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The difference between water repellent, waterproof, breathable, breathable and windproof fabric 2020.11.06

The water-repellent properties of water-repellent fabrics refer to the special treatment of water-repellent fabrics. The surface of the fabric can make water droplets bead-shaped, and will not penetrate or diffuse to wet the clothes, achieving a lotus-like water-repellent function (lotus effect). The water repellency is usually divided into zero to five grades. The test standards generally require that the tested fabric must be at least four (ISO) water repellency grades (that is, reach 90 or more (AATCC) water repellency). The water repellent layer is actually a layer of special treatment covering the surface of the fabric. Generally, DWR is added when the finished fabric is shaped. Water-repellent processing uses this principle to attach a layer of ultra-fine "needle bed" to the surface of the fabric with various chemical materials, so that the surface tension of the fabric is less than the cohesive force of water. Therefore, after water droplets, water droplets will roll away. Not spread out and soaked. If this layer of needle bed structure is flattened or covered by oil, the water repellency of the fabric will be greatly reduced, and even start to absorb water.


The functional treatment of water-blocking and pre-repelling water infiltration. Current water-repellent treatments often use water-repellent membranes to block the penetration of water molecules, but the membrane itself is too fragile, so it depends on the coordination of the surface cloth, membrane, and lining to achieve the function of water blocking . The water blocking capacity is expressed by the water pressure resistance value, that is, a water-repellent cloth of a fixed area is used to block the continuously rising water pressure. When the surface sees a third drop of water, it is the water pressure resistance value of the cloth, usually more than 1000mm. Achieve the most basic water blocking ability.
Breathability refers specifically to the function provided by the indirect moisture permeability and water blocking film, not to mention the moisture permeability, because it is two different moisture permeability mechanisms, although it can eventually allow the sweat to pass through the fabric to the outside world. Breathing requires waiting for the sweat to be absorbed by the hydrophilic non-porous membrane to become sweat molecules inside and to move to the outside of the membrane in a micro-brown leisure way, affected by the difference in humidity and pressure between the inside and outside of the work clothes, and then turn into gas to be discharged through the surface cloth. So it is called indirect moisture permeability.
Moisture permeability specifically refers to the function provided by the water-repellent porous water-repellent membrane in the water-repellent and moisture-permeable membrane. Moisture permeability is to allow gas to pass directly through the voids of the "water-repellent porous membrane". Because of the faster speed, it is called direct moisture permeability.
Wind choke fabric at a wind speed of 30 miles per hour, the air penetration value of the fabric is 1 cfm (cubic feet per minute). A real windbreaker can prevent heat loss caused by air convection. As long as the fabric has a certain wind blocking function, the closer the fabric is woven, the stronger the wind blocking ability. Those with poor moisture permeability generally have stronger wind resistance. High-quality fabrics are the perfect combination of moisture permeability and wind resistance.

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