Besides raw materials, how to improve yarn strength?

1. Raw material properties

Length, fineness, breaking length, maturity, short fiber content, etc. The fiber length is long, the uniformity is good, the fiber fineness is fine, the more the number of fibers per unit cross-section, the higher the twisting efficiency, the higher the yarn strength, the smaller the strength unevenness ; If the unevenness of fineness is large, the yarn strength will decrease.

2. Influence of spinning process on fiber properties

The influence of the pre-spinning process on the strength of the yarn. The cleaning and carding process should reasonably choose the opening and impurity removal process parameters. Under the premise of sufficient opening and carding, avoid excessive fiber damage, and eliminate short piles and impurities as much as possible; Reasonably configure the drafting process and drafting form to ensure the control of the fibers during the drafting process, improve the straightness and parallelism of the fibers, appropriately increase the temperature and humidity of the roving, increase the moisture regain of the roving, and facilitate the straightening, guaranteed by the disappearance of fiber stress, Reducing the drafting gap stabilizes fiber movement, resulting in rovings with good evenness and structure. At the same time, control the difference in the ration of cooked sliver, reduce the ingot difference of winding elongation, strengthen equipment maintenance and basic management, and reduce the generation of weak rings. Reduce the property difference rate of raw materials, enhance the uniform mixing of raw materials in pre-spinning, improve the carding effect, increase the mixing between single fibers, increase the number of combinations in combing and drawing processes, etc. The raw material components are evenly distributed in the yarn, so that the yarn The strength of each fiber in the thread is fully utilized during the drawing process.

3. Yarn structure

The straightness and parallelism of the fibers and their arrangement and distribution in the yarn, the twist of the yarn, etc., the tension, width, tightness, fiber arrangement and straightness of the strands before twisting have a certain influence on the yarn strength. . Compact spinning is a good method to improve the structure of the beard before twisting, reduce the hairiness of the finished yarn and improve the strength of the yarn.

4. Yarn uniformity

Weight unevenness, unevenness and unevenness of twist, etc. affect the evenness of spun yarn mainly in the process of the front area and the reasonable distribution of the friction field, the distance in the front drafting area, the length of the floating area, and the jaws of the apron. The size of the yarn, etc., the unevenness of the yarn weight per 100 meters is controlled within 2%, the unevenness of the lap is within 1%, and the rate of combed short staple is within 8%, which can improve the unevenness of the yarn. The speed consistency between spindles is the direct factor that affects the uneven twist of the yarn. The spindle belt and splice method, and the spindle belt tension device are the basis for ensuring the stability of the spindle speed. The improvement of yarn strength should start from the reasonable selection of raw materials, reducing mixing differences, improving the quality of pre-spun semi-finished products, improving semi-finished products and yarn structure, improving spun yarn evenness and rationally selecting twist coefficients.