01 Enhanced carding
Enhanced carding can straighten the fibers, decompose them into single fibers, separate the fibers from impurities, and loosen neps. Therefore, the accuracy of the main carding distance and the sharpness of the carding elements are extremely important.
02 Removing impurities requires a reasonable division of labor
It is most beneficial to know which impurities fall in which processes and locations, that is, the elimination of impurities must be reasonable Division of labor, impurity removal in each part of the carding machine itself also requires a reasonable division of labor. For impurities that are generally large and easy to separate and remove, the principle of falling early and breaking less should be implemented, and falling early in the cleaning process. Fiber impurities with greater adhesion, especially long fiber impurities, are more advantageous to eliminate on the carding machine. Therefore, when the maturity of raw cotton is poor and there are many harmful fiber defects, the carding machine should be appropriately increased to remove impurities and waste. The licker-in part of the carding machine should eliminate broken seeds, stiff flaps and short lint, as well as small impurities with shorter fibers. The cover is suitable for removing small impurities, neps, short lint, etc.
For general domestic cotton, the total noil rate of carding cotton is greater than that of blowroom cotton. The impurity removal efficiency of cleaning cotton (containing impurities in raw cotton) should be controlled at 50%-65%, the impurity removal efficiency of the carding roller part (containing impurities in cotton rolls) should be controlled at 50%-60%, and the cover plate should remove impurities The efficiency is controlled within the range of 3%-10%, and the impurity content of the raw sliver should generally be controlled below 0.15%.
The focus of impurity control on the carding machine is the licker-in part. In production, this is achieved by adjusting the process parameters of the small drain bottom and the dust removal knife, such as the small drain bottom inlet spacing and the third The four-point distance, the height of the dust removal knife, etc. When the maturity of the raw cotton is poor and the cotton roll contains a lot of impurities, resulting in an increase in the impurity content of the card sliver, adjustments should be made by adjusting the spacing between the entrance to the drain bottom and increasing the length of the impurity area. The suction tube on the licker-in cover should not be blocked, otherwise it will cause abnormal cotton waste and increase white waste on the rear belly. The chord length of the small leakage bottom is too long, the teeth of the licker-in are not suitable, etc., which will increase the impurity content of the card sliver. The card clothing specifications of the cylinder and the flat plate, the distance between the front upper cover plate and the cylinder, the height of the upper front cover plate and the flat plate speed, etc., also affect the impurity content of the card sliver and the number of neps.
03 Reduce fiber rubbing
The neps produced on the carding machine are mainly due to return, twisting, and fiber Formed by rubbing. For example, when the spacing between the cylinder to the doffer and the cylinder to the flat plate is too large and the needle teeth are blunt, the fiber will be rubbed excessively. Also, if the licker-in and cylinder twisting will increase the number of neps. Severe winding in the blowroom process, too high moisture regain of cotton laps, too large mixing ratio of recycled cotton and reused cotton, or uneven feeding will all lead to an increase in card sliver neps.
Rational distribution of cotton and strengthening temperature and humidity management can play a significant role in reducing neps and impurities. Several indicators that have a greater impact on yarn knotting during cotton blending, such as maturity, harmful defects, impurities, etc., should be strengthened to control the differences in indicators. When the moisture regain of raw cotton and cotton laps is low, impurities are easy to fall, and the cotton end yarn can also be reduced. Therefore, the moisture regain of cotton laps should be controlled not to exceed 8%-8.5%, and the moisture regain of raw cotton should not exceed 10%-11%. Control the lower relative humidity in the carding workshop, for example, control the relative humidity at 55%-60% to dehumidify, increase the rigidity and elasticity of the fiber, and reduce friction and congestion between the fiber and the card clothing. However, if the relative temperature is too low, static electricity is easily generated, and the cotton mesh is easily broken, adhered or broken. This phenomenon is more obvious especially when spinning chemical fibers. If the relative humidity is too low, it will also reduce the moisture regain of the card sliver, which will be detrimental to the subsequent drafting process.
Using high-quality alloy card clothing, strengthening the carding function, and increasing the dust suction points and air suction volume on each carding machine can greatly reduce card sliver contamination. . </p
