Silicone, often confused with silicon, includes a wide group of synthetic polymers consisting of repeating units of siloxane. Two silicon atoms and one oxygen atom are typically paired with carbon and/or hydrogen. The resulting heat resistant compounds have qualities similar their rubber and have become a staple in sealants, adhesives, injection molding, medical devices, cooking utensils, automotive gaskets and many thermal insulation products.
F.S. Kipping was a pioneer in isolating the siloxane polymer group and in 1901 coined the term “silicone”. While silicon is part of the silicone compounds, its crystalline structure has vastly different chemical and physical properties from the true siloxane group. Although silicone is a technically incorrect description, it has been widely used and shows no signs of changing.
One of the products most widely associated with silicone is everyday caulking. The ability of silicone to adhere to smooth glass-like surfaces, combined with its thermal stability make it a nature choice for watertight seals. Silicone’s resistance to ultraviolet light and heat makes it a great option for many construction and fire protection.
Since silicone does not support microbial growth, it has been the go-to material for many medical device manufacturers. It also has a high gas permeability, roughly 400 times that of butyl rubber, making it ideal for oxygen delivery systems and other medical applications where increased aeration is needed. Advances in silicone molding has leveraged these unique properties and allowed engineers to push forward the design and implementation of many new life saving devices.
During the silicone molding process, there is always a certain amount of residual material, or flash, that remains with the part after it is processed. In some instances the flash can be removed with cryogenic methods, but in other cases, where the flash is thicker or when the part has critical surface finishing requirements, mechanical deflashing is necessary.
ISO Finishing has worked with silicone molding companies to develop centrifugal barrel finishing processes to remove the unwanted flash while preserving all critical part dimensions. By selecting the proper mass finishing equipment, tumbling media, compounds, speed and duration, we can customize the isotropic finishing system for your specific application.
