Skein Lengths DIN 53840

L1 — Length Under Heavy Load mm

Filaments pulled straight; the crimp-free reference.

L2 — Length Under Light Load mm

After hot relaxation, crimp fully developed.

L3 — Recovered Length After Load Cycle mm

Yarn Nominal

Yarn Linear Density dtex

Filament Count no.

Crimp Rigidity

— %

Crimp retained after the yarn has been loaded and released

Crimp Profile

Crimp Contraction: — %
Crimp Stability: — %
Bulk Factor (L1 / L2): — ×
Linear Density per Filament: — dtex

Condition the skein and hold the relaxation bath time and temperature constant between lots — crimp readings move more with test conditioning than with most process changes.

DTY Crimp Rigidity & Contraction Estimator — free, with the formula and a worked example, at Textile School.