Innovation of the pocket attachment sewing process through research, design, and fabrication of a semi-automatic jig-fixture-template system for the Juki AMS-221EN/2516 programmable sewing machine

Abstract

Pocket facing attachment in veston/jacket production is commonly performed on single-needle sewing machines. During sewing, operators must manually fold and continuously hold the facing edge to ensure stitch-line accuracy, while retrieving and arranging semi-finished parts after sewing. These manual operations increase the sewing cycle time and lead to quality variation. This study proposes an innovative pocket-facing sewing process on the Juki AMS-221EN/2516 programmable sewing machine using a semi-automatic jig-fixture-template system. The system integrates a pneumatic edge-folding and clamping mechanism controlled by a PLC using a cycle-state control scheme synchronised with the sewing motion, and automatically retrieves and arranges semi-finished parts after sewing; consequently, interlocks are clearly managed and operational reliability is improved under repeated operation. Production trials were conducted 30 times over 30 days (4 hours per trial; n=30 for each method). Results show that the mean cycle time decreased from 11.9±0.7 s/part to 8.3±0.5 s/part (-30.3%; Welch’s t-test, p<0.001), corresponding to an output increase from 1212 to 1739 parts per 4 hours (+43.5%). The topstitch line became more stable and less
dependent on operator skill due to the elimination of manual edge holding.