Anatomical and Chemical Characteristics of Bambusa multiplex for Pulping

Bambusa multiplex is a small-diameter bamboo with potential as a non-wood pulping raw material, but its pulping-related characteristics remain insufficiently evaluated. In this study, B. multiplex was assessed by integrating culm-wall anatomy, chemical composition, radial alkali-treatment response, kraft pulping, bleaching, and handsheet testing. The culm wall contained 44.53% fibers, increasing radially from 25.80% in the inner part to 62.20% in the outer part. The material contained 51.50% α-cellulose and 18.02% total lignin. Mild alkali treatment caused a greater mass loss rate, structural deformation, and FTIR spectral changes in the inner culm wall, indicating non-uniform radial reactivity. Under the selected kraft cooking condition, the total unbleached pulp yield was 45.90%, with a kappa number of 17.34, and an intrinsic viscosity of 1292.96. The bleaching yield was 90.20%, giving an overall bleached-pulp yield of 41.40%. Handsheets prepared from the bleached pulp had a grammage of 73.59 g/m2, a tensile index of 49.50 N·m/g, a tear index of 13.82 mN·m2/g and a folding number of 1341. Under the selected experimental conditions, these results indicate preliminary pulping and papermaking potential for B. multiplex, although replicated cooking trials, process optimization, and more comprehensive pulp-quality and paper-property evaluation are still needed.