Fabric Manufacture: Weaving Preparatory, Weaving, Knitting and Non-woven Basics
What the exam tests
This domain covers the route from yarn to fabric: preparatory processes, loom motions and the three basic weaves, plus the loop structure of knitting and the web-and-bond route of non-wovens.
Weaving preparatory
Winding clears faults and builds a sound package; warping assembles the sheet of ends; sizing coats warp yarns to reduce breakage; drawing-in and denting pass ends through heald wires and reed dents. Weft is wound on pirns or cones.
Loom motions and weaves
- Primary: shedding, picking, beat-up.
- Secondary: let-off and take-up.
- Tertiary: warp stop, weft stop, weft feeler.
- Plain (1/1): maximum interlacing, strongest and firmest. Twill (2/1, 3/1, 2/2): diagonal line; floats give softness and drape. Satin: long floats, high lustre, but poor abrasion resistance.
Knitting and non-wovens
Weft knitting forms loops across the fabric width (single jersey, rib, interlock); warp knitting uses a warp sheet (tricot, raschel). Courses are horizontal rows, wales are vertical columns. Non-wovens are made by web formation (carded, spunbond, meltblown, wetlaid) followed by bonding (needle punch, thermal, chemical, spunlace).
Worked example
A plain cotton fabric has 100 ends/inch and 80 picks/inch of 40s count. Cover factor K = threads per inch ÷ √count. Warp: 100 ÷ 6.32 = 15.8. Weft: 80 ÷ 6.32 = 12.6. Total 28.4, above the limit of about 28 for plain weave - the cloth cannot be woven without cramming or excessive warp breakage, so a twill weave or finer count is needed.
Traps
Swapping wale and course; claiming satin is the strongest weave; forgetting that let-off and take-up are secondary motions; describing knitting as interlacing.