Spinning Process - The Major Steps

 

Spinning is a very ancient activity, and people have understood how to spin small fibers into long threads, which are subsequently weaved into cloth since prehistoric times. Spinning process, in general, is the act of twisting animal or vegetable fibers to make a continuous and infinitely expanding thread ideal for weaving.
Cotton spinning is the technique of spinning random short fibers such as raw cotton into continuous cotton yarn or cotton mixed yarn. Spinning is the process of transforming disordered fibers into fiber aggregates. Compressed cotton bales enter the cotton spinning mill as raw cotton. The fibers are blocky and disorganized, with different contaminants and flaws. As a result, it is important to loosen first and then assemble when spinning, that is, to break the superfluous link between fibers and remove them. Impurity flaws are organized axially to generate slivers of the desired thickness, which are then appropriately twisted to form cotton yarn.
Cleaning, carding, combing, drawing, roving, and spun yarn are the major steps in the spinning process. Each stage in the spinning process is described in detail below:

Cleaning process

The cleaning procedure removes the majority of the contaminants, flaws, and short fibers in raw cotton that are not appropriate for spinning. It is to take the raw materials from the cotton bales, combine them equally, open them into little cotton blocks or small cotton bundles, and eliminate any impurities or faults. Cotton layers of varying widths, thicknesses, and weights are then combined and wrapped into laps.

The main task of cotton cleaning process

Mixing
The blending of raw cotton entails the blending procedure as well as the blending quality. Cotton bag loose fiber blending, sliver blending, and weight blending are now utilized in spinning. Particular care should be taken to ensure the consistent blending of raw cotton with varying qualities, recycled cotton, and recycled cotton.
The more regular the mixing, the better it is for resolving color differences, color shift, improving uniformity, and lowering the coefficient of variation of single yarn breaking strength. To increase yarn quality, alternative cotton opening and cleaning techniques can be used for raw cotton with considerable differences in impurity concentration, and then blended on the draw frame.
Opening
Opening is required to guarantee that the blended cotton components are thoroughly mixed, that contaminants are eliminated, and that the fibers are single-fibrillated. According to the opening state of the feed material, opening can be classified as free or holding.
1. Unrestricted access
Free opening refers to raw cotton accepting the operation of the opening mechanism in a free condition, which can be further subdivided into free tearing and free blowing.
2. Hold and release
The raw material is fed into the machine in the holding condition while also being impacted by the opening mechanism, a process known as holding and opening. On raw cotton, it may be separated into two action modes: holding and hitting and holding and carding. The results of openness and impurity elimination are more liberated. The opening is robust, but the fiber damage and impurity crushing are more severe than free opening.
The notion of “slow down initially, then quick, progressive opening, and minimum fiber damage” should be followed during the opening process. In the process of impurity removal, impurities that are heavy, relatively large and easily broken, and have low fiber adhesion should be eliminated first in line with the technological principle of “early falling and anti-shattering”.

Machinery involved in the cleaning process:

Cotton opener, cleaning machine, cotton blending machine, lapping machine.

Carding process

Carding is the process of breaking tiny cotton bundles into a single fiber condition by needle surface movement, removing contaminants and non-spinnable short fibers, making the fibers parallel and straight, and ultimately making a sliver Roll into cans.
 After cotton cleaning, the fibers in the cotton roll or loose cotton are mostly in the form of loose cotton blocks and cotton bundles, and contain 40% to 50% impurities, the majority of which are small, highly adhesive fibrous impurities (such as broken seeds with fiber, seed scraps, soft seed skin, cotton neps, and so on), so the fiber bundle must be completely decomposed into single fibers, and the fine impurities remaining in it must be removed, so that the fibers.

The main tasks of the carding process

• Carding: In order to cause the least amount of damage to the fibers, the feed cotton layer is carded painstakingly and thoroughly to separate the bundled fibers into single fiber states.
• Impurity removal: After adequate fiber separation, completely remove residual impurities and flaws.
• Mixing: In the single fiber state, ensure that the fibers are thoroughly mixed and equally dispersed.
• Slivers: Make uniform slivers to particular specifications and quality standards and store them in sliver cans on a regular basis.

Carding machine

The carding machine is responsible for completing the carding process. The extent to which cotton bundles are split into single fibers on the carding machine is directly proportional to yarn strength and evenness. The effect of its impurity removal influences the nep impurities and evenness of the yarn significantly. The carding machine has the highest noil rate of the carding system’s single machines, and the noil has a particular number of spinnable fibers, therefore the quantity and quality of the carding machine’s noil are directly proportional to the amount of cotton utilized.

This post is reproduced from fyitester.