Besides the strength and skills of the anticipants themselves, outdoor activities also require the outdoor sportswear be ready to adapt to bad weather and complex geographical conditions in order to protect the personal safety of their owner. As a consequence of the factors of sports and outdoors, the requirements for outside sportswear are comparatively more strict. In outdoor activities, there exists much more heat and sweat produced, so the clothes must have good heat dissipation and drinking water vapor permeability; there'll be rainy, windy, snowy or foggy days in the open air, so the clothes should be waterproof.
The ability to resist drinking water and to dissipate heat created by the body in the same time is hard to be obtained. Luckily, the sweat maded by body of a human is drinking water vapor of single molecule state, while the rain and snow is liquid h2o drops in the state of aggregation. Volume of these two sorts of water differs a lot. Besides, liquid h2o has a characteristic called rod mill which is the characteristic to aggregate itself in volume. If you mix a drop of detergent with a water drop, the h2o drop will scatter flatly immediately because the detergent can lower its surface tension.
Sportswear of waterproof capability and h2o vapor permeability perfectly makes use of this characteristic of drinking water, surface tension. It applies PTFE (same chemical component but different physical structure with Polytetrafluor ethylene, PTFE, best corrosion resistance) coating on the surface of the fabric to increase the surface tension of the fabric in order that the h2o drops keep themselves together instead of scattering and infiltrating into the surface. In this way, water drops will not be capable to go through the clothes. Meanwhile, this PTFE coating is porous so the drinking water vapor of single molecule state can successfully undergo the tiny holes in the fabric and be dissipated to the surface of the clothes.
After large level of movement, if we stop to rest in the rod mill, there may be h2o drops inside our clothes since it's cold outdoors and the sweat cannot be dissipated in time. It will make us feel not so comfortable. There is a type of film of polyurethane (PU) and nano-ceramic powder which is often coated on the surface of the fabric so to absorb the sweat vapor when we are sweating. This coating will refrain from the h2o vapor inside the clothes from turning into water drops because the drinking water vapor has exceeded the saturated vapor pressure.
Besides this characteristic, PTFE has other special functions. To illustrate, since PTFE has low-loss and small dielectric constant, PTFE film has become the perfect insulation material to make capacitors, insulated cables and transformers. PTFE film is also one of several indispensible materials of making electronic components in aviation and space industry, etc. Many characteristics of PTFE make PTFE be widely applied in lots of fields like chemical engineering, petroleum, medicine, electronics and machinery.
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