1. Rengasamy, R. S. Study on dynamic needle thread tensions in a single needle lock stitch (SNLS) sewing machine. I. Effect of stitch length, check spring tension, fabric feed timing and needle thread in-take length / R. S. Rengasamy, D. Samuel Wesley // Fiber and Polymers. — 2014. — Volume 15, Issue 8. — pp 1766-1772.
Abstract. This paper, the first of a two-part series, aims to find the effect of stitch length, check spring tension, fabric feed timing and needle thread in-take length on tension peaks occurring on a spun polyester needle thread during a sewing cycle of a SNLS sewing machine. The pre-tensions on the bobbin and needle threads and sewing speed were kept constant. A PC interfaced measuring instrument was fabricated to measure dynamic sewing tension on needle thread above the needle bar. Four prominent tension peaks were detected. Longer stitch length causes higher tension peaks; and shorter length stitch requires higher pre-tension to obtain a balanced stitch. The check spring tension has no effect on tightening tension. Incorrect timing of feed dog can cause very high tightening tension. The change in the position of thread length guide alters the friction of needle thread at critical guides which determines the length of thread to be released through tensioner; release of longer length of thread results in lower tension peaks (1, 2 and 4) and vice versa.
Перевод названия: Исследование динамического натяжения игольной нитки в одноигольной швейной машине челночного стежка. I. Влияние длины стежка, сжатия пружины узла натяжения, времени подачи материала и диаграммы потребления игольной нитки.
2. Rengasamy, R. S. Study on dynamic needle thread tensions in a single needle lock stitch (SNLS) sewing machine. II. Effect of sewing speed, thickness of fabric plies, thread linear density and pre-tensions of threads / R. S. Rengasamy, D. Samuel Wesley // Fiber and Polymers. — 2014. — Volume 15, Issue 8. — pp 1773-1778.
Abstract. This paper reports on the effect of pre-tensions on needle and bobbin threads, sewing speed, thickness of fabric plies and the linear density of the threads on the tension peaks occurring on needle thread during sewing on a single needle lock stitch machine. The needle thread tensions are measured at two locations: above the needle bar (bottom segment) and above the needle thread tensioner (top segment). A factorial design approach is used to study the four parameters. The role of bobbin tension is studied in a separate experiment, while keeping the pre-tension on the needle thread constant. The highest tension observed on the needle thread is the stitch tightening tension which is directly affected by the pre-tension set on the needle thread disc tensioner. Heavier threads develop lower tightening tension which may affect the seam balance. The thickness of fabric plies does not affect the needle thread tension. Sewing speed has marginal influence on the stitch tightening tension near the needle thread tensioner. The pre-tension on the bobbin thread affects only the needle thread tension when the take up lever pulls up the needle thread loop to release it from the rotary shuttle hook gib.
Перевод названия: Исследование динамического натяжения игольной нитки в одноигольной швейной машине челночного стежка. II. Влияние скорости шитья, толщины ткани, линейной плотности нитки и предварительного натяжения ниток.