Lean Management: Achieving Zero Defects In Combing Components

As we all know, combing cylinder or top comb damage, applique and other factors will lead to increased combed noil rate and long fiber damage, loss, and then deteriorate yarn quality. At present, textile enterprises to solve combed cylinder and top comb damage and mosaic measures are: properly adjust the brush into the cylinder depth, increase the brush speed, replace the brush with too small diameter or sparse palm and poor elasticity, appropriately extend the cleaning interval of the brush, shorten the cleaning cycle of the cylinder and top comb, and replace the serious Combing Equipment for damage and mosaic. In order to better solve the problems of combing cylinder, top comb damage and applique, Shandong Liaocheng Huarun Textile Co., Ltd. has adopted some technical measures.

　　 optimization Density arrangement of Xilin rack

Strengthening the front area rack roughing efficiency

Embedded sawtooth monolithic cylinder is widely used because of its strong spinnability. In order to ensure the maximum carding efficiency of Xilin, it is possible to reasonably deploy and appropriately increase the rack density of the pre combing area within the limited cylinder lining interval, and strengthen the comb efficiency of rack puncture, grabbing and loosening in the front area, while avoiding the overtightness of the rack in the front area, reducing the carding efficiency of the carding area, and preventing the comber from breaking the edges and breaking holes at high speed. In this regard, some foreign textile machinery manufacturers have made some optimization at present. For example, the German schle company optimized the arrangement of pin angle and pinion density: the front 90 rack of the 90 series combing cylinder cylinder with a tooth surface angle of 90 degrees is 25 teeth / square centimeter, 62 teeth / square centimeter, and the comb point can be increased by changing the rack density in the back area. The maximum carding point of this series of Xilin is only 30305 points, while the new two series of Xilin's top two rack density is 53 teeth / square centimeter, 88 teeth / square centimeter, and the maximum carding point can reach 38980 points. At the same time, when we grasp the gradient configuration, we should appropriately increase the rack density in the back area so as to eliminate smaller neps, achieve single fiber and improve the efficiency of small neps and short linen, which is conducive to the overall improvement of yarn quality.

The reasonable arrangement of rack density in the front and back area of the combing cylinder and the proper increase of the total number of cylinder carding points have great influence on improving and stabilizing the yarn quality. It has also attracted the attention of the technical personnel of the spinning workshop. At the same time, domestic and foreign comber makers are actively developing and matching the high quality combing carding elements to meet the rapid development needs of the modern high efficiency comber.

According to customer demand, the density of each rack and the total grooming point of the cylinder were scientifically and reasonably arranged. A spinning mill increased the total carding point of five split cylinder cylinder to 90 points (mainly increasing the rack density of the carding area), and the speed of the starting and output cotton web was lower than that of the cylinder. The speed of the machine was reduced from 380 times per minute to 380 times, until it was reduced to 300 times per minute / minute, and the normal output web quality was obtained. The density of the top two groups was increased appropriately, such as the increase of the rack density of three groups, such as the increase of three rack rack density, and the total grooming point of 47 thousand cylinder. It can meet the technological requirements of fast puncture, loosening and carding, and the yarn quality km+200% neps drop down to 25%~30%. How However, due to the larger density of Xilin rack in the middle and rear area, the blade is too thin and the strength is too low, so it is difficult to adapt to the high speed and heavy quantitative process requirements. The use of the first row of gear rack will break tooth phenomenon in the third groups of gears, resulting in the occurrence of the cylinder inlaid phenomenon. From this point of view, the total grooming point of Xilin is not as big as possible, but the best arrangement of teeth density and the general combing point should be determined through testing according to the processing fiber condition and customer quality requirements.

　 rack Sharpness degradation affects quality

Reasonable adjustment of insertion depth of cylinder

In order to cater for the demand for increasing the total carding point of the cylinder, the processing of the cylinder rack density is becoming more and more large, the number of carding points is getting higher and higher, and the tooth piece is getting thinner and the strength of the tooth piece is gradually decreasing. Although carding component manufacturers have made unremitting efforts in the selection of material, process optimization and surface summary processing, they still can not solve the contradiction between the high speed and high efficiency of the comber and the shortening of the sharpness degradation cycle of the Xilin rack. This is because the carding process of the high speed comber with variable speed cylinder grooming has quickened the speed of the instantaneous line (1.38~2.2 times). Take the speed of 500 tongs / mins as an example, in fact, the speed of carding is comparable to that of Yu Heng speed combing cylinder 690 times / minute ~1100 clamp times / minute speed.

In the embedded sawtooth holing cylinder, when the cylinder is in place, it usually occurs in the first group and the third group. The tooth face angle is 90 degrees, and the 4 segmental cylinder inlaid flower occurs in second groups. The first row of toothed rack has been damaged by 90 times magnifying glass. The observation shows that the first row of five pieces of the mosaic tooth has been damaged. If the inlaid flower caused by the damage of Xilin rack is taken into account, other technical measures such as adjusting the insertion depth of the brush into the cylinder, increasing the brush speed and improving the cleaning time of the brush can not solve the problem of applique. Only by removing the old rack and replacing the new rack can the aim be achieved. Once the cylinder's sharpness is degraded or the damage caused by rack teeth is affected, the impact of the cylinder inlaid on the yarn quality is greater. It shows that the percentage of droppings increases by 0.5 percentage points when the same noil spacing and cylinder grooming spacing are applied. Production practice showed that the short staple rate of combed sliver and combed sliver increased, and the yarn quality deteriorated rapidly.

When the conventional technical measures for processing Xilin are not effective, do not haste to adjust the depth of the brush palm into the cylinder. This will not only be harmful to the processing of Xilin inlaid flowers, but will also aggravate the damage of brush hair and shorten the service life of the brush. If the brush is used properly, the imported brush can be used for 6~7 years, and the domestic brush can be used for 4~5 years. The use of the brush is equivalent to increasing the depth of the brush into the cylinder by 1 millimeters. This technology can effectively and thoroughly remove the inlaid flowers in Xilin toothed sheet. Now we have all replaced the domestic brush. This is mainly due to the poor elasticity of domestic brush hair. After a period of time, the brush bristles will be dumped to one side, which will greatly reduce the cleaning efficiency of the brush.

Prolonging cylinder life by changing rack

　　 strict Control spacing to reduce neps

The common carding point of the conventional domestic cylinder is (41186 points). The first, second sets of Xilin rack have the same specifications, the rack skew pieces are beige, and the first group and the first row of tin rack rack are easy to damage. When the cylinder is in use for about 8 months, the first, second sets of Xilin rack can be exchanged for use, so that the service life of the cylinder rack can be prolonged while ensuring the cleanness and zero defect of the cylinder tooth surface. When replacing the Xilin rack uniformly, it is possible to select and store some good Sn rack (rack tooth surface damage, non applique and dirt free) to facilitate replacement of the cylinder liner with embedded flower at any time, so as to ensure the clean zero defect of the cylinder tooth surface and achieve zero defect, zero defect and zero cost.

While properly increasing the density of the Xilin rack in the front and rear regions, it is very important to strictly control the three points in the cylinder clearance (the front, middle and back areas). Xilin carding spacing is small, can reduce yarn neps, but too easy to cause fiber damage, and the damage probability of Xilin rack also greatly increased. Therefore, the determination of cylinder carding spacing should be based on the different manufacturers' Xilin, small volume quantitative and customer quality requirements to find the best combination point.

In the process design of the combing preparation process, priority should be given to improving the parallelism, straightness and separation degree of the cotton fiber, which will not adhere to the combing process, and the fiber damage will be small.

All employees of the company adhere to the requirements of lean management, take the initiative to participate in the maintenance activities of the equipment, so that the combed cylinder is always in the state of no flower and no damage, while the Xilin tooth surface can always work in clean and zero defect state.

In production practice, lean production management (TPM), zero defect rule, TPM framework, self preservation and function, professional preservation, quality preservation and self checking are advanced management concepts. It is also an endless process of excellence. If we insist on the zero defect rule in our work, everyone insists on doing the first thing right, and does not let defects occur or flow to the next process or other jobs. Then our work can reduce the cost of dealing with defects and mistakes, and the quality and efficiency of work can also be greatly improved, and the economic benefits will also increase significantly.