Effects of Soy-adhesive/PF Mixture on the Shear Strength of Plywood

This study examined modification of soy-adhesive and the effects of the ratio of chemical modified soy-adhesive to phenol formaldehyde resin(PF) on the shear strength of poplar plywood. Sodium hydroxide, milk of lime, and sodium silicate were used in various portions to modify soy flour-based adhesive. Plywood bonded with optimized soy-adhesive met the requirement ofⅢtype plywood. When this soy-adhesive was mixed with PF in the ratio of 1:1,and plywood bonded at 160℃temperature for 5min or at 150℃temperature for 6min,the plywood prepared met the requirement ofⅠtype plywood. However,PF should be added in a reasonable rate for best linking. This study explores the possibility of utilizing environmental friendly natural adhesive in wood composite industry.