Effect of Filler Types on Phenol-Formaldehyde Resin Adhesive for Plywood

충전제의 종류가 합판용 페놀수지 접착제에 미치는 효과

Residues such as walnut, pinenut and peanut shells were used as a filler in adhesive for bonding radiata pine plywood. The nutshell residues were prepared by simply drying to 8% moisture content and grinding the dry material using a laboratory Wiley mill with a $75{\mu}m$ (200 mesh) screen. The nutshells residues were compared to a commercial filler commonly used in adhesives by the structural plywood and laminated veneer lumber industry in the United States. The adhesive mixes were made by following the recommended procedure of Georgia-Pacific Resins, Inc., using phenol-formaldehyde resin. For each filler type, three-ply plywoods, 6 mm nominal thickness and 30 by 30 cm in size, were fabricated at two press times (4 and 5 min) and around 30 minute assembly time. Evaluations of the nutshell residues were carried out by tension shear tests after cyclic boil tests on plywood. The results of the performance test included tension shear strength and wood failure. All plywoods made with the nutshell fillers were comparable to those made with the control filler. These results indicate that nutshell residues would be suitable as filler for plywood adhesives.