1 Blowing process
The focus of the blowing process is to reduce fiber damage. When the impurity content of raw cotton is not high, reducing the speed of each beater and enlarging the distance between holding and striking points will improve both hairiness and neps.
Keep the air flow smooth and avoid choking and traffic jams. Choking is the main factor causing neps in the cords, and these cords will produce a large amount of short velvet during carding, which will greatly increase the hairiness; at the same time, smooth airflow can remove part of the short velvet dust from the dust cage, which is beneficial to the downstream process. process processing.
Maintain a certain humidity so that the cotton rolls are in a dehumidified state until carded, which is beneficial to carding and carding and reduces short lint and neps. In fact, the moisture regain rate of cotton rolls is an indicator that air conditioners should focus on controlling.
2 Carding process
The process idea is: reduce damage, eliminate short lint, Improve the straightness and parallelism of fibers.
Measures taken: Use a lower lick-in roller speed, a larger speed ratio between the cylinder and the lick-in roller, an appropriate distance between the lick-in roller and the cotton feeding plate, and adjust the cover When the plate rotates forward, a slightly larger distance between the cylinder and the front upper cover plate is used. When the cover plate is reversed, a slightly larger distance between the cylinder and the rear upper cover plate is used to appropriately increase the running speed of the cover plate.
The focus of the equipment is to ensure the mechanical condition and card clothing condition. After the licker-in speed is reduced, the check of the licker-in condition should be strengthened. In order to compensate for the carding degree after the licker-in speed is reduced, If it is not enough, you can use a lickerin rack with thin tooth tips and large tooth density. The inverted teeth on the lickerin must be repaired in time, and the dust suction port on the machine must maintain sufficient negative pressure. Cleaning should be strengthened during operation to prevent short lint from adhering.
3 Combing process
The combing process is to reduce yarn An important process of hairiness. It is mainly reflected in: greatly eliminating short fibers, maximizing the straightness and parallelism of the fibers, and providing the most effective help in reducing hairiness; therefore, combed yarn has less hairiness, good evenness, and smooth yarn.
To reduce the short lint content of cotton slivers, under a certain noil rate, increasing the short lint content of noil is an effective measure to save costs and improve quality. In addition to the condition of combing equipment, the preparation process of combing is particularly important.
In the combing process, the cotton slivers are fully combed and the fibers are straight and parallel, so the cohesion force is very poor. A little carelessness in operation and transportation will cause the tops to break and cause quality problems. question. In order to prevent these problems, some factories have taken many measures, such as: using a nylon silk hat to cover the cotton sliver after the bobbin is dropped, using talcum powder when blocking the joints of the lathes, strictly fixing the length to prevent the bobbin from falling high, etc. The purpose is to The effect is very good in preventing the strips from breaking.
4 Drawing process
The focus of the drawing process is optimization Drafting process to improve fiber straightness. The number of pre-merging mergers and the total draft multiple should be small but not large. The draft multiple of the rear area should be large but not small. The spacing of the rear area should be large and not small. The number of mergers and total draft multiples of the second merger should be large. Large, not small, the drafting multiple of the rear area should be small, not large, the drafting multiple of the front area should be large, not small, the front and rear areas should implement the process ideas of heavy pressure, tight spacing, and strong control; for pure cotton Combing adopts single and parallel belt self-levelling, which is of great benefit in preventing over-mature fibers, poor cohesion, easy tatters of slivers, and increased hairiness.
It is worth noting that the smoothness of the drawing channel is an effective measure to reduce yarn defects and reduce hairiness. It is very simple to do, but the key is to persist in doing it well for a long time. Some factories pursue the can capacity one-sidedly and set the length to be very long, which causes a lot of friction and fluffing of the upper sliver, seriously affecting the quality. These problems must be eliminated. In addition, the quality of the can is poor and the static electricity is serious. A layer of lint will appear around the can, which seriously affects the smoothness of the sliver. At the same time, when the sliver is unwinding after the machine, if the height of the sliver and the position of the can are inappropriate, the sliver will be seriously bumped and fuzzed, resulting in an increase in hairiness in the post-processing process. These humble tasks have a big impact on hairiness and require serious attention.
5 Roving process
The focus of the roving process on reducing hairiness should be In terms of increasing the tightness of the whiskers, improving the straightness and parallelism of the fibers, and improving the smoothness of the roving, the following points should be achieved:
①The total draft ratio of the roving is too small It is better to control the distance of the back area as large as possible and the draft ratio of the back area as small as possible (the best control is 1.08 times to 1.15 times of elastic draft);
② The twist coefficient of the roving should be larger under the premise of meeting the normal draft of the spun yarn, which is beneficial to reducing hairiness;
③ The roving adopts a four-roller drafting type with a finishing area, which is beneficial to Reduce hairiness;
④ Use front and rear area cotton collectors with appropriate openings and select appropriate false twisters to help reduce hairiness;
⑤ Properly increase the moisture regain of roving (control it between 6.5% and 7.5%), which will help reduce hairiness;
⑥ Properly store and transport rovings to prevent hairiness on the surface of the rovings , which helps reduce hairiness.
6 Spinning process
The spinning process is the production of twisting hairiness This point is also the serious increase point of hairiness in the process; therefore, the various conditions of the spinning process have a great impact on hairiness, and it is a key process to control hairiness. The following aspects should be done well.
1) Optimize the reasonable spinning process
① The lighter the roving, the greater the spinning draft, the more hairiness;
② Increase the rovingTwist coefficient;
③ Increase the roller gauge in the back area of the spun yarn;
④ Reduce the draft multiple in the back area of the spun yarn, and then Small draft area is beneficial to hairiness, evenness and weight CV value;
⑤Choose the appropriate spinning speed. The higher the spindle speed, the more hairiness will grow;
⑥ Appropriately increase the forward impulse of the front rubber roller to the front roller, which is beneficial to the transfer of twist and reduces the length and width of the twisting triangle area, thereby achieving the effect of reducing hairiness.
2) Reasonable selection of drafting components
①Select automatic tension Adjust the nylon upper pin;
②Select a new stepped lower pin (such as MD-1 type);
③Select a low hardness and high Elastic high-quality rubber roller;
④ Use inner and outer pattern rubber rings.
3) Selection of travellers
①Good adaptability, The maturation period is short and there are few broken ends;
② It is easy to carry the end, especially when the yarn is small, it should not be too heavy and the joints are easy;
③The channel is wide, preventing the yarn channel from crossing the traveler track and causing friction and cutting the head;
④The anti-wedge performance is good during high-speed operation, and the yarn channel is wide and The balloon is stable and does not cause problems of being too tight, too loose or shaking;
⑤It has a long service life;
⑥The wire ring should not be too wide to avoid hanging flowers and greatly increasing its weight;
⑦The weight of the wire ring should be based on the temperature and humidity conditions, the aging degree of the steel ring, and the spindle speed. To determine, try to ensure that the balloon does not touch the yarn bobbin end and the yarn separation plate. When there are few ends breakage, focus should be placed on control.
4) Selection of steel rings
①The material has fine grains ;
②The surface hardness is moderate and uniform;
③The inner and outer runways are smooth, and the friction factor is small and uniform;
④The smaller the inner diameter roundness deviation, the better;
⑤The consistency between one batch and one batch, and between batches is good;
⑥The flatness of the top surface of the steel ring and the parallelism between the top surface and the bottom surface should be good.
5) Selection of yarn guide hook
Aperture of yarn guide hook The smaller it is, the better it will improve hairiness; the yarn guide hook should be smooth and wear-resistant.
6) Strengthen equipment management
① Strict process on the vehicle , straighten the three rows of rollers, and strictly control the distance between the jaws and the roller components;
② Ensure the level of the ring plate and the spindle;
③ Make the yarn guide hook, steel ring and spindle three coaxial;
④ When spinning at the lowest position, the yarn guide hook is far away from the top of the yarn tube 25 mm to 30 mm is appropriate;
⑤Correct the distance between the cleaner and the ring;
⑥The ring plate There is no frustration in the up and down movement;
⑦The spinning channel is smooth and burr-free;
⑧Do a good job of cleaning and refueling the spindle to reduce the number of spindles Vibrate, replace the numb hand spindle.
7) Strengthen operation management
Every part should be cleaned Work, patrol in time, handle broken ends, and strictly prevent sticking, entanglement, hanging, and blockage.
8) Strengthen air conditioning management
Strengthen air conditioning management and strictly control Workshop temperature and humidity. On the premise that the rubber roller is not wrapped, increasing the relative humidity is beneficial to eliminating static electricity, and improving the winding conditions is beneficial to reducing hairiness. Generally, the humidity is 60% to 65%, the temperature is 22°C to 32°C, and the moisture regain is (7±0.5)%. It is appropriate.
7 Winding process
Due to the winding speed of the winding process High, the winding speed of each point of the tapered bobbin is different, and the yarn will produce greater slip during the winding process; therefore, the hairiness of the bobbin after the warp bobbin will be seriously deteriorated, which is a serious occurrence of hairiness in the yarn process. point is also another important focus for us to solve the hairiness problem.
1) Winding speed
Since the deterioration of yarn hairiness increases with the increase of winding speed; therefore, in order to control The hairiness deteriorates and the winding speed should not be too high.
2) The surrounding arc of the yarn on the grooved cylinder
The shorter the arc length of the yarn’s surrounding arc on the grooved drum, the less deterioration of hairiness after the meridian drum. On the GA014 winding machine, the bobbin holding arm was increased by 1 cm (to reduce the length of the arc surrounding the yarn on the grooved drum). The deterioration of hairiness was reduced by 60%, and the kilometer neps were also reduced by more than half, achieving good results. Effect.
3) Winding tension
The winding tension is large and the yarn The friction between the thread and the machine parts increases, and the hairiness increases.
4) Mechanical condition
Trough cylinder quality, paper tube quality , The bobbin’s beating, the sensitivity of the probe rod, the damping of the grip arm’s descent, the smoothness of the channel, the position of the yarn in the electro-cleaning detection tank, etc., are all closely related to the increase in hairiness.
5) Temperature and humidity
Appropriately increase the temperature in the winding workshop Humidity is conducive to reducing hairiness. The relative humidity is generally controlled at 70% to 75%, and the temperature is controlled at 22°C to 30°C.
6) Bobbin quality
The more bobbin hairiness, The greater the growth after the meridian tube.
In summary, solving the hairiness problem is a systematic project that requires careful attention from five aspects: man, machine, method, material and environment. Effective work; the spinning process is not only the production point of twisting hairiness, but also the serious increase point of process hairiness. Therefore, various conditions in the spinning process have a great impact on hairiness and are a key process to control hairiness. </p
