Effects of application methods and species of wood on color changes of varnishes

In this study, the color effects of wood materials to coloring with different application methods (brush, roller sponge and spray gun) and waterborne varnishes were investigated according to ASTM-D 2244. For this purpose, the experimental samples of Scots pine (Pinus silvestris L.), oriental beech (Fagus orientalis L.) and oak (Quercus petreae L.), which are commonly used woods in the carpentry and furniture industry in Turkey, were prepared and varnished with one and two-pack waterborne varnishes in accordance with ASTM D 3023. According to the result of the research, significant color changes in coloring as red and yellow tones on the sample surfaces of varnished wood materials were found. The highest color change was obtained in the samples of oak, when varnished with brush and spray gun while the lowest value was obtained in roller sponge in respect to the application methods for waterborne varnishes. However, the application method of spray gun for self crosslinked polyurethane, topcoat-clear, (SCPt) gave the highest metric chroma value among the three different application methods

The effects of impregnation chemicals oncombustion properties of laminated wood material

WOS: 000186925600006In this study, the effects of impregnation materials, sodium perborate, sodium tetraborate, Imersol-WR 2000, and Tanalith-CBC, on combustion properties of three-ply laminated wood material produced from Uludag fir ( Abies bornmulleriana Mattf ) were investigated. The wood samples were impregnated with chemicals via a dipping method. Prepared materials have been bonded with Desmodur-VTKA adhesive and tested according to the procedure of ASTM-E 69 standards. As a result, the highest mass reduction in massive wood samples impregnated with Tanalith-CBC were determined. CO and CO2 ratios were obtained in massive control samples, which were unprocessed. Temperature variation in laminated samples impregnated with Tanalith-CBC, O-2 ratio in massive wood samples impregnated with sodium tetraborate, and ash ratio in laminated samples impregnated with sodium perborate were obtained

Effect of Tenon Geometry, Grain Orientation, and Shoulder on Bending Moment Capacity and Moment Rotation Characteristics of Mortise and Tenon Joints

Bending moment capacity and moment rotation characteristics of mortise and tenon joints as a function of tenon geometry, grain orientation, length, and shoulder fit were examined. Bending moment capacity of all joints in which tenons were fully inserted in mortises was 54% greater than for joints in which tenons were not fully inserted. Jointswith 25.4-mm-long diamond-shaped tenons had greater moment capacity than either rectangular or round tenon joints, whereas joints with 38- or 51-mm-long rectangular tenons had greater capacities than jointswith diamond or round tenons. Similarly, for joints inwhich tenonswere not fully inserted, rectangular tenons had the greatest moment capacity regardless of grain orientation or length

The effect of heat treatment on bio-oil properties obtained from pyrolysis of wood sawdust

Heat treatment is becoming increasingly popular and is growing as an industrial process to improve wood properties. The Finnish wood heat treatment technology, ThermoWood, is the most commonly used technology in the industrial area. In this study, pyrolysis of untreated and heat-treated ash wood (Fraxinus excelsior L.) was carried out using a fixed-bed reactor at different pyrolysis temperatures. The influences of the heat treatment process and the pyrolysis temperature on the yields and chemical composition of products were investigated. The maximum bio-oil yield was 46 wt% at a pyrolysis temperature of 550 °C for untreated wood, while the bio-oil yield was found to be about 41 wt% at a pyrolysis temperature of 500 °C for heat-treated wood. The elemental composition and higher heating value (HHV) of the bio-oil was determined. The chemical composition of the bio-oil was investigated using some chromatographic and spectroscopic methods, such as gas chromatography–mass spectrometry (GC/MS) and 1H-NMR. It was found that the heat treatment process significantly reduced the organic acids, ketones and aldehydes, while it increased the phenolic compounds. These results show that heat-treated wood sawdust should be used as a valuable feedstock for production of the bio-oil. © 2015, Springer-Verlag Berlin Heidelberg

Technical Note: Static Versus Cyclic Load Capacity of Side Chairs Constructed with Mortise and Tenon Joints

The effect of cross-sectional tenon geometry on static and cyclic load capacity of side chairs constructed with round-, rectangular-, and diamond-shaped mortise and tenon joints was investigated. Cyclic load capacity averaged about two-thirds of static load capacity for the joint configurations tested. For the configurations included in the test, chairs with mortise and tenon joints constructed with round-, rectangular-, and diamond-shaped tenons had static load to cyclic passing load ratios of 56.5, 66.8, and 69.2% for rectangular-, round-, and diamond-shaped tenons, respectively. These results indicate that useful relationships existed between static and cyclic performance of round mortise and tenon joints, which may simplify the design process for chairs that must pass cyclic performance tests