Effect of Manufacturing Variables on Stability and Strength of Wet-formed Hardboards

摘要

Eight variables in the manufacture of high-density wet-formed hardboard from Douglas-fir and aspen were analyzed to determine whether any one or certain combinations increased the strength and the dimensional stability of the boards. The variables were wood species, pulp freeness, type of refiner, forming-water temperature, resin type, resin amount, pressing temperature, and heat treatment of the board. Wood species proved statistically the most important factor in increasing dimensional stability; the stability of the Douglas-fir boards was greater than that of the aspen. Pressing temperature and type of refiner used for processing the Asplund fiber also influenced the dimensional stability. Type of resin had the greatest effect on strength and stiffness. (Author)