Preliminary Exploration Of Stretch-Breking Process In Silk Spunning

The silkworm cocoon-opened continous fibres in traditional silk-spunning process were disorderly. So fixed-length cutting will produce many short-fiber and ultra-long fibers. Based on stretch-breaking process can effectively control fibers'length,this article will lead stretch-breaking process into conventional silk-spunning process. Preliminary discussion the influence of stretch-breaking process on silkworm cocoon-opened continous fibres'performance, and the feasibility of stretch-breaking process applied to silk-spunning process.The main contents of this paper and conclusions are as follows:First, single factor cutting experiments of the amount of roller pressure, quantitative feeding,stretch-breaking distance. By single factor experiments,to determine the effects of every factor to the physical properties of cocoon-opening mulberry silk cotton.The results show that fibers become thinner after stretch-breaking process,their strength and elongation are slightly lower,but the strength and elongation unevenness are significantly improved.The effects of every factor are as follows:(1)With the increase in the amount of pressure,the amount of long fiber,Short fiber content, fineness, strength, elongation and initial modulus will become'ower. Fiber length irregularity will first decrease and then increase with increasing the pressure,we will get the lowest fiber length irregularity when the pressure value of one side is about 154kg;(2)Lesser quantitative feeding will get better stretch-breaking effects. Fiber fineness, short fiber content, fiber length irregularity, breaking strength and its irregularity, elongation and initial modulus gradually increased to varying degrees with the increase of quantitative feeding;(3)After the stretch-breaking in different spaces, the average length of fibers is slightly longer than the space.Short stretch-breaking will enlarge the extent of fiber damage.With the gradual increase of stretch-breaking length, fiber strength and elongation unevenness will continually be improved.Second,spinning with stretch-breaking silk floss. Mulberry silk floss will first get through the stretch breaker, whose stretch-breaking length is 85mm,then use stretch-breaking silk floss for conventional spinning and improved conventional spinning,and test the qualities of yarn,compare the qualities of conventional cut spinning, conventional stretch-breaking spinning and improved stretch-breaking spinning.The following are results:(1) The yarn quality of conventional stretch-breaking spinning is nothing near so well as the conventional cut spinning, and the continous fold is 5 percentage lower.The reason is:the straight mulberry silk intertwine mutually after the cotton-mixed process,they will be snapped in carding, which leads to the increase of short fiber and nep,and the decrease of comb fold.(2)The improvement of stretch-breaking spinning process means leading the mulberry silk sliver directly to the FK081 carding machine.The yarn quality of improved stretch-breaking spinning is better than the conventional stretch-breaking spinning,especially the yarn strength. The most important thing is manufacturing success rate (about 59.1%) of fine drafts after improved stretch-breaking spinning is increased by 5 percentage,which is slightly higher than conventional fine drafts.Third,improving spinning process with different fiber lengths. The cocoon-opening cotton are stretch-broken and span at different stretch-breaking lengths(60mm,80mm and 100mm).The best fit of stretch-breaking silk to the existing spinning equipment and technology is discussed.The conclusions are:(1)Spinning quality is greatly affected by fiber length,particularly embodied in carding process and sliver blending process. Appropriate fiber length will make lower short fiber rate and continous knot number, and combing manufacturing success rate.In this paper, stretch-breaking silks at 80mm stretch-breaking length are suitable for this process route.Compared with conventional spun silk,its number deviation decreased by 82%,weight unevenness has about 27% improvement,silver unevenness reduced by 4.8%,fine points reduced by 50%,thick places reduced by 33%,white flake reduced by 60%,strength improved by 5.7%, strength and elongation uneveness are improved by 32% or so.(2) Stretch-breaking silk silver of three fiber lengths can be applied directly to the existing spinning machinery and equipment.In this paper, stretch-breaking progress and conventional spinning process were slightly improved in order to explore ways to improve the quality of stretch-breaking; Tracking and testing the quality of semi-finished and finished products through the entire stretch-breaking and spinning process,in order to prove that the stretch-breaking technology can be used in the existing silk spinning production. If we want to make the stretch-breaking spinning technology better than the conventional spinning, stretch-breaking spinning progress and the equipment must be improved.