Effects of two fiber treatments on properties of hemlock hardboard

The effects of fiber treatments (stream and acetylation), resin content: and wax content on mechanical and physical properties of dry-process hardboard made from hemlock were investigated, Sixty 10-inch by 10-inch by 0.125-inch boards were tested. Various board properties such as modulus of rupture, modulus of elasticity, tensile strength parallel to the surface, internal bond, water absorption, thickness swelling, and linear expansion were studied. Test results showed that both acetylation and steam pretreatment improved board dimensional stability. This demonstrates that both treatments reduce the hygroscopicity of the hemlock fibers. Water absorption, thickness swelling, and linear expansion were reduced greatly by acetylation. Increasing resin content significantly improved board mechanical and physical properties. However, some mechanical properties of the boards were somewhat decreased by the fiber treatment of acetylation.