A study on the needle heating in heavy industrial sewing ‐ Part 1: analytical models

In heavy industrial sewing, needle heating has become a serious problem that limits the further increase of the sewing speed, and hence the productivity. The high temperature in the needle can degrade the strength of the thread. At the same, it may cause the wear of the needle eye, which would further damage the thread. It can also scorch the fabric, as well as temper and weaken the needle itself. Therefore, it is important to develop a model that can predict the needle heating and, hence, find remedies to minimize its effects. According to a literature survey, most research on needle heating focuses on experimental methods, such as infrared radiometry, infrared pyrometry, etc. This paper is the first part of our research on needle heating. In this paper, two analytical models are presented: the sliding contact model and the lumped variable model. These models are relatively simple and easy to use. Given needle geometry, sewing condition, and fabric characteristic, they can predict the needle temperature rise starting from initial heating to steady state. The simulation results are rather accurate. Hence, the models can be used to quickly identify the potential needle heating problems on the shop floor. In Part 2 of our study, a finite element analysis (FEA) model is presented together with the experiment results.