Experimental Simulation and Analysis of the Yarn Motion Track in a Hairiness-Reducing Nozzle

A visible magnified and simulated nozzle was designed and installed on a winding machine according to the similarity principle of Reynolds number,to study the yarn motion track in hairiness-reducing nozzle.High-speed photography was used to observe the yarn instantaneous motion state in the nozzle.The results show that the yarn motion track seems to be a cylindrical helix which is close to inner wall in the twisting chamber and kept the same with different technical parameters,such as diameter of the twisting chamber and jet pressure in orifices.According to simulation results and reasonable simplification,the motion track equation and the rotational equation of the yarn could be derived.The velocity of the swirl and hairiness is faster than that of the yarn balloon,so there is enough time for hairiness to be wrapped into the main body of yarn and hence the hairiness is reduced.