Hydrophobic polytetrafluoroethylene (PTFE) membrane is also known as polytetrafluoroethylene hydrophobic composite membrane (laminated membrane). The pore size of the membrane is 0.05 μm, which has the advantages of high flow rate, good consistency and good mechanical properties. It is widely used in dust filtration, air filtration, air pressure balance, device protection, organic solvent filtration and so on.