How is moisture-wicking performance achieved?
Fiber
The moisture absorption and sweat discharge performance of fibers depends on their chemical composition and physical structure. The gaseous moisture evaporating from the skin surface is first absorbed by the fiber material,and then discharged through the surface of the material; while the liquid moisture on the skin surface is adsorbed, diffused and evaporated on the surface of the material through the capillary effect generated by the pores (capillary pores, micropores, grooves) inside the fibers and the gaps between the fibers.
The forms of fiber moisture absorption can mainly be divided into two types: immersion and capillary suction. The former refers to the situation where liquid water conducts along the surface of a single fiber or a fiber aggregate in an immersed form, while the latter refers to the capillary suction effect of the fibers within the aggregate or the pores of a single fiber on the liquid.
Among them, wettability is the foundation and prerequisite of capillary action. The wettability of fibers can be characterized by indicators such as contact angle, wettability force, and spreading speed, while the capillary action of fibers can be represented by two indicators: capillary height and capillary speed.
The combined effects result in the migration of water. The former effect is mainly related to the chemical composition of the macromolecules of the fibers, while the latter effect is related to the physical structure and morphology of the fibers.
Wicking and moisture-wicking fibers generally have a high specific surface area. Their surfaces are covered with numerous pores or grooves, and their cross-sections are usually in special irregular shapes. By utilizing the capillary effect, these fibers can quickly absorb moisture and sweat from the skin surface and transfer it to the outer layer of the fabric.
The development of moisture-absorbing and moisture-wicking fibers
In order to alleviate the discomfort caused by the characteristic of cotton fibers that they readily absorb moisture but are difficult to dry, people began to consider whether it was possible to accelerate the transmission and evaporation of moisture through changes in yarn or fabric structure, or even through post-treatment methods. The popular polyester-cotton products of that time are a typical example.
Subsequently, with the development of fiber technology, products based on differentiated synthetic fibers as the main raw materials, such as moisture-wicking and quick-drying products (referred to as moisture-absorbing and quick-drying products in China), have begun to enter the market.
Chemical moisture-absorbing and sweat-discharging fibers mainly utilize the anisotropic shaping of the fiber cross-section (such as Y-shaped, cross-shaped, W-shaped, and bone-shaped, etc.) to form grooves on the fiber surface. Through the core suction and moisture-absorbing structure of these grooves, they can quickly absorb moisture and sweat from the surface of the skin and immediately discharge them from the body. Then, the fibers on the fabric surface will diffuse the sweat and quickly evaporate it, thereby achieving the purpose of moisture absorption and sweat discharge, and regulating body temperature, allowing the skin to remain dry and cool.
Weaving process
During the weaving process, through the design of jacquard technology, by appropriately arranging the thickness of the fabric, the areas with jacquard patterns and the elastic zones, it is possible to meet the requirements of human body for ventilation, pulling and elasticity, while also enabling the fabric to have a certain moisture absorption and sweat discharge function.
Fabric weave structure
A one-way moisture-wicking double-sided knitted fabric was developed using the structural method. The fabric adopts single-sided jacquard or ribbed variation organization, or double ribbed variation organization. The inner layer uses hydrophobic fibers such as fine-denier polyester or polypropylene to weave honeycomb or mesh point-like structure, while the outer layer uses hydrophilic fibers such as cotton, wool, or viscose to weave a high-density organization structure. This increases the differential capillary effect between the inner and outer layers of the fabric, and can also achieve the one-way moisture-wicking function.
Unidirectional moisture transport
Furthermore, when developing moisture-wicking fabric using multi-layer structure textiles, the inner layer is generally composed of ultra-fine filaments such as polypropylene and polyester, the middle layer is an absorbent layer made of cotton yarn, and the outer layer is made of strong and highly permeable fibers. It can be woven using a double ribbed composite structure, and this can also achieve the functions of moisture-wicking, breathability and soft hand feel of knitted fabrics.
