What is breathable film
The principle of permeable film
Water in the form of steam, its particles are very small, and the waterproof breathable film in the micro hole, can let these water vapor smoothly through, the water vapor out, thereby forming vapor penetration. In the outside world, when the water condenses into droplets, the particles will become larger. Due to the interaction between the water column, the water column cannot effectively penetrate to the other side of the fabric, thus preventing water infiltration and making the film waterproof and breathable.
Breathable membrane material
The permeable membrane technology was first introduced from foreign countries. However, due to the large number of manufacturing processes in many domestic factories, the quality of the products produced is uneven, forming a unified and effective standard quality. But in the actual manufacturing process, breathable membrane is mainly divided into three layers: PP spun-bonded non-woven, breathable polymer film, PE PP spun-bonded non-woven, in this structure, really breathable effect or in the middle of the PE breathable polymer film, textile and nonwoven main role or enhance the surface tension and protection in the middle of the film.
Waterproof breathable membrane identification method: mainly two, one is a laboratory, a simple manual.
(1) laboratory testing
Test items: a. temperature resistance b. air permeability c. hydrostatic pressure
The real waterproof breathable film will not use glue to compound, so the temperature is generally in -40,100 degrees, this is the CE standard of the European Union and the ASTM standard of the United States. Of course, the breathable film will not use polyethylene or TPO film production, the air permeability should be more than every 241,500 grams of square meters, if the use of polyethylene or TPO film, the air permeability will be very poor, basically it is not breathable. There is also PP material if ultraviolet radiation, will speed up the aging process, some fake waterproof breathable film in this aspect of the production of the material is very poor, so this poor waterproof breathable film in the construction process is very easy to explain the aging.
(2) simple manual detection
It can be seen from the surface that there are very obvious pressure points on both sides of the waterproof breathable film, because its production process is mainly hot-pressing composite, but please note that it is not the non-woven fabric itself that will produce dot marks, but very obvious overlapping dot marks. After tearing open the permeable film, the middle should be a layer of permeable film, milky white, very soft. In addition, you can use a light pressure non-woven cloth and film, if there is a feeling of sticky hand, then you can conclude that this is counterfeit.