Generally speaking, the sealing performance of the contact seal is good, but limited by friction and wear, it is suitable for the occasions where the linear velocity of the sealing surface is low. Non-contact seals have poor sealing properties and are suitable for higher speeds.
1. Silicone rubber
Silicone rubber has outstanding high and low temperature resistance, ozone resistance and weather resistance. It can maintain its unique use elasticity, ozone resistance and weather resistance in the working temperature range of -70 to 260 °C. Sealing gaskets required, such as strong light source lampshade sealing gaskets, valve gaskets, etc. Because silicone rubber is not oil-resistant, has low mechanical strength and is expensive, it is not suitable to make oil-resistant sealing products.
2. Nitrile rubber
Nitrile rubber has excellent resistance to fuel oil and aromatic solvents, but it is not resistant to ketones, esters and hydrogen chloride and other media, so oil-resistant sealing products and nitrile rubber are mainly used.
3. Neoprene
Neoprene has good oil and solvent resistance. It has good resistance to gear oils and transformer oils, but not aromatic oils. Neoprene also has excellent weathering and ozone aging resistance. The cross-linking breaking temperature of neoprene is above 200°C, and neoprene is usually used to make door and window seals.
Neoprene also has good corrosion resistance to inorganic acids. In addition, because neoprene also has good flexibility and airtightness, it can be made into diaphragms and sealing products for vacuum.
4. Natural rubber
Compared with most synthetic rubbers, natural rubber has good comprehensive mechanical properties, cold resistance, high resilience and wear resistance. Natural rubber is not resistant to mineral oils, but is relatively stable in vegetable oils and alcohols.
In the hydraulic brake system of the brake fluid composed of n-butanol and refined castor oil mixed liquid, the rubber bowl and rubber ring used as seals are all made of natural rubber, and the general sealant is also commonly made of natural rubber.
Methyl Phenyl vinyl silicone Gum
