SINOPSIS

In industrial sewing, needle heating is a key problem that limits a further increase of sewing speed, and hence the productivity. A high temperature of the needle affects the quality and productivity of sewing. This study deals with the analytical modeling of needle temperature in an industrial sewing machine. Based on the friction heat generated between the needle and fabric and the needle and thread, the authors show that the needle temperature is dependent on the geometry of the sewing machine's driving mechanism and on the sewing speed. In the present paper, the objective is to analyze the heat transfer mechanism in an industrial sewing machine and to develop a simpler model for predicting a maximum temperature of the needle. An experimental method of determining the needle temperature by inserted thermocouples is described. The developed analytical model is validated through comparison with experimental results. Compared with experimental results, the proposed analytical model can better predict the needle heating than the models described in the literature. In fact, the relative error between experimental and analytical results does not exceed 6%.