Knit Fabric Properties and Characterization

Structural parameters: Stitch length (l, length of yarn in one loop, 2.0-5.0 mm typical, controlling fabric tightness and GSM—longer stitch = lighter, softer, more stretch), Courses per cm (CPC, horizontal rows, 8-20 for apparel), Wales per cm (WPC, vertical columns, 10-25 for apparel), Stitch density (stitches per cm² = CPC × WPC, 80-500 typical), and Tightness factor (TF = √tex / stitch length, typical 9-13, <9 too open/unstable, >13 too tight/stiff). Fabric dimensions: Width (flat width measurement, influenced by finishing, typically given in inches for circular knits), GSM (grams per square meter = (tex × CPC × WPC) / stitch length, calculable from structure or measured, 100-300 GSM apparel typical). Mechanical properties: Stretch (width 30-60%, length 10-30% for jersey, higher for ribs), stretch recovery (elastic recovery after stretch, >90% critical for shape retention), bursting strength (400-600 kPa for jersey t-shirts), and dimensional stability (shrinkage after washing, controlled via heat-setting, target <3-5%).