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Wood Materials (wood + material)

Distribution by Scientific Domains

Chemistry	28%

Selected Abstracts

The influence of the impregnating chemicals on the bonding strength of impregnated wood materials

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Ayhan Özçifçi
Abstract In this study, it is aimed to determine the bonding strength of white oak (Quercus petreae L.) and chestnut (Castanea sativa Mill.) woods impregnated with borax and zinc chloride. Within this purpose, the experimental samples were bonded with Polyvinyl-acetate and polyurethane based Desmodur-VTKA (D-VTKA) adhesives according to BS EN 205 standards after they had been prevacuumed with a pressure equal to 760 mmHg,1 with impregnating at 2 atm pressures for 60 min according to ASTM-D 1413 standards and applied vacuum-impregne-vacuum method. During the experiments, the retention amount, the retention proportion, and the bonding strength values of the samples were determined. According to the test results, the highest values of retention amount, and bonding strength were obtained from the wood material impregnated with zinc chloride. The impregnating materials had a negative effect on bonding strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Variability in Transport Properties for Blackbutt Timber in New South Wales: Within and Between-Tree Variability

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1-2 2006
S. J. Cabardo
Variability is a key issue in the processing of biological materials, in this case the hying of hardwood timber. This paper reports the measurements of variability of transport properties. which are relevant to the drying of blackbutt, Eucalyptus pilularis Sm, from northern New South Wales. Specifically, within-tree and between-tree variations are reported for two blackbutt regrowth logs. An analysis of variance showed that some timber properties were affected by the board positions within-trees and between-trees. Circumferential and radial efects were significant for the within- tree variability of most transport properties. Similarly, radial and circumferential effects were signlficant for most of the transport parameters between trees, but can be tentatively stated because only two regrowth logs were assessed. Timber boards with high initial moisture contents had higher rates of diffirsion and low basic densities using principal components analysis. A possible reason is that if there is less wood material per unit volume, these vacant spaces may be occupied by water, and there is also less resistance for diffusive transport of moisture. [source]

Prudent practices for the design and installation of heat-producing devices near wood materials

FIRE AND MATERIALS, Issue 2 2007
Vytenis Babrauskas
Abstract The conditions required to cause ignition of solid wood materials under short-term heating are examined, and it is found that the appropriate ignition temperature applicable under these conditions is 250°C. It is then shown that ignition requirements are different if long-term heating is involved and that ignition can occur at exposure temperatures much lower than the ignition temperature pertinent to short-term heating. It is shown that hot surfaces of 77 °C or higher, if located for a long duration next to a wood member are liable to lead to its ignition in a self-heating mode. Recommendation is made that prudent practices for design or installation must also involve a suitable safety factor. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Particles from fires,a screening of common materials found in buildings

FIRE AND MATERIALS, Issue 6 2003
Tommy Hertzberg
Abstract Small combustion generated particles are known to have a negative impact on human health and on the environment. In spite of the huge amount of particles generated locally in a fire accident, few investigations have been made on the particles from such fires. In this article, 24 different materials or products, typically found in buildings have been exposed to burning conditions in order to examine their particle generating capacity. In addition, a carbon fibre based composite material was tested in order to investigate if asbestos-resembling particles could be generated in a fire situation. The majority of the experiments were performed in the small-scale cone calorimeter, and some further data were collected in intermediate scale (SBI) and full scale (room-corner) tests. Additional testing of the composite material was made in a small-scale tubular reactor. The amount of particles and particle size distributions were measured by the use of a low-pressure impactor and particle aerodynamic diameter sizes from 30 nm to 10 ,m were measured. The results from the project show that the yield of particles generated varied significantly between materials but that the shape of mass and number size distributions were very similar for all the materials tested. The maximum amount of particles was obtained from materials that did not burn well (e.g. flame retarded materials). Well-burning materials, e.g. wood materials, tend to oxidize all available substances and thereby minimize the amount of particles in the smoke gas. It was found that asbestos-resembling particles could be produced from under-ventilated combustion of the composite material tested. Copyright © 2003 John Wiley & Sons, Ltd. [source]

The influence of the impregnating chemicals on the bonding strength of impregnated wood materials

Separation and recovery of cellulose and lignin using ionic liquids: a process for recovery from paper-based waste

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2009
Huma Lateef
Abstract BACKGROUND: The production of paper makes use of cellulose and lignin as a raw material, and almost all cellulose and lignin production comes from raw wood materials, contributing to deforestation and resulting in potential environmental harm. It is therefore beneficial to develop technologies for cellulose and lignin recovery for re-use and sustainability of resources. RESULTS: Three imidazolium based ionic liquids (ILs), 1-(2-cyanoethyl)-3-methylimidazolium bromide (cyanoMIMBr), 1-propyl-3-methylimidazolium bromide (propylMIMBr) and 1-butyl-3-methylimidazolium chloride (butylMIMCl), were synthesised by microwave technology and fully characterised by mass spectrometry, thermogravimetric differential scanning calorimetry, thin layer chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopies. Cellulose and lignin were soluble in all three ILs with solubility being greatest in cyanoMIMBr. Regeneration of cellulose and lignin was achieved from saturated solutions of cellulose in IL and lignin in IL for all three ILs. The ILs propylMIMBr and butylMIMBr have been used for the first time in the separation and recovery of cellulose and lignin and regeneration of the IL from a mixture of cellulose and lignin in IL. FTIR analysis confirms successful recovery. CONCLUSIONS: This work demonstrates the ability of ILs to separate and recover cellulose and lignin from a mixed system. Copyright © 2009 Society of Chemical Industry [source]