Superior polyester spun yarn for knit

Spun yarn is a fine yarn made from roving, used for weaving or spinning.

Hairiness is mainly formed in spinning process and increased in winding process. The yarn hairiness is complex, such as end hairiness, loop hairiness, floating hairiness, and the ring spinning hairiness is mostly end hairiness. The key to solve the problem of yarn hairiness is to control the main factors that affect hairiness in spinning process and reduce the formation of hairiness. Generally, spinning technology, mechanical state, artificial operation, workshop temperature and humidity have a great influence on hairiness.

Hairiness control in spinning process

I. spinning process

1. Spinning twist coefficient

With the increase of twist coefficient, the hairiness of the spun yarn is obviously reduced. Because the twist coefficient increases, the twisting moment of the fiber increases, and the twist transmission is closer to the front jaw, which increases the binding force on the fiber in the twisting triangle area, reduces the number and length of the fiber extending out of the yarn body, and thus reduces the hairiness. But when the twist coefficient is very large, the number of hairiness increases sharply with the increase of twist coefficient.

2. Total draft ratio

The number of hairiness increased with the increase of the total drafting ratio. In the reasonable range of spinning drafting times, the hairiness rise is not large; the total drafting times increase. When the drafting times in the back area are not changed, the drafting times in the front area increase, the number of sliver fibers entering the front area increases, and the number of floating fibers increases. At the same time, the linear speed ratio of the front and middle rollers increases, and the acceleration of slow fiber turning into fast fiber increases, and the fiber movement is not stable. Because the free fiber at the head end of the twist triangle is not controlled by the twisting moment, it can not be drawn into the yarn body to form hairiness, and the number of hairiness increases.

3. Front rubber roll position

When the front cot moves forward, the yarn hairiness decreases. Because the front rubber roller moves forward, the surrounding arc on the front roller of the whisker bundle is reduced, the twisting moment is closer to the front roller jaw, and the control ability of the fiber in the twisting triangle area is strengthened. However, the effect of hairiness reduction is not obvious when the amount of forward movement is too large. Generally, it is better to control the amount of forward movement at 2-3mm. In addition, if the diameter of the front upper cot is increased to 30mm, the control ability of loose fiber can be increased.

4. Front and back draft Technology

The draft technology in front and back areas should follow the principles of small floating area length in front area, small jaw spacing, small roller center distance, large roller center distance in back area, large roving twist coefficient and small draft multiple.

5. Spindle speed

Because of the high spindle speed, the centrifugal force on the sliver is large and the hairiness is increased, the varieties with high hairiness requirements should be properly controlled at a low spindle speed.

II. Equipment status

1. In twisting and winding, if the parts are not smooth, or repeatedly stretched and relaxed in post-processing, or friction with the yarn guide hook, hairiness is easy to form.

2. The rubber roller has high hardness and good surface finish, which can effectively reduce hairiness.

3. If the weight of steel wire ring is properly increased, the hairiness can be reduced.

4. It is necessary to polish, regrind and discard the ring in time, and reasonably determine the diameter of the ring.

5. The variable frequency speed regulation technology of spinning frame can reduce the spindle speed of small yarn and large yarn, and increase the spindle speed of medium yarn, which can reduce the hairiness difference between different yarn segments.

6. Selecting proper caliber cotton collector, internal and external pattern rubber ring, pressure bar, nylon upper pin, and some new lower pins (such as the top shape modification) are helpful to reduce flying flowers and hairiness.

III. manual operation

1. The barring workers strictly implement the operation method of each channel of yarn, strengthen the cleaning, and effectively reduce the increase of hairiness.

2. When cleaning the machine, the barring worker does not slap or brush the spinning section, which can prevent flying flowers from attaching and reduce the formation of hairiness.

3. Attention shall be paid to equipment maintenance, problems found shall be repaired in time, and equipment shall be kept in good condition.

4, reasonable use of antistatic agent, spinning roving antistatic agent, spinning after static 24h, can reduce the rejection between fibers, thereby reducing hairiness.

IV. workshop temperature and humidity

In spinning workshop, the humidity is too high to master, which can improve the moisture regain of semi-finished products and reduce hairiness.