There are two main types of PTFE membranes: micro porous membranes and turned membranes. The biggest difference between the two is that the micro porous membrane is breathable, which is produced by biaxial stretching. Here, we mainly talk about the micro porous membrane.
The micro porous polytetrafluoroethylene membrane is made of polytetrafluoroethylene resin particles. After expansion and stretching, a micro porous membrane is formed. It is also divided into the following types:
1. Air filtration micro porous membrane
PTFE filter membrane can be used for atmospheric dust removal, air purification, etc. The membrane pore size can be controlled at 0.2um, and the porosity can reach more than 88%. It can be used in conjunction with filter materials such as needle felt, woven fabric, non-woven fabric, and glass fiber. Phase composite materials can obtain membranes with surface filtration properties. The filter material coated with PTFE membrane has the characteristics of high peel strength, large air permeability and uniform pore size distribution. As a dust bag or pleated dust filter element installed in dust removal equipment, it can quickly and effectively intercept ultra-fine powder calculated in microns. The dust removal efficiency can reach more than 99.99%, the service life is as long as 3 years, and the air permeability can reach 3-6m/min, it is the most advanced air filter material in the world. It is the best choice for various vacuum cleaners, air filter elements, air purification equipment, high efficiency air filters, etc.
2. Waterproof and moisture-permeable micro porous membrane
The PTFE waterproof and moisture-permeable microporous membrane is made through a special process and is biaxially stretched. The surface of the microporous membrane can reach billions of micropores per square inch, and the diameter of each micropore (0.1um-0.5um) is smaller than water. The minimum value of the smallest light mist in the molecule (20um-100un), the minimum value is much larger than the molecular diameter of water vapor (0.0003um-0.0004um), this diameter can allow water vapor to pass, but water droplets cannot pass. This kind of microporous structure can achieve excellent waterproof and moisture permeability; in addition, because the holes are very small and the longitudinal direction is irregularly bent, the wind cannot pass through, and it has wind resistance and good warmth retention. Special treatment of PTFE membrane greatly improves its firmness and durability. After being compounded with other fabrics, it can be widely used in military clothing, medical clothing, casual clothing, special protective clothing, such as biochemical, anti-virus and water immersion operations, accessories, such as materials of outdoor sportswear, shoes, hats, gloves, sleeping bags and tents.