DIMENSIONAL STABILITY OF MODIFIED COMPOSITE PANELS

Authors

  • Luis Molina Irribarra Oxiquim S.A. & Oregon State University
  • Frederick A. Kamke Oregon State University, Corvallis, Oregon USA
  • Scott Leavengood Oregon State University, Corvallis, Oregon USA

Keywords:

Water resistance, accelerated weathering, heat-treatment, chemical impregnation

Abstract

Dimensional stability of wood-based composites with changing moisture content remains an important challenge in the industry for many applications. Wood identification technologies have shown significant promise to improve dimensional stability. The main objective of this research project was to study the effectiveness of impregnation and heat treatments on wood composites when exposed to selected moisture environments. Moisture exposure conditions included one-sided water spray, one-sided liquid water contact, constant high RH, and cyclic exposure to high and low RH. Commercial moisture-resistant medium-density fiberboard (MDF) and birch plywood panels, as well as laboratory manufactured birch plywood panels, were modified by impregnation with phenol-formaldehyde (PF) resin, 1,3-dimethylol-4,5-dihydroxyethylenurea (DMDHEU) resin, or subjected to heat treatment at 205oC for 2 h to improve dimensional stability. All treatments improved moisture resistance. Plywood impregnated with PF or DMDHEU resin showed the lowest thickness swelling values, with maximum values not higher than 5% after 192 h of exposure. Heat-treated MDF and heat-treated plywood samples resulted in 11% and 6% thickness swell after water spray exposure, respectively. The heat-treated plywood resulted in lower linear expansion (LE) than untreated plywood, with an average reduction of 54%; whereas the heat-treated MDF material did not show improvement of LE relative to control MDF samples.

Author Biographies

Frederick A. Kamke, Oregon State University, Corvallis, Oregon USA

JELD-WEN Professor of Wood-Based Composite Science

   & Site Director for NSF Wood-Based Composites Center

Scott Leavengood, Oregon State University, Corvallis, Oregon USA

Professor and Director, Oregon Wood Innovation Center

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Published

2021-11-10

Issue

Section

Research Contributions