THE EFFECTS OF PRE-MICROWAVE TREATMENT ON IMPREGNATION PROPERTIES AND SOME MECHANICAL PROPERTİES OF SPRUCE WOOD TREATED WITH CCA
In this study, spruce wood speciemens were subjected to microwave (MW) pre-treatment prior to impregnation. The samples had an initial moisture content (MC) of 60% and were exposed to MW irridation in a microwave oven for 5, 5.5, and 6 min, while maintaining a constant power level of 800 W. Following the MW pre-treatment, the speciemens were impregnated with a 1.5% CCA solution using a vacuum-pressure method consisting if an initial vacuum phase of 20 min followed by a pressure stage of 30 min. Retention values and penetration depths were subsequently measured for each treatment group as well as for untreated control samples. The results indicated that MW pre-treatment significantly improved both retention and penetration performance. The retention values obtained for speciemens treated for 5, 5.5, and 6 min were 5.37, 6.04, and 6.18 kg/cm3, respectively, whereas the control samples exhibited a retention level of 3.64 kg/cm3. These findings demonstrate that MW pre-treatment enhances the impregnation efficiency of spruce wood. However, the treatment also led to reductions in certain mechanical properties, including modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS).