Using Twisting to Improve the Yarn Strength of Textile Fibers

Twisting is mainly to improve the strength of the yarn. Twist cannot be used to compare the twist degree of different thickness yarns. The twist direction of the yarn has a great impact on the appearance and feel of the fabric. In addition to moisture absorption, the water absorption of textile fiber materials is also closely related to the wearing comfort of clothing fabrics.

Twisting is to make the two cross sections of the sliver rotate relatively, and then the textile fibers in the sliver that were originally parallel to the yarn axis are inclined into helices. For short textile fibers, twisting is mainly to improve the strength of the yarn. Twisting of filament can not only improve the strength of yarn, but also produce some effects. The amount of yarn twist and the combination of twist direction and twist degree of yarn in the fabric have a great impact on the appearance and performance of the product.

The indexes of twisting property include twist degree, twist coefficient and twist direction indicating twisting direction. The twist angle of the yarn is twisted for one turn. The number of twists per unit length of yarn is called twist. Cotton yarn in China adopts special twist system, which is expressed by the number of twists within 10cm of yarn length; Combed wool yarn and chemical filament yarn use metric count twist, that is, the number of twists per meter; In addition, there is an inch count twist expressed in turns per inch.

Twist cannot be used to compare the twist degree of different thick and thin yarns, because with the same twist, the inclination degree of the textile fiber of thick yarn sliver is greater than that of thin yarn sliver. In practical production, twist coefficient is often used to express the twist degree of yarn. Twist coefficient is a relative value that represents the twist degree of yarn in combination with linear density. It can be used to compare the twist degree of different thickness yarns. The twist coefficient can be calculated according to the twist of yarn and the linear density of yarn.

The twist direction of the yarn has a great influence on the appearance and feel of the fabric. By combining the twist direction of the warp and weft yarns with the fabric structure, fabrics with different appearance and feel can be woven. When textile fibers are placed in the air, they will continuously exchange water vapor with the air, that is, textile fibers continuously absorb water vapor in the air, and also continuously release water vapor into the air. The performance of textile fiber in absorbing or releasing water vapor is called the moisture absorption of textile fiber.

Moisture absorption of textile fiber is one of the important physical properties of textile fiber. The size of moisture absorption of textile fibers has a certain impact on the shape, size, weight, physical and mechanical properties of textile fibers, which also affects their processing and use performance. The moisture absorption capacity of textile fibers also directly affects the wearing comfort of fabrics. The textile fiber with high moisture absorption capacity can easily absorb the sweat discharged by the human body, regulate the body temperature, relieve the feeling of dampness and stuffiness, and make people feel comfortable. Therefore, attention should be paid to the hygroscopicity of textile fibers in commercial trade, textile fiber performance testing, textile processing and textile selection.

Among the common textile fibers, wool, hemp, viscose textile fibers, silk, cotton, etc. have strong moisture absorption capacity, while synthetic textile fibers generally have poor moisture absorption capacity, of which vinylon and nylon have slightly better moisture absorption capacity. At present, synthetic textile fibers with poor hygroscopicity are often blended with natural textile fibers or viscose textile fibers with strong hygroscopicity to improve the hygroscopicity of fabrics.

In the hygroscopicity of textile fibers, in addition to hygroscopicity, the hygroscopicity of textile fiber materials is also closely related to the wearing comfort of clothing fabrics. The water absorption of textile fiber refers to its ability to absorb liquid water. The moisture and sweat generated by people during activities are mainly superior to the moisture absorption and water absorption properties of materials, which can be absorbed and dispersed outward, thus making people feel comfortable. Generally speaking, the coat is mainly soaked by rain, so the textile fiber with small water absorption can be selected as the coat material; Underwear is mainly affected by the invisible evaporation and sweating of the body, so it is necessary to choose textile fibers with high moisture absorption and water absorption as underwear materials.