Mechanical Application Brief

Fabric Testing

The Problem

As garment manufacturers compete to increase rates of production, an increasingly important objective of research in the industry is to find fabric and thread combinations that can be sewed at high speeds without producing defects. Sewing is one of those ancient human activities that is difficult to automate because there are too many variables with wide parameters. Putting together a garment, for instance, requires choices of fabric and thread, variation in stitch size and thread tension, and the ability to compensate for aberrations in materials, among other factors. Richard Chmielowiec of the Hong Kong Polytechnic in London, is conducting research into setting up a system for testing a factor he calls "sewability"- the capacity of a fabric and thread combination to be sewn without producing defects such as seam buckling. He investigates dynamic conditions during high-speed sewing to determine which variables involved in sewing a good seam can be tested reliably.

Software for Sewing Analysis

Chmielowiec's RSTM/SPMS instrumentation is called an ETS (Experimental Testing Sewability) station, where RSTM stands for Richard's (Chmielowiec) Sewability Testing Method, and SPMS stands for Seam Pucker Measuring System. The instrumentation consists of a state-of-the-art Pfaff lock-stitch sewing machine with several sensors attached and uses a textile evaluation method called image processing analysis. The station's data analysis software must be flexible enough to perform many kinds of analyses, and it must be menu-driven, so researchers can learn to use it in minimal time. Finally, it must be highly compatible with other software and hardware components, to accommodate changes in instrumentation and analysis methods over time.