High strength polyester spinning yarn

The value of spinning mainly depends on the tensile strength. If the spinning does not have a certain strength, no matter how smooth the appearance of the sliver is, it will not play its due role.

What are the causes of the influence on the minimum strength of spinning and the solutions?

Solution 1:

on the whole, the minimum strength of yarn can be improved from two aspects:

① the raw material determines the average single strength;

 ② the evenness, Twist Unevenness and hairiness of yarn determine the difference between the minimum strength and the average strength of yarn. Improving any one of the three indexes can improve the minimum strength of yarn.

Solution 2:

under the same raw material, the smaller the spinning yarn number, the more likely the yarn with low strength will appear with the rise of the evenness CV value. To improve drawing evenness and reduce roving defects, the drafting ratio of back area can be reduced properly in spinning, and the hardness of cot can be selected properly, which is beneficial to improve yarn evenness and reduce details, so as to reduce the CV value of spinning strength.

Solution 3:

to improve the strength, first of all, control the short fiber rate of the semi-finished products, the high short fiber rate and the strength will decrease; at the same time, the evenness of the yarn, the size of the yarn, the strength unevenness will increase, and the probability of the emergence of the yarn with low strength is large.

Solution 4:

under the condition that other conditions are unchanged, the key to improve the minimum strength of yarn is to reduce the yarn evenness and eliminate some yarn evenness caused by backward spinning spindles.

Solution 5:

① raw material properties such as length, linear density, breaking length, maturity, short fiber content have an impact on the yarn strength. The fiber length is long, the uniformity is good, and the fiber is thin. The more the number of fibers on the unit section is, the higher the twisting efficiency is, the higher the yarn strength is, and the strength unevenness is small.

② in the carding process, the process parameters of opening and impurity removal shall be reasonably selected. Under the premise of fully opening and carding, excessive damage of fibers shall be avoided, and short fibers and impurities shall be eliminated as much as possible. In addition, the draft process and draft type shall be reasonably configured to ensure the control of fibers in the drafting process, improve the fiber straightness and parallelism, properly increase the temperature and humidity of roving, increase the moisture regain of roving, and be easy to fiber The roving with uniform structure can be made by reducing the draft distance and stabilizing the fiber movement. At the same time, it can control the quantitative difference of cooked sliver, reduce the spindle difference of winding elongation, strengthen the maintenance and basic management of equipment, and reduce the generation of weak ring.

3the yarn structure, such as the straightness and parallelism of the fiber, the arrangement and distribution of the fiber in the yarn, and the twist of the yarn have some influence on the yarn strength. ④ evenness of yarn, such as weight unevenness, evenness of yarn evenness and twist unevenness, affects evenness of yarn evenness, resulting in low strength of yarn. In order to improve the yarn strength, it is necessary to select the raw materials reasonably, reduce the mixing differences, improve the quality of the semi-finished products, improve the semi-finished products and the yarn structure, increase the yarn evenness and select the twist coefficient reasonably.

Solution 6:

factors affecting single yarn strength:

① the single yarn is unevenly dried, that is, there are many thick and thin sections, resulting in uneven arrangement of fibers in the yarn and unequal number of fibers per unit section of the yarn. Roller, rubber roll bending, rubber roll surface damage; up and down rubber ring pin assembly is not in place, rubber ring deviation, damage, rotation is not flexible; floating area is too large, too small and so on will cause single yarn unevenness.

② due to the inflexible rotation of the twisting parts and insufficient oil, the spindle speed changes instantaneously, resulting in uneven twist of cotton yarn, especially the existence of weak twist, which reduces the strength. For example, the length of the spindle belt is different, shaking, the spindle pulley is short of oil, the bearing is worn and shaken, the spindle oil is insufficient, the service cycle is too long, the spindle rod is shaken, shaken, the bobbin is bouncing, the head draft drive gear and bearing are worn, and the gear meshing is not good, which will reduce the yarn strength.

3 too much and too long hairiness of single yarn will cause fiber loss, poor cohesion of fiber, relative reduction of fiber number per unit section of yarn, and decrease of strength. The main influencing factors of this problem are the long service life of the ring, the improper configuration of the ring, the hanging and abrasion of the ring, the large spacing of the ring cleaner, the crooked spindle, the crooked guide hook and the screen plate, the different height positions of the leaf plate, and the grooving of the guide hook.

Solution :

improve the mechanical state of the equipment from the drafting area and the twisting area, strictly carry out the process of getting on the car, make the configuration of the steel ring and the steel wire ring, make sure the process is accurate, the state is good, the channel is smooth and clean, optimize the configuration, stabilize the single yarn strength, and reduce the strength CV value. Stabilize the state of the draft area and control the variable speed movement of the fiber; the operator on duty should be familiar with the performance of the equipment and find out the problems in time, do a good job of feedback and increase the strength of the equipment maintenance tour, so as to continuously improve the low strength value of single yarn and reduce the probability of short details.