Single Fibre Tensile Testing
category
Single fibre tensile testing measures the mechanical properties of individual filaments using specialised micro-tensile instruments (Textechno Favimat+, Diastron MTT, Instron 5848 MicroTester) at gauge lengths of 10–50 mm and load ranges of 0.1–10,000 mN — essential for characterising fibre-to-fibre property variability, establishing Weibull strength distributions, and determining properties of fibres too small or too valuable for bundle testing. Textechno Favimat+ (automated single-fibre tester, 50 tests/hour automated): fibre clamped between upper (load cell, 0–10,000 mN, ±0.1 mN) and lower (linear actuator) jaws at programmable gauge length 10–50 mm; linear density measured simultaneously by resonance vibration method (plucked fibre vibrates at resonant frequency f = (1/2L)√(T/µ) where T = tension, µ = linear density — dtex calculated from f at known T and L, ±0.5% accuracy on single filament); tenacity (cN/tex = breaking force / dtex), elongation, initial modulus, and work to break computed per test. Statistical analysis: mean, SD, CV%, Weibull shape parameter m and characteristic strength from 30–100 test results. Fibre types routinely tested: natural (cotton single fibre, wool single fibre, silk, flax, hemp), synthetic staple (PET, PA, PP, acrylic), and high-performance (carbon, aramid, glass, basalt, UHMWPE) — each requiring specific gauge length, pretension, and extension rate optimisation to avoid jaw break artefacts (>15% jaw breaks invalidates test series).
Role
Single fibre tensile testing provides the fundamental mechanical property data at the individual filament level that is inaccessible from bundle or yarn testing — Weibull statistics from single-fibre tests establish the strength distribution needed for composite structural reliability calculations, while fibre-to-fibre tenacity CV% data diagnoses spinning process problems impossible to detect from average bundle measurements.