Core Spun Yarn Manufacturing Process
1 Opening and Cleaning Process
The main tasks of this process are:
(1) Opening: Through the tearing and blowing action of the brad nails, beaters in each individual machine of the cleaning and cleaning machine, the compressed block fibers in the fiber package are loosened into small fiber bundles weighing 0.3-0.5g, which are used for impurity removal and cleaning. Blending creates the conditions for separation into single fibers. Minimize debris fragmentation and fiber damage during opening.
(2) Impurity removal: at the same time of opening, removing 50% to 60% of impurities in raw cotton should reduce the fall of spinnable fibers and save fibers.
(3) Mixing: Mix all kinds of raw materials in proportion, the fibrils will be loosened well, and the mixing will be more uniform.
(4) Uniform roll: make a certain weight, a certain length and a uniform fiber roll for the next process.
2 Carding Process
After the opening and cleaning combined machine processing, the fibers in the fiber roll are mostly in the state of loose fiber blocks and fiber bundles, and contain 40% to 50% impurities, most of which are small and highly adhesive fibrous impurities. It is necessary to completely decompose the fiber bundle into single fibers, remove the small impurities remaining in it, make each component fiber fully mixed in the single fiber state, and make a uniform sliver to meet the requirements of the subsequent process of core spun yarn manufacturing.
The tasks of the carding process are:
(1) Carding: Under the premise of as little fiber damage as possible, the feeding fiber layer is carefully and thoroughly carded to separate the bundle fibers into single fibers.
(2) Impurity removal: On the basis of sufficient separation of fibers, thoroughly remove residual impurities and defects.
(3) Uniform mixing: the fibers are fully mixed and evenly distributed in the single fiber state.
(4) Sliver: Make the uniform fiber sliver of certain specifications and quality requirements and place it in the fiber sliver can regularly.
We use flat cards for this process in our core spun yarn factory, and some core yarn factories also use roller cards.
3 Drawing Process
The fiber material has been opened and carded before the process, and has been made into a continuous strip of semi-finished products, that is, sliver, but it cannot be directly spun into spun yarn, because the quality and structural state of the sliver are far from the final. There is still a big gap in the requirements for yarn formation, and the straightness and separation of the fibers are poor. For example, most of the fibers in the green sliver are still in a buckling or hooked state, and some small fiber bundles exist; while the combed sliver has better straightness of the fibers, but the evenness of the evenness is poor. If these slivers are directly spun through the roving, it will inevitably affect the quality of the final core spun yarn, so they must be processed by the drawing process first. This is an essential process for producing high-quality core spun yarns.
The tasks of the drawing process are:
(1) Merging: 6-8 fiber slivers are combined and fed into the drawing frame to make a fiber sliver. Since the thick and thin sections of each fiber sliver have the opportunity to overlap each other, the unevenness of the long segments of the sliver is improved. Rate. The weight unevenness of the raw sliver is about 4.0%, and the weight unevenness of the cooked sliver should be reduced to less than 1% after combining.
(2) Drafting: The sliver is stretched and thinned to the original level, and the state of the fibers is improved by drafting, so that the hooks and crimped fibers can be further straightened and paralleled, so that the small fiber bundles are further separated into single fibers. By changing the draft ratio, the ration of the sliver can be effectively controlled to ensure that the weight deviation and weight unevenness of the spun yarn meet the standards.
(3) Mixing: The mixing of single fibers is further realized by the method of repeated merging to ensure that the composition of the sliver is uniform and the yarn quality is stable. Due to the different dyeing properties of various fibers, the sliver made of different fibers can be combined on the drawing frame, so that various fibers can be fully mixed. An effective means of producing color difference, especially when chemical fiber and cotton are blended.
(4) Sliver formation: The fiber sliver made by the drawing frame is placed in a regular circle in the fiber sliver can for transportation and storage for the next process.
4 Roving Process
In the core-spun yarn factory, roving is the fourth process, and the sliver can be processed into rovings of different counts and twists for the spinning process.
The tasks of the roving process are:
(1) Drafting: The cooked slivers are evenly stretched and thinned, and the fibers are further straightened and paralleled.
(2) Twisting: appropriate twisting of the drafted sliver, so that the sliver has a certain strength, which is convenient for roving winding and unwinding on the spinning frame.
5 Spinning Process
Spinning is a very important process in spinning. It is to spin roving into spun yarn with certain properties, quality standards or customer requirements for twisting, weaving or knitting. The quality of the spun yarn reflects the production technology and management level of a core spun yarn factory.
The spinning process mainly completes the following tasks:
(1) Drafting: The fed roving is evenly stretched and thinned to the required number of spun yarns.
(2) Twisting: adding an appropriate twist to the drafted whiskers, so that the yarn has certain physical and mechanical properties such as strength, elasticity, luster and feel.
(3) Winding and forming: The spun yarn is wound on the bobbin according to certain forming requirements, so as to facilitate transportation, storage and subsequent processing.
After this process, the single-strand core-spun yarn is completed. However, in order to be used in the production of textiles, post-processing is also required.
6 Post Processing
(2) Improve the appearance quality of products