The Study On The Spinnability And Blended Yarn Development Of Hemp Fiber

Hemp fiber is a population which has a long history,extensive distribution and multiple forms.It has been used as a textile fiber by human beings for a long time.As one of the natural cellulose fibers,hemp fiber not only has excellent properties of dye,moisture absorption and abrasion resistance,but also has excellent properties of natural bacteriostasis and health care,anti-ultraviolet and anti-radiation.Hemp products have unique ecological properties and can degrade by themselves under the action of microorganism and photoheat.However,due to the rough nature and poor spinnability,it is difficult to produce exquisite and high-quality hemp products.In addition,due to the policies and other reasons in the last century,the researches on hemp fiber has been in a state of slow development.Use hemp fiber for spinning,it needs to be degummed into processing fiber first.Degumming quality will directly affect the spinnability.It is necessary to properly remove non-cellulose materials in the fiber bundle,prevent degumming from damaging the fiber bundle interior and the fiber bundle being completely disintegrated into single fibers.The properties of degummed hemp fibers,such as poor length uniformity,high torsion resistance,etc.,make it difficult to successfully spin hemp fibers in cotton spinning equipment,which further restricts the development of hemp fibers in textile.This paper explores the adaptability to pure spinning process of hemp fibers with different specifications,and combines the predecessors’ researches to explore the hemp cotton blended yarn spinning process and solve the problems in the spinning process,then develop the hemp/cotton blended yarns which have high strength and meet the requirements of weaving process,finally study the antibacterial properties of hemp cotton blended fabric to pursue the high value-added development space of hemp products.The specific research Content as follows:First of all,the basic properties of hemp fibers of different specifications were tested.The test results had be taken as the basis for exploring pure spinning process parameters of limiting linear density.Test results show that the six kinds of hemp fibers are different in length,fineness,besides,the initial modulus,breaking strength and specific resistance are high in general.Second,pure hemp fiber spinning process was studied,and the results shows that the different specifications of the fiber has different limiting linear density,the influence to the limiting linear density of fineness are maximum.There is a big gap between the number of fibers in the final yarn section with the ideal state,which indicates that the line density of pure hemp yarn has much room to improve.Then the yarns with different hemp fibers of the same linear density were spun and tested.Low breaking strength cannot meet the requirements of weaving.Therefore,combined with the test results of the limiting linear density spinning part,the relatively long and thin fiber was optimized to blend with cottoned.Thirdly,Spinning hemp cotton blended yarns with different blending ratios,It is found that the content of hemp is lower,the quality of the yarn is better,and the critical blend ratio is 50/50(hemp/cotton).In order to give consideration to the characteristics of hemp fabric,the blending ratio of 40/60(hemp/cotton)is finally selected.Fourthly,in the process of exploring the single factor,the twist factor,draft multiple in the rear section and nip gauge have great effects on the strength,evenness and hairiness respectively.Then orthogonal experiments were carried out at three levels of these three single factors.Next,the orthogonal experimental results were analyzed successively by range and variance analysis,and the optimum process parameters are obtained: twist coefficient is 420,draft multiple in the rear section is 1.35,nip gauge is 3.5mm.Then the parameters are verified,and the yarn strength is obviously improved.Finally,the antibacterial properties of hemp blended fabrics were discussed.The hemp/antibacterial viscose/cotton blended yarn with the blending ratio of 35/5/60 and the hemp/cotton blended yarn with the blending ratio of 40/60 were spun and knitted into knitted fabrics separately to test their antibacterial properties.The results show that the anti-bacterial viscose is added to the blended yarn.The results show that the blended yarn fabric with antimicrobial viscose has better antimicrobial properties.