First, material advantages: polytetrafluoroethylene (PTFE), also known as Teflon / Teflon or plastic King (F4), is a copolymer of tetrafluoroethylene monomer. The PTFE seal material
has the following advantage:
1. chemical stability: almost all chemical resistance, strong acids, strong alkali or strong oxidants and organic solvents do not work for it.
2. thermal stability: the cracking temperature is above 400 C, so it can work normally at -200 C ~+350 C.
3. wear resistance: the friction coefficient of PTFE material is very low, only 0.02.
4. self lubrication: the surface of PTFE material has a prominent self-lubricating property. Almost all viscous substances can not adhere to its surface.
Two, fill and modify: but pure PTFE is not wearable. If it is practical, it must be filled with modification. We use two methods: one is inorganic filler modification, adding PTFE into glass fiber, carbon fiber, graphite, molybdenum disulfide and so on. The other is organic filler modification, adding polyphenylene ester and polyphenylene sulfide in PTFE. The wear resistance of PTFE is increased by 2000 times by modification, and the rigidity and thermal conductivity are increased, so that the mechanical oil seals
meet the requirement of high life.
Third, ptfe mechanical seal
principle: the lip of the oil seal is the trumpet in the process of processing, because PTFE has the ability of memory shrinkage after drawing, the friction heat produced in the work will continue to shrink, so it does not need the help of the spring, it will hold on the axis so that it does not exist with the shaft surface, and it can compensate for wear and tear.