Silicone Foam is manufactured from a low viscosity liquid silicone which is cast on a smooth liner and cured through inline ovens. Silicone foam can be supplied as an open cell, closed cell or combination of both, open and closed cell material.
Silicone sponge, on the other hand, is mixed and calendered on a rubber mill then cured via inline ovens or stationary mold press.
Silicone foam is typically lighter in density, compresses with less force and has a lower compression set than silicone sponge. Both products have good sealing properties, however the sponge has higher tensile strength and the foam has better flame resistance. All materials can be supplied with high temp acrylic adhesive or in custom die cut configurations.
Silicone Sponge or Silicone Foam? What is the Difference?
Silicone sponge is derived from a thin sheet of uncured silicone gum that is chemically blown or expanded while curing in a high temperature press or rotocure. Silicone sponge products are considered to be fully closed cell, meaning the cells are non-interconnecting, therefore they do not allow water to wick through. Silicone sponges are tougher and have better tear resistance than silicone foams. Silicone sponge often provides better water sealing in heavy wash-down applications as compared to silicone foam.
Silicone foams are lightweight products derived from liquid silicone ingredients that are cast onto a liner and cured in an oven. Low density silicone foams have open cell structure that may allow moisture to pass through the cell structure. Open cell silicone foam can be compressed to collapse the cells offering a water tight seal. In contrast, higher density silicone foam products will have a higher proportion of closed cells compared with medium or low density grades. As with all gaskets, with the proper deflection, a good long term weather seal can be achieved.