The Effect Of Winding Tension On Seam Allowance Imprint During Knitted Fabric Cold Pad Batch Dyeing

Knitted products used so wide that almost involved in all fields of human life.With the advantage of short process flow,high production efficiency and low pollution,the cold pad batch dyeing plays a more and more important role in dyeing process.However,in the actual production,the knitted fabric easily have seam allowance imprint after wound,which seriously affects the dyeing quality and increases the cost of fabric dyeing.In this paper,plain knitted cotton fabric as the research object,to explore the impact of tension on seam allowance imprint.The main research contents of this paper include the following parts:1.The fabric physical property parameters were determined,including the thickness,density,friction coefficient,compression modulus,elastic modulus and Poisson's ratio of fabric.Compared with fabric parameters under dry and wet condition,reasonable calculation values were determined.2.The equivalent model of the fabric web was determined.According to the force condition of knitted fabrics with large extension in the winding process,the conclusion of the friction force is enough to resist the Poisson effect was obtained,so the model can be equivalent to axis-symmetric plane strain.3.A mathematical model of winding tension was established.According to the principle of elastic thick wall cylinder and the theory of Darren Bell principle,the relationship between the winding tension with inner radial pressure and residual tension was analyzed,mathematical model and iterative formula were established.4.Optimum design of winding tension of knitted fabric.The impact of numerical result which calculated by the mathematical model on the winding quality were compared under constant tension winding,taper winding,constant torque winding.A new winding method – power winding was proposed with the aim of reducing the number of fabric with seam allowance imprint and ensuring the fabric roll shape,and the power winding to get the winding tension with best winding effect was optimized by genetic algorithm.Finally,experimental verification is carried out on the unwinding and winding experimental device.5.The optimization system of winding tension under power winding was designed.