Abstract
The following six extensional properties were examined, i.e., (1) work done in stretching specimen to 20% in length, (2) energy loss, (3) maximum stress at 20% elongation, (4) Young's modulus, (5) recovery percentage and (6) resilience.
To investigate the differences between silk and other fibers, the extensional properties of knitted fabrics of other than silk fibers were also measured and the results were compared with those of the silk knitted fabrics. The data were analyzed by the method of“Multivariate Analysis”, i. e., Principal Component Analysis (PCA) . The results obtained were as follows:
1) The recovery percentage of the silk knitted fabrics was slightly less than that of knitted fabrics of wool or acrylic spun yarns, and showed close resemblance to that of knitted fabrics of cotton or acrylic filament yarns.
2) The resilience of the silk knitted fabrics was less than that of knitted fabrics of wool, acrylic spun or filament yarns, and showed close resemblance to that of cotton knitted fabrics.
3) Variables may be classified into three groups by PCA.
Group 1 : Variables of“hardness”or “rigidity”comprising work, energy loss, Young's modulus and maximum stress at 20 % elongation.
Group 2: Variables of“recovering”or“elasticity”comprising recovery percentage and resilience.
Group 3: Variables of“thickness”comprising thickness only.
