WOOD RESEARCH Volume 62, Number 5, 2017
Osman Emre Özkan, Ali Temiz, and Hasan Vurdu

Effects of heat treatment on Turkish fir wood properties

In this study, Turkish fir wood (Abies nordmanniana subsp. bornmulleriana) was subjected to two heat treatment process with varying temperatures (150, 180 and 200°C) and durations (2, 4 and 6 h). Some properties of the heat treated Turkish fir wood; mass change, water absorption, volumetric swelling, bending strength, modulus of elasticity (MOE), compression strength parallel to grain, color change and surface roughness have been tested and evaluated by statistical analysis. Consequently, volumetric swelling and water absorption values of the heat treated wood samples reducing. Bending strength, modulus of elasticity and compression strength parallel to grain values were decreased by heat treatment at high temperatures. Additionally, color change and surface roughness values of heat treated wood decreased with weathering compared to those of control samples.

WOOD RESEARCH Volume 64, Number 5, 2019
Mustafa Öncel, Hasan Vurdu, Hakan Aydoğan, Osman Emre Özkan, and Alperen Kaymakci

The tensile shear strength of outdoor type plywood produced from fir, alnus, pine and poplar wood

In this study, it is aimed to determine both the tensile-shear strengths of plywood that produced by using phenol formaldehyde resin from Uludağ fir (Abies nordmanniana subsp. bornmülleriana Mattf.), alder (Alnus glutinosa L.), scots pine (Pinus sylvestris L.) and Samsun poplar (77/51 Populus deltoides Bartr.) trees rotary cut veneers combinations of poplar-pine, poplarfir, poplar-alder and poplar wood along with the effect of wood types on adhesion quality of glue. According to standards TS 3969 EN 314-1, and TS EN 314-2 adhesion class 3, the test specimens were prepared and tested for the adhesion quality. The obtained data were analyzed statistically by using SPSS 22 statistical program. As a result, the tensile-shear strength values of poplar, pinepoplar, fir- poplar and alder-poplar plywood types were found to be as averages 1.34 N. mm-2, 1.66 N. mm-2, 2.18 N. mm-2 and 2.46 N. mm-2 respectively. Also, it was found that there was no significant difference between the alder poplar and fir-poplar plywood types about tensile-shear strength. Since these all plywood combinations are satisfied the required 1 N. mm-2 strength value according to TS EN 314-2, all plywood types in this study are of suitable quality for outdoor uses.