substrates, including nylon/PA (PA66 or PA66 GF30, PA6 or PA6 GF30 plastic), Polycarbonate (PC), Acrylonitrile Butadiene Styrene (ABS, PC/ABS, Acetal (POM), PMMA, and so on. The final substrate material selection is dependent on the final purpose. If you are uncertain about the optimal material for your TPE overmolded parts, please reach out to us and we will provide you with some recommendations.

Surface finish on substrate and TPE overmold

Surface finish on the substrate will also affect the adhesion of TPE rubber. The stronger the adhesion, the less likely it will strip off, normally will be good polishing between merge surface between TPE and substrate, on the TPE cavity side, soemtime surface finish will effect to the TPE overmold as well, sometime higi polishing to the TPE cavity mold, the TPE overmolding part will stick to cavity side, add some small VDI texture will improve this.

TPE overmolding part design tips

Part design, as previously mentioned, plays a crucial role in creating a high-quality TPE overmolding product. Generally, the design of the substrate part is similar to that of other plastic injection tooling parts. For further details, please refer to the page on plastic part design for injection molding. But there are some factors on the merge area between the substrate and TPE overmoled area; there is no standard design for this era since different parts have different geometries, but there are some key points that you need to think about when you do the overmoled part design. Those factors will be:

How to seal the TPE overmolding well and provent from flash When you do the overmoling part design: 

TPE material easily exhibits flash (0.03 mm gap), and bondable TPE materials meet more stringent criteria than standard TPE polymers. The same holds true when designing parts. Unlike traditional part design, two-component part designs must account for shrinkage from two different thermoplastic materials. Both substrate and over-molding have their own gate and runner systems, which must be tailored to the individual material properties used.

To meet the best cycle time, substrate and overmolding wall thickness should be consistent. In most over-molding applications, 1-3 mm wall thickness ensures satisfactory bonding. Thicker pieces should be cored out to reduce shrinkage, weight, and cycle time. To avoid backfills and gas traps, wall thickness transitions should be gradual. Add radius to the sharp coners to reduce stress issues. Avoid deep, unavailable blind pockets or ribs. Long draws should have a 3-5 degree draft angle for easy demoulding. In overmolded compounds, deep undercuts can be designed if an advancing core is used when the mold opens, the part has no sharp corners, and the elastomer bends during ejection.

Most TPE compounds have significant flow direction tool shrinkage and moderate cross-flow shrinkage. After ejection from the tool, the over-molding compound may contract more than the substrate. This can stretch the substrate, usually in the overmolding material’s direction. This is especially true for long, thin parts or components with a low-modulus substrate or one thinner than the over mold. Use higher-modulus substrate materials and stiffening ribs to mitigate this. Thinner coatings and lower-hardness over-mould grades assist. Relocating the gate to affect TPE flow may also help.

If you can enhance the design to ensure a tighter bond between the TPE material and the substrate, such as by increasing the cross-sectional area, without compromising its functionality or appearance, it would be beneficial. Below is one of exmple of overmolding part design tips.

Overmolding part design tips

Avoid designing too many separated areas on the TPE overmolding part, as this can complicate the overmold manufacturing and moulding process. Especially many areas are designed to the parting line area; this will be hard to solve the flash completely when you design the TPE overmoulded part, designing as simple as possible, unless some function purpose.

TPE overmolded

Tips for overmold desgin:

When we design injection mold for overmolding parts, the first mold (substrate tool) we will add shrinage rate according to plastic shrinakge rate, but for the over molding mould (second tool), we will not add any shinakge rate on the injection over mold.

Overmolding cost

The base cost of an overmolding is not a fixed number that will be the same for every application. It has a varying value that can fall between 1 and 10 dollars.

This is an extremely wide price bracket. The right value changes based on several components involved in the overmolding process. These factors that influence the cost are:

Injection molding Equipment

The upfront cost of equipment for injection moulding can change greatly depending on its application and type.

There is little-scale injection moulding equipment that businesses keep in house. Then there are big overmolding machines generally used by service providers and those in the big-scale manufacturing industry with large production volumes.

Professional industrial overmolding equipment costs between $50,000 and $200,000. There may be shipping costs involved. These machines are not for amateurs and hobbyists, as they need skilled operators.

Over-mold manufacturing costs

While the overmolding equipment is a one-time investment, creating the over mold according to each custom design is an additional cost, and each single unique overmold part design will require a unique over mould. It is an expense for every different part produced. So, over mold manufacturing costs are one of the most vital driving factors for overmolded parts.

This over mold cost can vary depending on the part design, part size, and quality required to create the molds. Generally, three factors are employed for this objective, which are listed below:?

Design complexity

Highly complex designs with more cavities and top mold polish result in extra costs. Such designs need development, research, and technical skill. For this objective, you can hire a professional for the design process. Both options incur expenses.

Part size

Over mold is the same as other injection molds; a large size will require a large moldbase and molding machine, which will increase the over mold cost and unit over moled part cost.

Labor costs

Most steps involved in overmolding are automated and run by software systems. For example, CNC machines are run by computer numerically controlled programs; 3D printers run on their own programs; and injection molding also has mechanical processing.

Final summarize for the overmolding cost

If you are looking for over-molded parts or over mold for your custom injection molding parts, then you do not need to pay any cost on the injection molding equipment, because your over molding supplier should have this, but you need to pay for the over mold cost, over-moulding process cost, materials cost, packing cost, and so on. If you want to know the price of your overmolding project, please contact us and we will quote you in 24 hours.

metal insert molding

Metal insert molding

How to reduce overmolding cost

Overmolding is the preferred manufacturing process due to its cost-effectiveness and reliability.

While the process is affordable compared to its alternatives, you can further decrease the costs. For that objective, here are some pointers that you need to take into account:

Optimizing the CAD design

A single part can be approached via different CAD designs. Anyway, not every design idea is perfect. Some designs for the same part may lead to time and resource waste. So, simplifying part complexity via efficient CAD design ensures optimal utilization of resources.

Reducing part size

Bigger parts are not always excellent parts. When the size of the parts rises, so does the expense of the injection molds needed for the parts. If the same process can be accomplished by decreasing the part size, it is a good idea to opt for it.

Resuing over molds

Make full use of the over molds by reusing them for many applications. You cannot just use the same mold for the same part but also for similar parts as well. This can be performed by making adjustments or molding wherever possible.

Using DFM analysis

DFM stands for design for manufacturing. DFM in overmolding refers to producing a part that serves the objective of the customer and is within their stipulated budget.

For DFM, analysts consider many factors based on science, art, and technology to find the most successful design, resulting in reducing injection over mold costs. Go to design for manufacturing page to know more.

over mold

Both over molding and 2k injection molding are very similar processes, sometime both molding processes can work on the same part, but something can only be molded with single overmolding or 2K injection molding, this is completely depending on the part design.

Advantages of injection overmolding

  1. Compared to 2K injection molding, over molding is easier to make. You can use a normal injection molding machine to make two or three different colors in one molded part or two or three different materials in one end part.
  2. For some small quantities of two-color molding part projects, you do not need to invert or hire a 2K injection molding machine; using the overmoulded process is the best and most cost-effective way to meet customer requirements.
  3. It increases the design diversity and also exalts the end product in many material compositions.
  4. With reduced assembly costs, there are fewer secondary activities or processes carried out on the end products. This reduces the cost of labor. Also, after manufacture, no more costs are incurred.
  5. The parts have a high level of stability and constitution since, after being left to mechanically interlock, they become one.
  6. Products overmolded using plastic have high resistance to vibration and shock due to the plastic resins having been structured perfectly.
  7. The plastic molding parts are more reliable because there is no bonding at the production stage.
  8. The end items are of the desired standard, such as eye-catching designs and firm components.

Disadvantage of injection over moulding

  1. Since the over moulding process involves moving the first molded substrate part to another over mold, the tolerance is not as good as in the 2K injection molding process.
  2. The production capacity is not as efficient as 2K injection molding, as it requires robots or manual labor to insert the substrate into the overmoulded tool. This will take time, and the molding parameter is sometimes not stable, especially when two or more substrates are in one tool. This will lead to additional problems and a higher waste rate, resulting in twice the amount of waste (from the substrate and overmolded material).
  3. With the overmolding process, there are fewer available choices in terms of plastic compatibility. Some materials may not bond well together or may not be able to withstand the high temperatures and pressures of the injection molding process.
  4. There are no secondary practices carried out on the end products of over-moulding. When the molding material becomes cold, activities and adjustments come to a complete halt.
  5. In cases where products are scarce, it is expensive to run such an operation. Sincerely, you need someone to put the substrate into over mold, so the cycle time and production cost are increased accordingly.
  6. The overmolding process normally requires two molds, one for substrate and one for over mold, so the initial tooling cost will be higher.
  7. Overmolding is a more complex process than traditional injection molding, requiring precise coordination between the two injection systems and a proper mold design.
  8. If there is an issue with the overmolding process, troubleshooting and fixing problems with overmolding can be more difficult than with traditional injection molding.

What is 2k injection molding? (Two-shot moulding)

Two-shot injection molding, or 2K injection molding, is a manufacturing process used to create two colors or materials into one plastic. This two-shot molding technology blends two materials or two different material colors into one plastic part by using a 2K injection moulding machine.

The chemical bonding process involved in this process is very important because it is capable of combining two or more materials into one part. When using the 2K injection molding technology process, material selection will be an important factor in the success of the project or not.

2k injection molding

Benefits of 2K injection molding 

2K injection moulding provides a number of benefits over traditional one-material injection molding. Some of these benefits contain:

Cost-effective

The 2-step process needs just one machine cycle, rotating the primary mold out of the way and putting the secondary mold around the item so that the second, compatible thermoplastic can be inserted in the second tooling. Because the method uses only one cycle instead of separate machine cycles, it costs less for any production run and needs fewer employees to make the end product while delivering more items per run. It also ensures a powerful bond between the materials without the need for additional assembly down the line.

Improved efficiency

Two-shot molding permits multiple components to be molded with one tool, decreasing the amount of labor required to run your parts and eliminating the need to join or weld components after the molding process.

Better quality

Two-shot is carried out within one tool, permitting lower tolerances than other molding processes, a high level of accuracy and repeatability, and reduced scrap rates.

Complex molding

Two-shot molding permits the creation of complex mold designs that incorporate different materials for functionality that cannot be achieved via after-molding processes.

2 shot injection molding

Disadvantages of 2K injection moulding

2K injection molding has many advantages, but like everything, it has its pros and cons.

A disadvantage of 2K injection molding is that the mould costs are higher than traditional injection mold. because 2K injection tooling requires two molds, the first shot and the second shot (that is why we call it two-shot molding), and making 2K injection molds are more difficult than making two separate traditional molds because those two moulds will run together in the same machine (a two-shot injection moulding machine). so it needs two moulds to switch over without any problem.

Additionally, the 2K injection molding process must use a 2K injection machine, which also makes the machine more costly and requires a special technical operator to adjust the machine. This is also a higher cost than traditional injection tooling. Ultimately, we recover the 2K injection molding costs by reducing labor and assembly costs, as the manual application of, for example, a seal is no longer necessary. This eliminates an assembly step.

Another disadvantage of 2K injection molding is that it makes the recycling of plastic items difficult because often two different plastics are gathered. Even when the plastics are “from the same family,” the quality of return flows will be very low, which makes it hard to reuse the plastic for a high-standard application.

How to choose overmolding and 2K injection molding services

You may have questions about when you need to use over molding and when you should use the 2K injection molding process. Here are some simple suggestions:

  1. If the quantity of the overmolding or 2K molding part is only a few thousand or ten thousand, it is recommended to use the overmolding process instead of 2k molding process as it can significantly reduce mold costs.
  2. If you require more than 500,000 parts, 2K injection molding is the most cost-effective molding process. This is due to the high labor costs associated with overmolding and the high initial cost associated with 2K moulds, two-shot injection molding machines, and related equipment.
  3. Overmolding is the only method available for some parts, while the double injection molding process is required for others. This depends on the part design structure. If you’re unsure, send your data to info@plasticmold.net. We can check this for you and provide a price for your reference.

Looking for over molding or 2k injection molding service?

Sincere Tech is one of the best injection molding companies in China. If you are looking for overmolding, insert molding, 2K molding, or any other custom molds, send us your 3D design drawing and your requirements; we will never share your data with anyone else. We are willing to sign an NDA document to ensure the safety of your project.

We will offer you the most competitive price for high-quality overmoulded parts, 2K tooling and moulding, plastic tooling, and plastic parts for the long-term business relationship, and we will suggest the best injection molding process for your products.

More than 18 years of experience providing plastic mold making and custom mold services in overmolding, 2K molding, die casting, machining, and so on, plus 18 years of fluent technical English communication (technical English communication is very important to work with worldwide customers).

Small orders are accepted. Main export markets: Asia, Australia, Central and South America, Eastern Europe, North America, Western Europe, and the worldwide.

TPE injection molding

What is TPE injection molding?

TPE injection molding refers to the process of injecting thermoplastic elastomers (TPEs) into a mold to produce a finished product. TPEs are a type of material that exhibits the characteristics of both thermoplastics and elastomers. They are often used to produce products that require flexibility, durability, and resistance to weathering.

TPE injection molding is a versatile process that can be used to produce a wide variety of products, including automotive parts, consumer goods, medical devices, and more. It offers many benefits over traditional manufacturing methods, including lower costs, faster production times, and greater design flexibility.

TPE molding

What is TPE material?

TPE (thermoplastic elastomers), sometimes referred to as the material of thermoplastic rubbers, is a class of copolymers or a physical mix of polymers that consist of materials with both thermoplastic and elastomeric properties. The materials have the potential to be recyclable since they can be molded, extruded, and reused like plastic. And they have the typical elastic properties of rubbers, which are not recyclable owing to their thermosetting characteristics. Want to know more about TPE? Go to the TPE-safe page to learn more.

These materials are available in different configurations and features as per the requirements of the client. The TPE material, with no need to add reinforcing agents, stabilizers, or cure systems, is sourced from reliable vendors on the market who use superior-quality raw materials in the manufacturing process.

The selection of the material is an important decision in injection molding. The material has a significant impact on the properties of the product, whether these are regarding its appearance, stability, interaction with other materials, or physical property. Material is a basic element in the production of any product, so it has a big impact on the cost, which is an important element in decision-making.

When you choose TPE (thermoplastic elastomers) for your injection molding parts for your project, you should know what the property is. Basically,  TPE overmolding and 2K molding are the normal molding processes we work on. like PTE over ABS, TPE over PC, TPE over PP, etc. This material is a type of synthetic resin that starts melting when exposed to heat and hardens when the temperature drops, but without changing its chemical properties.

TPE injection molding

TPE injection molding

Process of TPE injection molding

In the process of TPE injection molding, a hopper is used to enter the TPE pallets into the machine and, after that, into the barrel. Here, the high temperature of the barrel makes the material a liquid resin. This liquid resin is fed into a closed mold with high pressure. When the molten polymer makes the finished document dry and cool, it is then taken from the mold.

Although injection molding is a good solution for a number of problems, custom injection molding is used to resolve the problems. However, the use of appropriate material is crucial. Injection molding is a fast process, and the properties of TPE plastic make it a desirable material for injection molding. The products in which TPE is used are thermoplastic polyurethanes (TPU), thermoplastic olefins (TPE-o), synthetic block copolymers (TPE-s), thermoplastic copolyesters, elastomeric alloys (TPE-v or TPV), and thermoplastic polyamides.

How to Select TPE Shore Materials

Sometime we will see the information on the TPE data sheet that has TPE shore A xx, for example, shore A 30, shore A 50, etc. What does this mean? Single explain that TPE shore means the hardness of TPE material.

When you plan to use TPE, the first thing you need to think about is what hardness of the TPE you need to use, which means what shore degree of materials you need to use. But here are some normally used materials on the market today: the most popular hardness of TPE used will be from shore A 40–80,

If you are not sure what shore degree of materials you should use, the best option will be using the TPE shore A 50 at first; you can change to shore A 40–80, so if you are not sure what shore degree of materials you should use, the best option will be using the TPE shore A 50 at first; you can change to shore A 40  or 60 after the first mold trial.

Of course, when you select the TPE materials, there should be many other factors that you should think about, for example, UV resistance, food degree, FDA degree, and so on.

Advantages of using TPE injection molding

  • As the plastic pallets are liquefied at high temperatures and under high pressure, they are molded into a component that can be converted into the desired shape by curing without the use of a chemical bond. It implies that this type of molding can be easily melted and reshaped to make corrections to the product, and the resin is reusable multiple times.
  • TPE plastic injection molding has been used in various industries for making impact-resistant devices and component housings, sealing rings, some food-contact-approved applications such as bottle cap and closure liners, baby bottles, and toddler cup spouts (provided proper FDA regulatory compliance is met), PVC, silicone, seals, etc.

Disadvantages of using TPE injection molding

Thermoplastic elastomers (TPEs) have many advantages. However, the use of TPE injection molding has its drawbacks. When you plan to use TPE plastic materials for your injection molding parts, you need to think about the following things in advance.

One of the primary disadvantages of TPE injection molding is that it is a little more complex during injection molding. Compared to other hardened thermoplastic injection molding materials, TPE molding requires high-quality mold design and manufacturing because TPE is very easy to go flash.

Furthermore, the viscosity of TPE materials can pose challenges during the injection molding process. TPEs generally exhibit a higher melt viscosity than traditional thermoplastics, which can result in longer cycle times, sticking to the cavity side, easy distortion, hard control of the dimensions, etc.

Another significant drawback of TPE injection molding is the limited part design. Due to the properties of TPEs, it is not possible to make complex part designs or deep rib designs. That is why TPE is mostly used in the overmolding process.

Additionally, the environmental impact of TPE injection molding must be considered. The manufacturing of TPE-based products can result in a higher energy footprint and a larger carbon dioxide (CO2) footprint compared to other plastic materials. This is primarily due to the energy-intensive nature of the injection molding process and the potential difficulties in recycling or disposing of TPE waste.

TPU injection molding

Applications of TPE Injection Molding

TPE injection molding parts are used in many industries. Below,  we will list a few industries that use TPE materials for their products.

Automotive industry

Due to the flexibility of TPE, some gaskets and interior components are used in car components.

Consumer industry

There are a lot of TPE injection molding parts used in this industry, such as TPE spoons, TPE handle grips, TPE bowls, and many more.

Medical industry

TPE injection moulding uses to the medical industry as well, those medical components include tubing and seals in medical equipment, syringe handles, and other places where user safety and hygiene are crucial.

This is only a few samples of TPE products, but there are many more industries using TPE materials. If you have a project that needs to use some soft materials, then TPE may be one of the options to think about.

Conclusion

In the injection molding process, the choice of material is a key decision because the main component of the molded product is material. Today, injection molding is being used as a solution to many problems. TPE is considered an appropriate material for injection molding due to its properties, which are considered desirable for the molding process. Although it has some disadvantages, proper handling will help to avoid such negative consequences.

If you have any project that needs TPE or TPU injection molding service, you are welcome to send us your requirements for a quotation. We are a custom injection mold and molding company that offers different types of custom molds and molded products for all of the industries, and we will provide you with the best solution.

Looking for a TPE plastic injection molding service? Welcome to contact us.