Ph.D. Tezi Görüntüleme

       In this study; some technological properties of the treated plywood produced with different wood species and the effects of adhesive, wood preservative types and treatment methods on the formaldehyde and volatile acid emission were determined. For this purpose, five-layer plywood panels were produced from beech and alder wood impregnated with three different wood preservatives in the laboratory. Two types of urea-formaldehyde and phenol formaldehyde resins were used and two treatment methods were applied. While first group panels were impregnated by soaking of individual veneer into 5 % aqueous preservatives solution, the second group samples were impregnated by adding preservatives into the glue mixture. Test specimens with the dimensions given in the national and international standards prepared from the experimental board were used for determination of following properties of the board; specific density, moisture content, bending strength, modulus of elasticity, shear strength, pH, buffer capacity, formaldehyde and volatile acetic acid emissions and combustion properties. As a result; formaldehyde and volatile acetic acid emissions of beech plywood were determined to be lower than that of alder plywood. The formaldehyde emissions were lower on the plywood produced with using phenol formaldehyde resin; however, the amount of volatile acetic acid was found to be significantly higher on the plywood produced with using the same resin. While borax and ammonium acetate put forward a reducing effect on the formaldehyde emissions of the plywood, boric acid showed an increasing effect. The weight losses of alder plywood obtained after combustion tests were lower than that of beech plywood panels. Shear strengths of all of the panel groups were reduced by impregnation, but no negative effect was determined on the other mechanical properties of test panels.

      Keywords:Plywood, UF and FF Adhesive, U/F Mol Ratio, Fire-Retardant, Formaldehyde Scavenger, Volatile Organic Compound, Formaldehyde and Acetic Acid Emissions.