Your search resulted in 73 documents. Displaying 25 entries per page.
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
Wood plastic composites from modified wood; Part 1 - Conceptual idea, mechanical and physical properties
2006 - IRG/WP 06-40338
Wood plastic composites, WPCs, are rapidly taking shares from preservative treated wood on the decking market. However, the long term performance of the WPC products in this application is uncertain. Therefore, in an attempt to increase the long term performance and durability, the substitution of the unmodified wood component with modified wood has been studied in the work presented in this paper...
P Larsson Brelid, B K Segerholm, M Westin, M E P Wålinder
Further discussion of biological durability assessments of acetylated wood from several European institutes
2006 - IRG/WP 06-40340
In the last decade, interest in the development of wood modification systems has increased in Europe. Alongside several industrial initiatives for heat treatments, there have also been scaling up and pilot plant projects for chemical wood modification. Between 2000-03, the European Commission funded the "Thematic Network on Wood Modification". This paper features a re-evaluation of work undertaken...
D Jones, W Homan, F Bongers
Influence of Acetylation on Fire Resistance of Beech Plywood
2006 - IRG/WP 06-40326
Influence of acetylation on fire resistance was studied in beech plywood. Beech layers were acetylated in a reactor with acetic anhydride at 120ºC for varying durations. Plywoods were made from the acetylated layers and directly exposed to burning flame from their edges for 60s according to ISO 11925-3. Ignition and glowing time were measured in samples. Results were analyzed statistically based ...
B Mohebby, A Talaii, A Karimi , S Kazemi Najafi
Wood plastic composites from modified wood. Part 2 - Durability in laboratory decay tests
2006 - IRG/WP 06-40353
The decay resistance of wood plastic composites, WPCs, was tested according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils, terrestrial microcosms, TMCs). The WPC materials were conically extruded profiles with 30% polypropylene content. The 70% wood content was untreated Scots pine sapwood, acetylated pine and heat treated Norway spruce, respective...
M Westin, P Larsson Brelid, M L Edlund, G Alfredsen
Durability of some alternatives to preservative-treated wood. Progress report 2: Results from field tests after 5 years’exposure
2007 - IRG/WP 07-30442
A number of alternatives to preservative-treated wood have been tested according to EN 252 (stake test) and a specially designed ground-proximity field test, the latter in Sweden as well as in Hawaii, USA. Seven untreated wood species and four alternative wood treatments labelled as environmentally friendly (acetylation, linseed oil, heat treatment, vinyl polymer) were included in the study. Four ...
M-L Edlund, J Jermer
A step towards a better understanding of fungal colonization of modified wood - QRT-PCR studies
2008 - IRG/WP 08-10653
The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is tak...
G Alfredsen, A Pilgård, A Hietala
Material properties of acetylated beech plywood
2008 - IRG/WP 08-40425
The effect of acetylation process on dimensional stability and mechanical properties of plywood made by Oriental beech layers (Fagus orientalis Lipsky) were studied. The layers cut into sizes of 200×200×2 mm and acetylated in 120°C for 30 and 60 min.
Thickness swelling (TS%), water absorption (WA%) and anti-swelling¬ efficiency (ASE%) of specimens were measured. Mechanical properties (MOE, MO...
A Talaei
Chemical modification of Scots Pine Sawdust by mixed anhydrides
2008 - IRG/WP 08-40439
By making react mixtures containing acetic-fatty anhydrides on Scots pine sawdust (SPS) without any solvent or catalyst; we synthesized mixed acetic-fatty esters of SPS. Such mixtures were synthesized by reaction between a carboxylic acid and acetic anhydride. These mixtures were obtained after reaction of acetic anhydride and a fatty acid that yields at equilibrium a mixture of five compounds: ac...
J Peydecastaing, E Borredon, S El Kasmi
Termite resistance of some modified wood species
2009 - IRG/WP 09-40449
During the last few decades, researchers worldwide have investigated and developed new treatment techniques to improve intrinsic wood properties. Some of these techniques were introduced to the market recently and are gaining in importance.. Various wood properties of these new materials have been studied intensively. These include physical-mechanical properties (dimensional stability, moisture ...
H Militz, B C Peters, C J Fitzgerald
Investigation of chemical changes in acetylated beech wood during weathering
2009 - IRG/WP 09-40460
In this study Beech wood (Fagus orientalis) acetylated and has been subjected to a variety of artificial weathering conditions (water only, light only, water and light together)in difference times (0,50,150 and 300 h), then wood surface analyzed using Fourier Transform Infrared spectroscopy (FTIR).Results shown that weathering process affected the functional groups on the wood surface. Light and w...
M Akhtari, M Arefkhani
The kinetics of catalytic acetylation of Pinus radiata (D. Don) using conventional and microwave heating
2010 - IRG/WP 10-40485
This study outlines the effect of catalyst and microwave heating on the degree of acetylation in radiata pine. Samples of radiata pine sapwood were impregnated with potassium acetate (KAc) dissolved in two different solvents (water and methanol). Impregnated samples were dried and subjected to acetic anhydride loading followed by conventional and microwave heating. The degree of acetylation was ev...
A Kumar Sethy, P Vinden, G Torgovnikov, S Przewloka
Study of Microscopy Properties of Modified Wood During Weathering Process
2010 - IRG/WP 10-40517
In this study spruce (Picea excelsa) and Beech (Fagus orientalis) wood acetylated and has been subjected of artificial weathering in difference times (0, 50,150&300 h), then wood surface analyzed using Scanning Electron Microscopy (SEM). The SEM results shown that the surface of wood exposed to weathering undergoes distinct physical changes and the surface degradation appears to be directly propor...
M Akhtari
Biological degradation of acetylated wood after 18 years in ground contact and 10 years in marine water
2010 - IRG/WP 10-40522
This paper addresses the resistance to biological degradation of acetylated wood.
Firstly, it presents results from an EN 252 test after 18 years’ exposure. The test is still running in Nordic NWPC test fields, Simlångsdalen in Sweden and Viikki in Finland. Results from this test were presented after 5 years’ exposure ( IRG/WP 97-30139), and showed that the resistance of acetylated wood wit...
P Larsson Brelid, M Westin
Lignin blocking effects on weathering process of wood plastic composites
2010 - IRG/WP 10-40529
The weathering of wood–plastic composites (WPC) causes discoloration which affects their aesthetic aspects. It has been proved that these discolorations are due to lignin degradation. Effects of blocking the susceptible structure of lignin assessed by chemical treatment such as acetylation and methylation are reported in this study. Surface chemical change of wood plastic composite (WPC) formula...
P Darabi, A Naghi karimi, S Ahmade Mirshokraie, M-F Thévenon
Biological resistance of acetylated particleboards exposed to white (Trametes versicolor (and brown (Coniophora puteana) rot fungi
2010 - IRG/WP 10-40534
This research was conducted to investigate the effect of acetylation on bioresistance of particleboard produced from acetylated wood chips of Fagus orientalis exposed to white (Trametes versicolor (and brown (Coniophora puteana) rot fungi. After 12 hours soaking in acetic anhydride, in order to achieve three level of weight gains, 5, 9 and 16%, acetylated particles were heated in an oven at 120 c...
M Ghorbani kokandeh, K Doosthoseini, A N Karimi, B Mohebby, H Asghari
The effects of acetylation level on the growth of Postia placenta
2011 - IRG/WP 11-10751
To understand the defence mechanisms utilized by decay fungi when exposed to different wood protection systems the study of gene expression can give us some answers. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by differen...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
The durability of acetylated radiata pine sapwood (Accoya). Results from five years testing
2011 - IRG/WP 11-30560
New Zealand grown radiata pine sapwood was modified using the Accsys PLC acetylation process (Accoya). Following treatment, various test samples were exposed in the Scion Accelerated Field Test facility (Fungus Cellar) and in exterior ground contact field tests. In the Fungus Cellar, performance was compared with that of radiata pine treated with CCA to Hazard Classes H3.2 (0.37% m/m Cu+Cr+As) and...
M Hedley, D Page, J van der Waals, K Nasheri, G Durbin
Acetylation Properties of Southern Pine and Radiata Pine
2011 - IRG/WP 11-40543
The chemical modification of wood via acetylation with acetic anhydride has been a well investigated technology and is of current commercial interest due to improved properties such as dimensional stability as well as resistance to termites and resistance to rot and decay fungi. Despite this, the acetylation of a board substrate requires further investigation in order to assess board properties a...
J Allen, T Guinn, J Dickerson
The effect of press time on springback and water absorption of acetylated particleboard
2012 - IRG/WP 12-40579
In this study the effect of press time on springback, thickness swelling and water absorption was investigated. After 24 hours soaking in acetic anhydride, in order to achieving WPG 17%, acetylated particles were heated in an oven at 120 0C for 360 minutes. Acetylated and nonacetylated (control) particleboards were produced with 10% melamine urea formaldehyde (based on the oven-dry weight of part...
F Bavaneghi, M Ghorbani, A Kargarfard
The effects of acetylation level on the growth of Postia placenta over 36 weeks
2012 - IRG/WP 12-40589
Genomic sequencing gives us a tool to systematically and rapidly discover novel genes, how their products function in the cell, and explore their interactions. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by different wood...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
A survey of factors affecting decay resistance of wood modified with acetic anhydride
2012 - IRG/WP 12-40594
From the range of information published, acetylation appears well suited to provide adequate protection against biological attack for materials derived from typically non-durable wood species. Acetylated wood is now commercially available both in Europe and in the USA. But still there are a lot of unanswered questions related to fungal decay mechanisms in acetylated wood. The paper summarize exist...
G Alfredsen, P O Flæte, H Militz
Correlation of %Acetyl and Fiber Saturation in Acetylated Southern Pine Boards
2012 - IRG/WP 12-40598
Wood acetylation represents a chemical modification that increases the hydrophobicity of wood. The level of acetylation in the wood structure determines the extent of hydrophocity with higher levels providing reduced moisture affinity. Due to the reduced hygroscopic nature of acetylated wood, performance features such as dimensional stability, resistance to termites, and resistance to rot and de...
J Dickerson, E Cwirko, J Allen
The resistance of high performance acetylated wood to attack by wood-destroying fungi and termites
2013 - IRG/WP 13-40621
The resistance of high acetyl solid timber (Accoya) and medium density fibreboard (Tricoya) to attack by wood-destroying fungi and termites was investigated under both laboratory and field conditions. Laboratory studies were conducted in Japan, New Zealand and USA. Field studies were conducted in Australia, Japan, New Zealand, Thailand and UK. The results of the laboratory and field studies agains...
J Alexander, J Hague, M Roberts, Y Imamura, F Bongers, E Suttie
Study of UV resistance and natural weathering of coatings on chemically modified wood
2013 - IRG/WP 13-40629
In this study, UV resistance and weathering performance of rubberwood (Hevea brasiliensis) and radiata pine (Pinus radiata) modified with benzoyl chloride and acetic anhydride was studied. Performance of polyurethane based wood coatings on modified wood was also evaluated. Unmodified and chemically modified specimens were exposed to accelerated and natural weathering. Modified and unmodified woo...
K K Pandey, K Srinivas