Fibre Thermal Analysis Testing

Fibre thermal analysis uses differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) to characterise melting, crystallisation, degradation, glass transition, and viscoelastic properties of polymer fibres — data essential for process parameter setting in spinning, drawing, heat setting, and dyeing. DSC (ISO 11357 series, Mettler-Toledo DSC3+, TA Instruments Q2000, 5–10 mg sample, 10°C/min scan rate, nitrogen atmosphere): measures melting enthalpy ΔHf (J/g), peak melting temperature Tm (°C), crystallisation temperature Tc (°C), glass transition Tg (°C), and crystallinity (ΔHf / ΔHf° × 100 where ΔHf° = 140 J/g PET, 203 J/g PE, 190 J/g PP). Key diagnostic values: PET drawn fibre Tm 254–258°C, ΔHf 40–55 J/g, Tg 78–85°C, crystallinity 38–45%; nylon 6 drawn Tm 220–226°C, Tg 50–60°C; Dyneema (UHMWPE) Tm 144–148°C, ΔHf 185–210 J/g, crystallinity 80–95%. TGA (ISO 11358, 10–15 mg, 10°C/min, air or N₂): onset degradation temperature (Td₅% = temperature at 5% mass loss): cotton 300–320°C, PET 395–420°C, Nomex 420–440°C, PTFE >500°C — critical for FR fibre blend safety assessment and thermal protective clothing design. DMA (ISO 6721, frequency 1 Hz, −100 to +300°C scan): storage modulus E' and loss modulus E'' providing tan δ = E''/E' — tan δ peak = glass transition Tg; secondary β-relaxation in nylon at −55°C indicates amide group mobility affecting low-temperature impact toughness.