Sewing Machinery
assembled garments in the line, but the capital cost of the installation is high. The requirement for pick up or stacking devices is nil but other work aids, as described, would still be used. In more recent developments in production organisation and garment handling, a style of team working has been introduced where the operators in a production line work standing up at machines on higher pedestals. Each operator is multi-skilled and can do several operations in the sequence of construction of the garment. Thus they move along several machines, taking a single garment through these several operations, until they meet another operator ready for work, when they pass the garment on and return to an earlier machine to begin working on another garment. Again, no pick-up or disposal mechanisms are required, and in this case there is no investment in garment handling equipment between operations, but investment in sewing machines may be higher because the production line usually contains more machines than operators. There is very little work in progress and throughput is very fast. This is the main aim of the system as it enables a fast response to be made to demands for style change but it also improves skill levels amongst operators and gives opportunity for greater job satisfaction. Machines are specialised to each operation, with all appropriate work aids, and are generally slowed down to improve machine reliability and the operators’ control of their work.
Simple automatics There are machines that sew a short, automatic cycle such as a buttonhole, bar tack, buttonsew or label. The machine sews only one stitch type and changes in the stitching configuration are limited. As is the case with the plain machines described previously, more possibilities are available with the advent of microprocessor control.
Buttonhole machines These come in a variety of types according to the type of buttonhole needed on the garment. The simplest buttonholes are used on shirts, blouses and other lightweight garments; more complex buttonholes are used on heavier tailored garments. An example of a buttonhole machine is in Fig. 4.14. The variables in buttonhole machines are the form and size of the buttonhole, the stitch type (lockstitch or single- or two-thread chainstitch), the stitch bight, the stitch density, whether the buttonhole is cut before or after sewing, and the presence or absence of a gimp. 165