There are three main types: 1. Casting compound. This process is made with hot molten plastic particles depend upon plastic bonding. Disadvantage is virtually airtight. 2014 world have no way to use this technology to produce really high high temperature resistance waterproof breathable membrane breathable. 2. glue or scraping glue (hot melt glue). This process was first used in sanitary towels and make water not wet, as well as on the protective clothing, domestic manufacturers are using this technology to produce highly breathable, waterproof and breathable material.
Drawback is the low air permeability, microporous breathable film actually was blocked by hot-melt Adhesive, in addition, the most fatal flaw is a high temperature is very low, only able to withstand temperature of 60 degrees. Because this glue is actually a pressure-sensitive adhesive (sticker). Simple example is the winter time, double-sided tape isn't sticky, layering, but during the summer, surface of double-sided tape adhesive will melt.
Waterproof breathable membrane quality with this process. Construction, as long as there is a certain temperature, non-woven plastic layer. When construction which can guarantee, a spread of waterproof breathable membrane covered roof right away? Therefore, this waterproof, breathable membrane can only be truly waterproof, breathable membrane of fake and shoddy products, in Europe and the United States have no market. 3. hot composites. In the domestic market was mixed, producing truly waterproof, breathable membrane manufacturers rarely, many factories or sellers are telling his good waterproof breathable membrane, most users do not expect, some manufacturers offer waterproof breathable membrane is not waterproof.