The hairiness of the ring spun yarns not only affects the appearance of the fabric, but also affects the other properties of the fabric, and at the same time reduces the subsequent processes, especially the production efficiency of the loom. Yarn with many feathers, fabric lines are not clear, easy to pilling, pilling, after the end of the process more broken, low production efficiency, a large amount of falling affect the rate of production. In addition, it will also cause the fabric to form uneven stripes and hangs, jumps, wefts and other defects. At present, with the diversification of the functions of the new type of chemical fiber, the production of chemical fiber blended yarns will become the mainstream trend. In particular, the proportion of viscose as raw materials and chemical fiber blended yarns will increase. Therefore, the method of controlling the hairiness of polyester-viscose blended yarns is discussed. necessary. Polyester-viscose yarns have fewer chemical fiber crimps, and viscose fibers have a smooth feel, poor cohesion between fibers, and static electricity during the production process. Therefore, the hairiness will be heavier in production. Therefore, the reasons for the production of viscose yarns from ring-spun yarns were investigated, various factors affecting the ring spinning hairiness were analyzed, and measures were taken to reduce hairiness to meet the user requirements. From the cross section of the yarn: hairiness is present around the yarn. Seen in the axial direction of the yarn, the hair yarns of the elongated yarn body are each different in length and shape. Generally divided into three basic forms: Hairiness feathers: The ends of the fibers protrude from the surface of the yarn core, while the rest is wrapped in yarn. For end hairs, the direction of the yarn is divided into head hairiness, tail hairiness and two-way hairiness. Normally, hairy feathers account for the majority of hairiness in ring spun yarns. Circle hairiness: Both ends of the fiber are wrapped by yarns, and the middle arches out to form a circle or ring. Floating hairiness: Loose fibers attached to the yarn surface. According to the formation mechanism of hairiness, the hairiness of the ring spun yarn is divided into a plus hairiness and a process hairiness. Twisting hairy feathers are mainly defects formed during the twisting process. When the fiber is twisted, the front roller will have a flat sliver and the fibers will be aligned parallel to the yarn axis. The turnaround of the traveller is transmitted through the turnaround jaw jaws. The jaws at the jaws rotate around the axis. The width of the drawstring gradually shrinks, and both sides gradually fold into the center of the sliver to form a twisted triangle zone. In the twisted triangle, the width and cross section of the sliver change, gradually forming an approximately cylindrical spun yarn from the flat ribbon shape. When the strands are twisted, in addition to changes in the geometry, there is also a shift in the inner and outer layers of the fibers. Under the effect of spinning tension, the centripetal pressure of the fibers outside the central fiber and the mechanical condition of the fibers in the twisted triangle due to the spinning tension cause the edge fibers to squeeze toward the center and squeeze the center fibers toward the edges. When the edge fiber is squeezed into the center, the centripetal pressure it receives tends to zero, and it is also extruded by some edge fibers. One fiber often goes from the inside to the outside, and from the outside to the inside, the fibers of the inner and outer layers transfer to each other repeatedly. When the tip of the fiber is squeezed out of the cohesion with other fibers, it is no longer pressed against the inside due to the absence of tension and centripetal pressure, but remains on the surface of the yarn body to form hairiness. From the above analysis, it can be seen that the twisting triangle plays a decisive role in the formation of hairiness on the yarn surface. The width of the control roller prior to the control of the spun yarn is a key factor in controlling the twisting of the yarn. The width of the yarn is small, the fiber is subjected to a small range of centripetal pressure fluctuations, and the fiber is repeatedly transferred to each other with a small degree of fibrillation, which helps to reduce hairiness. Has been verified by the compact spinning process. At the same time, the state of the fiber structure, the content of fluff, the mutual cohesion of the fibers, and the control of the spinning tension are also crucial to the hairiness of the yarn. The process hairiness is mainly the hairiness formed by the yarn rubbing with the yarn channel during the spinning process. The sliver and roving in the production of polyester-viscose yarns have poor cohesion. Due to the non-smooth passage of the channel, the running resistance increases or is affected by the external force. The friction is easy to wipe the hair, increasing the chance of becoming a hairiness; the yarn is not passed through the yarn channel. Smooth, the original short hairs of the yarn may be scratched and stretched, or the fibers whose both ends have been embedded in the yarn body may be scratched and broken at the middle end, or may be scraped off at the fiber end of the yarn body. Hairy feathers deteriorate further or new hairlines form. The conductive properties of chemical fiber are poor. Static electricity is generated when the flowing sliver and the rotating roller or the component contact with each other, and the fiber is subjected to the force due to the electrostatic effect and there is no regularity. The fiber ends outside the sliver are diffused outward to become hairiness. From the above analysis, it is easy to see that the main factor influencing the process hairiness is scratching, which is closely related to the passage of the yarn, the tension of the yarn passing through the passage, and the size of the static electricity. Among them, it is closely related to the state of the ring traveler of the spun yarn, the state of the drum, the arc length of the yarn on the drum, and the speed of the winder, as well as the low oil content of the fiber, the low ambient humidity, and the fact that the static electricity is not easily eliminated. Hairiness parameters are generally expressed by the hairiness index, and the number of hairiness is relatively intuitive, while the control of hairiness is mainly to control harmful hairiness, ie hairiness of 3 mm or more. (1) The greater the torsional and flexural stiffness of the fiber, the more difficult it is to twist and bend the fiber. On the one hand, it is difficult to completely twist it into the yarn body; on the other hand, the fiber ends that have been broken into the body of the yarn The yarn body may pop up, causing hairiness to increase. (2) The length of the fiber is long because the number of fibers per unit length of the yarn is reduced and hairiness is reduced. On the other hand, the fiber is easily twisted and twisted to make the structure tight. On the contrary, hairiness will increase. (3) The effect of the fineness of the fiber on the hairiness is that there are many fiber coarse feathers and less fiber fine hair feathers. (4) Strictly control the proportion of returning flowers, because chemical fiber will cause fiber damage after repeated blows, and the loss of surface oil after use will cause increase of hairiness. The use of recycled flowers cannot exceed 5%. (5) The viscose fiber has strong moisture absorption and release properties, and it is necessary to loosen the cotton bale in advance and balance the moisture in the fiber, which is beneficial to the control of hairiness. Therefore, when the raw materials are selected, the fineness, length, and uniformity of the fibers should be controlled according to the requirements of the yarn on the hairiness, so as to create favorable conditions for reducing the hairiness. Chemical fiber should pay attention to the content of oil, content is small, easy to produce static electricity, causing hair gauze; high content, easy to stain the channel to make the channel astringent hair pulling requirements, will increase the hairiness, but also cause poor carding drawing, Reduce the quality of semi-finished products. The focus is on reducing fiber damage. The chemical fiber contains almost no impurities, which reduces the speed of each beater and enlarges the distance to hold the strike point, which has an improved effect on hairiness or nep. The air flow is smooth, no cars, no traffic jams. Air flow is not easy to cause obstruction and obstruction is the main factor that causes wire nep, and these wire will produce a large number of short fibers in the carding, which will greatly increase the hairiness. Smooth airflow can eliminate some short fibers and dust, which is beneficial to the subsequent processing. Due to the chemical oil containing oil agent, the cotton-transporting pipeline is prone to produce grime and increase the resistance. It is necessary to remove the scale dirt regularly and keep it open. In particular, the clean steel linkage system should pay attention to it. Maintaining a certain humidity allows the fiber to be in a state of dehumidification to the carding, which facilitates carding of the carding and reduces short fibers and neps. The moisture regain of viscose fiber bars is controlled at about 10%, which is beneficial to the post-processing and hairiness control. Process ideas: reduce damage, eliminate short fibers, and increase fiber parallelism. Measures taken: Lower licker-in speed (below 800 r/min), larger cylinder and licker-in speed ratios, suitably large licker-in-feed gauges, according to hard fibres in chemical fiber raw materials, The filaments and filaments in the filaments or cover flowers are used to determine the running speed of the cover plate, and the speed is as fast as possible, and as slow as possible. The focus on the equipment is to ensure the normal state of the machine and the good condition of the clothing. After the speed of the stabbing roller is reduced, the inspection of the state of the stab roller should be strengthened. To compensate for the insufficient degree of the combing after the speed of the stabbing roller, thin teeth and dense teeth can be used. The lancing saw blade, the chaotic tooth on the licker-in must be repaired in time, and the dust suction mouth on the machine keeps enough negative pressure. The operation should be strengthened to prevent the short fluff from entering. Timely removal of combing skeins and looper fouling requires the carder to clean the cluster horn and coiler with alcohol before digging each shift. Clean the machine table at any time, especially in the triangle area of ​​Xilin and Daofu. Keep the dust-absorption mouth unblocked and dust-free, and the large-and-small-leakage-bottom cleanliness should be thoroughly stopped. The focus of the drawing process is to optimize the drafting process and increase the parallelism of the fibers. Process ideas: the number of head pre-combinations and the total draft should be small, not too large, the rear area draft multiple should not be small, the posterior area should not be too large, and the number of the two combined and the total draft is basically the same The rear zone draft multiple is smaller than the first one, and the rear zone should not be too large. The number of the three combined and the total draft is basically the same, the draft multiple of the rear zone should not be large, and the front zone draft multiple. Should not be too small, should be implemented before and after the heavy pressure, tightly spaced, strong control. It is worth noting that the smooth and clean channel is an effective measure to reduce yarn defects and reduce hairiness. Clean the channel regularly. Barrels of appropriate capacity, a long fixed length, resulting in a large number of upper sliver friction hair, seriously affecting the quality. In addition, the quality of the barrel is badly electrostatically and seriously affects the smoothness of the sliver. At the same time, when the machine sliver is unwinding, the sliver is high or low. If the position of the barrel is not appropriate, it will seriously bump the hair and pull the sliver, which will increase the hairiness of the process. These humble jobs have a great impact on hairiness and require careful attention and resolution. If the viscose-viscose blended yarns are mixed in parallel, under the premise of guaranteeing the blending ratio, according to the number of blended yarns, “Dianyiyiyiyijiaoyidi†shall be arranged alternately, so that the blending is both uniform and beneficial to the control of hairiness and yarn defects; The feeding of the slivers should be parallel, and the center should be aligned with the centerline of the clustered horns to help control the hairiness. Roving process to reduce hairiness should focus on increasing the tightness of the sliver, increasing the parallelism of the fiber, and improving the roving finish. The total draft of the roving is relatively small and it is appropriate to grasp, and the back zone has a larger gauge, and the back area has a smaller draft. Roving twist coefficient is large enough to reduce hairiness on the premise of satisfying the normal draft of the spun yarn. The roving uses a 4-roller finish with a finishing zone to help reduce hairiness. Appropriate collector openings should be used. The smoothness of the collector or the size and geometric shape of the opening have a great influence on the yarn hairiness. The opening of the collector should not be small, but it must be able to collect the whiskers so that the rovings are tight and smooth. It is not because of the friction between the slivers and the collectors; the use of a suitable false twister will help reduce hairiness. Paying attention to the smoothness of the draft zone components and flyers helps reduce hairiness. The upper and lower rubber rings and rubber rollers are cleaned and replaced periodically. The jaws formed by the upper pin and the rubber ring are in close contact with the lower pin and are flush with the upper Shaw. They are both conducive to effective control of fiber movement, and regularly clean the flyer to keep the flyer clean. Smooth and smooth rovings help reduce hairiness. The proper storage and transportation of rovings to prevent the roving surface hair, is conducive to reducing hairiness. The spinning process is both the point of creation of the plush hairiness and the serious increase of the process hairiness. Therefore, each state of the spinning process has a great influence on the hairiness and is a key process for controlling the hairiness. (1) Optimized spinning process: Roving light weight. The larger the draw ratio of the spun yarn, the more hairiness. When the draft of the yarn is smooth, the roving degree is appropriately increased. Increase the roller area in the back area of ​​the spun yarn. Reduce the draft multiple in the back area of ​​the spun yarn. The small draw in the rear zone helps to reduce hairiness and improve stem CV% and weight CV%. Choose the right spinning speed. The higher the spindle speed, the more hairiness grows. Appropriately increasing the frontal roller's frontal roller's forward momentum is beneficial to the transmission of the circuitous, reducing the length and width of the twisting triangle so as to reduce the hairiness. (2) Reasonable selection of spinning equipment: On the use of automatic tension adjustment nylon pin. The rubber roller uses low hardness and high elastic quality rubber roller. The roller chooses Shore A hardness of 65 degrees, which is conducive to the control of the fiber, which is conducive to the control of hairiness, CV% of the stem, detail, thick section and other indicators. Use internal and external pattern aprons. Travellers: Choose a good adaptability, short walking time, less broken ends; wide channel, to prevent the yarn channel and the track runway cross to cause friction cut off head; steamed bread refreshing, especially in the small yarn should not be too heavy and The joint is easy; as far as possible, the balloon does not touch the pipe head, does not touch the yarn-stencil, and it is under the control of less breakage. Special attention should be paid to the cycle management of the steel wire. When the wire ring wears badly, it is easy to produce cross-overs, and the yarn will be scraped at the notch where it is worn to produce more hairiness. Ring: The surface hardness is moderate and even, and can be adapted to the traveler; the inside and outside runways are smooth, the coefficient of friction is small and uniform; the deviation of the inner diameter roundness is as small as possible; only and only, the consistency between batch and batch is good; steel Make the top surface parallelism and the top surface parallel to the bottom surface better. The length of use of the ring also affects the hairiness, so the ring can not be used for extended periods. The smaller the diameter of the yarn guide hook, the better the hairiness improvement; the yarn guide hook should be smooth and wear-resistant. The use of a front area collector for the spun yarn is a very effective measure to reduce yarn hairiness. (3) Strengthen equipment management to ensure that components are clean and smooth: During the spinning process, the yarn guide hooks wear and groove, and the smoothness is reduced. It is easy to shave the slivers and increase the hairiness of the yarns. The yarn guides that wear the grooves should be replaced in time. The yarn guide hooks, rings and spindles are not the same, causing the balloon to be inconsistent, causing the sliver to rub and impact with the stencil, rubbing against the top of the tube, and multiplying the yarn hairiness. If the distance between the bead cleaner and the ring collar is too large, the cleaning effect will be lost, and the bead looper will increase, and the hanging flower will grind the sliver. Keep the stencils clean and smooth, without fouling, and prevent the balloon from colliding and increase hairiness. Do a good job of removing dirt and light from the bell mouth. Therefore, in actual production, it is necessary to keep the sliver passage clean and bright, and pay attention to equipment maintenance. The problems should be promptly repaired and the equipment maintained in good condition. (4) Strengthen operation management: Do a good job in cleaning the various parts, timely tour, handle broken ends, and prevent sticking, winding, hanging, and blocking. Eliminate floating feathers formed by the externally accumulating flowers, short velvet and flying flowers during the twisting process of the spun yarn. During the twisting process, flying in and flying short fibers are the main cause of floating feathers. In the specific production process, the cleaning of the bobbins of the roving, the drafting position and the winding position, and the timely removal of the accumulated hairs of the hair rollers can effectively reduce the hairiness. After each doffing, it is necessary to remove the yarn from the spindle and clean the flowers. (5) Strengthen air-conditioning management and strictly control workshop temperature and humidity: Temperature and humidity affect the rigidity and electrical conductivity of the fiber, and thus have a certain influence on the yarn hairiness. Relatively large humidity, the fiber will be more flexible, easy to be infiltrated into the yarn body, static electricity easily eliminated, in the premise of the roller is not winding, increase the relative humidity is conducive to the elimination of static electricity and improve the winding conditions to reduce hairiness. The humidity is about 60%, the temperature is about 32°C, and the moisture regain is controlled according to the fixed moisture regain of the blended yarn, which is beneficial to controlling the hairiness. The airflow in the workshop is disturbed, and the flow of air driven by spinning of high-speed spindles of spinning spindles, increased fly and short loops, and irregular movements can cause increased floating feathers. The difference in temperature and humidity in the area is not conducive to the control of hairiness. Do not disturb the airflow when adjusting the air conditioner, and reduce the difference in temperature and humidity in the area. Low speed and low tension are the keys. The automatic winding process is the one with the most increase of hairiness. Generally, it is increased by about 3 times. In particular, the hairiness of 3 mm or more is increased, which is a geometric increase. This is mainly caused by the friction of yarns caused by various mechanical parts. . Because the winding speed is high and the winding speed of each point of the cone is different, the yarn will generate a large slip during winding. Therefore, the hairiness of the bobbin after passing through the bobbin will cause serious deterioration. Therefore, the winding process is a serious occurrence point of the hairiness of the yarn process, and it is also another important concern for us to solve the hairiness problem. The comparison of the yarn hairiness of package yarn and package yarn is shown in Table 1. (1) Do a good job of optimizing the process to control the growth of hairiness: The winding speed and winding tension are preferred, and the winder tension and winding speed of the automatic winder have a great influence on the hairiness. Winding speed and winding tension should be considered as a whole when adjusting the process. If only one process parameter is considered, it will be counterproductive. When the specific optimization is combined with each other, the effect of high speed running hairiness will not be increased. The effect of wind speed on hairiness is shown in Table 2. The winding hardness is preferred and the tension of the winder is optimized, which helps to control the growth of hairiness. The bobbin winding hardness increases, the bobbin contact trough pressure decreases (P4 pressure is greater, the smaller the contact pressure is), and the growth rate of hairiness decreases. (2) Strengthen the operation of cleaning and brake work: Do a good job of cleaning the yarn passage area and the trays in a timely manner to reduce the accumulation of flying flowers and increase the attachment of hairiness. The splicer is cleaned, the inside of the bobbin holder is cleaned, and the nozzle is cleaned. When the handover class is clean, it must be parked at the same time. It cannot be carried forward or backward. (3) Transfer and protection of the spun yarns to the winder should be done well to prevent the occurrence of yarn jamming. (4) The relative humidity is controlled at 70-73%. Appropriately increasing the humidity in the winding workshop helps reduce hairiness. (1) In addition to focusing on selection and production, the rubber roller should also pay attention to maintenance. Filament, roving, stencil roller coating and cleaning cycle, for the chemical fiber easy to produce static electricity, after the preparation of anti-static agent to be added to the coating; cleaning cycle, a weekly, roving once every half a month, spinning yarn and wire ring synchronization. Because the oil roller and apron are easy to collect grease, they are cleaned with a cleaning agent with a strong grease removal cycle and dried before use. Satin African Print Fabric,Satin Fabric,100% Polyester Satin Fabric,Beautiful Morocco Satin Fabric shaoxing sherry import and export co.,ltd , https://www.sherryfabric.com
Technology | Causes and Control Methods of Hairiness of Polyester and Viscose Yarns in Ring Spinning
This article analyzes the causes of the hairiness of the viscose yarn produced in the ring spinning and the various factors that affect the hairiness. It eliminates the static electricity generated by the polyester fibers in the production process, and comprehensively processes, equipment, equipment, operation, temperature and humidity control, and management. There are many factors that put forward the main methods and measures for controlling hairiness. It has certain guiding significance and effect on the control of hairiness in the production of polyester-viscose yarn by ring spinning.