The processing of raw cotton or various staple fibers into yarn needs to go through a series of spinning processes. And the opening and cleaning process is the first process in the spinning process. The opening and cleaning combine of this process completes the following tasks:
- Opening Loosen the pressed block fiber in the cotton bag into small cotton blocks or bundles.
- Impurity removal Remove 50% ~ 60% impurities from raw cotton.
- Mixture Fully mix various raw materials according to the proportion of cotton.
- Roll It is made into a uniform cotton roll with a certain weight and length for the next process. When the blowing carding unit is used, the output cotton flows to the cotton storage box of each carding machine in the carding process.
carding machine process
There are two technological processes in the production of cotton yarn: carding system and combing system. For textiles with high quality requirements, such as high-grade T-shirts, fine poplin, tire cord threads for special industries and high-speed sewing machine threads, their yarns or threads are spun through combing process. Compared with the combed cotton yarn, the combed yarn has 10% ~ 15% higher strength, 50% ~ 60% less NEP impurities and significantly improved evenness. The combed yarn has excellent mechanical and physical properties and appearance characteristics of good luster, uniform evenness, less knot and impurity, high strength and so on.
- Carding: carding small cotton bundles and small cotton blocks into a single fiber state;
- Impurity removal: remove small impurities and seed chips with fiber in small cotton blocks;
- Uniform mixing: mix raw cotton with different components among fibers, and make the output uniform;
- Sliver forming: sliver made to meet certain specifications and weight requirements and placed in the sliver barrel
Combing machine process:
Short fibers are excluded to improve the average length and uniformity of fibers. The lint content in the sliver accounts for about 12% ~ 14%, the noil rate in the combing process is 13% ~ 16%, and about 40% ~ 50% of the sliver lint can be excluded, so as to improve the length uniformity of the fiber, improve the yarn evenness, reduce the yarn hairiness and improve the yarn quality.
- Eliminate impurities and neps in sliver and improve the appearance quality of yarn. About 50% – 60% impurities and 10% – 20% neps can be eliminated in the carding process.
- Straighten, parallel and separate the fibers in the sliver. The fiber straightness in carding sliver is only about 50%, and the combing process can increase the fiber straightness to 85% – 95%. It is helpful to improve the evenness, strength and luster of yarn.
- Combine evenly, mix and strip. For example, the weight unevenness of carding sliver is about 2% – 4% (the weight unevenness of 5 meters of sliver), while the weight unevenness of combed sliver is about 0.5% – 2%.
- The combing process is composed of combing preparation machinery and combing machine. The combing preparation machinery is to provide combed small rolls with good quality for processing by the combing machine.
Draw frame process
Merge 6 ~ 8 slivers are fed into the drawing frame to improve the unevenness of sliver length. The weight unevenness of raw strips is about 4.0%, and the weight unevenness of cooked strips can be reduced to less than 1%.
- Drafting in order not to thicken the sliver made after merging, it must be thinned by drafting. Drawing can straighten the fibers with curly hooks in parallel, separate the small cotton bundle into single fibers, and improve the structure of sliver.
- Through the merging and drafting of each drawing frame, the fibers with different properties can be fully mixed.
- Quantitative control Through the fine adjustment of sliver ration, the weight deviation rate of cooked sliver is controlled within a certain range to ensure that the weight deviation rate of spinning meets the requirements and reduce the weight unevenness of spinning.
Roving frame process
Drafting: drawing sliver into roving.
- Twisting: add a certain twist to the roving to improve the roving strength.
- To avoid accidental elongation during winding and unwinding, and prepare for spinning drafting.
- Winding: winding the twisted roving on the bobbin. It is made into rolls of a certain shape and size for storage, handling and adaptation to the feeding on the spinning frame.
Technological process of roving frame
- Feeding mechanism: strip cylinder, strip guide roller and bell mouth.
- Drafting device: the drafting roller, the drafting roller and the pressurizing device are of the same grade.
- Twisting and winding mechanism: spindle, spindle wing, bobbin, upper and lower ribs.
Ring frame process
- Draft: draft roving to the required number.
- Twisting: make the yarn have certain strength, elasticity and luster.
- Winding: winding spinning yarn into tube yarn for transportation and post-processing.