What are the factors that affect yarn hairiness?

Yarn hairiness refers to the fiber ends or loops that protrude from the main body of the yarn.

Hairiness contributes to the fuzziness of the yarn appearance and reduces the glossiness of the yarn appearance. Excessive yarn hairiness will affect the normal sizing, and in the weaving process, the opening will be unclear and the ends will increase. The amount and distribution of yarn hairiness has a significant impact on the quality of the cloth and the dyeing and printing quality of the fabric, and it will also cause the problem of pilling during the wearing process of the fabric. In particular, the hairiness above 3 mm will seriously affect the downstream production, affecting the appearance, feel and performance of the yarn and its final product. Therefore, the yarn hairiness index has become an important quality assessment index at present

The effect of raw materials on hairiness

The fiber length, fineness, maturity, short staple rate, and impurities carried by the fibers of the raw cotton will have a direct impact on the generation of hairiness during the formation of the yarn.

The higher the torsional stiffness and bending stiffness of the fiber, the more hairiness of the yarn;

The higher the torsional stiffness and bending stiffness of the fiber, the more hairiness of the yarn;

The finer the fiber, the more fibers in the yarn section, the greater the possibility of the fiber tip being exposed, and the greater the probability of causing yarn hairiness;

The impurities carried by the fiber itself are prone to produce defects during the spinning process, which affect the normal operation of the whiskers and the straightening and parallelism, which increases the chance of the fibers being exposed to the yarn body and produces hairiness;

If the fiber maturity is good, the length is long, and the uniformity is good, the less the number of fibers per unit length, the less the yarn hairiness will be.

In the daily production process, we should strictly control the quality of cotton blending and the utilization rate of back flower to improve the consistency and stability of raw materials.

Influence of each process of pre-spinning on yarn hairiness

The blowroom-carding unit keeps all parts in good condition, and the parameters are set reasonably. Reduce the scratching and damage to the fiber, so as to avoid more fibers that are broken during the high-stretching process of the spun yarn, which will make the wear resistance of the yarn worse and the hairiness increases. Enhances carding efficiency while minimizing the chance of short piles, straightening fibers and reducing the chance of hairiness.

Generally speaking, carded yarn has 30%~40% more hairiness than combed yarn. Combing removes a large number of short fibers in the sliver, improves the straightness and parallelism of the fibers, and reduces the yarn hairiness. In the combing preparation process, attention should be paid to reducing the sticking and rolling phenomenon, appropriately increasing the noil in combing, keeping the top comb, cylinder and brush in good working condition, and the entire cotton conveying channel should be smooth and free of burrs.

In the drawing process, attention should be paid to the drafting distribution, to improve the straightness of the fibers, and to reduce the probability of hairiness.

The roving process should increase the twist coefficient of the roving to a certain extent to reduce the yarn hairiness. At the same time, all the places where the sliver passes through should be kept clean, and there should be no hanging flowers. The mutual friction between the plastic sliver can and the sliver used in the pre-spinning process is easy to generate static electricity, and the fibers repel and attract each other. Some short piles cannot be normally covered to form hairiness. The plastic sliver can be clean and free of burrs.

Influence of Post Spinning Process on Yarn Hairiness

Spinning is the key process of spinning, and the quality of its spinning equipment has a great influence on the hairiness of the finished yarn. Such as: inaccurate diameter of the ring, poor roundness and flatness, or ripples, burrs, unevenness and unsmoothness, unevenness or deformation of the ring plate, and the up and down movement is not vertical; the traveler and the ring are poorly matched, embedded Flowers; yarn guide hook grooves, friction on the yarn sliver; inaccurate spindle to the center of the spindle tip, etc., will lead to increased yarn hairiness. Spindle speed, process conditions and equipment status in the twisting zone, draft distribution, and twist coefficient will all affect yarn hairiness.

The weight of the traveler directly affects the hairiness. The traveler is too heavy, the spinning tension is large, and the balloon is small, which increases the friction of the traveler on the yarn sliver, and causes the yarn to rub against the top of the bobbin to generate hairiness. At the same time, the yarn is also easily scratched to form neps. If the traveler is too light, the spinning tension is small, and the balloon is too large, so that the yarn collides with the yarn separator and produces hairiness.

The winding process is the process with the most hairiness increase, and the reason is mainly caused by the friction of the winding machine components to the yarn. The hairiness of the winding speed increases with the increase of the winding speed, and the winding speed should be selected reasonably. In the winding process, all components in the winding channel should be kept intact and clean, so as to avoid friction and static electricity generated during the movement of the cotton yarn, which will lead to an increase in the hairiness of the cotton yarn.

Influence of temperature, humidity and other factors

Theoretically, humidity is one of the main factors affecting hairiness, but in actual production, due to the instability of various conditions, it is difficult to quantify its impact on hairiness, which can only be seen from long-term monitoring. Its effect on hairiness trends.

If the humidity is high, the fiber volume will expand, the air permeability will be poor, and the strength of the single fiber will increase. Under the same conditions, the resistance strength of the yarn will increase, the friction resistance will increase, and the hairiness will decrease. Therefore, in the spinning and doffing process, the processing environment is appropriately increased. Humidity, which is conducive to the reduction of hairiness.

The friction of the yarn itself will also produce hairiness. The cop or packaged yarn falling from the spinning frame will also rub against each other during unwinding, transportation and storage. Therefore, in the production process, care should be taken to handle it with care to minimize the chance of hairiness.