Textile Technology Key And Process Control For Yarn Dyed Yarn

Preface：

In order to meet the quality requirements of high-grade yarn dyed yarns, our company has Yarn dyed yarn The quality requirements are strict, and the physical indexes of the yarn must reach 15% of the 2007 Ulster communique. In order to achieve this requirement, we have optimized the existing equipment flow of the company, and have carried out a series of optimization in the aspects of technology, cotton blending and operation. The technical measures and the production process are described below for reference to similar problems in production.

1. Raw material matching:

In terms of cotton blending principle, we should focus on quality, arrange in an all-round way, take all factors into consideration, ensure the key points, look ahead and backward, and make good use of both ends. In order to achieve this goal, we keep in touch with our customers in a timely manner, and maximize the guarantee of customer's coloring style. The specific measures are as follows:

1. there is a great relationship between the absorpting ability of the fabric and the properties of the fiber. The light coloured cloth does not require high raw cotton, but it can not use raw cotton with low maturity and large index difference. Otherwise, it will cause uneven mixing of fibers and stain or streak will appear after dyeing. Therefore, light colored cloth should be used with raw materials with less impurity and better color and maturity. So when we use yarn in textile category, we use 100% Xinjiang cotton, 85% Xinjiang 8401 long staple cotton and 15% Xinjiang Hongchang long staple cotton. The average grade is 1.09, the main body length is 36.7mm, the quality length is 40..2mm, the single strength 5.5CN, the maturity coefficient 1.8, the micron value is controlled at 4.20, the impurity content is 2%, and the short fiber percentage is 7.6%.

2. average grade 1.24, main body length 36mm, quality length 40.36mm, single strong 5.7CN, maturity coefficient 1.87, micron value controlled at 4.35, impurity 1.93%, and short staple rate 7.2%.

3. printing cloth can lower the requirements for raw cotton, because after printing, it can cover some cotton yarn defects and crossbars, adopt four cotton with Xinjiang cotton blending, 55% Xinjiang 8401 long staple cotton, 20% Xinjiang Hongchang long staple cotton, 10% real estate cotton, 15% Pima cotton and cotton 10%, and color column 5%; The average grade is 1.65, the main body length is 36.mm, the quality length is 40.15mm, the single strength 5.32N, the maturity coefficient 1.65, the micron value is controlled at 4.20, the impurity content is 2.4%, and the short fiber percentage is 7.8%.

Raw cotton should be balanced for at least 24 hours before reaching production to achieve moisture balance.

Two, process flow

In the process configuration, we follow the principles of fine grasping, full mixing, gradual loosening, early breaking and less crumbs, beating with comb, and less damage to fibers.

BDT-019 grabbing cotton machine MFC double axial flow open cotton to SC gold fire detection > TV425 cotton conveyor fan > MCM multi warehouse to CXL cleaning machine SCFO DK903 separator; DK903 carding machine to DYH500 pre drawing frame; E32 strip and reel machine; E62 combing to draw high speed drawing frame to roving frame to yarn spinning machine to connect the cylinder machine to the doubling and winding machine to turn VI to 10 times twister.

Three. Opening and cleaning process.

Due to the large proportion of single cotton cleaning machines in our production process, there are many striking points. Cotton fiber The hidden danger of direct damage or potential damage is not only easy to form short lint but also directly affect the yarn strength of the post process. Therefore, we first revised and optimized the technological parameters such as speed, spacing, suction and negative pressure of each attack point. The specific measures are as follows:

According to the comprehensive index of raw cotton, the beat speed of the cotton picker is reduced from the original 1300rpm to the current 1000rpm, the speed of the clutch is revised to 25m/min, the drop of the driver is 0.5mm, and the roller roller speed is 20rpm. It has achieved the goal of "grasping frequently and grasping less" in the process of opening and cleaning cotton. In order to improve the smoothness of Baotou and increase the rate of manual packing, it is very easy to cause the unevenness of the smoothness of the raw cotton. The purpose of improving the smoothness of Baotou is to use the self-made square gauge to tamp the loose cotton to improve the evenness of Baotou. The double axial flow is "free negative" dust removal and less damage to fiber. Therefore, the speed of our first, second hits is respectively 423rpm/min and 410rpm/min, the grid spacing is controlled at 8mm, the negative pressure control at the outlet of the dust control system is at 1100bra, and the seed breaking rate is controlled at 2.5%.3.5%. And timely check the suction pipe three links, observation window hanging flower situation, protect raw cotton in the pipeline without rollover phenomenon.

Secondly, the CXL cotton cleaning machine with many damage points has been partly reconstructed. Reduced Short pile The purpose of producing and damaging fibers and controlling neps effectively. Specific measures are as follows:

The transformation of CXL- cleaning machine: in order to reduce the blow to the fiber and avoid the danger of damaging the effective fibers, we have reformed the cxL three rollers: the original full angle nail roller, the second sawtooth roller, the transformation to remove the sawtooth rollers, the encryption (the original 16 pin / inch, the current 28 pin / inch). The speed control is less than 1000rpm/min, the adjusting wing is controlled at 80%, the cotton feeder BE963 speed is controlled at 650rpm/min. After modification, the Worster index has been greatly improved.

Four. Carding process

Carding process is the core process of spinning; we are in line with "carding to exclude small impurities, short staple, neps". We should optimize the matching clothing, rationally control the replacement cycle of all kinds of card clothing, and adopt the method of precisely grinding the cylinder and flat clothing on the machine, so that the sharpness is always kept in good condition. In order to fully exclude the short pile, we adjusted the cover speed from the original 220mm/min to 320mm/min and the movable cover five gauge to 1/1000 (9/8/7/7/7). At the same time, the speed ratio of cylinder roller increased from 2 to 2.25. The control rate of carding rate is about 6.5%, and the difference between noil and litter is less than 1.5%. The impurity control of raw strips is 0.08 to 0.15% to meet the requirements of stripes. Recitation and divination can greatly reduce the amount of impurity and neps in the latter process.
 

{page_break}

Five. Combing process

Combing process is a key process to remove short fiber and carding fiber hook to make the fibers parallel and straight. If the effective control is effective, the cohesion force of the fiber will be greatly increased, and the evenness and strength of yarn will be increased: the hairiness will be reduced. During the production process of the E62 comber of Lida, repeated process experiments have proved that the cotton feeding way, the amount of cotton feeding, the thickness of the feeding cotton layer, the density of the top comb, the dropping scale and the overlap scale are very important for improving the quality of the carding quality cotton net. By modifying the above process parameters, we finally choose the following process parameters:

The cotton feed back to cotton, and the back cotton gives more times to the cotton during the same cycle than the advancing cotton, which helps to remove the short fiber and improve the parallelism of the fiber. The amount of cotton is 4.3mm, the amount of cotton rolls is 68g/m, and the weight of cotton pads is of great significance for improving the carding effect of the clamp board. The top comb density is controlled by Graff 30 pin /cm; the noil scale is controlled at 12.5, and the falling rate is between 16 and 17%. On the basis of the unified noil scale, the machine controls the clearance between the lip and the separation roller accurately (0.01mm between the stations) to ensure that the difference between the lower and the lower stations is less than 1%. The overlap scale is controlled at.0.7 to ensure that the fibers are connected in parallel. In order to better exclude impurities and short linen, the speed of cylinder control is 300r/min and brush speed is increased to 1200r/min. Through the above measures, the fiber hook is effectively controlled, and the parallelism of the fiber is ensured, so as to improve the yarn quality.

Six, drawing process

Emphasis is placed on adjusting the uniformity of the long segment in the sliver by combining the number and optimizing the roller spacing, and improving the elongation and parallelism and separation of the fibers through reasonable matching of drafting multiple. In order to prevent accidental drafting in the guide bar, we revised the draft area from 1-3 to 1.15. At the same time, the positioning of the cylinder is fixed, and the center of gravity of the guide bar and the barrel is strictly adjusted. Regular cleaning of cotton sliver passage, Slitter and roller is made to ensure that the fiber is straight and not adhesion during drafting process.

Seven. Roving process

Follow the "two big two small" yarn dyed yarn technology. The larger rear area spacing and smaller back zone drafting ratio are adopted, the larger twist factor and smaller floating interval ensure the tight structure of the roving bar entering the back area of the spinning, preventing accidental elongation and improving the evenness. Spindle speed is controlled within 1000r/min. The main process parameters are: roller spacing 10mm * 22mm * 35.5mm, rear area drafting multiple 1.17, twist factor 116, quantitative 3.4lg/10m, and regular cleaning of cotton wax for roller, flyer and yarn channel. Specification requirements for roving roving Front Connectors and sliver wrap. The deviation control of roving tension is less than 1.5%.

Eight. Spinning process

The use of compact spinning device improves yarn strength, reduces yarn hairiness, and reduces the pressure of the back process, so that the quality of colored spun yarn has risen to a new level, and closer to the needs of customers. In order to better achieve this effect, we have adopted a proper process to reduce the twist coefficient of colored spinning compact spinning. By comparing the drafting ratios (1.10, 1.15, 1.25) of different back zones, it is found that the drafting ratio is adjusted to 1.25, which is relatively good. We also made a comparative experiment on various special equipment, and chose the best machine to produce.

In view of the fact that the short pile is easy to gather and the vacuum pump is discharged and the air flow is disorder, the adjustment is carried out by strengthening the roving cleaning, installing the PVC pipe to centrally discharge, and adjusting the suction mouth of the earth, thereby effectively preventing the occurrence of yarn faults. Compact spinning can only enhance the quality of products. Solid equipment management, standardized operation management and strict quality management are the basic conditions.

The data of different parts of spinning process and comparison of different process parameters are for reference only.

Finally, we chose the imported anti winding roller AccotexJ463 roller, the PGl/2 side width 2.6mm bearing ring and the imported Breck C1EL12/0 steel wire ring, the workshop temperature and humidity selected 32 degree relative humidity 52% and the central air conditioning to ensure constant temperature and humidity. The twist selected 127 twists /10cm, the back area draft multiple choice 1.25 times.
 

{page_break}

Nine. Winding process

In order to further optimize the winding quality and achieve the purpose of improving the quality of worsted yarn dyed yarn, we have applied the technology of twisting water twist to AC338 twister. Air twisting and water twisting are microscopically speaking, the working process of air splicing is relatively lively. Air twisting is due to the force generated by cyclones acting on the fibers, while the cyclone has poor controllability due to factors such as air pressure and so on. Its force acting on fibers is indirect, sometimes a little variable and not stable. Water twisting uses cyclone combined with water spinning force to directly act on the fiber, and its force is controllable. For example, the water twister can easily wrap up the fibers in the joint, and how many twists are the number of twists. It can be done very accurately, and every spindle on the whole car can do this in a consistent manner, but it is very difficult to empty twists.

In the process, the winding process uses smaller yarn tension and low speed, and maintains the smooth and good mechanical state of the winding channel, so as to reduce the growth of yarn hairiness.

Ten. Operation management

A large number of experiments on the degree of smoothness of the cotton sliver channel show that the smoothness of the cotton sliver channel has different effects on yarn quality. In order to avoid quality fluctuation, we do a cleaning and other procedures for each part of the cotton sliver passage in each half class of the drawing process. Through long-term persistent efforts to a certain extent, to ensure the quality of stability.

In order to maintain the quality of high-grade yarn dyed yarns, the operation method is also an important aspect that can not be ignored. For example, if the net is not pinched, the strip is too long, the roving joint is not good, and the spinning winding roller has different effects on the product quality.

Concluding remarks:

The production of high grade yarn dyed combed yarn is a yardstick for representing the comprehensive level of an enterprise. It requires the cooperation of many links in the process, equipment and operation management. The weakness of any link can not produce the products that meet the requirements of customers. In addition, selecting the right spinning equipment, improving the quality of the existing spinning equipment, and constantly optimizing the process structure are also the key steps to improve the quality of the spinning.