二重環縫ミシン縫製における動的縫糸張力とシームの縫糸消費長および伸長性について

In this study, dynamic thread tension during machine sewing (type: 401, 2-thread chain stitch machine) was measured and the infuluence of the tension on the thread consumption and the stretchability of seams was considered. The results obtained were as follows:<BR>(1) Three characteristic peaks were observed in each chart of needle and looper thread tension. The looper thread tension tended to be affected by the needle one.<BR>(2) The change in setting of needle thread tension caused the difference in the thread balance of the stitch. The stitched seams were classified into two groups whose stitches were balanced and unbalanced ones. It was possible to distinguish these two groups, using the observed peak values of the needle thread tension from the discriminant analysis.<BR>(3) A relation between the thread consumption and the tension was obtained by the multiple regression analysis that the dependent and independent variables were ML_n-L_nand the peak values of both the dynamic tensions respectively. Where, ML_nis the needle thread length per stitch in balanced state without fabric deformation and L_nis nneedle thread length per stitch obtained actually. There was a linear relationship between ML₁-L₁and ML_n-L_n. Where, subscript 1 stands for looper.<BR>(4) A linear relationship was observed between the stretch ratio of seams at break and the sum of needle and looper thread lengths per 10mm of seam.<BR>(5) It was possible to predict the thread balance of the stitch, thread consumption and stretch ratio at break of seams using the results mentioned above in optional sewing conditions.