In current industrial world many applications require gaskets & sealing materials, which need to perform optimally in the toughest weather, environmental & physical conditions. Additionally, it may also require meeting safety, hygienic & compliance requirements. Gasket & rubber seals made out from silicone rubber offers range of excellent benefits, which is very hard to match with gasket made from other elastomers. It offers high as well as low temperature resistance, which makes it suitable for indoor as well as outdoor applications. Here, in this two part blog series we will explore more about silicone rubber gasket and seal.
Part I : How silicone rubber gasket can be made using different process and what kind of silicone material grades can be used for making it
Part II : Applications of silicone rubber gasket and how it offer better value compare to other rubber gasket
What Is Silicone Rubber Gasket?
A silicone rubber gasket can be defined as a high-performance versatile mechanical seal, which can support working conditions from high to low temperature, shows excellent UV and ozone resistance and provides purity & safety.
How it can be made?
Silicone rubber gasket mostly made by selecting one of the three broadly using gasket making process extrusion, molding and die-cut. After detail understanding of requirements from engineer/s & other stakeholders of the project, gasket manufacturer select & suggest correct method and material for making gasket, and thus, provides optimal solution to the customers. For suggesting right method & right material, gasket manufacturer mostly considers physical, mechanical, geometrical, applicational and budgetary requirements of gasket and other aspects of project.
Extruded Silicone Gasket: In extrusion process, continuous length of cross section profiles like Silicone Cord, U channel, D shaped, P Shaped, T Section, E Shape, Bulb Shape, etc.. is made by pushing silicone rubber material in extruder machine through a desired shaped cross-section die. Later, as per gasket or O-Rings circumference requirements it need to cut in required length piece/s and then both ends in case of round gasket or four corners in case of frame gasket are joined together using hot splicing/vulcanize or glue join process.
Molded Rubber Gasket: Using rubber molding process, uncured rubber material transforms to required shape of product. In pre-shaped steel mold cavities, rubber material is placed or poured under certain pressure & temperature condition for fixed amount of time, which convert uncured rubber material to real rubber part. Depending upon the size, shape, complexity, volume and other factors different kinds of molding processes are used (compression molding, transfer molding or injection molding). Using this processes end-less gasket are made with tight tolerance. In these processes initial mold cost is much higher than extrusion tooling.
Die Cut Rubber Gasket: Using this process simple flat shape rubber gaskets are made economically from stocked calendar rubber sheet. Depending upon material, tolerance, quantity and other requirements different kind of cutting processes: press cut, kiss cut, laser cut, water jet cutting are used for making these gasket. Most of these cutting processes doesn’t require tooling and turnaround time is much faster.
Material Grades Used for making Silicone Rubber Gaskets
Silicone Rubber is available in liquid, solid & as silicone rubber sheet. Depending upon selection of gasket making process right form of silicone rubber, the raw material is used for making these gaskets. Gaskets are made using extrusion, compress & transfer molding processes normally using solid slab or roll form of silicone rubber. While injection molding process use liquid form of silicone rubber. Die cut, kiss cut, laser cut, water jet cut, and other cutting process normally use the sheet forms of silicone rubber .
Each gasket & sealing application is unique and has its very own constraints, demands, specifications, safety & compliance requirements. Silicone rubber are available in commercial as well as special spec material grade that can accommodate wide varieties of gasket application needs. Silicone gasket used in food & beverage industry usually required to be made from food grade silicone rubber. If gasket used is in medical equipment, mostly it will be made from medical grade platinum cure silicone. Same way if application is in defense industry it may require MIL spec silicone material, while very high temperature applications may require high temperature or flame retardant silicone rubber. Silicone rubber has poor resistance with petroleum and hydrocarbon oil however, gasket made from fluorosilicone rubber (FVMQ) overcome this limitation and offers excellent solution to the industry.
Compare to other elastomers, silicone is easily pigmented which offers wide spectrum of color matching possibilities. Also as per customer special requirements, custom silicone compounds can be formulated which satisfy special color matching, heat-resistance, chemical-resistance, low-toxicity, food grade, conductive, non-staining, or non-harmful properties for silicone rubber gasket .
Please feel free to contact us if you have any questions about your custom silicone gasket project or need more information about silicone rubber gasket process, material choice and other possibilities available with Accurate Rubber Corporation. We are more than happy to help you !!!