Research On Yam And Fabric Property Of Condensing Spinning By Flow Numerical Simulation Using FEM

Lattice apron-type compact spinning is one of the most widely used compact spinning system, which is achieved by utilizing airflow condensing equipment to condense fibers in bundle before twisting and improve yarn properties. At present, these aspects needed profound and systematic study, such as the accuracy of compact mechanism, the correlation between flow velocity and yarn property and fabric property, which are beneficial to optimization and improvement of condensing equipment and development and design of fabric. In this paper, three-line rollers compact spinning and four-line rollers compact spinning are studied. Reseach on numerical simulation of three-dimensional flow field is using ANSYS software. Flow velocity on motion path is obtained and then compact mechanism and fabric property are discussed.First, three-dimensional flow field model is built by AUTOCAD software and numerical simulation is using by ANSYS software, and then flow velocity can be obtained. Spun yarn 9.72tex, 14.58tex and 29.15tex are spun and motion path are obtained by the high-speed camera. According to figures, motion path of fibers in bundle are described in two-dimension coordinate system and corresponding flow component are obtained. Combined with additional twist, compact mechanism have been studied Finally,9 fabric samples is weaved by 9.72tex,14.58tex and 29.15tex yarn. The entire drawing process was recorded by the high-speed camera. The digital information of fabrics’ extension till break was analyzed, obtaining fabric tensile curve and the dynamic changes of length and width. Four aspects were analyzed in this paper:fabric tensile, dynamic change of local length and length and width over time.The results show three aspects:(1) In three-line rollers and four-line rollers compact spinning spin process, fibers in bundle are under transverse flow component and under vertical direction flow component. (2) Additional twists produce by transverse compacting function, vertical control force and friction force produced by lattice apron. Because of additional twists, fibers in bundle arrange more tightly with more hairiness in yarn. The yarn evenness, the hairiness and the strength have been improved. (3) The breaking strength and breaking length of lattice apron fabric is better than traditional ring spinning. The partial length and the tensile rate of lattice apron fabric is less than traditional ring spinning, which means that the concentration tension deformation of traditional ring spinning fabric is in the middle part. Transverse shrinkage and the rate of traditional ring spinning fabric is more obvious than lattice apron fabric. The air permeability, the crease recovery and the pilling property of lattice apron fabric is better than traditional ring spinning. The air permeability and the crease recovery of lattice apron fabric change along with yarn fineness.