1. The concept of carding
Carding is to use a flat plate or roller carding machine to card the small cotton bundles into a single fiber state with the help of needle movement. , to further remove impurities and non-spinnable short fibers, straighten the fibers in parallel, and finally make cotton slivers and coil them into sliver cans.
Because after being processed by the blowroom combined machine, the fibers in the cotton roll or loose cotton are mostly in the state of loose cotton pieces and cotton bundles, and contain 40% to 50% of impurities, most of which are small, For fibrous impurities with strong adhesion (such as fiber-broken seeds, seed dust, soft seed skin, neps, etc.), it is necessary to completely decompose the fiber bundles into individual fibers and remove the small impurities remaining in them to make each fiber The cotton component fibers are fully mixed in the single fiber state to make uniform cotton slivers to meet the requirements of subsequent processes.
2. The role of carding process:
1. Carding will cause as little damage as possible Under the premise of removing fibers, the fed cotton layer is carefully and thoroughly carded to separate the bundle fibers into single fiber state.
2. Impurity removal: Completely remove residual impurities and defects on the basis of full separation of fibers.
3. Mix evenly so that the fibers are fully mixed and evenly distributed in the single fiber state.
4. Make uniform slivers of certain specifications and quality requirements into strips and place them regularly in sliver cans.
3. Tasks of the carding process:
1. Card the cotton pieces or bundles Carry out careful combing to basically separate it into a single fiber state.
2. Continue to remove impurities with small fibers or strong adhesion impurities remaining in the cotton roll or cotton flow, so that the impurity content in the card sliver is reduced to 0.1 %about.
3. Uniform mixing: Use the “suction” and “release” functions of card clothing to achieve uniformity and mixing in the single fiber state.
4. The slivers are made into slivers that meet certain specifications and weight requirements, and are regularly circled in sliver cans.
IV. Process flow and functions:
1. Cotton feeding and licker-in parts.
The main functions of the cotton feeding and licker-in parts are to feed the cotton layer into the machine, hold and comb the cotton layer, and remove impurities and short lint.
Cotton feeding The holding effect of the cotton feeding part directly affects the carding effect of the licker-in, so it requires firm grip, even horizontal grip, and appropriate grip force. Otherwise, the licker-in will be unevenly carded in the transverse direction, the cotton layer in the weakly held areas will be of poor carding quality, and the cotton bundles will not be fully decomposed.
The carding magazine function of the lick-in roller part. The main function of the licker-in part is to use the serrations on the surface and the serrations on the surface of the licker-in carding plate to pierce and comb the cotton layer and remove impurities and short lint. The carding quality directly affects the carding quality of the cylinder cover, and is closely related to the number of neps and impurities in the card sliver, the evenness of the sliver and the degree of fiber damage. The main factors that affect the carding effect of the licker-in roller are: licker-in speed, cotton feeding plate technology, licker-in tooth specifications, carding plate technology, etc.
2. Cylinder, cover plate and doffer part.
The cylinder, cover plate and doffer part are mainly composed of cylinder, rotating cover plate, front and rear fixed cover plates, doffer, front and rear cover plates and large drain bottom. The fibers that have been initially carded by the licker-in roller are further carefully combed between the cylinder covers to remove some small impurities and short lint. The doffer condenses the fibers carded by the cylinder covers into fiber layers. The fibers are carded. And complete the uniformity and mixing during the coagulation process.
3. Stripping and looping parts.
The function of the stripping device is to strip the fiber layer condensed on the surface of the doffer into a web.
The function of the coiling device is to pull and compress the sliver output from the large pressure roller through the small pressure roller, and then coil it into the sliver can through the coiler.
4. Card clothing.
The cylinder, cover plate and doffer surface of the carding machine are covered with needle teeth of different specifications and models. This covering is called card clothing. In order to ensure good carding, impurity removal and uniform effects, the card clothing should have the following properties: 1. Good puncture ability and certain holding ability. 2. Good transfer ability. 3. Good ability to absorb and release fiber. 4. The needle teeth should be sharp, smooth and wear-resistant, and the needle surface should be smooth.
5. The relationship between carding machine and carding quality
The task of the carding process is completed by the carding machine. The carding machine loads cotton. The degree to which the bundles are separated into single fibers is closely related to the strength and evenness of the yarn; the effect of its impurity removal largely determines the neps, impurities and evenness of the yarn; the carding machine is in each unit of the carding system. The waste rate in the carding machine is the highest, and the waste contains a certain amount of spinnable fiber, so the quantity and quality of the carding machine waste are directly related to the amount of cotton used. </p
