PREPARATION AND PIGMENTED POLYESTER COATING OF SAW DUST PARTICLE BOARD USING ULTRAVIOLET IRRADIATION

Abstract

Experiments on the preparation and pigmented polyester coating of saw dust particle board have been conducted using ultra-violet (UV) radiation curing. The adhesive used for preparation of particle board was the mixture of eugenol and isoeugenol residue as by product of clover oil distillation. Dry saw dust (20 – 40 mesh) was mixed with adhesive at concentration of 16% b.w. The mixture then was hot pressed at 160, 170, and 180 kg/cm 2 , temperature of 160 °C for 30 minutes. Particle boards obtained have the density of 0.85 - 92 g/cm 3 , water content of 5.4 – 6.8 % and thickness swelling 45 – 62% ( 2 hr immersion) and unmeasurable for 24 hr immersion due to brittle condition. It was found that particle boards have properties of modulus of rupture = 64 – 71 kgf/cm 2 , modulus of elasticity = 402 – 447 kgf/ cm 2 , and internal bond of 0.52 – 0.57 kgf/cm 2 . Cured coating made of the mixture of polyester resin, photoinitiator (2 and 3% b.w) and pigment (1 and 2% b.w) on particle board and irradiated at 1 – 4 m/min have pendulum hardness = 25.0 – 63.9 sec, pencil hardness = HB – 2H, % remaining = 92 – 100 %, glossy = 42.3 – 58.8 %, and color value of L = 54.3 – 73.9, a = -1.3 – 1.9, and b = 0.4 – 3.3. The cured coatings resist to chemical, solvent and stain, except against 10% NaOH solution and red permanent marker stain. Keywords: Particle board, Coating, Polyester, Ultra violet irradiation.