The custom injection molding of Liquid Silicone Rubber (LSR) uses much of the same process and equipment as injection molding.
In both processes, the mold is heated and closed before the uncured rubber is injected. Unlike high consistency rubber (HCR), also known as gum stock, liquid silicone is a high viscosity liquid that comes in two parts, Part A and Part B. Both parts are liquid but one part contains the platinum compound.
The two parts are mixed and delivered to the barrel of the injection press via a mixing pumping system. The liquid silicone is then injected into the mold. Once in the mold, the silicone cures much faster than typical high consistency silicone due to its platinum cure system.
As a result of this rapid cure cycle, the part price is frequently lower than parts made using conventional molding processes such as compression, transfer and injection molding.