An important factor affecting fabric comfort is the Air Permeability of the fabric. Sportswear and windproof and winter clothing have higher requirements for fabric Air Permeability. Some industrial textiles, such as aircraft parachutes and filter cloths, have special requirements for fabric permeability. Fabric air permeability is determined by the number and size of warp and weft yarns and fiber gaps in the fabric. It is also related to warp and weft density, warp and weft yarn characteristics, and yarn twist. It is also related to factors such as fiber properties, yarn structure, fabric thickness and bulk weight.

Fabric air permeability test and principle:

The so-called fabric air permeability refers to the air permeability of textile fabrics when there is a pressure difference between the two sides of the fabric. That is, the volume of air per unit area of the fabric flowing in a unit time under the prescribed pressure difference on both sides of the fabric, the unit is L / mm2s. Because the pressure difference is a necessary condition for the air to flow, only when a certain pressure difference is maintained on both sides of the tested fabric can air flow occur in the fabric.

The air permeability test is based on a fixed pressure difference as the benchmark for the air permeability test. The pressure difference stipulated by the test standards in different countries is not consistent. For example, the American ANSI / ASTM, K773, FS191 / 5450 and Japanese JISL1096 stipulate 127.4Pa (13mm water column); French NFG07-111 stipulates 196Pa (20mm water column); German DIN 53387 stipulates Clothing fabric is 100Pa (10mm water column), parachute fabric is 160PA (16mm water column), filter fabric and industrial fabric is 200Pa (20mm water column); British BS5636 stipulates 98Pa (about 10mm water column) and so on.

Test Equipment：Air permeability testing machine GT-C27

Different fabrics have very different air permeability requirements. Even for the same fabric, due to different use requirements, the pressure difference between the two sides of the fabric is often different. Therefore, different pressures should be selected according to the characteristics of the fabric's own materials and the use requirements Drop to test.