Abstract:

Objective It is true that the function requirements on female sports underwear are getting higher and higher. In order to improve the thermal and wet comfort of sports underwear, a fine thermal and wet partition design for sports underwear was carried out, combined with flat braid technology to reduce the seam of sports underwear and improve the comfort.

Method Based on the study of the distribution of thermat and humidity in women's upper body, a thermat and humid partition model for forming sports underwear was constructed. At the same time, using DTY as raw materials, eight types of structures suitable for flat knitting sports underwear were designed and developed, and their moisture permeability, moisture absorption, sweat drainage and air permeability were tested. Based on the experimental results, the thermal and humid comfort of the eight structures was evaluated by fuzzy comprehensive evaluation method, and the order of thermal and humid performance was obtained.

Results Through the analysis of thermal and humid distribution in the upper body of the human body, it is found that the heat in the upper chest, the middle chest and the back is the highest and the distribution of sweat glands is the most dense. The chest heat is higher, but the distribution of sweat glands is less than the upper chest, the middle chest and the back. Underarm heat is relatively low but sweat glands are densely distributed; The distribution of heat and sweat glands in abdomen and back triangle was medium. The remaining areas are at the edges of the body, where they emit less heat and have fewer sweat glands. The thermal and humid test results show that the moisture permeability of the fabric is inversely proportional to the total density of the fabric. This is because the greater the total density of the fabric, the tighter the water vapor will pass through the pores of the fabric, which will also lead to more contact points between water vapor and the fabric, resulting in poorer moisture permeability of the fabric. The moisture absorption and perspiration of the fabric is determined by the number of connecting channels between the front and back of the fabric.The more connected channels, the better the moisture absorption and perspiration, because these connected channels will form a microporous structure on the surface of the fabric, giving it a good single guide wet performance, and promote the improvement of the moisture absorption and rapid drying of the fabric. The air permeability of a fabric is mainly determined by the size and distribution of pores in the fabric. The larger and more pores, the better the air permeability of the fabric, because when the fabric is larger and more pores, the looser its structure, the easier the flow of gas inside the fabric, resulting in a higher air permeability of the fabric.

Conclusion According to the analysis of thermal and humid distribution of female upper body, the thermal and humid partition model of formed sports underwear is constructed, which is divided into five zones. Zone I is high thermal and high humid partition, II for high thermal and humid areas, III is medium thermal and high humid area, IV is area of moderate heat to moderate humidity, and V is the area of low thermal and low humidity. Through fuzzy comprehensive evaluation analysis, it can be seen that the comprehensive thermal and humid performance of the double-layer tissue is better than that of the single-layer tissue, and the honeycomb mesh tissue in the double-layer tissue has the best thermal and humid performance, which is mainly caused by the number of connecting channels between the front and back of the double-layer stitch. A flat knitting sports underwear was designed and developed by combining the thermal and humid zoning model and the comprehensive evaluation results of the tissue structure, and the function of improving the heat and humidity balance of human body was verified by infrared thermal imaging test.

Key words: flat knitting, full-forming, sports underwear, partition design, thermal and humid comfort