Simulation of airflow in the condensing zone of a modified compact spinning device and analysis of its yarn properties

Compact spinning is a new type of ring spinning. Its main purpose is to reduce the yarn hairiness and widely put into practice in stable fiber spinning. In this article, a new compact spinning device for long fiber is put up: lateral compact spinning with pneumatic groove. The simulation and characterization of the flow field in the condensing zone are made by computational fluid dynamics software. Then the distribution rules of static pressure and velocity in the condensing zone are carried out at the different position of the lateral groove. In the numerical simulation, the results show that the condensing airflow is largest at the center of the lateral groove and the gathering velocity is largest at the edge of the lateral groove. Meanwhile, the four different yarns are spun and the yarn properties are compared. By testing the hairiness, strength and twist properties, analyzing and comparing the results with the data of four spinning yarns, we find the best fibrous strand feed in position. The theory analysis gives foundation and explanation for the experiment, and also provides a theoretical basis for optimizing the properties of long fiber compact spinning yarns in production practice.