Technical Support : HWAQ
Waterproof and breathable membrane (breathing paper) is a new type of polymer waterproof material. In terms of manufacturing technology, the technical requirements of waterproof and breathable membranes are much higher than that of ordinary waterproof materials; at the same time, from the perspective of quality, waterproof and breathable membranes also have 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 motion, it can smoothly penetrate into the capillary to the other side, so that the vapor permeability phenomenon occurs. When the water vapor condenses into water droplets, the particles become larger. Due to the surface tension of the water droplets (the water molecules “pull against each other”), the water molecules cannot smoothly escape the water droplets and penetrate to the other side, which prevents Water penetration occurs, so that the vapor-permeable membrane has a waterproof function.
The technology of waterproof and breathable membrane was first introduced from European and American countries. However, the production process of domestic products is diverse, and the quality of various manufacturers' products is uneven, which has not formed a unified quality standard. In fact, the waterproof and breathable film mainly consists of three layers: PP spunbond non-woven fabric, PE polymer breathable film, and PP spunbond non-woven fabric. The function of spunbond non-woven fabric is mainly to enhance the tensile force and hydrostatic pressure and protect the intermediate layer (breathable film). The real breathability mainly depends on the middle layer PE polymer breathable film.