In this investigation, 27 cotton fabrics of various weights and constructions were used as samples. The fabrics were tested for thread count, thickness, and tensile strength by the standard methods as described by the government specifications for textiles. In order to determine stiffness of the fabrics, Pierce's cantilever bending method was used. From the bending strength, the bending modulus was computed and it was this figure that was used as a measure of the stiffness of the fabric. Seams were made from these fabric samples and they were all sewed under the same conditions, that is, the speed of the sewing machine, the sewing thread size, the sewing machine needle size, the stitches per inch, and the tension of the sewing thread were the same for all samples. Each sample was then tested for seam strength, yarn severance, and seam resistance to slippage. These tests were performed in a manner similar to the methods described in the government specifications for textiles. Seam efficiency was computed from the seam strength data. In addition, another method for determining the sewing machine needle damage was developed. The decrease in tensile strength of the fabric, because of the needle damage, was determines and this figure divided by the original tensile strength of the fabric was expressed as a percentage. This calculation was defined as a sewing machine damage and was used though the study as the measure of needle damage. From the experimental data, linear correlations were computed between seam efficiency and each of the three variable factors, namely, sewing machine damage, seam resistance to slippage, and stiffness as measured by the bending modulus. Multiple correlation was computed between seam efficiency and these three factors, after which the intercorrelations between these three factors were also computed. From the significant results obtained from the correlation computations, it was concluded that sewing machine damage, seam resistance to slippage, and stiffness of the fabric as measured by the bending modulus, individually affect the seam strength. Also, the combination of these three factors affect the seam strength. Finally, there is a large amount of intercorrelation between these three factors, that is, a change in any one factor will probably result in a change in the other two factors.

http://archive.org/details/astudyoffundamen1094514664