The broken end of rotary cup spinning is one of the common conditions in the production of rotary cup spinning. After breaking the end of pure cotton yarn production, quality and finish rate need to lead to certain harm, the higher the broken end ratio, the greater the damage. The joint quality produces a certain length, short and thick section, which is obviously harmful to yarn quality. In addition, the broken end is the actual reflection of the management ability in the process of spinning. Therefore, it is an effective way to increase production, high efficiency and high quality to avoid the occurrence of broken ends in manufacturing.

First, the reason of the broken end of the spinning cup

The key cause of broken ends in rotary spinning is the super strength and weak ring of chemical fibers in the whole process of cohesion and merging. The rotating speed ratio of the rotating cup is very high, the centripetal force and the negative pressure in the rotating cup are very high, so the friction resistance of the whisker in the rotating cup is also very high in the whole twisting process. When the fiber ring is still in the whisker link after leaving the cohesion tank, because of its twist back, so at this time its anti - torsion ability is very poor. If the super strength of the yarn is lower than the supporting force generated by the friction, friction and centripetal force in the rotary cup, the yarn will break.

Practical experience has proved that the breakage of the cup yarn is mainly caused by the breakage point and the filament segment of the false twist. In fact, it can be divided into two kinds: before twisting and after twisting. Twisted yarn broken ends before the key reason is the transport chemical fiber to the cohesion of tank, chemical fiber sorting in cohesion, merger process by different forces destroyed, happened happened ahead of or behind the fitness movement, the key is in the semi-product residue, fly ash, dead cotton and its actual operation and negative pressure beam of instability. The key to breakage after twisting is that in the whole process of twist transmission, the damage of twist is large, and the yarn volume and twist change caused by the breakage.

Second, the root cause of end breaking in rotary spinning

2.1 Temperature and humidity

Relative temperature and humidity is too large, the whisker is not easy to open loose to remove impurities, resulting in broken head; The air humidity is too low, the chemical fiber bulging and holding together is poor, resulting in a broken head. The sliver moisture regain is controlled in the middle of 6.1%-7.2%, which is beneficial to the carding of silver and the migration of chemical fibers, and is beneficial to the twisting of the cup. The high moisture recovery rate increases the difficulty of sorting and migrating flax fiber, and it is very easy to hang flowers on the tooth ends of the carding stick, resulting in corticospinal tract, resulting in broken head.

2.2 Practical operation reasons

Flying flowers attached to the sliver, cohesive force tank cleaning is not immediately and embedded, cohesive force tank too much smoke and dust, processing process exhaust system pipe blocking, processing process exhaust pipe blocking, false twist head around flowers. Cohesion rotor slot of the running state of the yarn into a standard and beheaded have key hazard, if the cohesion tub has many small dust particles and group, this time into the tub cohesion of chemical fiber in is not symmetrical, also harm twist transmission, the flax fiber in less that one section of the article must be from the super powerful must be low. In the other case, due to the overdue application or wrong operation of the rotary cup, the grinding surface of the cohesive tank falls off, which makes the disengagement of the chemical fibers difficult and leads to the broken end. Empty canister, touch silicified top, straight row canister is not immediately, sliver too high.

2.3 Machine and equipment reasons

Carding gear and rack should be smooth and sharp, so as to benefit the carding, impurity and migration of chemical fibers. But in the production process of carding wheel, it is inevitable to cause the situation of inverted teeth and bent teeth, which is very bad for the migration of flax fiber, and will gather the flax fiber to produce cotton bundle, resulting in broken yarn. False twist disc in the whole process of spinning twist effect, false twist plate and yarn touching arc surface and hole need to be very smooth, in order to facilitate the production and transmission of twist back, and can reduce the friction on the yarn, reduce the cause of broken end. The silica gel sealing ring of the safety channel for fiber transportation is damaged or falls down, which reduces the negative pressure in the rotary cup, and makes the migration and cohesion of the flax fiber difficult and causes the yarn to break. If there is a gap or a burr under the steel beam inset at the end of the bell opening of the safety passage for cotton delivery, it will cause the hanging flower condition. The hanging flower will accumulate into a bundle and enter the rotary cup together with the negative pressure cyclone, resulting in the broken end. The cotton roller and the cotton plate, the cotton plate working pressure is too large, if there is oil stains in the middle of the magnetic block and the bevel gear at the lower end of the cotton roller shaft or dust and flower accumulation under the cotton roller, it will cause a hit in the whole process of transportation of cotton sliver. The installation position of miscellaneous pipe is not good. The gap between the outlet end of miscellaneous pipe and the entrance and exit of the safety channel of the spinning machine is maintained at 0.8mm, which is beneficial to the removal of residues. The large distance leads to the excessive filling of the surrounding cyclone to the miscellaneous pipe, the reduction of negative pressure, which leads to the blockage of the miscellaneous pipe and the broken end.

2.4 Reasons for processing technology

The air exhaust system of the rotary cup holder is not smooth, and the cyclone in the rotary cup can not be discharged smoothly, which produces vortexes in the rotary cup, so that the cyclone in the drawing tube and the carding chamber is blocked to flow and divide the yarn towards the rotary cup, resulting in the broken yarn. The distance between the concave groove on the front of the feeding board and the opposite of the carding chamber is 68.5mm, 0.1mm. The above processing technology does not conform to the regulations will lead to abnormal feeding of cotton, loss of sliver operation efficiency, resulting in poor actual effect of carding or resulting in coarse joints resulting in yarn breaking. Turbine rate and yarn drawing rate design is not equipped scientifically, which will lead to broken ends. Overlap working pressure is too large, support index selection is not good will cause the broken end.

2.5 Raw material elements

The raw materials used in rotary spinning are mostly low grade cotton and reused cotton, which contain large impurity, more smoke and dust, high short lint rate, the behavior body of chemical fiber is not long enough, and the super strength is low, which will lead to the broken edge of the cotton roll and the broken end of the carding cotton, improving the difficulty coefficient of spinning, and increasing the probability of the broken end caused by the yarn sliver. Therefore, under the condition that the standard will not be changed, the yarn breakage can be reasonably reduced by increasing the cotton blending level. Tampon in the mixed short lint defects, sliver thick section, split, multi - feed. The "three filaments" often contained in the raw material are thicker and stiffer, so the generation and transmission of twist back cannot be carried out, resulting in untwisted area and weak ring, which destroys the continuity between the strips and causes the yarn to break.

Control method of breaking end of rotary spinning

3.1 The general standard and mode of the broken operation of the rotary cup

The overall standard of broken end control for rotary spinning: resolving cause, overall regulation, classification control.

Specific methods: distinguish general head break, repeated head break, partial head break, large-scale head break; The overall adjustment is the system software adjustment of the whole step from raw cotton, opening and cleaning cotton, carding cotton, drawing and spinning. Categorized manipulations include general, repeated, partial and large-scale decapitated manipulations.

3.2 Control method of general end break in rotary spinning

Generally, the reason caused by the broken head is very casual, and the processing technology, temperature and humidity has no great relationship, the vast majority of which is caused by random factors. Practical attention to the actual operation of machinery and equipment. Practical operation level control methods: pay attention to the quality of part of the cleaning, yarn flying, broken empty canister is not immediately replaced, sliver defects and other factors caused by the broken end. Machine and equipment level control method: mainly the machinery and equipment vibration and other casual factors lead to the weak ring of chemical fiber cohesion and merging, and pay attention to its randomness when operating, such as the broken end caused by the cotton roller.

3.3 Control method of repeated end breakage in rotary spinning

Repeated end breaking means that the same spinning module is broken for two or several times continuously. The damage of the broken head is greater. Emphasis on processing technology reasons, machinery and equipment reasons. Large-scale repeated breaking when taking into account the actual operation, temperature and humidity, raw material elements, the actual cleaning effect of the rotary cup, etc.

Control method for practical operation: immediately catch the periodic defects in the sliver, the internal cleaning effect of the spinner is excellent, and the carding chamber is free of wax oil stains, impurities and floating dust.

Control method of machine equipment: the key is to do well the feeding board, feeding roller, carding, fiber safety channel deformation damage, unsalable goods immediate maintenance. In particular, the probe of the lack of fixed adjustment screws, resulting in excessive air supply, miscellany is very easy to cause a broken head. The bending of the feeding shaft and the uneven magnetic block of the rotation shaft of the feeding roller shall be repaired and removed immediately. Exhaustion system hole sealing gasket, fiber transport safety channel to maintain smooth, Turner cup burrs properly handled.

Control method of raw material elements: after repeated breakage, when the impurities and dust in the rotary cup are lifted again after removal, attention should be paid to the impurities in raw cotton and the ratio of interuse of reused cotton should be adjusted.

Process reason control method: the winding machine support force is too small is very easy to cause repeated breakage. Generally, the support force index of 0.94 is not harmful to the actual effect of the winding machine, and is beneficial to reduce the number of broken ends. The negative pressure of the rotary cup is maintained for a long time, and the actual effect of the close connection of the exhaust pipe and the exhaust pipe of the processing process is good. The negative pressure of the rotary cup is stable between 2601080A and 3201080A. The working pressure of the strap and guide roller is the same as 26.5N±1.5N. Too small will usually result in repeated broken ends. The distance between the feeding board and the feeding roller is 0.05mm, too large or too small will cause repeated broken ends. The total exhaust air volume of the gray generator should exceed the total air volume of the rotary cup spinning machine, and the first-stage overburden working pressure of the gray generator should be maintained at 701080A. The speed of turning cup is 54mm in diameter and must exceed 45000rpm; When the diameter is 66mm, the speed must exceed 35000rpm, otherwise it will cause insufficient negative pressure and large-scale repeated breakage. The working voltage of the spinner should not be less than 19V, otherwise it will cause repeated broken ends.

3.4 Control method of the broken end of the spinning part of the rotary cup

Partial head breakage increased significantly, and comprehensive factors were considered for different species. Part of the machinery and equipment is focused on the mechanical equipment elements, processing process elements of the operation.

Raw material elements: the key to the operation of different types of partial breakage are the raw material elements and effective selection and processing technology. The adjustment of raw materials should be based on the number of the spinning yarn, and the raw materials containing large impurities and poor quality indexes should be reduced in the spinning of coarse yarn. Pay attention to the proportion of raw cotton when spinning fine yarn.

Practical operation control: effectively grasp the time of turret accumulation, according to different types of turret spinners to clean. When spinning the yarn number above 58.3tex, a cleaning must be done once it falls in the middle. When spinning the yarn number below 58.3tex, no cleaning can be done.

Part of the machine and equipment breakage focuses on the processing process control. Pay attention to whether the negative pressure of yarn drawing and the negative pressure of the exhaust system of the processing process is effective, whether the supporting force of the wire winding machine, the working pressure of the leather wheel and the speed ratio of the rotary cup meet the requirements of the processing technology. According to the number of spinning yarn, cotton blending condition, operation condition of machine and equipment and quality of spare parts, the effective rotating speed ratio and yarn drawing rate of the design scheme should be selected in the manufacturing process. The yarn number is fine, the relativity of cotton matching is better, and the running state of key parts such as rotating cup, carding and false twist is also better. At this time, the rotating speed of the rotating cup can be higher than that of the selection, and the yarn drawing speed can also be higher.

Machine equipment level pay attention to maintenance cycle time, mechanical equipment and the actual effect.

3.5 Control method for large-scale end breaking of ring-cup spinning

Large-scale breakage refers to the breakage of a part of the species and a part of the machinery and equipment. The key cause of this kind of situation is the negative pressure of processing technology, temperature and humidity and the configuration of raw materials.

Temperature and humidity control measures: high air humidity fiber is not easy to open loose, residue can not be removed, chemical fiber cluster, corticospinal tract is very easy to lead to broken head. When the air humidity is too low, the chemical fiber bulges, and the chemical fiber holds together poorly. In the whole twisting process, it is very easy to lead to super strength and weak ring, leading to large-scale broken ends. Selection scope: summer temperature 32℃ ~ 33C℃, air humidity 67% ~ 70%; In winter, the temperature is 26 ° C ~ 28° C, and the air humidity is 63% ~ 65%. In addition, the temperature and humidity of opening and cleaning cotton, carding cotton and drawing can be effectively controlled to reduce the situation of winding in production and manufacturing.

Negative pressure process control measures: negative pressure is one of the key factors that harm the end breaking and also the quality of yarn. The harmful effect of process negative pressure on large-scale breakage is related to the operation of the exhaust system of machinery and equipment and the ash removal power generating unit. In the specific production and manufacturing, the operation of centrifugal fans should be improved to avoid low wind speed and poor exhaust system. When applying secondary filtering in the ash removal power generating unit, pay attention to the agglomeration of the filter material and the negative pressure caused by the actual effect of filtering.

Control measures of raw material elements: the suitable short pile rate of raw materials is generally not more than 20%, the quality index index of raw materials, the water content of impurities should be as little as possible, and the proportion of return flowers should not exceed 15%. Mixing standard: cross type low supplement, short medium clip long, improve the actual mixing effect of raw materials. When raw cotton, recycled flowers and other raw materials are used, the moisture regain is controlled within 7±1.5%.

Process reasons control measures: open clean cotton blending to ensure symmetry; Cotton grabber as far as possible using round knife process or negative knife process, to ensure the mixing of uniform; The cotton blender stipulates the technology standard of early fall of large miscellaneous and shatterproof; Appropriately increase the wind speed of the condenser to improve the working ability of removing dust and short lint; Carding cotton to reduce chemical fiber damage control short lint increase as the standard, both finishing the actual effect of impurity, unified cotton drop, unified spacing to reduce the table difference; The drawing process avoids the sliver being cut by the coil and the bell-opening process is effectively adopted. When the strip is in the middle of 18~2lg / 5m for quantitative analysis, the diameter of the sliver is 3.8 mm. Two and the use of 3.6 mm horn period is beneficial to reduce the broken end. Effely clear the quantitative analysis of ripe sliver, to avoid sliver breakage caused by sliver layering when it is too heavy.

Control measures for practical operation: control the quality of the package connecting head of the carding and drawing process to reduce the splitting condition of the silicified wool strip; Increase the range of cleaning, reduce the addition of flying flowers; Increase the capture range for sliver defects. The guard shall do the cleaning work in accordance with the prescribed time and regulations, so that the air supply holes (openings) and the safety passageways of the weavers can be maintained smoothly. When changing the sliver bucket, the sliver should not be pressed too much to avoid sticky sliver. On the other hand, tampons are not suitable for too long. When connecting the head, it is necessary to clean up the residue and dust in the cohesive tank of the rotary cup and the short pile around the exhaust hole to make the circulating air flow in the rotary cup unobstructed.

Control measures for machine and equipment: the parts touching the flax fiber must be smooth, so as not to cause hanging flower condition. To ensure the sharpness of the carding gear rack and pinion, and can not have the situation of inverted teeth. On the rotary cup, carded Kun, false twist head, cotton safety channel according to the cycle time to carry out maintenance and replacement. Regularly check and adjust the main process parameters of the textile, such as the working pressure of the feed board, the distance between the feed board and the feed roller, and the inlet and outlet positions of the feed board shaft. And make sure that the feeding board and the feeding roller are in good posture. Regularily maintain and replace the spacing between the wearer and the sealing rubber plate, whether it is damaged or dropped, to avoid causing leakage of steam and harming the negative pressure in the rotary cup. On time to turn the cup, carding at every turn to oil and dismantling.

Four,

Rotating cup textile breaking is a comprehensive reflection of the process, machinery and equipment, actual operation, raw materials, temperature and humidity in the process of rotating cup textile. Different control measures should be adopted to reduce the general, repeated, partial and large-scale breaking, and strengthening management can reasonably reduce the breaking.