Trouser and Tongue Tear Test Methods

Trouser tear test (ISO 13937-2, ASTM D2261) cuts a 50 mm × 200 mm specimen with a 100 mm central longitudinal slit creating two 'trouser legs', clamps each leg in opposing jaws of CRE tensile tester (gauge 0 mm, extension rate 100 mm/min) and records the force-displacement curve as tear propagates through remaining 100 mm of fabric — result: peak force (N) and mean force over propagation length. Trouser tear advantages over Elmendorf: applicable to knits (moderate extensibility accommodated by crosshead travel), nonwovens, coated fabrics (coating cannot bridge — tear initiates directly), and very light or very heavy fabrics outside Elmendorf capacity range. Force-displacement trace interpretation: flat trace = uniform tear resistance (woven fabrics with consistent yarn spacing); sawtooth trace = stick-slip behaviour from yarn pull-out (warp-knitted technical mesh); rising trace = progressive yarn entanglement (nonwoven needle-punched — fibres progressively pulled from web increasing resistance). Tongue tear (ISO 13937-3, T-shaped specimen, 75 mm wide with 75 mm central slit creating tongue, extension rate 100 mm/min): measures force to tear 'tongue' from wider fabric body — used for coated and laminated technical fabrics where trouser jaw clamping of thin leg causes slip. Wing rip tear (ISO 13937-4, hourglass specimen, used for technical fabrics requiring controlled crack path initiation). Geotextile tear resistance (ASTM D5587 trapezoid tear: 150 mm × 200 mm trapezoid with 15 mm slit in shorter parallel edge, 300 mm/min — ISO 13937-3 tongue tear alternative for geotextiles): woven PP geotextile minimum 500 N, needle-punched PP minimum 800 N per typical geotextile project specification.