When Should I Use Plastic Injection Molding?

Plastic is a highly useful material, but plastic resin needs to be made into an object, part, or component for it to be put to use. One way to create the part is through a plastics injection molding. The raw plastic material is referred to as a resin. The resin is first melted and is then forced into the mold using an injection. Then, the mold is allowed to cool and the plastic component is then removed from the mold. However, the actual process is more complex than it might seem.

How the Process Works

The resin used to create the plastic part is a powder or grain that has to be melted through the process of "plasticization." The liquid plastic is then injected into the mold. All of the parameters of this process are carefully controlled through several cycles. However, when the parameters are properly set, it's possible to mass produce plastic parts. 

Methods Used for Creating Plastic Parts

Molds are not used under all circumstances. For example, a mold is not used to create a pat through extrusion. In some cases, the mold is closed such as with blow molding, complex molding transfer molding, and compression molding. In other cases, the mold is open throughout the process. This is the case with intrusion molding.


Injection molding is ideal for mass production but is often not used for prototyping. This is because the specific dimensions of the part might not be fully determined and it does not make economic sense to create a mold yet. Instead, the prototype part is created using 3D printing.

Injection molding is necessary when the part has been finalized and the parts now need to be mass produced so they can be put to use. The mold that is created at this stage is for a permanent part and is usually made out of steel so that it is highly durable.

Permanent and Reversible Plastics

One of the questions to ask is whether you want the plastic part to be molded into a permanent part or if you want it to be possible to melt the plastic back down to create a different part. Thermoset plastics cool down into a permanent state. However, with thermoplastic polymers, the plastic can be melted down into a liquid and can then be solidified again and become solid. Once you have the right setup, you will be able to affordably mass produce plastic parts. To find out more, look into plastics injection molding in Mexico.