The stretchability of seams sewn by a chain stitch sewing machine (stitch type: 101) has been studied. The results obtained were as follows. 1) A linear relationship was observed between stretchability (stretch ratio at break) and thread consumption of seams. 2) The thread tensions were obtained during machine sewing. The tension Fr·p observed when the thread was held by the center of a looper body was connected with the tightening of stitches and was important for the thread consumption of seams. 3) A linear relationship was approximately shown in a log-log graph between (lt-la) and Fr·p. Where, lt; thread length per stitch in the ideal state which is equal to (3le+2t), la: thread length per stitch obtained from seams, le: stitch length, and t: thickness of fabrics sewn. 4) By using the results mentioned above, it is possible to predict the thread consumption and the stretchability of seams by using Fr·pmeasured in sewing process.
The aim of this study is to find out the solvent characteristic suitable for drycleaning. As solvent, in Part 1, the fatty acids were used to get the systematically changed structures. The solvent characteristics affecting the solubility of fatty acids were determined. The solubility of each solvents was explained by three characteristics; solubility parameter (SP value), three kinds of intermolecular forces and group in molecule. Out of 81 solvents, the solubility of 53 solvents was explained by SP value, the solubility of 8 solvents was explained by the intermolecular force, the solubility of 11 solvents was explained by the group in molecule and the solubility of the remaining 9 solvents was unexplainable.