Over Molding Molds Productions

What is over-molding?

Over-molding is also known as 2-pass injection molding in China. Compared to third party material bonding, the over-molding process makes the process faster and more cost effective, and it has been widely used in plastic design.

Types of over-molding

Insert molding, two-shot molding, and co-injection molding are the three types of overmolding.

Insert the molding. Insert molding is the most cost-effective method of overmolding. It is most typically used to mold soft elastomers into stiff plastics. The hard segment is pre-separated into a tool in the insert design, and the soft material is expelled into it.

Mechanical locking, chemical bonding, and other methods can be used to join elastomers. To accomplish chemical bonding, the elastomer must be heated sufficiently to melt the surface of the hard section.

Two over-molding. This overmolding process necessitates the use of two injection molding machines. The hard segment is injected first, followed by the elastomer mold to the injection molding machine to complete the hard segment injection into the elastomer. The heated base material is commonly semi-solid or gel. These molds enable the design and shaping of the hard segment's lateral protrusion onto the substrate. This enables a strong mechanical connection.

Co-injection molding. In co-injection molding, although the hard substrate and elastomer are injected into the same mold, compatibility between the materials is critical and it must be carefully controlled.

Co-injection molding It is exceedingly expensive and difficult to control; it is the least employed method when compared to the other two. However, because the hard substrate and soft substrate elastomer are entirely molten, it gives the best bond between the soft and hard components as well as the greatest molded part quality.