Effect of Resin Particle Size on Waferboard Adhesive Efficiency
Keywords:Waferboard, phenol-formaldehyde, resin efficiency, fluorescence microscopy
AbstractA powdered phenol-formaldehyde resin was synthesized incorporating a fluorescent dye. The resin was sieved to produce five different particle-size fractions. Each of the resin fractions was used in the fabrication of waferboard panels from Populus tremuloides flakes. Fluorescence microscopy was used to observe the cured glue-lines following an embedding and polishing sample preparation technique. All of the panel strength properties determined (modulus of rupture, modulus of elasticity, and internal bond strength) displayed better values when smaller resin particle-size fractions were used. Panels produced using smaller resin particle-size fractions exhibited less sensitivity to moisture as demonstrated by lower thickness swelling values and a greater retention of bending properties after an accelerated aging treatment. Fluorescence microscopy showed that more continuous glue-lines and better flake coverages were achieved with smaller resin particle-size fractions than with larger size fractions.
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