The main effect of adhesive percentage is summarized in Table
5 which demonstrates positive effects of adhesive percentage on TS
properties. Generally, TS properties improved with increasing
adhesive levels from 9% to 11% by 9.05%. Although mechanical
properties of experimental boards improved by the increase of
adhesive percentage, no significant difference is observed in
MOR, MOE and IB (P < 0.05). This result is due to the increase of
bonds between wood and resin as well as the reduction of water
absorption areas (Hydroxyl groups) as the result of increasing resin
content (karegarfard et al., 2003; Habibi et al., 2003). This finding is
also compatible with previous literature (Labosky et al., 1993; Karegarfard
et al., 2003; Habibi et al., 2003).