Thermoset Moulding

Thermoset moulding of thermoset materials is the most automatic method of processing these materials and has become the most common.

The main difference between thermoset and transfer molding is reduced material handling.

With Thermoset moulding, the material is fed directly into the hopper of the molding press, eliminating preforming, preform storage, and preheating.

An Thermoset moulding press consists of two major sections, which are the clamping section and the material processing section.

An Thermoset moulding press consists of two major sections, which are the clamping section and the material processing section. The clamping section, which is similar to a compression press, is basically a hydraulic cylinder that closes the mold halves and holds them together under pressure. In the case of a toggle press, there is a cylinder and linkage mechanism that closes the mold halves and holds them together under pressure. In addition to the clamping mechanism, this part of the press also provides the mechanism for removing the parts from the mold.

What are the advantages of Thermoset Moulding?

• Material handling is reduced because the press hopper will usually hold sufficient material to mold parts for an extended period of time.
• Longer and smaller diameter core pins may be used because they can be supported on both ends.
• With the mold being closed before any material is injected into it, parts containing metal inserts can be molded without having material flash the inserts.
• Relatively tighter tolerances across parting lines are possible.
• Parting line flash can be held to a minimal thickness if the mold is designed properly and well maintained.
• Thermoset moulding of thermoset materials lends itse lf to automating the process which can result in lower piece costs.