The ePTFE is a kind of micro porous membrane formed from polytetrafluoroethylene by extrusion.

lt is found that the surface of the PTFE membrane is full of fibrillary micropores, and there are as many as 9 billion micropores per square inch.The cross-section is a kind of network structure, and the three-dimensional structure of the pore has very complex structures, such as network connection, hole inlay, channel bending.The diameter of the water vapor molecule is 0.0004um, while the diameter of mist with the smallest diameter in rainwater is 20um.the diameter of the drizzle is as high as 400um, the pore diameter of polytetrafluoroethylene varies from 0.1um to0.5um.As we can see, the pore diameter of the expanded PTFE membrane is between water vapor and rainwater, so it is the top waterproof and breathable material. The composite fabric is made of expanded polytetrafluoroethylene film(ePTFE) and polyester fiber by a special process.