Chemical Crimp and Texturization of Synthetic Fibers

Chemical crimp in synthetic fibers is achieved through bicomponent spinning (side-by-side or eccentric sheath-core) where differential shrinkage of two polymer components such as PET/PTT or nylon-6/nylon-66 induces helical crimp upon heat relaxation at 120–160°C. Crimp frequency reaches 8–15 crimps/cm with elongation of 150–300%. Asymmetric quench cooling during melt spinning also induces latent crimp. Solvent-based texturization via DMF exposure at 30–50°C for acrylic achieves bulking of 30–40%, producing wool-like handle in 100% synthetic yarns.