| The main functions of carding process are carding,impurity removal,mixing and stripping.The fibers in the cotton rolls sent from the previous carding process are in the form of small fibers or bundles,and there are many impurities.The carding process of carding machine is to loosen and carding small fibers and bundles with high density needle teeth on the card cloth,so that single fibers are fully straightened and separated from each other;Remove impurities concealed in small fibers and bundles;evenly mix and carding straightened single fibers and output into strips.Carding process is an important process in spinning,The impurity content of carding sliver,the straightness and separation degree of single fiber output from carding machine have an important impact on the quality of final products.In the mid-nineteenth century,after the emergence of carding machine with rotary cover,the structure of carding machine hasn't changed much in nearly a century.In the 1960 s,the application of metal card clothing greatly improved the ability of carding machine to handle fibers,and increased the output of carding machine to 50kg/h.Since then,in order to adapt to the modern carding concept of high-speed and high-yield carding machine,the specification parameters of metal card clothing have changed greatly,further improving the carding ability of carding machine.After entering the 21 st century,the innovation of metal card clothing is insufficient,which has little contribution to the development of carding machine.At the same time,the structure of each part of carding machine has matured,and the development of carding machine has entered the bottleneck.Further analysis shows that the carding quality of carding machine restricts the further development of carding machine.We should focus on the development of efficient carding clothing.Firstly,this paper discusses the design basis of misaligned card clothing.It is pointed out that compared with the traditional card clothing with the same parameters of needle teeth,the density of transverse needle teeth increases and the density of longitudinal needle teeth decreases,which can comb the fibers more fully,reduce the impact on the fibers and improve the carding quality.Starting with the manufacturing process of traditional metal card clothing,this paper points out several difficulties in the manufacturing process of misaligned card clothing,and then briefly introduces the manufacturing method of misaligned card clothing in this paper.Secondly,in order to verify the carding effect of misaligned card clothing,the traditional cylinder card clothing AC2030 *01550(denoted as A)and the misaligned card clothing processed on the basis of it(denoted as B)are experimented in this paper.Comparing the data of sliver generation rate and sliver index of the two schemes,the results show that the experiment of misaligned card clothing: sliver generation rate increased by 1.07 percentage points;fiber-knot removal rate increased by 2.8 percentage points and impurity removal rate increased by 3.3percentage points;The growth rate of staple fibers in scheme B is higher than that in scheme A;the longer fiber length and average fiber length of scheme B are higher than those of scheme A.Finally,in order to further verify the influence of misaligned card clothing on the final product spun yarn,we have made single sliver trial spinning based on misaligned card clothing and traditional cylinder card clothing.We compare the relative indexes of yarn evenness and strength between the two schemes.The results show that in the experiment of misaligned card clothing,the breaking strength of spinning yarn increased by 5.5%,and the CV value of breaking strength decreased by 15%;The CV value of yarn evenness decreased and the CV value of inter-tube evenness decreased by 20%,and the number of fiber-knot and thick or fine section in kilometers is reduced by more than 13%.Therefore,the use of misaligned card clothing has a positive impact on the quality of the spun yarn. |
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