Top 4 Types of Plastic Molding Systems

Plastic molding system is basically a process with which liquid or melted plastic is poured into a particular container or mold so as to harden and customize it into an intended shape.

These molded plastics are used for a vast range of purposes and applications. There are a wide number of plastic molding solutions available in the market according to the different types of molding systems that are present.

Continue to read till the end to learn about the top 4 types of plastic molding systems that are used in general.

1. Extrusion Molding

In extrusion molding, hot melted plastic is pressed through a particularly shaped hole in order to produce a lengthy shaped plastic component. This shape through which the melted plastic is pressed can be customizable and known as die.

The die is basically custom made for obtaining a particular outcome. This type of molding system feels almost like pressing a cookie dough through a mold to make the cookies. The extrusion molding system is commonly used for creating simple parts with a fixed cross-sectional profile.

Products such as PVC pipes, plastic decking, hoses and straws, etc. are created from this mold system.

2. Blow Molding

The blow molding system results in forming custom plastic parts that are thin-walled and hollow. This method is suitable for creating plastic parts that have a requirement for uniform wall thickness.

This molding system is very much similar to the process of glass blowing. The machine using this type of system operates to heat up raw plastic until it turns into liquid and then air is injected into it like in a balloon.

The plastic is blown and molded into the desired shape. The bigger it gets, the more it gets pressed against the mold’s walls and takes its shape eventually. This type of molding method is used for creating a small to medium thin-walled and hollowed plastic part or products such as bottles, fuel tanks, etc.

3. Injection Molding

It is sort of similar to an extrusion molding system. The primary difference here is that in injection molding the melted plastic is directly injected to the custom mold.

The injection is performed under high-pressure so that the mold is filled and a solid part is created. This type of molding system is ideal for creating any kind of plastic product or part when there is a requirement for more than 30,000 pieces a year.

The injection molding method is used to manufacture plastic bottle caps, electrical switches, medical devices and more.

4. Compression Molding

Compression molding method includes the pouring of raw liquid plastic into a heated mold. It is then compressed together to create the desired shape. 

This molding method ensures good strength in the final product mainly due to the high temperature being used the entire time during the process. The final operation involves cooling down the poured liquid plastic in order to keep its form and then being removed from the mold and trimmed down to perfection.