Investigating the heat measurement techniques of sewing needle

Industrial lockstitch sewing machines have an unavoidable issue with the heat generated by the sewing needle during high-speed sewing. This needle heat causes thread breakage, burn spots on fabric and poor seam strength. Garment manufacturers and technical textile producers are forced to slow down production or use expensive cooling techniques, such as needle coating, thread lubrication, and forced cooling. In this research, the techniques used in needle heat measurement are summarised and show why the classical technique of thermal camera shows false readings. The research work shows repeatable results from a unique technique of embedded thermocouple technique to measure sewing needle temperature and compares with other techniques. The overall setup of this technique, including the types of thermocouples and receiver, is deeply explained in the article. This technique shows significant improvement in the needle temperature measurement methodology, which is tested at different sewing speeds and with the most common sewing threads used in the market. The article is useful for researchers and also for the industry to know exactly the needle heat before sewing and consider the machine parameters accordingly for better seam quality.