Hydraulic Mullen Burst Test

Mullen hydraulic burst testing (ISO 13938-1, ASTM D3786) inflates a rubber diaphragm beneath a clamped circular fabric specimen at a controlled rate (170 mL/min ±5%) until the fabric ruptures, measuring the maximum hydraulic pressure (kPa or psi) at failure and the dome height distension (mm) at rupture — two independent parameters that together characterise fabric biaxial behaviour. Instrument: SDL Atlas M021A, James Heal Titan 5 burst tester — clamping ring 100 mm diameter, test aperture 30.5 mm standard (7.3 cm² area); burst pressure sensor ±1 kPa resolution; distension gauge ±0.5 mm. Diaphragm correction: rubber diaphragm pressure at failure measured separately without fabric (blank reading, typically 30–80 kPa for new diaphragm) subtracted from total burst reading to obtain fabric-only burst pressure. Fabric burst pressure ranges: hosiery (40 g/m² PA 22 dtex): 60–100 kPa; standard single jersey T-shirt (160 g/m² Co Ne 30 ring): 200–350 kPa; compression knitwear (280 g/m² PA-elastane): 400–700 kPa; woven base cloth for coating (200 g/m² PET): 600–900 kPa; needle-punched geotextile (400 g/m²): 1,200–2,000 kPa. Distension at burst (ductility indicator): brittle fabrics (woven glass, aramid) burst at low distension 5–10 mm; extensible fabrics (jersey, stretch woven) distend 20–40 mm before bursting — high distension indicates fabric can accommodate local stress concentrations by deformation before catastrophic failure. Wet burst testing (fabric soaked 10 min distilled water, tested immediately, ISO 13938-1 wet variant): cotton knit wet burst 100–110% of dry (slight strengthening); wool knit wet burst 70–85% dry (weakening — important for wet weather apparel integrity).