Silicone is exceptionally resistant to extreme temperatures; it can function without disruption between -55°C to +300°C.
Other rubber gasket materials like Viton can show signs of degradation at temperatures exceeding 200°C. Also, unlike natural rubber, silicone is resistant to UV rays and ozone cracking, both of which qualities make silicone a more reliable material for sustained outdoor use.
Silicone is also highly inert in terms of chemical reactivity, and it can be used in chemical processing and some medical device applications. The major defect of silicone rubber is its relatively low tensile strength.
Silicone has a low tensile strength even compared to natural rubber, the use of which has been progressively phased out in favor of synthetic rubbers. For this reason, silicone is limited in its applications as gasketing material.
Automotive gaskets, for example, must be able to withstand constant torquing, compressing and other kinds of tension. Though silicone is sometimes used for gasketing in such contexts, it is unusual.
Silicone is more commonly used for gasketing material in consumer product contexts and some light industrial applications. Silicone gaskets can be used to waterproof swimming goggles, as sealant for baking materials and temporary food storage containers and in many other low-demand consumer applications.
In medical device applications, silicone gaskets can be used in dialysis machines, incubators, infusion pumps and many other devices. The application for which a silicone gasket is used depends on the silicone’s grade; silicone rubber can be engineered to varying specifications.
Silicone rubber grades distinguish themselves from one another in terms of their qualities of electrical conductivity, steam resistance, chemical resistance, flame resistance and other properties.
Once the proper material has been chosen, the rubber can be formed through one of five different molding processes: injection molding, cast molding, compression molding, dip molding and transfer molding. Each process is different in terms of the possible configurations it can produce and the speed and efficiency with which it can produce parts.