There are three main ways for water vapor to pass through the fabric: first, water vapor diffuses through the micropores in the fabric; second, the fiber absorbs moisture and escapes at a place where the water vapor pressure is low; third, a large number of water molecules will produce condensation and diffuse through capillary action, and more evaporation occurs at the low water vapor pressure.
The moisture absorption, transmission and escape through the fiber are related to the fiber used in the fabric, the moisture absorption capacity, the expansion degree and the pores and channels in the fiber.
The moisture absorption and perspiration functional fabric requires that the non absorbent fabric has both water absorption and quick drying. Polyester fiber has a high crystallinity molecular chain structure, which makes polyester have the disadvantages of low water absorption and poor moisture permeability in terms of moisture absorption, but this just makes it have excellent quick drying ability. Natural fibers, such as cotton, have a large number of voids in the fiber structure, which makes them have advantages in hygroscopicity. However, the swelling effect after absorbing water strengthens the holding power of water, thus resulting in defects in quick drying performance.
