1. The influence of fiber raw materials on the yarn strength. The longer the fiber length, the better the fiber uniformity, the higher the yarn strength, and the smaller the strength variation coefficient. When spinning the same spinning yarn, the smaller the density of the fibers used in spinning, the more fibers there are in the section of the spinning yarn, which increases the internal and external transfer of the fibers during the twisting process. The contact area between fibers improves the cohesion and friction between fibers and improves the yarn strength. When other conditions are the same, the higher the single fiber strength is, the higher the yarn strength is.
2. The influence of the pre-spinning process on the yarn strength. In the cleaning process, the process parameters should be reasonably selected, the opening efficiency of the machine should be improved, and the large impurities and harmful defects should be fully eliminated early; the hitting points should be reasonably arranged or the carding should be used instead to reduce the damage to the fibers.
In the carding process, the card clothing should be reasonably selected and the process parameters of each part should be well designed to give full play to the carding function, remove short fibers and impurities, reduce the generation of new neps, reduce the damage to the fibers, and improve the yarn strength.
The drawing process should reduce the weight unevenness and evenness unevenness of the cooked sliver, thereby effectively reducing the weight unevenness of the roving and spun yarn, thereby improving the yarn strength.
The roving process should focus on improving the weight unevenness of short segments, control the periodic unevenness of the roving, and reduce its influence on the spun yarn strength and strength unevenness. Therefore, in the actual production, it is necessary to strictly control the ration of cooked sliver, reduce the table difference and eye difference, reasonably control the elongation of the roving, and strengthen the inspection and maintenance of the rubber roller, aprons, cradle and transmission system.
3. The influence of other quality indicators of spun yarn on the yarn strength. The better the evenness of the spun yarn, the better the yarn strength, and the smaller the variation coefficient of single yarn strength.
The weight unevenness of the 100-meter spun yarn is an important fabric manufacturer that causes the uneven strength between the cops. Generally, the weight unevenness of the 100-meter spun yarn should be controlled below 2% to avoid the coefficient of variation of the spun yarn strength exceeding the standard.
The size of the spun yarn twist coefficient and the twist unevenness have a great influence on the yarn strength. With the increase of twist, the yarn strength gradually increases, but after reaching the critical twist, the yarn strength decreases when the twist continues to increase.