Analysis of the Extension and Contraction of Warp-knitted Fabrics Based on Experimental Conditions

The lengthwise and widthwise deformation of warp-knitted fabrics with different sizes and loading modes were evaluated. Moreover, five tricot samples cut in three directions were compared under four test conditions (A–D). In tests A and B, 500 and 250 g loads were applied on a layer of 20 × 20 and 5 × 10 cm2 samples, respectively. In test C, a 20 × 20 cm2 sample was folded in half over a rod, and 500 g load was applied to each half. In test D, a 20 × 20 cm2 sample was sewn in a loop and subjected to a 500 g load. The lengthwise extension and widthwise contraction analysis results indicate that test B affords the largest values. However, analysis results of the warp-knitted fabric normalized through conversion to a 1 g load and 1 cm sample width indicate that the largest values are afforded for test D. Therefore, pattern reduction may vary depending on the measurement method and properties of the knitted fabric used for the compression wear production, causing variations in the finished product. Thus, an appropriate measurement method must be adopted based on the compression wear design and knitted fabric to be used.