Study On The Spinning Of Ramie Stretch-Broken Into Cotton Length Fiber

Because many of overlength and multiple length staple fiber exist in raw ramie fiber, the length of ramie fiber has very high variation, which cause many difficultier in ramie conventional spinning processing. At present, the degummed fiber or combed sliver was cutted into cotton length fiber, and then cutted fiber were blended with cotton to producing ramie/cotton blended yarns with high metric count and quality. But the processing has some disadvantages, such as high content of short fibers were produced when the ramie fibers were cutted off, and unsuitability of cotton comber to coarser and harder ramie fibers.Nowdays, some researchers began to use the strteth technology on ramie yarn. But there were still some problems based the poor quality of silvers stretch-broken and spinning efficiency. In the study, the ramie silvers which is more straight and loose than ramie were stretch-broken into cotton type fiber,and the silvers stretch-stretch-broken was produced on the cotton equipments,so the yarn quality and spinning efficiency were greatly improved.On the other hand, the stretch-breaking technology was used to produce ramie/cotton yarn,it has open up a new processing way to ramie/cotton.In this thesis, researches have been done are:(1) Study on the influence of stretch breaking effects with changing parameters on the quality of silvers stretch-breaked.The parameters are stretch-breaking gauge length,pre-stretch-breaking gauge length,draft multiple of stretch-breaking and roller pressure.(2) Study on the spinning for stretch-broken ramie fiber. Pre-drawn silvers of ramie and the pre-combed silvers of ramie were stretch-broken into the fiber with around40mm, similar to the length of cotton fibers, and then the silvers stretch-broken were drawing, roving and spinning on the cotton system. The process parameters of cotton equipments were studied and designed, the quality of ramie yarns of stretch-broken and conventional processed yarn were compared and analyzed.(3) Study on the spinning for stretch-broken ramie/cotton blended yarn. The ramie silvers produced by different processes mentioned above were stretch-broken into the fibers with cotton length, and then the silvers were blended with the silvers of cotton silvers. The process parameters were studied and optimun, the quality of ramie/cotton blended yarns of stretch-broken and of conventional processing were compared and analyzed.The results found are shown as follows:(1) The influence of stretch-breaking gauge length on the quality of silvers stretch-stretch-broken. The uneven fiber length rate increases with the increasely stretch-breaking gauge length,and the short fiber rate and long staple rate reduce with the increasely stretch-breaking gauge length. When the stretch-breaking gauge is same or integer times with pre-stretch-breaking gauge, the short fiber rate can be effectively reduced.(2) The influence of draft multiple of stretch-breaking on the quality of silvers stretch-broken. In a certain range, the long staple rate reduce with the increasely draft multiple of stretch-breaking. When the ramie were all broken, it need to a more draft multiple of stretch-breaking.(3) The influence of roller pressure on the quality of silvers stretch-broken. In a certain range, the long staple content in stretched sliver reduce with the increasely roller pressure.(4) The spinning efficiency was effectively improve by cotton spinning equipment to produce stretch-broken ramie yarn. The quality of ramie stretch-broken yarn carded system is some poor, but the quality of ramie stretch-broken yarn carded system is much better than the ramie yarns of conventional processing.(5) The quality of ramie/cotton yarn by stretch-breaking carded silvers, pre-drawing silvers, pre-drawing silvers and pre-combing silvers is some poor. After adjusting spinning process parameters, the quality of ramie/cotton yarn by stretch-breaking combed silvers is much better than the ramie/cotton yarns of conventional processing.(6) The critical twist factor of the stretch-breaking ramie/cotton yarns is around445, and the critical twist factor of the conventional ramie/cotton yarns is around475. So it was much easier for the stretch-broken ramie/cotton yarns to have better hand feeling and luster than the conventional ramie/cotton yarns.