Hygroscopic and perspirant textile products are a kind of functional textile products with rapid development in recent years, especially in sports, leisure, outdoor and travel clothing products, which have become a bright spot in guiding the market and consumption. Hygroscopic and sweat-wicking fabrics may seem complicated, but they're not entirely high-tech. It can be designed from the aspects of hygroscopic and hygroscopic fibers and fabric structure. In order to achieve the relevant functions simply and quickly, the moisture absorption and sweat wicking fabrics on the market are mostly thin fabrics, including single-sided fabric, double-sided fabric or multi-layer fabric.

1. Hygroscopic fiber

The hygroscopic and perspiratory properties of fibers depend on their chemical composition and physical structure. The gaseous moisture evaporating from the skin surface is first absorbed by the fibrous material (i.e. hygroscopic) and then dehumidified through the material surface. The liquid water on the skin surface is absorbed, diffused and evaporated (dehumidification) by the capillary effect generated by the pores (capillaries, micropores and grooves) inside the fibers and the Spaces between the fibers.

Fiber humidification can be divided into two types: infiltration and core aspiration. The former refers to liquid phase water conduction along the surface of single fiber or fiber aggregate in the form of infiltration, while the latter refers to the capillary core absorption of liquid in the body of the fiber aggregate or single fiber hole. Among them, infiltration is the basis and premise of core aspiration. Fiber infiltration can be measured by contact Angle, infiltration force, spreading speed and other indicators. Fiber core absorption can be characterized by core absorption height, core absorption speed and other indicators. The result of two kinds of action is that the water migrates. The former action is mainly related to the chemical composition of the macromolecules of the fiber, and the latter is related to the physical structure and morphology of the fiber.

Hygroscopic and perspirant fibers generally have a high specific surface area, with numerous holes or grooves on the surface, and their cross sections are generally special different shapes. The capillary effect is used to enable the fibers to quickly absorb moisture and sweat on the skin surface, and then transfer to the outer band hair through diffusion.

2. Development of hygroscopic and perspiratory fibers

The first product to introduce the concept of hygroscopic sweating or hygroscopic quick drying in China is a functional textile product developed based on the characteristics of natural fibers. In order to improve the uncomfortable feeling caused by the characteristics of cotton fiber, which is easy to absorb moisture but not easy to dry, people began to consider whether to accelerate the conduction and evaporation of moisture through the change of yarn or fabric structure, or even through the way of finishing, so as to achieve the effect of moisture absorption and quick drying. Polyester cover cotton products that were popular in those years are a typical example. Later, with the development of fiber technology, moisture-guiding and quick-drying products based on differentiated synthetic fibers have begun to enter the market. picture

Chemical hygroscopic perspiration fiber is mainly used to shape fiber section (Y shape, cross shape, W shape and bone shape, etc.) to form grooves on the fiber surface. With the core hygroscopic and hygroscopic structure of the grooves, it rapidly absorbs moisture and sweat on the surface of the skin, and instantly drains out of the body. Then the fiber of the cloth surface diffuses sweat and evaporates rapidly, so as to achieve the purpose of hygroscopic perspiration and temperature regulation. Keep skin dry and cool.

3. Weaving of perspirant fibers

In the weaving process, through the jacquard process design, reasonable arrangement of fabric thickness, jacquard and elastic area, can meet the human body breathable, lifting and elastic needs, while making the fabric itself has a certain moisture absorption and sweating function. For example, RSJ 5/1 EL warp knitting machine is used to design suitable jaka fabric, so that the fabric forms different sizes of mesh, to ensure that the fabric air circulation is smooth, so that the fabric has excellent moisture permeability performance.

4. Organization structure of sweat wicking fabric

The single guide wet double-sided knitted fabric is developed. The fabric adopts single side added yarn jacquard structure, rib change structure or double rib change structure. The inner layer adopts hydrophobic fibers such as fine denier polyester, polypropylene and other woven honeycomb or mesh point structure. Can also achieve a single wizard wet function.

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In addition, the inner layer of hygroscopic and sweat-wicking fabric developed by multi-layer structural fabric is generally made of polypropylene, polyester and other extra fine fibers, the middle layer is made of cotton yarn hygroscopic layer, and the outer layer is made of fiber with high strength and good permeability. The double rib composite fabric can be woven to realize the sweat conduction, breathable and soft feel of knitted fabric.

The three-layer structure of hygroscopic fabric: (1) is the outside of the outer layer of the fabric, namely the hygroscopic moisture storage layer of the fabric; (2) is the middle part of the outer layer of the fabric, namely the core hygroscopic layer of the fabric; (3) the inner side of the outer layer of the fabric, namely the strong hygroscopic moisture storage layer of the fabric; (4) is the middle layer of fabric, is the elastic film of fabric (polyurethane fiber formed after melting and shaping) middle layer; (5) is the inner layer of the fabric, which is the moisture absorption and quick drying layer of the fabric.