Customized Hemp Pulp Extraction via Laccase–Pectinase Pretreatment for Improved Waste Pulp Papermaking

The reuse of waste pulp presents a sustainable alternative to petroleum-based polymers in packaging, contributing to the mitigation of environmental and resource-related challenges and fostering sustainable development. Repeated reuse of waste pulp significantly deteriorates the fiber structure, which adversely affects vital performance metrics such as tensile strength. In response to this challenge, we introduce a sustainable and energy-efficient strategy for fabricating tailored hemp pulp, designed to be incorporated into recycled waste pulp to enhance papermaking properties. The hemp material is first pretreated under diverse enzymatic conditions to facilitate the removal of lignin and pectin, followed by kraft pulping under atmospheric pressure. The incorporation of customized hemp pulp into recycled waste pulp (H _<i>X</i> MP) resulted in a notable enhancement of paper properties. The experimental results revealed that, compared to the control sample without hemp pulp (H₀MP), the 20% hemp pulp sample (H₂₀MP) exhibited notable improvements in mechanical properties: a tensile index of 43.00 N·m/g, a tear index of 6.03 N·m²/g, a burst index of 1.19 kPa·m²/g, and a folding endurance of 33 cycles. Its overall performance exceeded that of a commercial containerboard. In conclusion, this study presents a novel approach for the high-value utilization of hemp fibers and, more significantly, provides an effective solution for improving the papermaking performance of recycled waste pulp.