Combustion properties of Rowan wood impregnated with various chemical materials
The common use of Rowan wood (Sorbus aucuparia Lipsky) in the forest products industry of Turkey, was evaluated for some of the combustion properties after impregnation with various chemical materials. For this purpose, the wood test samples prepared from Rowan wood materials according to TS 345 were treated with Tanalith-E, Vacsol-Azure, Imersol-Aqua and Boron compounds (Borax and Boric asid) by the vacuum impregnation process in accordance with ASTM D-1413 standards and directives of the manufacturer. After impregnation, each sample was tested for observation of retention amount and combustion properties (ASTM E 160-50). It has been proven that combustion properties of the impregnated Rowan wood materials were affected by impregnated materials. As a result, combustion temperature was measured as highest in Imersol Aqua (458.686°C) and the lowest in Borax (439.023°C). The impact of impregnation material decreases after the ignition and the main impact was in flame sourced combustion. In addition, boric acid reduces the material loss in combustion, ensuring that the material is more resistant to sudden collapse and destruction. As a result, it appears that impregnation of wood material with appropriate boron treatment will further increase combustion temperatures and provide additional fire resistance and a degree of security. 
 
   
 
 Key words: Rowan wood, combustion properties, Tanalith-E, Vacsol-Azure, Imersol-Aqua, Boron compounds.
WOOD PRESERVATION.
Wood, being a biological product, is liable to deterioration unless it is properly protected. The main reasons of deterioration of timber in service are decay due to fungal infection, attack by insects (borers and white ants), marine organisms and fire. Protection of wood is carried out from these agents by using preservative which can properly be used by proper design of preservation plant. Proper design of such plant is very essential to increase the lifespan of wood economically. Among the various wood preservation techniques, pressure processes are the most permanent technique around the world today. In the Full cell process, wood is allowed to absorb as much liquid chemicals as possible during the pressure period, thus leaving the maximum concentration of preservatives in the treated area. Usually, water solutions of preservative salts are employed with this process but it is also possible to impregnate wood with oil. The desired retention is achieved by changing the strength of the solution. A Full cell pressure wood preservation system was designed and constructed in Mechanical Engineering Department of KUET and its performance was tested. The pressure cylinder was constructed using locally available materials and different physical properties of wood were measured. It was observed that the weight of wood reduces due to loss of moisture, density, retention, penetration of preservatives into wood due to pressure in the cylinder. The penetration is more or less uniform throughout the surfaces.
Fire resistance of Douglas fir (Pseudotsuga menzieesi) treated with borates and natural extractives.
The objective of this study was to determine fire resistance of Douglas fir (Pseudotsuga menzieesi (Mirb.) Franco) specimens treated with borate supplemented aqueous solutions of brutia pine bark powder, acorn powder, sumach leaf powder, and gall-nut powder. Boric acid (BA) and borax (BX) were used as borates which are the most commonly used fire retardants in wood preservation industry. Natural extractives (brutia pine bark powder, sumach leaf powder, acorn powder, and gall-nut powder) were also used which have toxic efficiency against insects and fungi due to their tannin contents. A commercial treatment compound Tanalith-CBC (copper-borate-chromate), which is an impregnation chemical, is used for comparison. The fire test method was performed in three stages: flame stage, without flame stage, and glowing stage. Results indicated that the lowest temperature for flame stage, without flame stage, and glowing stage were obtained for specimens treated with BA and BX mixture (7:3; weight:weight). The lowest mass loss was found for the specimens treated with a mixture of BA and BX. Natural extractives did not improve fire resistance of the samples. However, boric acid and borax had excellent fire retardant effectiveness over untreated and treated samples with natural extractives.