Research On Combing Process Of Long-staple Cotton

Long-staple cotton fibers with long length,low linear density,high breaking strength,good maturity and good spinnability are indispensable raw materials for processing high-grade textiles.The combing process of long-staple cotton can significantly improve the yarn quality,but most spinning enterprises adopt combing equipment,process parameters and carding elements used in the combing process are mostly based on the experience of fine cotton combing,and there are still some problems.Cylinder,tongs plate and detaching roller have poor coordination of movement,resulting in loss of spinnable fibers,high dropping rate and low combing processing speed;Long-staple cotton fibers fiber is longer,resulting in large drafting force of separation,and difficult to form a net;In the use of combing cylinder,cylinder of high teeth are often used.The load of needle teeth is heavy,the fibers are easy to be damaged,and inadequate carding,resulting in decreased quality of combed sliver;Single factor test is commonly used in the drafting process of comber.There is a lack of research on the interaction between factors and the worse evenness of combed sliver.Lack of research on combing technology of long-staple cotton based on fiber properties,the advantages of high speed,good quality and large output of the new high efficiency comber can not be fully utilized.In order to solve the above problems,and achieve high quality and efficiency in combing process of long staple cotton.In this paper,the length model of cotton web outside the separating nip is analyzed,and the driving mechanism of separating roller is optimized.The influence of cylinder location and circadian timing on cotton web tail length is studied when using constant speed and variable speed cylinder forms.Optimizing cylinder location and rotation timing for combing long-staple cotton to reduce dropping rate and increasing combing processing speed.The factors affecting the separation drafting force were analyzed.A special tongs plate for long-staple cotton is designed.Taking the position of feed roller as variable.Establishing clamping element model to solve the problems of large traction force and difficult netting when detaching and attaching.Designing a set of special Cylinder for combing long-staple cotton.The parameters such as the number of cylinder teeth,the density of teeth and the tolerance of needle teeth are rationally matched to reduce the load of needle teeth and avoid excessive carding of fibers and meet the requirements of yarn quality.Quadratic general rotary unitized design was used to optimize the drafting process of long-staple cotton combing,improve the evenness of the yarn,reduce fiber damage,and improve yarn quality.The results show:(1)Optimizing the driving mechanism of detaching roller can increase the suitable spinning fiber length of comber and meet the requirements of combing process of long-staple cotton.The combing process parameters with variable speed cylinder,cylinder location at 37 degrees and forward rotation timing at 15.5 degrees can not only ensure that the cotton web outside the separating nipper is not grasped by cylinder,but also ensure the best bonding quality of combed cotton web.(2)The back-moving tongs plate of feed roller can obviously reduce the separating drafting force of comber and improve the combing and yarn quality.The combing process with 11 mm noil gauge,backward feeding cotton,4.3-4.7mm feeding length,30 needles/cm top comb,and 0.5 top comb depth can effectively reduce the separation drafting force,improve the quality of combed cotton web,more uniform comb sliver evenness,better neps,impurities and short fibers removal effect,and better yarn quality.(3)A special cylinder for long-staple cotton was designed.Increasing the total number of cylindrical teeth can improve both combing and yarn quality.The optimum number of cylindrical teeth is 37180 teeth.Continuing to increase the total number of cylindrical teeth will lead to the leakage of combing of upper cotton bundle fibers and excessive combing of lower fibers,which will deteriorate combing quality and yarn quality.The long-staple cotton is combed with 130 arc surface cylinder,and the combing and yarn forming quality is better.(4)Optimizing the drafting process of comber tail by quadratic general rotary unitized design,the mathematical model of yarn quality index fits well with the actual test,and can be used to predict yarn quality index.The optimum process is: main drawing roller center distance: 44.7mm,back drawing roller center distance: 52.01 mm,drafting ratio at back zone: 1.35.