Abstract
The needle temperature was determined by means of infrared flux measurements with an accuracy of±1°C. The seam temperature was deduced by investigating the temperature of the thermal hysteresis on the fiber arround the seam with special dyeing using disperse dye. From the result of the experiment, it was found out that the seam temperature was higher than the needle temperature by 30°C to 50°C.
The fusible vinylon thread as the bobbin thread was used for removing sewing thread with ease, and as a result of it the appearance of the cut threads was found clearly and easily. From the dying property of the seam, the melted cut threads could be discriminated from the cut threads caused by the mechanical force. It was found that the seam temperature were correlated to the occurrence of the melted cut threads. Therefore, the sewing condition causing the melted cut threads was found out easily.
