According to tradition, there are three major systems of semi-worsted yarn engineering: woolen spinning, worsted spinning and semi-worsted spinning. The so-called semi-worsted spinning is a spinning process between worsted spinning and woolen spinning. But this argument can be explored. The so-called saying that semi-worsted spinning is between woollen and worsted spinning actually means that the length of raw material used in semi-worsted spinning is shorter than worsted spinning and longer than woolen spinning, rather than saying that semi-worsted yarn engineering is a bit like woollen, a bit like Worsted. In fact, the earliest semi-worsted spinning actually belongs to the worsted spinning category, but it is a simplified and incomplete worsted spinning project. With the advancement of technology, the concept of semi-worsted spinning has also changed accordingly. The original simplified wool worsted spinning system not only uses wool raw materials, but also uses cotton-type raw materials.
Cotton spinning equipment, so from the perspective of the use of raw materials and equipment, semi-worsted spinning has evolved into a spinning system between cotton spinning and wool worsted spinning. The raw materials are close to cotton spinning, and the equipment is mixed with cotton and wool. similar. Obviously, this spinning project is actually a simplification of the worsted spinning project, eliminating the top manufacturing part in worsted spinning. There are data showing that this spinning route is proposed for some wool with less grass content, and is mainly used for wool production. But this process has some fatal weaknesses. After omitting the top manufacturing part, this semi-worsted spinning system must use other methods to control the content of grass and weeds in the raw materials, control the short wool content in the raw materials and improve the carding effect of the tops, which originally belonged to the top manufacturing process. Practice has proved that, although there are certain effects by simply changing the equipment and changing the process, they are not ideal. Under such circumstances, the only way is to choose the raw materials.
In addition to the length and fineness of the raw materials, the raw materials are also required to contain less weeds and grass, and have less short hair content. Obviously, such semi-worsted spinning is uncompetitive. If the wool you use contains more weeds, then no matter whether you use cotton spinning or wool spinning ready-made equipment, these impurities cannot be handled well. Therefore, we must strengthen the treatment of weeding and weeding. Some units have added several cleaning points on the wool spinning carding machine, and even installed a special cleaning mechanism. Nowadays, many semi-worsted spinning materials are relatively clean, especially some raw materials such as Tencel cashmere, which contain very little impurities. Therefore, how to strengthen the carding of fibers without damaging the fibers is another difficult point. Carding involves spinning count and yarn quality. Without sufficient carding, the fibers in the sliver or curled or entangled not only directly affect productivity but also seriously affect yarn quality.
So some flat carding of cotton spinning was changed to roller carding, and some of the carding points of wool spinning were reconfigured. In some units, the phenomenon of circling the cylinder during carding is often not cleaned up in time, and a large number of wool particles appear in the sliver. Some units often encounter the problem of broken nets, and the uneven weight of the sliver exceeds the target. In response to these problems, many units adopt various methods, using small-gauge light carding methods to comb the fibers, and some use guide strip devices to avoid defects caused by broken nets. But for carding into a strip, adjusting the various process speeds and process gaps in carding is of course very important, but the most important thing is the card clothing. The card clothing model is not selected properly, and the process parameters cannot be adjusted to have a very ideal effect. It is also difficult to say absolutely what card clothing must be used for semi-worsted spinning. Wool spinning is steel wire card clothing, and cotton spinning is elastic card clothing, but the card clothing used in cotton spinning and wool spinning must be determined according to the unit used. The choice of card clothing used in semi-worsted spinning is also determined according to the raw materials used, during which the traditional experience and technical knowledge of the unit need to be considered.