PTFE membrane filter is made of polytetrafluoroethylene ultrafine fibers by hot-melt bonding together. Difference from glass fiber membrane, PTFE filter is a kind of membrane material for deep filtration. Membrane filter disc has the following characteristics: membrane filter 0.22 μm is produced from food-grade isotactic polypropylene. No additives in the whole process; stable physical and chemical properties and good compatibility.