The carding process can remove impurities, neps and lint, but it also produces neps and lint. The main factors that affect impurities, neps and short lint in the carding process include the condition of the card clothing, the rotation speed of each part, the main gauge, the sliver quantity and the sliver delivery speed. Therefore, we should reasonably configure the carding process parameters to reduce fiber damage and ensure fiber carding and timely transfer.
Preferred card clothing
raw strips The quality depends on the selection and matching process of metal card clothing. Factors such as product positioning, fiber performance, quality requirements, sliver quantity and output should be considered when selecting the matching type. Domestic and foreign card clothing manufacturers can provide different specifications of needles. cloth to meet user needs.
Under normal circumstances, the tooth density should be gradually increased from the licker-in carding plate to the rear fixed cover plate to the rotating cover plate to the front fixed cover plate to the cylinder card cloth. The principle of gradually strengthening the role. For example, the carding lick-in roller can use comb needle type or large horizontal dense card clothing to reduce the generation of short lint; the new type of cylinder card clothing has short, shallow, pointed, thin, dense and small needle teeth, and has strong puncture and holding capabilities. and other characteristics; the doffer can use a new type of card clothing with large tooth depth, small working angle, and curved back, which is conducive to the cohesion and transfer of fibers to the doffer.
As a key component of the carding machine, card clothing should be carefully selected when choosing a supplier. The card clothing should meet the needs of targeted adjustment of various carding process parameters to ensure the fiber quality. Carding effect, reducing the number of neps in the card sliver.
Process parameter setting
01Lick-in roller
The function of the carding roller is to pre-card the fiber bundles. In the process, dust and short lint are removed, and short lint is also produced. The rotation speed of carding rollers, the length of the cutting process, and the gage are the main factors that affect the production of short lint. When configuring the licker-in process, attention should be paid to: the licker-in speed should not be too high to reduce the production of short lint. Most of our companies set it at around 750r/min; the length of the splitting process should be consistent with the main length of the cotton fiber; the points of the splitting process The distance to the cotton feeding roller should also be appropriately enlarged to reduce the blowing force and stabilize the instantaneous grabbing amount of fibers. Most of the settings of our company are in the range of 0.8mm ~ 1.0mm; under the condition of ensuring that the available fibers are not scraped off, appropriate Use low-knife technology to enhance the elimination of impurities and short lint; in order to make up for the shortcomings of fiber carding at the relatively low speed of the lick-in roller, consider using large transverse density lick-in roller card clothing; the distance between the lick-in roller and the pre-carding plate should not be too small , adjust appropriately according to the specific situation to prevent fiber bundles from clogging the carding plate, thereby producing neps. Our company sets the distance at 1.5mm~2.0mm in accordance with the recommendations in relevant literature.
02 Cylinder
Cylinder Process setting is the core of carding process. The linear speed ratio between the cylinder and the licker-in affects the generation of neps; the rotation speed of the cylinder affects the removal of neps and impurities, as well as the carding of fibers and the generation of short lint; the distance from the cylinder to the cover plate affects the carding and detangling of neps. Carding and orientation of fibers.
The cylinder speed setting should ensure that the line speed ratio with the lick-in roller is 2:1 or above, so as to ensure the smooth transfer of fibers and avoid neps caused by back-flowering. Our company reduces the cylinder speed to about 360r/min according to the speed of the licker-in. Although the carding force of the fiber is reduced after the cylinder speed is reduced, the damage to the fiber is reduced and the interaction time between the fiber and the carding area is increased. Coupled with good card clothing specifications, the fibers can also achieve better carding effects.
The distance between the cylinder and the cover plate should be based on the principle of “coordination of size and gradual transition”. The spacing of the rear fixed cover is based on the principles of pre-carding and fiber orientation. It should not be too small to avoid clogging the carding plate and causing neps. It should be adjusted appropriately according to the output. The output of some of our company’s carding machines is 38kg. Left and right, the gap is set at about 0.6mm. The distance between the cylinder and the movable cover affects the carding length of the fiber. If the distance is small, the length from the carding point of the fiber to the fiber tail end is long, and the carding effect is good, and vice versa. Therefore, the five-point distance between the cylinder and the rotary cover should be tightly controlled to facilitate carding. The roundness and dynamic balance of the cylinder should be considered when setting. The distance setting of most companies in our company is basically 0.203mm. , 0.178mm, 0.178mm, 0.178mm, 0.178mm. The front fixed cover mainly plays the role of fiber orientation and combing, and is basically set at 0.203mm.
03 Rotary cover
High productivity The carding machine flat plate turns in the opposite direction to the movement direction of the cylinder when it enters the action area. The linear speed of the flat plate mainly affects the impurity removal and fiber carding effects. As the linear speed of the flat plate increases, the knots thrown by the cylinder to the flat plate by centrifugal force can be removed relatively quickly. At the same time, the action time of the needle teeth on the fibers is reduced, resulting in a decrease in the carding effect. Therefore, in order to fully card the fibers, the linear speed of the cover plates of some companies of our company is set at around 1l0mm/min, which achieves ideal results.
04 Doffer
Improve carding The transfer rate of the doffer is beneficial to reducing the generation of neps. Therefore, the distance from the doffer to the cylinder should be as small as possible. Our company generally sets it at 0.127mm, and some companies set it at 0.102mm. The gauge setting should also be adjusted appropriately according to the processing accuracy of the equipment to prevent the card clothing from being squeezed and damaged.
05 Sliver ration and output speed
Reasonable optimization of the process parameters of each process will help to reasonably grasp the sliver sliver quantity and sliver delivery speed. The sliver sliver quantity of some companies in our company is about 21g/(5m), and the sliver delivery speed is set at 140m/min~150m. /min, raw sliver qualityThe indicators are ideal. </p
