Three production processes of waterproof and breathable membrane

1. Cast composite

This process uses plastic particles to heat-melt and then relies on the viscosity of the plastic itself to compound. The disadvantage is that it is hardly breathable. As of 2014, no real high-breathability, high-temperature-resistant, waterproof and breathable membrane has been produced by this process worldwide.

2. Glue spraying or squeegee compounding (hot melt compounding)

According to Coating Online, this process was first applied to sanitary napkins, diapers, and protective clothing. At present, almost all domestic manufacturers use this process to produce highly breathable waterproof and breathable materials. The disadvantage is that the air flow is relatively low, because the micropores of the middle air-permeable membrane are actually blocked by hot melt adhesive.

In addition, the most fatal shortcoming is that the temperature resistance is very low, and it can only withstand a temperature of 60 degrees. Because this glue is actually a pressure-sensitive adhesive (self-adhesive). A simple example is that in winter, double-sided tape has almost no stickiness and will delaminate. But in summer, the glue on the surface of the double-sided tape will melt. The quality of the waterproof and breathable membrane made by this process can be imagined.

3. Hot pressing composite

At present, the domestic market is mixed, and there are actually very few manufacturers that produce real waterproof and breathable membranes. Many factories or sellers advertise that their waterproof and breathable membranes are good. Almost most users have never thought that the waterproof and breathable membranes provided by some manufacturers are not waterproof at all. .