Effect of Moisture Contents of Raw Materials on the Dimensional Properties of Thermomechanical Pulp Fibers

Abstract

This study examines the effects of moisture content on the fiber dimensions, fines fraction, and shive content of wood chips during Thermomechanical Pulping (TMP). The pine chips, stored at ambient temperature for 30 days to allow their moisture content to adjust naturally, experienced a significant decrease in moisture content from 81% to 3.1%, with the most rapid reduction occurring in the first 15 days. Correspondingly, the fines fraction increased from 1.9% to 5.5%, indicating greater fiber breakage due to increased brittleness. The length-weighted fiber length decreased from 1.83 mm to 1.42 mm as moisture content reduced, suggesting shorter and potentially weaker fibers. The shive content decreased slightly from 44.2% to 42%, indicating improved fiber separation with lower moisture content. These findings underscore the importance of controlling the moisture content of wood chips in the TMP process to optimize pulp quality, minimize fines generation, and enhance energy efficiency. The results provide valuable insights for industries relying on wood chips, enabling them to optimize their processes for better efficiency and product quality.