Insert Molding: What is it?

Insert molding is a specialized injection molding process where pre-formed components, often made of metal or other materials, are placed into the mold before the plastic is injected. This process integrates multiple materials into a single molded part, enhancing functionality and reducing the need for secondary operations. Insert molding is widely used in industries such as automotive, medical devices, electronics, and consumer goods.

This blog explores the options and variations available in insert molding.

How Insert Molding Works

Insert molding involves placing a pre-formed component (like metal or another plastic) within a mold cavity before injecting molten plastic. This encapsulates the insert, creating a single, integrated part with enhanced functionality and strength.

Typically, if you are including inserts with your parts, your mold or tooling for production will need to be adjusted. The extent of the mold modifications will vary depending on the complexity of the insert and, of course, the specific requirements of the application. In some cases, minor modifications may be sufficient, while in others, more extensive changes may be necessary.

Your tool designer will need to:

1. Insert Locating Features: The mold must incorporate features to accurately and securely locate and hold the insert in place during the injection molding process. These features can include:
   • Locating pins: to position the insert within the cavity.
   • Detents: these prevent the insert from shifting during injection.
   • Undercuts: these lock the insert securely in the mold
2. Consider Material Flow: The mold design must ensure that the molten plastic flows smoothly around the insert, completely encapsulating it without creating voids or air pockets. Modifications to the cavity shape or the injection gate location may be needed to prevent air pockets.

Originally published here: https://quickparts.com/specialist-injection-molding-processes-insert-molding/