Characterization of Thermomechanical Pulping Using Mixed Wood Chips from Pinewood Nematode-Infected Forests

Abstract

This study evaluated the use of mixed wood chips from nematode-infected forests for thermomechanical pulp (TMP) production, compared to traditional pine chips from Pinus densiflora. The mixed chips showed higher holocellulose and lower lignin content, suggesting improved yield and refining efficiency, though increased extractives and ash content may pose challenges. Despite these issues, the mixed chips enhanced stock throughput and reduced energy consumption during refining, leading to cost savings and increased production efficiency. The analysis revealed that TMP fibers from the mixed chips contained more fines but similar fiber length and lower shive contents compared to the pine chips. The bulk properties and tensile strength of TMP from both chip types were comparable. Interestingly, TMP from the mixed chips exhibited a 2% higher tear strength and lower pitch content than TMP from the pine chips. These findings suggest that the mixed wood chips from nematode-infested areas can be a viable, sustainable, and cost-effective alternative for TMP production, supporting raw material stability and sustainable forest management while mitigating the impact of pine wilt disease.