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Thermoset Injection Molding – What Is It, What to Expect?

When we say “thermoset injection molding” what do we mean? Thermoset refers to the type of plastic being melted down and injected into molds. These are polypropylene (PP), high-density polyethylene (HDPE), etc. These materials soften when heated up, but then harden again at room temperature.

You might think that thermosetting plastics are only used for making large plastic parts. There are actually many ways to use this versatile material. In fact, manufacturers use this process for aerospace and automotive parts to medical equipment and even toys! Let us explain how they work so that you can make an informed decision about whether this process is right for your project.

Thermoset injection molding is a manufacturing process that produces parts with a high strength-to-weight ratio. Also, it has excellent dimensional stability and good surface finish. The thermoset material used in the injection molding process can be molded into complex shapes. This is not possible with other processes such as compression or vacuum forming.

To learn more about some interesting facts about thermoset injection molding, read on!

What is Thermoset Injection Molding?


Thermoset polymers are materials that irreversibly cure. Also, you cannot melt it down for recycling. Most commonly, thermoset resins are mixed with reinforcing fillers such as silica, carbon or glass to make parts. The thermosets most often used in high-performance applications like molded automotive parts are polyurethanes, epoxies, and phenolics.

Thermoset injection molding is a process that uses heat to improve the flow characteristics for more efficient manufacturing. It’s important to know how they work because of their irreversible nature.

Thermoset polymers are the result of a chemical reaction that cures chemically instead of evaporating or melting. This means that these materials are non-recyclable, only reused in other parts.


What to expect from Thermoset Injection Molding?


Long term durability

It is important to understand that plastics can be broken down by either heat or deformation. Thermosetting polymers with their cross-linked structures can take a massive amount of heat without any signs of damage. Therefore, it means you won’t have problems in the future when your product faces excessive strain.

Resistance to wear and tear

One of the most difficult environments for anything plastic is in constant contact with water or oil. Thermoset injection molding materials are highly resistant to this sort of damage. In fact, this means that your product will not only look good, but will also stand up to years.

High tolerance to stress

Products that are under constant duress by their environment. So, they will often experience significant wear where one surface comes into contact with another. This is not a issue when you use thermoset injection molding. Also, they are highly resistant to deformation.


The benefits of thermoset injection molding go beyond the properties associated with the materials themselves, So, it is important to remember that this process allows for incredibly fine detail. Also, you will get very smooth transitions between layers, which means it looks just as good as it performs. Since you’ll be able to choose the exact color of your product, you can rest assured that it will look pristine.


How will thermoset injection molding benefit you?


1. Adaptability and versatility.

Thermoset injection molding is not just one of the most effective ways to create a durable and long-lasting product. It’s also highly versatile. You can be modified to suit a variety of needs. So, you don’t have to settle for an off-the-shelf product when your company is much more individualized.

2. Enables automation.

In the world of injection molding, companies prefer automated machinery. Because it’s much faster and requires less maintenance than manual machines. Thermosetting polymers are particularly easy to work with when it comes to automation. Because of their inherently solid and often smooth composition. As a result, you can enjoy the best results without wasting time and energy on constant adjustments.

3. High throughput potential.

Whenever possible, it is always advisable for injection molding companies to opt for the fastest production times. Thermoset injection molding is well known for its high throughput potential.

4. Improved product performance.

For injection molding companies, this is perhaps the number one reason why people prefer thermoset injection. This process ensures you make your products more durable, long-lasting. Also, the product will be resistant to common types of damage that would otherwise pose a problem over time.


The Future for this Industry and Why it Matters to You

Thermoset Injection Molding is a very widely used process in the polymer processing industry.

Companies adopted this for use in automotive, appliance, and other critical parts due to its durability and ability to achieve high degrees of precision.

In addition, there are several emerging applications that have huge potential for this process.

Two such applications that have contributed to the evolution of thermoset injection molding are surface engineering and material thickening or 3D printing.

These two fields allow for more design flexibility, better efficiency in production, and even smaller lot sizes than ever before.

The most common type of thermoset in current use is epoxy.

Epoxy has the amazing property of being able to be heated up and melted, injected into a mold cavity where it cools down, solidifies, and you have a finished part.

As with all thermosets, this process allows for high degrees of precision when done right.

Thermoset injection molding is a key component in the medical, automotive and consumer industries. The industry has been around for almost 100 years. However, it has come a long way since its first widespread use in electrical applications and military hardware. It will continue to innovate and grow as new applications are discovered and the dynamics of industry players changes.

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