What is the role of polytetrafluoroethylene film in the petrochemical industry? Modern petrochemical industry increasingly high requirements for sealing materials, sealing gasket resistance to a variety of media erosion requirements, a wide range of applicable temperature, at high temperatures with sufficient mechanical strength and can maintain dimensional stability.

From both corrosion resistance and temperature resistance, PTFE film is undoubtedly the most ideal material, in addition to alkali metal complexes, almost will not be any other medium erosion, wide temperature range, long-term resistance -200 ℃ ~ 200 ℃, gas permeability is asbestos, rubber and other traditional gasket material is much smaller. However, pure PTFE PTFE material also has its limitations, the most deadly is the existence of pure PTFE gasket creep problem, after a period of time, due to creep, the thickness of the gasket decreases, making the flange The tightening force is reduced, causing leakage.

In order to provide effective sealing in various harsh environments, the gasket material must be easily compressed, has good elasticity, chemical corrosion resistance, high and low temperature resistance, gas permeability and other characteristics, the first use of PTFE coated rubber gasket method, in some occasions for the success of the promotion. However, due to the poor rubber, the case of organic solvents prone to swelling, low mechanical strength, and the outer layer of the PTFE membrane is easy to rupture, resulting in erosion leakage, so people look forward to the development of 1 new materials, to provide a long period of effective sealing.

As early as the mid-1980s, foreign countries began to study the use of filling modification methods to improve the sealing performance of PTFE materials. In 1990, GARLOCK Company of the United States developed a multi-layer composite filled PTFE gasket with high-pressure retraction elasticity. Inorganic hollow material and pure PTFE three-layer composite were used to obtain gasket materials with good mechanical properties and compression resilience. At present, the successful commercial brands mainly include GYLON3504,SIGMA500 and so on. Such gaskets are easy to be compressed and can achieve effective sealing with only a small bolt tightening force. Therefore, PTFE film can be used in glass equipment and occasions with low bolt load and high sealing requirements, and can replace PTFE coated gaskets. There are also domestic manufacturers of PTFE film in imitation, but there is a big gap between the formulation and processing methods of PTFE film and foreign countries. The products have poor compression recovery, easy leakage, easy to break, short service life, and use. Inadequacies such as small range.