Fabric Weight and Construction Testing

Fabric weight and construction testing characterises the physical structure of woven, knitted, and nonwoven fabrics through areal mass, thickness, thread count, fabric cover, and weave/knit structure analysis — foundational parameters that determine all downstream mechanical, comfort, and functional properties. Areal mass (ISO 3801, circular template 100 cm² cutter, ±0.5% accuracy, minimum 3 specimens per fabric roll position): g/m² is the universal fabric weight specification — lightweight shirting 80–120 g/m², medium denim 300–350 g/m², heavy canvas 400–600 g/m², geotextile nonwoven 150–800 g/m². Thickness (ISO 5084, foot pressure 2 kPa for apparel, 20 kPa for industrial, foot area 20 cm², ±0.01 mm): cotton shirting 0.25–0.40 mm; denim 0.80–1.20 mm; 3-layer shell 1.5–2.5 mm; geomembrane 2.0–5.0 mm. Thread count (ISO 7211-2, pick glass 25 mm, count threads per 10 mm warp and weft): 600-thread-count Egyptian cotton 60 ends/cm × 60 picks/cm; standard shirting 40 × 38 per cm; denim 20 ends/cm × 14 picks/cm — thread count determines fabric cover, tear resistance, and air permeability. Fabric cover factor (Peirce formula: K = n × d × 100% where n = threads/cm, d = thread diameter cm — cover factor 0–1): plain weave maximum cover at K = 1.0 (impossible to achieve); standard shirting K = 0.85–0.92. Courses and wales per cm in knitted fabric (ISO 4921: counted under magnification, 5 cm measurement, ±2 per cm accuracy): single jersey 14–20 courses/cm × 14–18 wales/cm.