ePTFE is a microporous membrane formed by expanding and stretching polytetrafluoroethylene as raw material. The experiment found that the surface of the PTFE membrane was covered with fibrillar micropores, and each square inch had up to 9 billion micropores. The cross section was a network structure, and the three-dimensional structure of the pores had mesh connection, hole inlays, and curved channels. And other very complex structures. The diameter of the water vapor molecule is 0.0004 microns, and the diameter of the lightest mist in the rainwater is 20 microns. The diameter of the drizzle has been as high as 400 microns. The diameter of the PTFE micropores varies from 0.1 to 0.5 microns, and the pore diameter is in the water. Between steam and rain, it is the top waterproof and breathable material. The composite fabric is made of expanded polytetrafluoroethylene film (ePTFE) and polyester fiber by special process.
Windproofness of ePTFE membrane:
Before the advent of PTFE, there was no ideal solution to the requirements of both waterproofing and breathability in the textile industry. Existing materials can only be waterproof and breathable to a low degree, or not both. Due to the mesh microporous structure of the ePTFE membrane, the air flow rate per second through the e-PTFE membrane is 3.6mm, or 3.6mm / s, the air molecules are difficult to penetrate, and the external airflow cannot directly contact the human body through the fabric. The wind passes through the fabric, but does not directly pass through the e-PTFE microporous membrane, so it has good wind resistance. Windproof: The special vertical and horizontal three-dimensional cross-arrangement structure of TEX microporous film, its air penetration is only one-half of the general man-made fiber or down clothing.
ePTFE membrane water resistance:
ePTFE membrane also has the characteristics of non-wetting. Its water pressure resistance can reach 1800mbar, that is, it can only penetrate when the pressure is greater than 18 meters of water column. The waterproof degree of general waterproof nylon is only 1000-2000mm, which can only withstand general showers; the better one is 5000mm, which can withstand heavy rain; the US military standard is only 7000mm, and the waterproof degree of PTFE can be as high as 20000mm. Water resistance: The water pressure resistance of general waterproof nylon is only 1000-2000mm, which can only withstand general showers, and the better is 5000mmH2O, which can withstand heavy rain; TEX has a water resistance of 10000 mm.
Moisture permeability of ePTFE membrane:
 The micro-porous structure of e-PTFE membrane can expel steam from the body more and faster, so that sweat vapor does not accumulate and condense between the body surface and the fabric, making the body dry and comfortable. The general detection value is 10000g / m224h, that is, the water vapor passing through the PTFE membrane per square meter reaches 10000g in 24 hours. Generally waterproof and breathable fabrics are only 2000-3000g / m224hr. Moisture permeability: The specification of moisture permeability is g / m2 / 24h (grams per square meter per 24 hours), the general waterproof and breathable fabric is only 2000-3000 g / m2 / 24h, and the moisture permeability of TEX is up to 8000-10000 g / m2 / 24h!
Other protection:
Except for molten alkali metals, PTFE is hardly corroded by any chemical reagents. For example, boiled in concentrated sulfuric acid, nitric acid, hydrochloric acid, or even in aqua regia, its weight and performance have no change. PTFE does not absorb moisture, does not burn, and is extremely stable to oxygen and ultraviolet rays. At the same time, it has very strong biological adaptability, will not cause rejection of the body, and has no physiological side effects on the human body.
The e-PTFE fabric currently produced is made by laminating e-PTFE membrane and fabric through a special process. Generally divided into single paste fabric, double paste fabric. Single sticker (two-in-one): e-PTFE microporous membrane is made of nylon or polyester fabric as the surface layer; double sticker (three-in-one): nylon or polyester fabric as the surface layer, nylon warp knitted fabric as the inner layer, The middle is laminated with e-PTFE microporous membrane. Experiments have shown that when the temperature of the microclimate zone in the clothes close to the human skin is around 32 ° C and the humidity is around 50, the human body is in the best physiological state. Sweating of the human body is an effective means of heat dissipation in thermal balance adjustment. 80% of the heat dissipated by the human body is evaporated through the skin of the body. For a long time, although PVC, PU, ​​TPU and other coatings and laminated fabrics have a certain effect on the waterproofness and warmth of the clothing, because they cannot exhaust the sweat to the outside of the clothing, the sweat can accumulate in the clothing and make the human body feel wet and cold. Bored phenomenon. The special micro-porous structure of e-PTFE fabric makes it have excellent waterproof, moisture-permeable and wind-proof functions. It truly achieves waterproof, moisture-permeable, wind-proof and breathable, and makes the human body feel dry and comfortable. It is called "breathing fabric".
ePTFE membrane application areas:
Polar scientific research winter clothing, fire protection clothing, military protective clothing, tents, sleeping bags, raincoats, high-end civilian raincoats, work shoes, leisure travel clothing. Currently mainly used in high-end functional fields such as outdoor supplies, military uniforms, medical protection and so on.

ePTFE waterproof and moisture permeable composite fabric