The On-line Inspection of Sewn Seams

Apparel manufacturing is traditionally very labor intensive due to the extensive style and fabric variation of the products. Most of the sewing machine manufacturers and some of the larger apparel companies have developed semi-automated sewing stations to perform operations which are constant across a large style range. These normally require an operator to load the machine, which then automatically sews and stacks the components. Although such stations improve production efficiency, they remove the almost unconscious operator inspection of the operation. The result is that only major seam faults such as thread breaks are observed. Other faults, skipped stitches or non-included seams for example, may not be detected until the garment is completed or perhaps not until after laundering. At this point, the manufacturer’s cost is at a maximum. In order to reduce the number of defective garments it is necessary to develop complete seam monitoring systems that meet the apparel manufacturer’s requirements of flexibility, cost, and reliability. Several techniques capable of detecting faulty seams on-line have been investigated which include thread line monitoring and the use of a beta-particle transmission gauge. Prototypes have been developed for testing and demonstration of these techniques. The details and results of these investigations are provided. GOALS: SHORT TERM: Design, develop, and evaluate sensor technologies to measure and quantify the quality of seams. The production of proof-of-concept prototypes will demonstrate the suitability of those technologies recommended for real-time monitoring systems. LONG TERM: Produce a “black box” to be attached to a sewing machine which would provide information that would allow for the real-time adjustment of the sewing machine settings in order to optimize performance. TECHNICAL QUALITY AND ACCOMPLISHMENTS: An interdisciplinary team of researchers from the College of Textiles at North Carolina State University and the School of Textile & Fiber Engineering at Georgia Institute of Technology have collectively addressed the following tasks: 1) industrial collaboration in order to compile a technology survey and determine design specifications, 2) the fundamental research of fabric and seams, 3) the investigation of technological concepts which could potentially be used in a seam monitor, and 4) the construction of proof-of-concept prototypes to demonstrate those techniques of greatest feasibility. The technical quality of the research is reflected by progress made thus far in the second year of the project. A brief summary of the research effort for this reporting period is also provided. National Textile Center Annual Report: August 1995 221