Casting and Mold Making

SILOCONE AS A CASTING (as opposed to molding) MATERIAL
Silicone isn't always used to make molds, sometimes it is the final product. It is a desirable material for some applications because of chemical inertness and high temperature tolerance.

Chemical inertness means nothing sticks to it or grows on it and it keeps its suface qualities. This makes it "biocompatible" and thus silicone castings are used extensivly in medical devices and in food-contact situations.

Heat tolerance of 480F (250C) puts silicone in a class by itself among elastomers. Silicone can be used for high temperature gaskets and seals, and wherever you need a rubbery thing that will get hot. The electrically shielded heating pad being cast at right is an example.

Casting silicone is easy: since it sticks to nothing (except other silicone) you can use just about anything as the mold