Manufacturing Medium-Density Particleboards from Wood–Bark Mixture and Different Adhesive Systems*

Abstract

Abstract The disposal problem of bark residues and the shortage of wood raw material supply in some regions make the use of bark an attractive option for the industry. In this study, medium-density particleboards were manufactured from mixed black spruce bark and spruce-pine-fir wood particles at a weight ratio of 50/50. Different adhesive systems were used as binders for the bark-based panels, including commercial phenol-formaldehyde (PF), urea-formaldehyde (UF), polymeric methylene diphenyl diisocyanate (pMDI) resins, and a laboratory-synthesized lignin-PF resin containing 30 wt% lignin substitution for phenol. The objective was to investigate the suitability of utilizing bark residues in the manufacture of particleboards for the floor underlayment (PBU) application. The resulting boards were evaluated according to the ANSI A208.1‐2009 standard for internal bond (IB), modulus of rupture, modulus of elasticity, hardness, thickness swell, and linear expansion. The test results indicate that all panels made with these resin systems can meet the PBU requirements in terms of IB and hardness and that those bonded with 8 percent PF or 5 percent pMDI can meet all the requirements by the ANSI A208.1‐2009 standard for the floor underlayment application in terms of the properties evaluated. Results of this study imply that it is feasible to use bark as a raw material to manufacture medium-density particleboard for the floor underlayment application.