Early-stage enzymatic treatments of scutched hemp fiber: Impact on fiber properties

Although hemp fibers are widely recognized for their sustainability benefits, their intrinsic stiffness and significant structural heterogeneity present processing challenges that limit their applicability in textile manufacturing, particularly in high-quality spinning systems such as flax wet spinning. To overcome these limitations, this study investigates early-stage enzymatic treatments of scutched hemp fibers aimed at enhancing their fineness and flexibility. This work introduces a novel approach, implemented earlier than usual, and employs enzymatic agents instead of conventional chemical methods, providing a more sustainable alternative. Two commercial enzymatic formulations, Peclyve SF and Pectinex Ultra SPL, were tested at 0.5 % and 3 % (v/v) at 50 °C for 60 min. Treated fibers were comprehensively characterized regarding their physical properties (linear density and fiber diameter), morphology (optical and SEM imaging), thermal behavior (TGA/DTG), crystallinity (XRD), colorimetric parameters (CIELAB system), chemical composition (FTIR), and tensile performance. Enzymatic treatments led to a 48–73 % reduction in fiber diameter and a 9–16 % increase in crystallinity. Color analysis revealed higher Hunter whiteness and decreased Yellowing index with increasing enzyme concentration. Treated fibers exhibited reduced tenacity and, notably, a 47–63 % reduction in specific modulus, indicating improved flexibility. These findings demonstrate that early-stage enzymatic treatments can effectively tailor the properties of hemp fibers, particularly by improving their flexibility, thereby facilitating fiber handling and potentially improving their processability in flax wet spinning, broadening their applicability in the textile industry. • Early enzymatic treatment enhanced hemp fiber flexibility and fineness. • Enzymes selectively removed pectin, lignin, and hemicellulose from hemp fibers. • Mild conditions reduced fiber diameter by 77 % and Young’s modulus by 63 %. • Enzymatic degumming enhanced cleanliness and separation of scutched hemp fibers. • Treated hemp fibers show potential for flax wet spinning of high-quality yarns.