Discuss the relationship between the cylinder speed of […]
Discuss the relationship between the cylinder speed of the carding machine and the color spinning neps, the obvious color knots and other quality indicators. The test results show that increasing the cylinder speed in an appropriate range is conducive to the increase of the single fiber carding force and reduces the color spinning. Neps and obvious color knots, it is proposed that the main motor of Xilin be changed to variable frequency speed regulation, which is helpful to determine a reasonable combing force and achieve the best combing effect.
The cotton yarns of different colors and natural cotton fibers are mixed in a certain proportion, and the color spinning yarns are spun.The large or prominent neps formed by the colored cotton fibers and the natural cotton fibers in the yarn are very eye-catching on the cloth. It seriously affects the quality of the fabric, and is usually called the obvious color knot. The obvious color knot is an important technical index for color spinning yarns, which is a difficult problem to solve in the production process of color spinning. Color spinning produces obvious The main factors of color knot are raw cotton performance, carding process and finishing process. As the market of color spinning products gradually expands and product grades continue to improve, the obvious color knitting yarn color knot has an increasingly prominent impact on product quality. Carding machine is to remove cotton The most effective knot, the process with the strongest capacity, and the carding quality determines the size and number of colored spinning neps and obvious color knots. This article explores the reasonable choice of the cylinder speed for the impact of the cylinder speed on the carding quality. The purpose of reducing neps and obvious color knots
1 Characteristics of cotton fiber after dyeing
After the cotton fiber is dyed, various physical properties change. Table 1 is a comparison of the physical index of the cotton fiber before and after dyeing. Table 1 shows that the fiber micronaire value increased by 4.7%, the strength decreased by 8.2%, the neps increased by 10.5%, and the main body length was shortened. 3.0%, short pile increased by 2.36 percentage points. The cotton wax on the surface of the fiber is basically removed. During the spinning process, the fiber will produce more short pile, neps and obvious color knots after strong carding and multiple carding.
2 Cylinder speed is closely related to combing force and combing degree
2.1 Relationship between cylinder speed and combing force
Among the various forces acting on the fiber, the carding force is the larger force for carding directly, and its size can reflect the role of the needle teeth holding the fiber, reflecting the strength of carding, so it is combed with carding, removing impurities, and extending the fiber. There is a certain relationship directly. Xilin, the approximate calculation formula of the total combing force of the cover area:
In the formula:-Xilin, total combing force (N) in the cover area;
N—the power consumed by the cylinder and cover plate when the fiber is fed (kW);
N 0—Power consumed by the cylinder and cover plate when the empty vehicle is running (kW);
V—Cylinder linear velocity (m / s); 1kW = 999.6N · m / s｡
According to domestic research reports, when the cylinder speed is increased, the average carding force of single fibers can be significantly increased, the neps are reduced, and the short pile is increased. At this time, the transfer rate of the doffer is also increased.
2.2 Cylinder speed affects the carding degree
High cylinder speed and high carding degree can improve fiber separation and straightening parallelism, which is helpful to reduce neps and eliminate impurities.
When the speed of the cylinder and the spur roller is increased under a certain output condition, because the amount of fiber output by the cylinder in a week is inversely proportional to the cylinder speed, and the centrifugal force increases in proportion to the square of the speed, the transfer capacity from cylinder to doffer And significantly reduce the amount of free fiber and needle load on the cylinder cover. Cylinder growth can also enhance the transfer of fibers from the cylinder to the cover. Therefore, cylinder growth can make the weight of undecomposed cotton bundles in the cotton net And quantity reduction. It can be seen that increasing the speed of the cylinder is to increase production and ensure quality. Even an effective process measure to improve quality is also an essential process measure for high yield and quality.