Waterproof breathable membrane (also known as PTFE membrane) is a new type of polymer waterproof material. It has breathable, waterproof and oil-proof functions due to its micro porosity, hydrophobicity and oil resistance. It has been widely used in medical, precision electronics, LED outdoor lighting, car lights, communications, chemicals, security and other industries.
In terms of production process, the technical requirements of waterproof and breathable membrane are much higher than those of general waterproof materials; from the quality point of view, waterproof breathable membrane has functional characteristics that other waterproof materials do not have.
In the state of water vapor, the water particles are very small. According to the principle of capillary movement, they can smoothly penetrate the capillary to the other side, thus causing vapor transmission. When the water vapor condenses into water droplets, the particles become larger. Due to the effect of the surface tension of the water droplets (the water molecules "pull and counter each other"), the water molecules cannot smoothly escape from the water droplets and penetrate to the other side. In other words, the penetration of water is prevented, and the breathable membrane has a waterproof function.