Your search resulted in 457 documents. Displaying 25 entries per page.
Efficacy of anhydrides as wood protection chemicals
1997 - IRG/WP 97-30162
Wood samples treated with anhydrides of various compositions have been examined for their decay resistance and moisture behaviour. For this purpose two brown rot fungi (Coniophora puteana and Gloeophyllum trabeum) and two white rot fungi (Trametes versicolor and Pycnoporus sanguineus) were used in conventional and modified soil block tests. The modified soil block tests conformed to the method as ...
S C Forster, M D C Hale, G R Williams
The effects of chemical modification on the physical properties of alder and spruce particleboards
2005 - IRG/WP 05-40300
In this paper, it was aimed to improve some physical properties of chemically modified particleboard, made from spruce and alder species, spreading widely at Black sea region in Turkey. Spruce and alder chips were reacted with acetic, succinic, maleic and phthalic anhydrides at constantly heat for 3 hours then, hot pressed at 150 °C by using Phenol formaldehyde (PF) resin. Target board density wa...
E Dizman, Ü C Yildiz, H Kalaycioglu, S Yildiz, A Temiz, E D Gezer
Sphaeroma terebrans Bate: A note on distribution and preservative tolerance in Florida coastal waters
1987 - IRG/WP 4135
Treated test panels were installed in January 1984 in a Florida estuary where Sphaeroma terebrans had severely damaged pilings treated with copper chromate arsenate (CCA). Test treatments were CCA at three retentions, coal-tar creosote at three retentions, creosote with chlorpyrifos, dual treatment with CCA and creosote, and three types of chemical modification of the wood test panels. We describe...
B R Johnson, E D Estevez, S A Rice
The biological effectiveness of wood modified with heptadecenylsuccinic anhydride against two brown rot fungi: Coniophora puteana and Gloeophyllum trabeum
1992 - IRG/WP 92-3705
A modified soil block test was carried out using wood samples reacted with heptadecenylsuccinic anhydride (ASA). This modification gave good resistance to decay brought about by the brown rot fungi Coniophora puteana and Gloeophyllum trabeum during the twelve week exposure period. Results indicated that there was a good correlation between increased loading of modifying reagent and an increase in ...
C Codd, W B Banks, J A Cornfield, G R Williams
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
Tunnelling bacteria
1983 - IRG/WP 1186
The micromorphology of decay in wood caused by a certain group of single-cell bacteria, called tunnelling bacteria (TB), is described. TB are characterised by their tunnelling ability within the secondary cell walls of wood fibres. Pure cultures of TB have not yet been obtained although the typical decay patterns can be reproduced using mixed bacterial cultures. Some indications of lignin degradin...
T Nilsson, G F Daniel
The identification of organic compounds in wood using thermal desorption GC-MS - possibilities and limitations
2001 - IRG/WP 01-20224
There is a clear need for the analytical characterisation and identification of organic compounds and their derivatives in different phases especially in timber. In this context the paper describes a rapid and powerful gas chromatographic method for the determination of insecticides, biocides and "other" organic substances in treated and/or modified wood. The main advantage of this procedure is th...
P Jüngel, E Melcher
Influences of the hydro-thermal treatment on physical properties of beech wood (Fagus orientalis)
2005 - IRG/WP 05-40303
Influences of the hydro-thermal treatment on physical properties of beech wood were studied. Wood specimens (2×2×2cm) were treated in two steps. At first step, samples were treated at 160,180 & 200ºC for 4, 5 & 6 hours. At second step, treated samples were cured based on their first step treatment temperatures (160,180 & 200ºC) for 16 hours. The treated samples were soaked in water...
B Mohebby, I Sanaei
The Effect on Biological and Moisture Resistance of Epichlorohydrin Chemically Modified Wood
2002 - IRG/WP 02-40224
Southern pine solid wood and fiber were chemically modified with epichlorohydrin to help in understanding the role of moisture in the mechanism of biological effectiveness of chemically modified wood. The solid wood had weight gains from 11% to 34%, while the fiber had weight gains from 9% to 75%. After modification, part of the specimens were water leached
for 2 weeks or extracted for 2 hours ...
R E Ibach, B-G Lee
Thermal modification of non-durable wood species 2. Improved wood properties of thermal treated wood
1998 - IRG/WP 98-40124
Properties of wood treated in a new heat-treatment process called the PLATO-process have been studied. Several wood species have been treated using this new thermal modification process using a range of process conditions (mainly time and temperature). In this study the characteristics of the treated wood were determined using samples from whole planks treated on pilot plant scale. The modified ch...
B F Tjeerdsma, M J Boonstra, H Militz
Dimensional stability and decay resistance of wood upon modification with some new type chemical reactants
1994 - IRG/WP 94-40028
Solid wood of home grown species can be upgraded by chemical modification with environmentally acceptable chemicals. The best kwown example of modification reaction is acetylation with acetic anhydride. A continued search for reactive chemicals other than acetic anhydride is ongoing, aiming at the improvement of technical properties of wood. This contribution deals with the results of a screening ...
P Goethals, M Stevens
Assessing the bioresistance conferred to solid wood by chemical modification
1997 - IRG/WP 97-40099
The chemical modification of wood using straight chain alkyl anhydrides can considerably enhance its durability. This paper presents an assessment of the effectiveness of these modifiers in improving the biological resistance of a susceptible softwood when exposed to four different basidiomycete fungi, soft rots and the larvae of the house longhorn beetle (Hylotrupes bajulus). It was clear that so...
E D Suttie, C A S Hill, D Jones, R J Orsler
Comparison of thermally modified wood originating from four industrial scale processes – durability
2002 - IRG/WP 02-40229
This study examined the differences in biological wood properties of heat treated wood originating from four different European industrial heat treatment plants. The manufacturers of heat treated material were: PLATO Hout B.V./Netherlands, Thermo Wood/Finland, New Option Wood/France and Menz Holz/Germany where Oil-Heat treated Wood (OHT) is produced.
The results of miniblock tests with basidiomyc...
C R Welzbacher, A O Rapp
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
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
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
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
Characteristics of thermally modified wood in vacuum
2004 - IRG/WP 04-40287
In commercial thermal wood modification processes nitrogen, steam or oil has been used for the reduction of oxygen content in the reactor atmosphere. In present study no special heating medium, but an initial vacuuming step has been used for this purpose. Mass loss, resistance to fungal decay, dimensional stability, bending strength and modulus of elasticity of heat treated wood were evaluated and...
G Rep, F Pohleven, B Bucar
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
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
The commercialisation of ThermoWood® products
2006 - IRG/WP 06-40339
The concept of thermally modifying timber is well established, which has achieved a limited market breakthrough to date. Commercial application has mainly occurred within Finland, though recent years has seen market gain in several other European countries. This paper reviews the known properties of ThermoWood® timber, based on the combined work of the Finnish ThermoWood® Association, alongside ...
D Jones, E Suttie, J Ala-Viikari, N Bergstrom, D Mayes
Photo-degradation of modified and non-modified wood, coated with water borne acrylic coatings during artificial light exposure
2007 - IRG/WP 07-30416
A series of experiments were carried out to investigate photo-degradation of thermally modified (at 210oC and – 0.9 bars for two hours) and non-modified spruce wood (Picea abies L (Karst)), coated with transparent and semitransparent (with 3% pigment content) acrylic coatings during artificial UV light irradiation for 200 hours. Photo-degradation was evaluated in terms of colour changes througho...
M Deka, M Tomažic, M Petric
Effects of heat treatments on decay resistance and material properties of ponderosa pine and yellow poplar
2007 - IRG/WP 07-40374
The potential for using heat treatment to improve the properties of North American fenestration species was evaluated on ponderosa pine (Pinus ponderosa L) and yellow poplar (Liriodendron tulipifera L) treated using the ThermoWood process at various treatment temperatures and times. Soil block tests using Gloeophyllum trabeum, Postia placenta, or Trametes versicolor showed that durability was enh...
C Vidrine, C Freitag, J Nicholson, J J Morrell