Your search resulted in 336 documents. Displaying 25 entries per page.
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Microwave modification of Yellow Stringybark (Eucalyptus Muelleriana) posts for impregnation with Copper-Chrom-Arsenic (CCA) preservatives
2000 - IRG/WP 00-40185
Yellow Stringybark posts with diameters ranging from 60-100 mm were microwave conditioned using a 60 kW microwave (MW) generator. A substantial improvement in heartwood penetration of preservatives and relaxation of growth stresses was indicated such that there was no split formation following drying of the posts. High preservative absorption of copper-chrome-arsenic (CCA) was achieved ranging fro...
G Torgovnikov, P Vinden
Information from the COIPM Wood Group
1988 - IRG/WP 4146
Abstract from the COIPM minutes: Wood in marine environment:
Mrs Gambetta stated that the main item discussed by the Group was the collaborative work to test the durability of heat shrinkable polyolephin sheating materials for the protection of wood against marine organisms. The work began last year when wood samples were sent out to the participants. Three samples of Pinus sylvestris wrapped in ...
A Gambetta
Modification of solid wood: research and practical potential
1997 - IRG/WP 97-40098
The polymeric structure of the wooden cellwall mainly consists cellulose, hemicellulose and lignin. The most reactive sites on these components are the hydroxyl groups. The cellwall polymers (and its reactive hydroxyl groups) are responsible for most physical and chemical properties of wood. By changing the basic chemistry of the cellwall polymers, it is possible to change different undesirable at...
H Militz, E P J Beckers, W J Homan
Dimensational stabilisation of wood
1981 - IRG/WP 3171
A review is given of the studies on the dimensional stabilisation of wood which have been carried out in the laboratory 5.14 "Wood Technology" since 1967. All stabilisation methods known have first been compiled from the available literature. Practical studies were then started. Wood was treated with monomers (styrene, methyl metacrylate, isocyanate), formaldehyde, tannin and sugar. Despite a sati...
A Burmester
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
Three years of field tests with "Lignomer" stakes in ground contact
1981 - IRG/WP 3166
The "Lignomer" (Wood Polymer Composite) is a material obtained during the polymerisation of various monomers or its mixtures in wood. As laboratory tests have shown, this material is characterized by a high resistance against biological deteriorating agents. The laboratory investigations on the durability of various materials against biological deterioration are in many instances extended by field...
K Lutomski
Effects of steaming heat treatment of wood on the stimulation of termite feeding
1997 - IRG/WP 97-10212
At the 26th IRG conference, we reported that steamed Japanese larch heartwood samples were suffered a serious attack by subterranean termite, Coptotermes formosanus both in choice and no-choice feeding tests. This is possibly caused by the yield of termites stimulants in the wood samples resulting from the steaming process. Since the steaming heat treatment has often been applied to other several ...
S Doi, Y Kurimoto, M Takahashi, T Yoshimura
Bending strength of heat-treated spruce and pine timber
2002 - IRG/WP 02-40242
Heat-treatment of spruce (Picea abies) and pine (Pinus sylvestris) beams (45 x 145 mm) gave a reduction in bending strength of approximately 50%. The bending stiffness (modulus of elasticity) only decreased by 3.5%. Tests were carried out according to EN 408. Another effect of the heat-treatment was increased variation in bending strength. The 5th percentile value of the bending strength, the so c...
C Bengtsson, J Jermer, F Brem
Treatment groups and remedies for CCA treated hardwood and softwood poles
1999 - IRG/WP 99-40142
Different hardwood and softwood species from Bangladesh and Bhutan was investigated regarding density, green fiber stress, natural durability of heartwood and CCA treated sapwood, CCA treatability grades, sapwood thickness, and kiln-drying properties for long term use as electric poles. These properties along with the past service records for nineteen years, separated ten heardwood and five softwo...
A K Lahiry
Three-year field trials of polymeric formulations which provide a new basis for the invention and design of non-toxic wide-spectrum wood preservatives
1994 - IRG/WP 94-40029
Three types of non-toxic polymeric formulations invented using a new approach to wood preservation were challenged with termites and fungi in three-year ground-contact field trials in the sub-tropical climate of Natal. These formulations were copper soaps of carboxylic acid groups of unsaturated fatty acids of waxes and edible vegetable oils; of resin acids of rosin, and, of synthetic unsaturated ...
A A W Baecker, A Pizzi
Screening of the technical performance and aquatic toxicity of N-methylolacrylamide treated wood
2000 - IRG/WP 00-40166
In the course of the last decades chemical modification of wood species, with a limited natural durability, has been subjected to intensive research. As a possible alternative and supplementary treatment of non-durable wood in a range of applications it remains one of the major topics in the wood preservation world. Different modification systems have been scaled-up and are now in an industrialisi...
V Rijckaert, S De Geyter, J Van Acker, M Stevens
Durability of some alternatives to preservative treated wood
2004 - IRG/WP 04-30353
The environmental discussion in Sweden has lead to an increasing use of naturally durable domestic wood species and wood treated according to alternative methods for use above ground. A number of these alternatives have been tested according to field- and laboratory tests and compared to wood treated with preservatives for above ground use. Seven untreated wood species, four alternative wood treat...
M-L Edlund
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Less pollution due to technical approaches on accelerated steam fixation of chromated wood preservatives
1988 - IRG/WP 3487
Steaming of freshly treated wood at 100°C to 120°C initiates a spontaneous fixation of copper-chromate-containing wood preservatives. For the performance, a suitable anticorrosive equipment is necessary. Good results can be achieved using a separate steaming equipment which allows a rapid heating of the wood. While warming-up, in the wood some preservative solution extends and can be partly extr...
H Willeitner, R-D Peek
Test methods for modifies wood: The EU-Thematic network approach
2002 - IRG/WP 02-20255
The last decade wood modification systems have become new wood treatment methods in Europe. Alongside several industrial initiatives for heat treatments also scaling up and pilot plant projects for chemical wood modification have recently been carried out. In 2000 an initiative to create a network related to these new developments was supported by the European Commission. Within the work proposed ...
J Van Acker, D Jones
A Novel Type of Multiple Cavity Attack in Wood Cell Walls of Heat-treated Timber Exposed in Seawater – Preliminary Observations
2004 - IRG/WP 04-10523
Samples of untreated and heat-treated Norway spruce and Douglas fir were submerged in Langstone Harbour, Portsmouth for 4 years at a depth of ca. 0.3 metres. The heat-treated samples had been prepared using the Plato process. Samples were initially assessed for the severity of marine borer damage and were then examined microscopically for evidence of microbial decay. Longitudinal and transverse wo...
R A Eaton, C Björdal, T Nilsson
Formosan Subterranean Termite Resistance to Heat Treatment of Scots Pine and Norway Spruce
2003 - IRG/WP 03-40264
New challenges to the durability of wood building materials have arisen in the U.S. The Formosan subterranean termite (Coptotermes formosanus Shiraki) now infests sizable portions of the U.S. south and their range is extending. Heat treatments offer a unique opportunity for wood-based composites because many of the process techniques already employ various thermal applications and could be easil...
W R Smith, A O Rapp, C R Welzbacher, J E Winandy
Melamine resins as preservatives results of biological testing
1996 - IRG/WP 96-40061
Based on previous work of the authors on resins, the upgrading of wood with a true solution of a methanol etherificated melamine resin in low aqueous concentration was performed. For the relative assessment of the biological resistance against brown and white-rot fungi were used not only untreated controls of pine sapwood (Pinus sylvestris L.), but also heartwood of European larch (Larix decidua M...
A O Rapp, R-D Peek
Characterization of wood decay enzymes by MALDI-MS for post-translational modification and gene identification
2002 - IRG/WP 02-10442
The recent sequencing of the Phanerochaete chrysosporium genome presents many opportunities, including the possibility of rapidly correlating specific wood decay proteins of the fungus with the corresponding gene sequences. Here we compare mass fragments of trypsin digests, determined by MALDI-MS (Matrix Assisted Laser Desorption Ionization-Mass Spectrometry), with predicted mass fragments derive...
T H de Koker, P J Kersten
Effects of the sulfuric acid modification of CCA treating solution
1987 - IRG/WP 3415
Sulfuric acid modification of CCA treating solution is often used to control the formation of sludges and undesirable deposits on the surface of treated wood. The consequences of sulfuric acid addition are examined in this work and negative effects are shown to far outweigh any benefits. Major risks include the loss of copper due to leaching from treated wood and the accelerated corrosion of treat...
R F Fox, H J Fry, E A Pasek, A S Ross
Termite Response to Oil-Heat-Treated Norway spruce, Scots Pine and Eucalyptus Wood
2006 - IRG/WP 06-20325
The work here presented focused on the behaviour of subterranean termites (Reticulitermes grassei Clément) towards Oil-Heat-Treated (OHT) Norway spruce (Picea abies L.), Scots pine (Pinus sylvestris L.) and eucalyptus (Eucalyptus globulus Labill) wood, with a particular interest in the development of simple methods adequate to study the resistence of these materials to termite attack. Small test ...
L Nunes, T Nobre, C Welzbacher, A O Rapp
Identification of fungi colonising coated and modified wood exposed outdoors using sequencing and T-RFLP profiling
2006 - IRG/WP 06-20326
Wood decay and staining fungi are known to colonize coated and modified wood. Rapid and reliable ways of identifying fungi on coated and modified wood may improve diagnostics and product development. In this work nine fungi growing in painted wood panels exposed outdoors at a test field in Uppsala, Sweden, were identified using sequencing and T-RFLP (Terminal Restriction Fragment Length Polymorphi...
U Råberg, J Bijelovic, C J Land, S Bardage, N Terziev
High-energy multiple impact (HEMI)-test – Part 2: A mechanical test for the detection of fungal decay
2006 - IRG/WP 06-20339
The suitability of the high-energy multiple impact (HEMI)-test for detection of early fungal decay was examined. The HEMI – test characterizes the treatment quality of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are expressed by structural changes of the wood. Simil...
C R Welzbacher, C Brischke, A O Rapp
High-energy multiple impact (HEMI)-test – Part 1: A new tool for quality control of thermally modified timber
2006 - IRG/WP 06-20346
Thermal modification processes improve durability and dimensional stability of wood, but the strength properties, especially the dynamic ones, are compromised and need to be considered with respect to industrial quality control. Results from standard dynamic strength testing, such as impact bending tests, suffer from high variability, and therefore require a high number of replicates. To overcome ...
C Brischke, A O Rapp, C R Welzbacher