What material is the covering rubber made of?

The other way around – it doesn’t matter what kind of rubber is inside. As long as the outer layer is polytetrafluoroethylene, that’s fine. The rubber inside ensures elasticity, while the polytetrafluoroethylene on the outside provides corrosion protection.

The coating ring takes advantage of PTFE’s corrosion-resistant properties as well as the elasticity of rubber materials; therefore, the outer layer is made of PTFE, while the inner layer is made of EPDM or FKM rubber

A plastic-coated rubber O-ring is a special type of rubber O-ring that consists of a rubber O-ring as the core, with an outer layer made of plastic tubing or film that covers it entirely; it is created through a special manufacturing process. It can be used in special working environments such as certain chemical media where ordinary rubber O-rings are not suitable. The elasticity is provided by the rubber core, while resistance to chemical media is ensured by the seamless plastic coating. This product possesses both the elasticity and low compressive set properties of rubber O-rings, as well as the heat resistance, cold resistance, oil resistance, wear resistance, weathering resistance, and chemical corrosion resistance inherent to plastics. It can be applied in various dynamic and static sealing applications, serving as a replacement for some traditional rubber O-rings. Due to the more complex product structure ( ) and manufacturing process of rubber-coated O-rings, their price is higher than that of conventional rubber O-rings; therefore, users generally choose to use them only under special operating conditions. The manufacturing technology for plastic-coated rubber O-rings abroad has a history of over 40 years. Initially, polytetrafluoroethylene (PTFE) films were coated onto rubber O-rings using mechanical turning methods; depending on the requirements of the operating conditions, one or two layers of coating were applied, with the aim of minimizing the erosion of the rubber ring caused by leakage of the sealing medium. Due to certain drawbacks of this type of product, rubber O-rings with full coating made of perfluoroethylene propylene (FEP) and copolymers of tetrafluoroethylene and perfluoroalkyl vinyl ether (PFA) were developed. This is the most commonly used structure and type both domestically and internationally today. The materials used for coating rubber O-rings include fluororubber, silicone rubber, ethylene-propylene rubber, neoprene, and others

Thank you:lol:lol

Thank you, I understand:lol

I’ve learned it; thanks for the explanation, expert