Investigation of some technological properties of the laminated wood material applied heat treatment

In this study, to determine of some physical, mechanical and technological properties of lamineted wood materials applied heat treatment with different adhesives were aimed.For this purpose, the laminated wood materials were prepared from scotch pine (Pinus sylvetsris L.), Oriental beech (Fagus orientalis L.), sensile oak (Quercus petraea L.) and poplar (Populus nigra L.) woods which have been glued by using PVAc-D4, PU and MF adhesives in accordance with TS EN 386. The laminated wood materials were obtained in the form of ten layers by using wood veener at thickness of 2 mm. Prepared the panels at 185 and 212 ºC for 2 hours and total for 38 hours under the protection of vapour heat treatment was applied according to the thermowood method.Test samples were prepared in order to determine the performances of air-dried density and oven-dried density according to TS 2472, bending strength according to TS 2474, modulus of elasticity according to TS 2478, comppessive strength parallel to fibers according to TS 2595, screw withdrawal strength perpendicular to fibers (radial sections) and paralel to fibers (transverse section) according to TS EN 13446, dowel holding strength perpendicular to fibers (radial sections) and paralel to fibers (transverse section), Brinell hardness strength according to TS 2479, dimensional stabilization according to TS 4084, paralel to the surface adhesion strength TS EN 205 and TS 2475, perpendicular to the surface adhesion strength according to TS EN 205 and TS 2476, combustion performances according to ASTM E 160-50, prepared tests samples from these panels and treated with control samples as comparing were studied.According to the results of these tests, in subjected to heat treatment samples, in air-dry and oven-dried densities decreased of physical properties, improved the dimensional stability 40 %. There was loss of resistance depending on temperature in mechanical properties, while the high-up temperature increased resistance loses. Technological properties of decline were determining depending on temperature, in generally combustion properties better results were obtained from the heat treated specimens.As result, high density Oriental beech and sessile oak in terms of adhesive species melamine-formaldehyde (MF) have been identified gave better results than others. Therefore, especially important of mechanical properties applications, aplied heat treatment laminated wood material for use, prefering of high density typies, as adhesive MF adhesive use be recommended. In addition to, in order to minimize resistance losses and to improve further the exiting properties, investigate different heat treatment processes applications be recommmended.