Insert Molding

Insert molding is the process of injection molding a plastic material around an insert of a different material or substrate. Inserts are placed into the mold cavity either manually or robotically while the mold is in the open position. The mold is then closed and the plastic material is injected into the mold cavity, forming and solidifying around the insert.

The majority of injection molded products Le Sueur Incorporated produces each year contain a molded-in insert. Typical molded-in inserts include:

  • A pre-molded plastic substrate
  • Threaded inserts or fasteners
  • Metal stampings
  • Electrical conductors
  • Terminals
  • Filters / screens
  • Bushings / bearings

Threaded inserts are often used in plastic products which require assembly and disassembly. Threaded inserts can be either installed post molding via sonic welding and heat staking, or insert molded during the molding process. Molded-in threaded inserts provide greater retention strength.

Le Sueur Incorporated provides plastic injection molding and aluminum casting solutions for projects of all sizes. We use a range of equipment and technology to accommodate your unique requirements and offer design engineering assistance and prototype services to help ensure your design requirements are met. Contact us today to learn more about our injection molding services.