Characteristics and requirements of knitting yarn

Knitted fabric yarns, as the name suggests, are spun yarns used to produce knitted fabrics to distinguish them from woven yarns. Due to the difference between knitted fabric equipment and woven equipment, the spinning yarn is subjected to different forces during the production process. At the same time, due to the different characteristics and uses of knitted fabrics and woven fabrics, the knitted fabric yarns have the following characteristics and requirements. 1. Knitted fabric has a certain strength and elongation. The strength of the spun yarn is an important quality indicator for the yarn for knitted fabrics. Since the spun yarn is subjected to a certain tension and repeated load during the intended and weaving process, the yarn for knitting must have a certain strength. In addition, the spun yarn is subjected to bending and torsional deformation during the knitting process, and therefore the yarn for the knit fabric is required to have a certain elongation so as to be bent into a loop during the weaving process and to reduce the breakage of the spun yarn. 2. Knitted fabric yarn has good flexibility. The softness of the yarn for knitting is higher than that for woven yarn. Because the soft spun yarn is easy to bend and twist, and the coil structure in the knitted fabric is uniform, the appearance is clear and beautiful, and the breakage of the spun yarn and the damage to the loop forming machine during the weaving process can be reduced. 3, the knitted fabric yarn has a certain degree of twist Generally speaking, the yarn of the knitted fabric has a lower twist than the woven yarn. If the twist is too large, the softness of the spun yarn is poor, it is not easy to be bent and twisted during weaving, and the kinking is easily caused, causing woven woven fabric to damage the knitting needle; in addition, the excessively twisted spun yarn affects the knitted fabric. The elasticity of the object and the skew of the coil. However, the twist of the yarn for the knitted fabric should not be too low, otherwise the strength will be affected, the breakage during weaving will be increased, and the spun yarn will be loosened, so that the fabric can be simply pilling and the wearing property of the knitted fabric can be reduced. Therefore, the correct choice of twist is an important way to rationally choose spinning yarn. The use of knitted fabrics is different, and the twist requirements are also different. The jersey requires a smooth, tight, clean surface, clear lines, and a greater twist of the yarn, which is close to the warp yarn standard for the same linear density weaving. The twist of the spun yarn of the outer garment should be made larger to enhance the stiffness and improve the pilling phenomenon. Cotton cloth and elastic cloth are required to be soft and elastic, and the twist of the yarn should be slightly lower. Generally, the lower deviation of the weft yarn twist of the same linear density weaving is adopted. The yarn for the piled knit fabric is made for the convenience of brushing, and the thickness of the pile is uniform, and the twist requirement is smaller. The size of other twists also varies with the linear density of the spun yarn. The common twists of yarns for knitted fabrics are shown in the table below. 4. The linear density of the knitted fabric yarn is uniform and the yarn defect is small. The uniformity of the linear density of the spun yarn is the uniformity of the spun yarn, which is an important quality index of the yarn for the knitted fabric. The evenly spun yarn is advantageous for finishing the knitted fabric and ensuring the quality of the fabric, so that the coil structure is uniform and the cloth surface is clear. If there is a thick section on the yarn, the weaving will not pass smoothly, causing the yarn to break or damage the machine, and the "horizontal strip" and "cloud spot" are simply formed on the cloth surface to reduce the quality of the knitted fabric; With details, there is insufficient strength here, simple breaks, affecting the quality of the fabric and reducing machine productivity. Because the knitting machine has a multi-way looping system and the yarn is looped at the same time, not only the thickness of each spun yarn is required to be uniform, but also the thickness difference of the spun yarn between the roads must be strictly controlled, otherwise it will form on the cloth surface. Horizontal stripes, shadows and other rickets, reducing fabric quality. 5. Knitted yarns have good hygroscopicity The ability of the spun yarn to extract moisture in the air is called hygroscopicity. The hygroscopic capacity of various fibers varies greatly, and the amount of moisture absorption varies with the temperature and humidity of the air. The spun yarn used in the production of knitted fabrics should have a certain hygroscopicity. Under the same relative humidity conditions, the spun yarn with good hygroscopicity not only has better electrical conductivity, but also contributes to the stability and elongation of the twisted yarn, so that the spun yarn has good weaving. performance. 6. Knitted fabrics have good finish and a small coefficient of friction. The yarns for knitted fabrics should be free of impurities and oil stains, and should be very smooth. The spun yarn is not perfect, the wear of the machine parts is very bad, the damage of the machine parts is simple, and there are many flying flowers in the workshop, which not only affects the health of the workers, but also affects the productivity of the knitting machine and the quality of the fabric.