Moisture-absorbing and perspiration-wicking textile products are a category of functional textile products that have developed rapidly in recent years, especially in sports, leisure, outdoor and travel apparel products, which have become a bright spot to guide the market and consumption. Moisture-wicking fabrics may seem complicated, but it's not a completely high-tech problem. It can be designed from the aspects of moisture absorption and moisture conduction fibers, fabric structure and so on. In order to realize related functions simply and quickly, most of the moisture-absorbing and sweat-wicking fabrics on the market are thin fabrics, and the fabrics include single-sided fabrics, double-sided fabrics or multi-layer fabrics.

1. Moisture-absorbing and sweat-wicking fibers

The moisture-wicking performance of a fiber depends on its chemical composition and physical structure. The gaseous moisture evaporated from the surface of the skin is first absorbed by the fiber material (that is, moisture absorption), and then released through the surface of the material; while the liquid moisture on the skin surface is formed by the pores (capillaries, micropores, grooves) inside the fibers and the gaps between the fibers. The capillary effect generated by the voids enables the adsorption, diffusion and evaporation (ie dehumidification) of moisture on the surface between materials.

The form of fiber moisture conduction can be mainly divided into two situations: infiltration and wicking. The former refers to the conduction of liquid phase water along the surface of a single fiber or fiber assembly in the form of infiltration, and the latter refers to the absorption of liquid in the fiber assembly or the pores of a single fiber. capillary wicking. Among them, infiltration is the basis and premise of wicking. The wetting of fibers can be characterized by measuring indicators such as contact angle, wetting force, and spreading speed; the wicking of fibers can be characterized by indicators such as wicking height and wicking speed. The results of the two effects lead to the migration of water. The former effect is mainly related to the chemical composition of the fiber macromolecules, and the latter effect is related to the physical structure of the fiber.

Moisture-absorbing and sweat-wicking fibers generally have a high specific surface area, and there are many shock holes or grooves on the surface. Pass to the outer band hair.

2. Development of moisture-absorbing and sweat-conducting fibers

The earliest products to introduce the concept of moisture absorption and sweat absorption or moisture absorption and quick drying are functional textile products developed based on the characteristics of natural fibers. In order to improve the discomfort caused by the hygroscopicity of cotton fiber but not easy to dry, people began to consider whether it is possible to speed up the conduction and evaporation of water by changing the structure of yarn or fabric, or even by finishing. To achieve the effect of moisture absorption and quick drying, the polyester-cotton products that were all the rage back then are a typical example. Later, with the development of fiber technology, moisture-wicking and quick-drying products based on differentiated synthetic fibers as the main raw material have begun to enter the market.

The chemical moisture-absorbing and sweat-wicking fiber mainly uses the special-shaped fiber section (Y-shaped, cross-shaped, W-shaped, and bone-shaped, etc.) to form grooves on the surface of the fiber. With the help of the wicking and moisture-conducting structure of the grooves, it quickly absorbs moisture and moisture from the skin surface. Sweat is discharged from the body instantly, and then the fibers on the cloth surface diffuse and evaporate the sweat quickly, so as to achieve the purpose of moisture absorption and perspiration, regulate body temperature, and keep the skin dry and cool.

3. Weaving of sweat-wicking fibers

In the weaving process, through the jacquard process design, the thickness of the fabric, jacquard and elastic areas are reasonably arranged, which can meet the needs of the human body for ventilation, lifting and elasticity, and at the same time make the fabric itself have a certain moisture absorption and perspiration function. For example, RSJ 5/1 EL warp knitting machine is used to design a suitable jacquard structure to form mesh holes of different sizes in the fabric, so as to ensure the smooth air circulation of the fabric and make the fabric have excellent moisture permeability and breathability.

4. The structure of sweat-wicking fabric

Develop unidirectional moisture-wicking double-sided knitted fabrics. The fabric adopts single-side plating jacquard weave, rib change weave or double-rib change weave, and the inner layer uses hydrophobic fibers such as fine denier polyester, polypropylene, etc. to weave honeycomb or mesh and other point-like weave structures. The outer layer uses hydrophilic fibers such as cotton, wool, viscose, etc. to weave a high-density structure, which increases the differential capillary effect of the inner and outer fabrics, and can also achieve a one-way moisture transfer function.

In addition, the use of multi-layer structure fabrics to develop moisture-absorbing and sweat-wicking fabrics generally uses ultra-fine filaments such as polypropylene and polyester as the inner layer, the moisture-absorbing layer as the middle layer of cotton yarn, and the outer layer is composed of fibers with high strength and good permeability. Weaving with double-ribbed composite tissue can also achieve the sweat-wicking, breathable and soft feel of knitted fabrics.

The moisture-wicking fabric with three-layer structure: (1) is the outer side of the outer layer of the fabric, that is, the moisture-absorbing and moisture-releasing layer of the fabric; (2) is the middle part of the outer layer of the fabric, that is, the wicking and moisture-conducting layer of the fabric; ( 3) is the inner side of the outer layer of the fabric, that is, the strong moisture-absorbing moisture storage layer of the fabric; (4) is the middle layer of the fabric, which is the middle layer of the elastic film (formed by melting and shaping of polyurethane fibers) of the fabric; (5) is the inner layer of the fabric layer, which is the moisture-absorbing and quick-drying layer of the fabric.