Compression Molding VS Injection Molding / What Is The Difference

Injection molding and compression molding are both types of plastic molding. Compression molding and injection molding are both methods of manufacturing high-quality components. They have similarities, but both types of plastic molding offer unique benefits. Therefore, we need to compare compression molding and injection molding to determine which method is more suitable for the current production needs. If you’d like to learn more, the specific differences between the two methods are detailed below.

What is Injection Molding?

Injection molding parts

Plastic injection molding is a method of using an injection machine to quickly inject molten plastic into a mold and solidify it, and finally obtain various plastic products.

Features of plastic injection molding:

1. Injection molding can be used for almost all thermoplastics, and can also be used for the molding of some thermosetting plastics.

2. It can form complex shapes at one time, with precise dimensions and high productivity.

3. However, the cost of equipment and molds is relatively high, which is mainly used for the production of large quantities of plastic parts.

How Does Injection Molding Work/ Plastic Injection Molding Process

Put the powdery raw material into the barrel from the hopper → push the plunger → the raw material is pushed into the heating zone → pass through the distribution shuttle → inject the molten plastic into the mold cavity through the nozzle → cool → open the mold → plastic product

Note: After the injection plastic parts are taken out of the mold cavity, appropriate post-processing is usually required to eliminate the stress generated during the molding of the plastic parts to stabilize the size and performance. In addition, deburring, polishing, surface coating, and other treatments can also be performed.

What is Compression Molding?

Compression molding is a method of adding solid pellets or prefabricated flakes into a mold, softening and melting them by heating and pressing, filling the mold cavity under pressure, and finally curing to obtain plastic parts.

How Does Compression Molding Work/ Compression Molding Process

Add solid pellets or prefabricated flakes into the mold→heat and pressurize→soften and melt the raw material→fill the mold cavity under pressure→cure→get plastic parts

advantages and disadvantages of compression molding

Advantages of Compression Molding

1. Compression molding is mainly used for thermosetting plastics, such as phenolic, epoxy, silicone, etc., and can also be used for thermoplastics, such as polytetrafluoroethylene products and polyvinyl chloride (PVC).

2. The pressing and forming equipment and mold are simple, and can produce large-scale products.

H3: Compression Molding Disadvantages

1. Long production cycle and low efficiency.

2. Difficult to automate.

3. It is difficult to produce thick-walled products and products with complex shapes.

Compression Molding VS Injection Molding

Advantages of compression molding over injection molding are:

1. Can use the common press for production.

2. Since the compression mold has no pouring system, the mold structure is relatively simple.

3. In compression molding, the plastic performance is relatively uniform, and the molding shrinkage rate is small.

The disadvantages of compression molding compared to injection molding are:

1. The fluidity is very poor, and it is difficult to form large flat plastic parts with small thickness.

2. The forming cycle is long and the production efficiency is low.

3. Plastic precision is difficult to control.

4. It is suitable for the production of simpler bulk products, compared with more complex injection molding products.

Should You Choose Injection Molding or Compression Molding?

The discussion about compression molding vs injection molding is still going on, your choice between compression molding and injection molding usually depends on your specific application, hope our compression molding vs injection molding comparison can help you to some extent.

Plastic fasteners

KENENG can provide plastic molding services, we produce a variety of plastic products, including battery holder, button cell battery holder and plastic hardware. We undertake customized service, you can send us drawings to get the latest quotation! Looking forward to hearing from you.

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