What is the difference between EPDM and silicone rubber seals?


EPDM EPDM (ethylene propylene diene monomer) means a si […]

EPDM (ethylene propylene diene monomer) means a single butadiene pe diene, a kind of styrene butadiene rubber for various applications. EPDM is commonly used in vehicles and construction industries for various sealing properties because it has high-quality resistance to environmental elements such as active oxygen, ultraviolet light, and general weathering layers. Typical applications of EPDM are door and window sealing strips (windows), waterproof boards and electrical equipment sealing rings. As everyone knows, EPDM has shortcomings in the heat resistance of polyurethane elastomer silicone rubber in its close market competition. Compared with silicone rubber, EPDM has a weaker endurance at higher temperatures because it can only achieve a high temperature of 130°C (266°F).
Silicone Rubber
Silicone rubber is an inorganic polymer composed of carbon, hydrogen, and oxygen. Silicone rubber is widely used in many fields and main purposes such as railway lines, aerospace, food/drinks and vehicles. Silicone rubber has many advantages, but it is widely spread and used because of its resistance to extreme temperatures. Unlike EPDM, silicone rubber is maintained for a long time, and its physical properties can be maintained above 230°C (446°F), while high-temperature silicone rubber can withstand temperatures up to 270°C. Silicone rubber not only has very high temperature resistance, but is also regarded as a sterile test polyurethane elastomer, which is why you can see it is used in the food and beverage fields, such as milk tubes and seals on food machinery and equipment. Rings and seals, and automatic sales tubes on beverage equipment.
Silicone rubber is considered to be a stronger polyurethane elastomer than EPDM because it shows additional benefits and generally shows a longer life span, which means less and less replacement costs and/or shutdown time.
The sealing ring is a fixed annular cover made of various silica gel as the raw material. It can be matched with the throwing ring on the rolling bearing or the intermediate gap of the sealing ring, and it is a special tool to avoid all kinds of water or oil leakage. . Regarding the performance of silicone sealing ring, many improvements have been made in recent years, which can be sorted into the following aspects:
(1) In view of the changes in the molecular structure of silica gel, the method of selecting copolymers makes the molecular structure of silicone materials converge with other single or high polymers, and then a new performance or a new performance can be obtained. An upgrade on the previous one.
(2) The improvement in the original performance, in conjunction with the changes and development trends of technical and raw rubber performance, has greatly improved the compressive strength, tensile strength, low shrinkage and other properties of silica gel. Similarly, a batch of silicone rubber types with high and low temperature resistance, flame retardancy, heat transfer, and excellent heat shrinkage properties have been produced, which can greatly improve the application range of silicone seal rings.
(3) Improved production and processing performance, developed silicone rubber that does not require divulcanized rubber, particulate silicone rubber (also known as powdered vulcanized rubber), and based on methacrylate-containing polysiloxane and oxygen content siloxane. Catalytic reaction addition reaction, the development trend of silicone rubber liquid injection molding system software.

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