Study On The Simulation About Condensing Process And Additional Twist Of Compact Spinning With Lattice Apron

Compact spinning with lattice apron is one kind of new textile technology based on the technique of conventional ring spinning, pneumatical condense is used in this system to get fiber bundle into yarn. This technology catches lots of career men's attention for its significantly enhance yarn properties. Currently, researches on spinning mechanism of compact spinng technology and compact-spun yarn structure as well as the relationship between spinning process and yarn quality were not thoroughly enough for its short developing history, which caused a great limited to optimizing compact system and improving compact technology. Therefore, system of different air suction slots of compact spinning with lattice apron were regarded as the subject investigated in this paper, influence on the condensing effect and the performance of the yarn of the change of air suction slots.Generating mechanism of additional twist and influence on the condensing effect of the change of hairiness length and elastic modulus was studied.After precision measurement on each condense component of compact spinning with lattice apron firstly, the computational fluid dynamic model was established and was computerized with parallel technologies & standardκ-εturbulent model by computational fluid dynamics software FLUENT for simulating and characterizing the flow field in condense zone. Flowing state of airflow was characterized in condense zone, also distribution rules of static pressure and velocity and their effect on fiber bundle in inlet curved surface of suction slot were analyzed. Previous studies showed that:distribution of static pressure of straight groove and oblique groove is from inside to outside from-1700 pa to-100 pa, distribution of Y-axial velocity is Equal and in opposite directions,symmetrical about the center of groove and the firbers will be compacted along the center of the groove. z-axial velocity are negative,so can adsorption the fribers. It From the center line to the present in decreasing distribution; distribution of static pressure of alien slot is from center to both sides from -1800 pa to -100 pa; distribution of Y-axial velocity is both sides of the borde to curve L from -30 m/s and 25 m/s gradually reduced to 0 m/s, the firbers will be compacted along L curve.The distribution of z-axial velocity is similar to the straight groove and oblique groove.But in the whole,the speed too large.Then,on the basis of obtaining and extracting the distribution of velocity, dynamic model of infinitesimal element of fiber was established, and force analysis on single fiber in the airflow filed was completed, trajectories of fibers at different initial positions were simulated by specially designed MatLab procedure lastly. The research concluded that:in the gathering area of the straight groove,the fibers will output along the center of the groove. In the gathering area of the oblique groove and alien slot,the fibers will output along S2, the alien slot have the best compacting effect.The second is oblique groove.,the worst is the straight groove.Establish disturbed flow field gathering area model of oblique groove, analysising the flow fieid shows that the rotating flow fieid is exist. Use the Matlab programming to simulate the fiber trajectory in the rotation flow field.Analysis of the fiber trajectory and think that the fiber prod- uce the additional twist.elastic models are builded to Analysis influence on the condensing effect of the change of hairiness length and elastic modulus.It is get that The greater the elastic modulus, the more difficult the adsorption the same elastic modulus, the longer the hairiness, adsorption is easier,and likely around the main fibers forming additional twist.Finally, according to the thought used in the theoretical research, experiment scheme was designed and yarns listed in the scheme were produced, then physical and mechanical properties of yarn had been tested and compared.Uster properties, hairiness, breaking force of yarn that is made by alien slot compact spinning with lattice apron, the second is oblique groove. The worst is the straight groove.yarns may generate additional twist by slot and oblique slot grid compact spinning device.