Onduran, Aytekin; Yasar, S. Sadiye; Altunok, Mustafa

In this study, wood modification (thermo-processing and impregnation) and outdoor conditions of storage (natural aging) the effects on the mechanical performance of industrial woodwork was investigated. For this purpose, naturally grown in Turkey and the commercial value of high Scots pine (Pinus sylvestris L.) and chestnut (Castanea sativa Mill) wood was used. Experimental examples are specifically woodwork has been applied in actual size. Considering the previously conducted research literature only diagonal L-type samples used, not on the actual size samples of woodwork. In addition, there is no study that the combination of the heat-treatment and impregnation. This reveals the original values of this study. For preparing of samples is used the double tenon-mortise corner joint from constructions method and as glue polyurethane based Desmodur VTKA and Polyvinyl acetate based two-component D4. Diagonal woodwork test samples prepared by Thermo S class (185°C temperature with a thermo-vapor process protections) applying. After application of the heat treatment, the test samples impregnated with a solution of 95 % natural pine cone resin and %5 pine tannin by dip method (2 hours). Then, the untreated samples (control), only heat-treated samples and heat treatment + impregnated samples kept for 1 year with outdoor conditions (aging). At the end of the aging, the samples tested according to the principles stated in TS 2472 and TS 7251 EN 107 standard. As result, the performance of woodwork decreased after aging in untreated and heat treatment pieces, the other side after aging - heat treatment, impregnation materials increased the values. The deformation value of woodwork increased after aging most untreated materials, Heat treatment and heat treatment-impregnated reduced aging effectiveness.

Perçın, Osman; Yasar, Şekip Şadiye; Altunok, Mustafa; Uzun, Oğuzhan

In this study, the screw withdrawal resistance of heat-treated hornbeam (Carpinus betulus L.), black pine (Pinus nigra Arnold) and Uludag fir (Abies bornmuellerinana Mattf.) was determined according to the ASTM D 1761 standard. For this purpose, wood materials were heat treated at 150, 170, 190 and 210 °C for 3 h. After the heat treatment, the screw withdrawal resistance of the wood was determined in radial, tangential and transverse directions. As a result, the screw withdrawal resistance values decreased with increasing heat treatment temperature and the lowest resistance was obtained in the wood heat-treated at 210 °C. In terms of wood species, the highest screw withdrawal resistance was found in hornbeam (Carpinus betulus L.), while the lowest value was observed in black pine (Pinus nigra Arnold). Additionally, in terms of the cross-sectional direction, the highest screw withdrawal resistance was determined in the tangential direction, while the lowest resistance value was observed in the transverse direction.