Properties of medium-density fiberboard related to hardwood specific gravity

Abstract

Boards of acceptable quality were made from barky material, pressure-refined from 14 species of southern hardwoods. Static bending and tensile properties (parallel to surface) of specimens were negatively correlated to stem specific gravity (wood plus bark), chip bulk density, and fiber bulk density. Bending and tensile properties increased with increasing densification ratio, but the rate of increase was much less than published information for flake board from 9 of the 14 species. Results for internal bond strength were inconclusive. By regression analysis, internal bond was independent of stem specific gravity, chip bulk density, and fiber bulk density. Measurements of fiber pH and Bauer-McNett screen classification also failed to explain the wide variation in internal bond.