Liquid silicone rubber (LSR) injection molding process

Liquid silicone rubber LSR injection molding process

 

The structure of liquid silicone (LSR) injection molds, in general, is similar to the mold structure used for thermoplastic compounds, but there are many significant differences. For example, LSR compounds generally have lower viscosity, resulting in very short filling times, even at very low injection pressures. To avoid air entrapment, it is critical to have a good vent in the mold.

In addition, LSR compounds do not shrink in the mold like thermoplastic compounds do, they tend to expand when heated and shrink slightly when cooled, so the product does not always stay on the convex surface of the mold as expected, but rather stays in a cavity with a larger surface area.