The unevenness of the blowroom cotton lap directly affects the weight of the finished yarn, and also affects quality indicators such as the evenness of semi-finished products and finished yarn, thus affecting the quality of the cloth surface. Therefore, how to reduce the unevenness of cotton laps and improve the uniformity level of cotton laps has become one of the important tasks in the blowroom process.
Uneven cotton rolls include longitudinal and transverse unevenness. In production, the main focus is to control longitudinal unevenness. Longitudinal unevenness refers to the difference in weight between cotton roll segments per meter (yard), which directly affects the unevenness of the card sliver weight (count) and the deviation of the spun yarn weight (count). Depending on the factory’s production technical conditions, the unevenness rate per meter (yard) of cotton rolls is generally 0.7% to 1.3%. While inspecting the longitudinal unevenness, the factory also uses lights to visually inspect whether the cotton rolls are uniform in the transverse direction. If you find that there are many holes or there is obvious unevenness in the horizontal thickness, you should also take timely measures to correct them.
Avoid dust cage clogging
During the operation of the equipment, The mesh of the dust cage is easy to adhere to cotton wax and dust. If it encounters hard debris or is squeezed by an excessively thick cotton layer, the surface will be dented, and even the mesh will be damaged, weakening the function of the dust cage. At this time, it must be cleaned or cleaned in time. repair.
The condensation effect of the upper and lower dust cages of the rolling machine is achieved by the negative pressure generated by the fan. If the air supply effect is not ideal, the cotton flow sent from the beater will float into the dust cage in groups, which is one of the important reasons for the horizontal unevenness of the cotton roll. Therefore, it is necessary to keep the air suction volume of the dust cage sufficient, the left and right wind force to be uniform, the surface of the dust cage to be smooth and clean, and free from flying debris to reduce the sticking phenomenon. It is very important to adjust the air volume ratio and exhaust air volume of the dust cage. The air volume ratio is generally 3:2 or 7:3. If the cotton layer is thick in the middle and thin on both sides, it means the air volume is small, and vice versa, it means the air volume is large.
There are two large and small cotton filtering boards between the integrated beater dust rod and the lower dust cage. The small filtering board is connected to the dust rod, and the large filtering board is on the side of the dust cage. When installing the cotton board, cut off 90 mm of the larger cotton board and slightly modify the smaller cotton board and raise it by about 30 mm. After such a small change, the air supply method will be adjusted, so that the original air supply on both sides of the fan is changed to a flat air supply. Small cotton bundles can be directly and evenly shot to the surface of the dust cage, reducing the large pieces of fibers floating into the dust cage. situation, thereby improving the transverse uniformity of the cotton roll.
Make good use of the balance adjustment device
The balance adjustment device is based on cotton The thickness of the layer changes and the cotton feeding speed is adjusted so that the cotton feeding amount per unit time remains constant. During use, it is necessary to adjust the leverage ratio and select the best point, that is, use the “positive volume correction method” for adjustment. When the rolled roll meets the weight standard, change the “V” shaped curtain inlet spacing to change the average thickness of the fed cotton layer. At this time, if the weight of the produced cotton roll is still within the standard range, it means that the leverage ratio and The original standard average thickness of the cotton layer is correct. Just adjust the “V” shaped curtain inlet spacing to the original size to make a relatively uniform cotton roll. If the finished cotton roll is heavier after the “V” shaped curtain inlet distance is changed, it means that the lever ratio is too small and the movement of the iron cannon belt is smaller than normal, resulting in the balance roller speed not being reduced to the amount corresponding to the increment of the cotton layer thickness. numerical value. In this case, it is necessary to readjust the fulcrum position of the balance lever until the weight of the produced cotton roll meets the standard.
Cancel the iron cannon and use auto-levelling. Autoleveling is an effective measure that uses microelectronic technology to transform traditional processes and improve the rolling rate and longitudinal unevenness of cotton rolls. It is the main content of roll modernization. It also replaces manual operations with modern control technology to increase the rolling rate and stabilize cotton. A reliable means of roll quality.
Maintain good mechanical condition
The raw cotton channel part should be kept smooth and clean . The horns of the cotton box machinery should be smooth, the length of the horns and the angle of the nail planting should be consistent, and the curtain canvas should maintain appropriate tension to reduce the difference in grabbing ability. Each machine dust rod should be cleaned of cotton wax regularly to prevent defects in the raw cotton passage, impurity removal, and stripping parts. The speed ratio of the beater to the fan must be appropriately configured. Strengthen temperature and humidity management to reduce fluctuations. At the same time, improve the operating technical level, implement the prescribed tour route, pay attention to cotton blending and threading operations, and adjust the weight of cotton laps.
Rectify the mechanical condition of the cotton picking machine, focusing on the rib beater part to achieve fine picking of cotton, grabbing less, grabbing more frequently, grabbing small, grabbing evenly, grabbing finely, and grabbing all the cotton, so that The cotton pieces fed into the mixed cotton opener are in a micro-bundled state, which allows the large impurities to be removed as much as possible under free blows, which is the soul of the adjustment process of the cotton opener and cleaning machine.
Strengthening management is an important aspect to ensure the realization of the process. Great attention should be paid to the design and execution of the bale arrangement diagram of the cotton picking machine. Strictly controlling the operation rate of each machine in the whole process is to improve the development. The basis for cotton cleaning, loosening, impurity removal and even mixing. At the same time, it is necessary to ensure quantitative supply, that is, for a complete set of combined opening and cleaning machines, the feeding volume and output volume of the front and rear machines per unit time should remain constant (the feeding volume is usually slightly greater than the output volume). Improve the operating rate of the cotton box machinery as much as possible. The operating rate of the cotton box machinery connected to the rolling machine should be 100%. The adjustment devices of each cotton box machine, such as the rocking grid (or rocking plate), mercury switch, etc., should be sensitive and accurate. In addition, the density of the raw cotton fed should be consistent. Tightly packed cotton bales should be pre-treated before use, and the returned flowers should be used in a balanced proportion.
Reduce the draft between rollers
Using A076 type coiling machine For example, considerThe center distance between the roll-to-lap roller and the pressing roller is long. In order to prevent the cotton layer from wrinkling during transportation and affecting the formation of the cotton lap, the machine is designed with a draft of 1.0452 times. When this section of cotton layer is stretched, the thin part of the cotton layer will be further stretched, which will worsen the uniformity of the cotton layer and cause greater damage to the card sliver and subsequent slivers. To improve this situation, the draft in this section must be reduced. The high and low shaft gears are changed from 32 teeth to 31 teeth, and the draft is reduced from 1.0452 to 1.013. This not only ensures that the uniformity of the cotton layer will not deteriorate, but also prevents the cotton layer from wrinkling, thereby improving the uniformity of the cotton roll in the longitudinal and transverse directions, and producing The two indicators of sliver dryness CV and raw sliver weight CV were significantly reduced. </p
