Effects of Biofiber Mixing Ratio and Processing Conditions on the Physical Properties of Paper Mulberry-Based Machine-Made Hanji

This study investigated the effects of the degree of beating, biofiber mixing ratio, and addition of a dispersant on the physical properties of machine-made Hanji prepared by blending long paper mulberry fibers with biodegradable biofibers such as PLA, Alginate, Rayon, and Tencel.The optimal beating degree (22.5 °SR) maintained an open fiber network with a bulk of 3.10 cm 3 /g, a tensile strength of 3.10 kN/m, and an air permeability of 85 µm/Pas.Tencel (1.7 denier) exhibited the highest tensile strength due to its fine denier and hydrophilic surface, which promote hydrogen bonding with paper mulberry fibers.As the biofiber content increased, thickness and bulk increased, while density and tensile strength decreased.The optimal laboratoryscale ratio was determined to be 8:2 (paper mulberry:Tencel, w/w) at 50 g/m 2 .For field-scale machine papermaking, the ratio was adjusted to 6:4 (w/w) at 90 g/m 2 to resolve flocculation issues and ensure stable production.Biodegradability testing (KS M ISO 14855-1:2012, 45 days) showed 104.5% for Sinbiji (6:4, w/w) and 85.4% for Tencel Crepe Hanji (5:5, w/w).Chemical safety tests confirmed non-detectable levels of aromatic amines and formaldehyde, and the combustion toxicity index (R = 0.03) was well below the safety threshold, supporting the application of these materials in hygiene products, construction materials, and industrial filters.