The production process of Waterproof vent

1. Casting compound. The technology of Waterproof vent was introduced from European and American countries earlier. However, the production techniques of domestic products are varied, and the product quality of each manufacturer is uneven, and a unified quality standard has not been formed. In fact, Waterproof vent is mainly composed 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 middle layer (breathable film). The real breathability mainly depends on the middle layer of PE polymer breathable film. This process relies on the viscosity of the plastic itself after hot-melting plastic particles. The disadvantage is that it is almost airtight. In 2014 there was no way in the world to use this process to produce a truly highly breathable and heat resistant Waterproof vent.

2. Glue spray or squeegee compounding (hot melt adhesive compounding). This process has long been used in sanitary napkins, diapers, and protective clothing. At present, almost all domestic manufacturers use this process to produce highly breathable waterproof and breathable materials.

3. Hot pressing compound. In the state of water vapor, the water particles of Waterproof vent are very small. According to the principle of capillary motion, they can smoothly penetrate into the capillary tube to the other side, thereby causing the phenomenon of vapor permeation. 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 and compete with each other"), the water molecules cannot smoothly escape from the water droplets and penetrate to the other side, which is to prevent the The permeation of water occurs, making the vapor permeable membrane waterproof.