Treatment of wood with thermosetting resins: Effect on dimensional stability, strength and termite resistance

The effect of thermosetting resins viz. phenol formaldehyde (PF) and melami ne formaldehyde (MF) on dimensional stability, strength property and termit e (Odontotermis spp) resistant capacity of a soft wood, bombax ceiba were a ssessed. The wood was treated with 30% resin concentration in 110 degreesC at 75 psi air pressure and then dimensional stability in terms of anti-shri nk efficiency (ASE) of 70.59% and 68.23% were achieved at 32.1 and 33.0 lev els of weight percent gain (WPG) for PF and MF resins respectively. Maximum bulking co-efficient (BC) of 15.39% and 13.28%, and moisture excluding eff iciency (MEE) of 45.31% and 41.39% were achieved for PF and MF treated samp les at the above two WPG levels. Three cycles of repeated wetting and dryin g did not cause any further change in BC and ASE. The treatment also increa sed modulus of rupture (MOR) by 21.6% and 19.48% and modulus of elasticity (MOE) by 12.86% and 11.10% over the untreated samples without any remarkabl e change in specific gravity. Furthermore, the treated wood showed resistan ce to termite.