Number of neps and impurities is an important index to measure yarn quality. It not only affects yarn internal strength and labor productivity, but also seriously affects the appearance quality of the final product. Therefore, it is necessary to control and reduce the number of knots and impurities in sliver.
- Raw cotton quality.
The raw cotton with moderate maturity has good elasticity, rigidity, high strength of single fiber, good compressive and bending resistance in spinning process, and the possibility of neps formed by rubbing and entanglement during processing is small.
The more short fibre percentage of raw cotton, the easier it is to diffuse and adhere to some parts of the passage. The more aggregated flying flowers such as cots and aprons, the more yarn knots.
The finer the raw cotton is, the softer the fibers are, the easier neps will be formed, and the neps will be formed with fiber seed chips.
- Opening and cleaning process.
The faster the beater speed of the cotton grabbing machine is, the greater the strike degree is. Although it is beneficial to impurity removal, it is easy to make the air supply in the cotton conveying pipeline insufficient, which is not conducive to the smooth transfer of cotton bundles, and easy to cause bundles of silk and neps. In order to reduce neps, the cleaning equipment should achieve: smooth cotton flow or cotton layer passage, corner nail, comb needle, blade and other components; smooth air flow; accurate separation between hitter and dust bar, hitter and cotton stripping knife; sensitive control of grille, mercury switch and electrical appliances.