Numerical prediction and experimental analysis of ends-together yarn splicing

Abstract

Pneumatic yarn splicing is a technical process for joining two yarn ends together. The process involves injecting compressed air into a splicing chamber. The inlet pressure and chamber slope determine the main parameters affecting this process. In this paper, large eddy simulation of the flow field in four selected splicing chambers is carried out. The chambers are used for splicing ends-together yarns. The results of these simulations are analyzed to investigate first the effects of the inlet pressure. Secondly, the effects of the geometry of the chambers on the flow field inside the splicing chambers are determined. These effects are studied and analyzed to interpret the experimental results, which have been obtained using the same splicing chambers. This provides further insight into the parameters that are important in order to obtain good splicing characteristics. It is demonstrated that the volume of the splicing chamber and the location of the air inlet channel play crucial roles in the splicing of the end-together yarns. The root mean square values of the velocity magnitude inside a splicing chamber have predictive values for the retained splice strength. The results provide solid evidence on the effectiveness of the computational fluid dynamics technology to study pneumatic splicing and optimize the geometry of an ends-together splicing chamber.