A Study on Easing by a Variable Top Feed and Differential Drop Feed Sewing Machine : Applications of Computerized Sewing to Easing in Sleeve Cap Seam

In the previous paper [1], we discussed an experimental method for estimating seam shrinkage along the optional direction of fabric using a variable top feed and differential drop feed sewing machine. In this study, we considered to apply computerized sewing to easing in sleeve cap seam using the results in the previous paper. The results obtained were as follows: At first we obtained seam shrinkage ratio of sewn fabrics under predetermined differential ratio conditions experimentally at 4 kinds of sewing angles, i.e. 45, 90, 135 and 180(0) degrees, where we defined 0 deg. as weft, 90 deg. as warp direction, respectively. On the basis of the results mentioned above, we showed a method to obtain the differential ratio by means of interpolation that desired seam shrinkage ratio could be completed in optional sewing direction. As for sleeve pattern selected, we divided the seam line in sleeve cap to several parts and shared total amount of easing with every divided part. The differential ratios to obtain the desired amount of easing were calculated in every sewing stitch in the divided parts. The data were input to the controller and computerized easing sewing was performed using various specimen fabrics. It was shown that the designed easing sewing was done contentedly although the appearances of sleeve samples differed from each other by the fabrics used. We confirmed that the method shown here for computerized sewing was very useful to easing in sleeve cap seam for fabrics with various properties.