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.

This study proposes the innovation of the pocket attachment sewing process through research, design, and fabrication of a semi-automatic jig, fixture, template system installed on Juki AMS 221EN/2516 programmable sewing machine to sew the semi-automatic pocket attachment of suits, jackets. The innovation of the pocket attachment sewing process focuses on the designing and integrating an automatic edge-folding mechanism based on a mechanical - pneumatic system, combined with a PLC-based programmable controller to synchronize the edge-folding motion, fabric clamping in sewing cycle, while simultaneously retrieving the semi-finished products after sewing and arranging them in sequence for transfer to the subsequent operation.

Experimental tests after using semi-automatic jig, fixture, template system were conducted under actual production conditions. The results show that the average sewing cycle time is reduced and the productivity of pocket attachment sewing increases by about 30% compared with the traditional method depending on the fabric type and pocket size; at the same time, product quality becomes more stable and less dependent on the operator’s skill level. The proposed solution has strong potential for widespread application in garment enterprises producing pocket-attached products such as suits, jackets, and trousers…