Study On Spinnability And Energy Saving Potential Of Recycled Cotton Fiber

In recent years,with the enhancement of environmental protection awareness of all sectors of society,the demand for green and renewable products is increasing.Textile industry,as an industry with serious pollution,is also constantly moving forward on the road of green environmental protection.As a way of waste reuse,mechanical recycling of waste textiles has the characteristics of simple shredding principle and limited pollution.Because of this,the market access threshold of mechanical recycling method is low which is same as mill management.Besides,the industry production is not standardized and tends to be less mechanized.The shredding of recycled cotton fiber in Cangnan area of China has been developed for decades.Up to now,a lot of work still needs to be done by labor force.The recycled cotton fiber shredded by mechanical method has poor strength,tidiness,short length and high short fiber rate.It is mostly used to produce some fabrics with low external requirements,which greatly limits the use of recycled cotton fiber and the industry development.At present,the research on recycled cotton fiber is mainly focused on the reuse of waste in each process of spinning mill.This kind of fiber has little damage and is easier to spin.In the aspect of research,this paper focused on the shredding of different fabrics and the spinnability of different types of recycled cotton fibers through the field investigation of the mechanical recycling enterprises of recycled cotton,and looked for the suitable spinning process for the recycled cotton fiber.At the same time,in order to further promote the recycled cotton yarn,the energy consumption of the production process of the original cotton and the recycled cotton was compared.The specific research work was as follows:First of all,the method of mechanical opening of recycled cotton fiber was introduced,and the shredding process of three different types of fabrics,A,B and C,was understood,and the performance of three types of recycled cotton fiber was tested.The results show that compared with virgin cotton,the strength of bundle fiber of recycled cotton fiber is similar to that of virgin cotton,but its elongation,short fiber rate and uniformity are poor.Secondly,the spinning process of recycled cotton fiber was explored,and the suitable spinning process was found.It is found that the use of fiber striper instead of carding process is conducive to reduce the damage of carding process on recycled cotton fiber.Then A,B,C three kinds of recycled cotton fiber and cotton were blended with the same linear density respectively.AHP is used to optimize the three kinds of recycled cotton yarn.The results show that the weight value of A-type recycled cotton yarn is 0.479,which means the quality is the best.Therefore,A-type recycled cotton fiber is selected for the next step of research.Thirdly,the best quality fiber in the previous step,the influence of A-type recycled cotton fiber was used to find how blending ratio was related to the performance of recycled cotton yarn.The blending ratio changed between 0-100%.The results show that the breaking strength of blended yarn decreases step by step with the increase of the blending ratio of recycled cotton fiber.When the blending ratio of recycled cotton is 53%,it reaches the critical blending ratio,where the breaking strength of yarn A decline dramatically.Due to the poor uniformity of the length of recycled cotton fiber and the influence of the mechanical working state,the yarn unevenness is larger than the theoretical value.The hairiness increased with the increase of the proportion of regenerated cotton fiber.When the blending ratio is 60%,the number of hairiness tended to be stable.Fourthly,in order to obtain the yarn with better performance,the rotor spinning process parameters of 37.5% recycled cotton yarn,such as rotor speed,combing roller speed and twist coefficient,were optimized.The second general rotation combination design was adopted,and the influence curved surface of each parameter on the yarn index is drawn with MATLAB.It is found that the rotor speed has a greater impact on the yarn quality.Then the random direction search method was used to find the optimal solution.The results show that when the rotor speed is 61420 r /min,the combing roller speed is 7405r/min,and the twist coefficient is 568,the yarn performance is the best.Through the yarn performance test,it is found that the yarn quality under this process parameter is greatly improved than before.Fifthly,in order to further promote the recycled cotton yarn and increase the green degree and recognition degree of the enterprise,the life cycle assessment theory was used to evaluate the recycled cotton products.The environmental impact of the recycled cotton products in its life cycle was estimated by Simapro software,and compared with the original cotton products.It is found that when the recycled cotton fiber is 37.5%,compared with the original cotton products,the environment is better and the comprehensive impact value decreased by 43.5%.