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Home » Blog » Thermoset Vs. Thermoplastic Injection Molding: A Comparison

Thermoset Vs. Thermoplastic Injection Molding: A Comparison

Thermoset is a type of plastic that retains strength and stiffness even when heated. On the other hand, thermoplastic is usually more malleable. Also, it can be remolded if heated. Thermoset plastics are typically less expensive than thermoplastic. Because they cannot remold the shape after heating, let’s talk about the differences between thermoset vs thermoplastic injection molding if you are thinking about getting one. You’re probably wondering which of these two technologies is right for your business.


Thermoset plastics are ideal for applications where high heat or pressure might not be an issue. They are also more durable than thermoplastics. So, it can cause them to outlive their product life-cycle. Thermoplastics often have a higher degree of transparency than thermosets. This makes them better for applications where appearance is essential.


Thermoplastic Composites (TPCs) are used to make parts for your cars and food storage containers. But the process is nearly the same as injection molding.


One of your options is to partner with an injection molding manufacturer that can consult on your manufacturing operation. The only problem is, it can seem like there are endless factors to consider. That’s why it is not easy to make a decision.


In this blog post, we compare the thermoset vs thermoplastic injection molding technologies side by side and help you decide if thermoplastic is the right one for your needs.


A brief Introduction of Thermoset and Thermoplastic Injection Molding

Thermoset molding is a process that uses high heat, pressure, and chemical reactions to shape plastic materials. Thermoplastic injection molding is a process that heats the resin until it is liquid. Then it injects it into the mold cavity.

Thermoset is more common in automotive applications because of its ability to create parts with cavities or deep recesses. Thermoplastic injection molding can be used for automotive applications and precision parts like circuit boards because of its ability to create sharp corners.

Thermoplastic injection molding uses a fast-cooling process that gives it an advantage over competitive processes. The process starts by heating the plastic pellets to at least 295°C. When heated, they are mixed with a liquid resin in a high-shear mixer to form a homogenous mixture. The molten mixture is then fed into the injection molding machine through a nozzle. Then it is injected under pressure into the mold cavity and cooled in less than 10 seconds. The cavity opens and ejects out the molded part while another moves in to take its place.


Thermoset vs. Thermoplastic Injection Molds – What’s the Difference?

Thermoset plastics are created when the polymer chains are cross-linked together. In contrast to this, thermoplastics are not. This means that even though thermoset plastics are rigid. So, They can be heated and softened at high temperatures without breaking down.

Creating thermosets differs from thermoplastics in how the polymers react to heat and curing agents. For example, if plastic is made out of polyester, epoxy, and metal particles, it is likely a thermoset. The most common applications for this injection molding process are wood composites, electrical insulation materials, and metal fixtures. Look below for a better understanding of thermoset vs thermoplastic injection molding.

Thermoset Molding

Thermoplastic Molding

1. Thermoset plastics are also known as thermosetting plastics. These are very tough, strong, and practically unbreakable. They are created by mixing two or more ingredients together to form a glue-like material that is then molded into the desired shape.

1. Thermoplastic injection molding process starts by heating up thermoplastic pellets until they are soft enough to be melted down into a liquid state. So, they can be injected into a mold where it cools off and hardens after being injected for about 10 seconds.

2. Techniques that use heat and pressure are referred to as thermosetting processes. Because the material being shaped becomes hard and inflexible after curing.

2. A thermoplastic material may be reshaped again before final curing without loss of physical properties since it doesn’t.

3. Thermoset molds are generally more expensive than thermoplastic injection molds. Thermoset molds are generally faster to use than thermoplastic injection molds.

3. Thermoplastic is cheaper and a bit slower than thermoset molding.

4. Thermoset offers quality and accuracy.

4. Thermo-plastics do not offer this level of precision.

5. Dental tools, silicone, electrical devices must be done by thermoset.

5. Plastic materials are done with thermoplastic molding.

6. You can not reuse thermoset materials.

6. Thermoplastic care reuseable.


How Do You Know Which One to Use for Your Project?

Thermoset molds are different from thermoplastic injection molds. Because they cannot be melted and reformed as thermoplastic injection molds can, when it comes to manufacturing, both have benefits and drawbacks. So, it would be best if you considered before choosing which one you would like to use. Once you decide on using one over the other, making the mold goes differently as well.

Thermoset plastics are hard and brittle. They are not suitable for many applications. Thermoplastics are more elastic than thermosets, making them more suitable for consumer products, which require flexibility.

Thermoplastic is a more expensive option than thermoset. This is because the thermoset does not need to be molded again after being made. Therefore, this means that it does not have any wastage.

Thermoplastics are usually cheaper because they are easy to process and mold into any shape or size required. Thermoplastic also gives you more options for coloring and adding textures. Whereas with thermosets, you only have one option for color and texture for each material.


Which one should You Choose?

Who wins the thermoset vs thermoplastic injection molding battle? The answer is it depends on you. The thermoset can be repaired, whereas the thermoplastic cannot be repaired? It is not easy to fix if an impact causes a stress crack. However, both can be recycled if made from recyclable materials such as PP or ABS plastics.

Thermoplastics are made up of resin, hardeners, and catalysts. Also, thermoplastics are typically high-performance parts that require a longer curing time. They are ideal for projects that require high tolerance to temperature extremes. Also, you have limited environmental exposure.

Thermoplastic is not as complicated as a thermoset plastic, but it is still out there. It is made up of two components which are resin and hardener. The third component is the polymerization initiator, which speeds up the curing process. So, this type of projects thermoplastics can be used relatively quickly in different applications.


Final Words

As we continue to innovate and develop new ways of making products. So, it is becoming increasingly difficult for manufacturers to keep up with the demand. As we move forward, there are more and more products on the market. We need to be made. Manufacturers need to stay afloat to find a way to produce these products at a lower cost.

Thermoset plastics are solid and durable materials used in various applications. However, the trade-off is that they cannot be easily recycled.

Thermoplastics can be easily recycled and have a lower melting temperature. You will also find that mold making is more flexible than thermoplastics. They also have lower strength and durability. Thermoplastics are generally opted for when you need something to flex or bend easily, while thermosets are better for projects where flexibility is not necessary. I hope this thermoset vs thermoplastic injection molding article will help you.

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