Your search resulted in 73 documents. Displaying 25 entries per page.
Moisture and Fungal Durability of Wood-Plastic Composites Made With Chemically Modified and Treated Wood Flour
2013 - IRG/WP 13-40648
Evaluating the fungal durability of wood-plastic composites (WPCs) is complicated by the influence of slow moisture sorption. Recently, the American Wood Protection Association (AWPA) Standard Method E10, Testing Wood Preservatives by Laboratory Soil-Block Cultures, was modified to incorporate not only solid wood, but also wood-based composites and WPCs. To simulate long term WPC performance, cond...
B K Segerholm, R E Ibach
Durability of alternatives to CCA-treated wood - Results from field tests after 11 years exposure
2013 - IRG/WP 13-30633
The present study was initiated as a consequence of restrictions against the use of CCA-type
wood preservatives in Sweden in the 1990s. New copper-based formulations were introduced on
the market and to some extent, also alternatives to preservative-treated wood, such as thermally
and chemically modified and linseed oil treated wood as well as heartwood of non-tropical
naturally durable wood s...
P Larsson Brelid, M-L Edlund
The resistance of Accoya® and Tricoya® to attack by wood-destroying fungi and termites
2014 - IRG/WP 14-40658
The resistance of high acetyl WPG 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 decay studies were conducted in Australia and New Zealand. Field studies were conducted in Australia, Japan, New Zealand, Thailand and USA. The results of the laboratory and field ...
J Alexander, J Hague, F Bongers, Y Imamura, M Roberts
Performance of some wood modification treatments against marine borers
2014 - IRG/WP 14-40668
Since some years, new treatment technology to protect wood against wood destroying fungi is introduced. Limited knowledge on their resistance to water organisms is available. Therefore, the resistance of chemically modified wood was assessed in a field test according to the European Standard EN 275 over a period of 3 resp. 5 years at sites in the North Sea and the Baltic Sea. Scots pine (Pinus syl...
A Klüppel, C Mai, H Militz, S Cragg
Measurement of Cell Wall Moisture in Acetylated Radiata Pine Using Low-Field Nuclear Magnetic Resonance
2016 - IRG/WP 16-20583
Understanding the interaction of water with acetylated wood is necessary to explain how the protective mechanism of acetylation functions. Low-field nuclear magnetic resonance is one technique for assessing water in wood. Pinus radiata earlywood sapwood samples were acetylated to various weight percentage gains and then analysed with this method. Increased levels of acetylation showed significantl...
H G Beck, C A S Hill
Role of cell wall specific moisture content on the brown-rot fungal attack on wood
2016 - IRG/WP 16-40736
Wood is a hydroscopic resource because the cell wall polymers contain hydroxyl and other oxygen-containing groups that attract moisture through hydrogen bonding. Moisture content varies with changing moisture content in its environment. The moisture content in wood is responsible for many of the performance properties we observe. The strength properties of wood are dependent on the moisture con...
R M Rowell
The effect of acetylation on physical properties of beech (Fagus orientalis) and Alder (Alnus subcordata) wood
2016 - IRG/WP 16-40759
In this study the effect of acetylation on physical properties such as water absorption, volumetric swelling and anti-shrink efficiency (ASE) of beech and alder were investigated. After 24 hours soaking in acetic anhydride, in order to achieving two surface of weight gains, acetylated samples were heated in oven at 120 0C for 90 and 360 minutes. Then water absorption and dimensional stability in...
M Akhtari, M Arefkhani
Consistency of performance of acetylated wood
2017 - IRG/WP 17-20608
It is well known that acetylation of wood improves the resistance against wood decaying fungi and insects, as well as its dimensional stability under varying moisture conditions. Accsys Group continues to support a variety of laboratory and field studies around the world to assess and monitor the durability, dimensional stability and uniformity of its products. To gain and maintain market acceptan...
F Bongers, J van Zetten
Accessibility of hydroxyl groups in anhydride modified wood as measured by deuterium exchange
2017 - IRG/WP 17-40784
Acetylated wood shows improved properties largely due to the reduced amount of water in the acetylated cell wall. However, the exact mechanism by which water is excluded in acetylated wood remains unclear. Acetylation reduces hydroxyl content by substitution of hydroxyl groups in wood polymers but may also hinder access to unmodified hydroxyls by physical bulking. This work assesses hydroxyl acces...
G Beck, S Strohbusch, E Larnøy, H Militz, C Hill
The potential and the challenges of acetylated wood in timber bridges - experiences from an ongoing project
2017 - IRG/WP 17-40792
Acetylated wood is known to be a durable and dimensional stable alternative for high performance materials, and has high potential for exterior timber structures. Research has shown that acetylated wood can be effectively bonded by various adhesive types. However, one of the most common used adhesives for timber constructions, Melamine Urea Formaldehyde (MUF), shows a high degree of delamination o...
A Treu, R Bredesen, F Bongers
Testing of the resistance of acetylated wood against marine borers at three Italian sites
2017 - IRG/WP 17-30719
The aim of this research is the determination of resistance of acetylated wood against marine biodeterioration in use class 5 (EN 335) in temperate sea waters. The resistance of acetylated Pinus radiata (radiate pine) in solid and MDF form is compared with that of the untreated radiata pine and other untreated wood of European species such as Fagus sylvatica (European beech) Castanea sativa (chest...
S Palanti, M Faimali, D Tagliapietra, M Andrenacci, M Anichini, M Sigovini
Termite resistance of wood-plastic composites made with acetylated wood flour, coupling agent or zinc borate
2018 - IRG/WP 18-10917
There is little published scientific literature on the laboratory or field testing of wood-plastic composites (WPC) against termite attack. Therefore, the objective of this research was to investigate termite resistance (both laboratory and field) of 5 different extruded WPC blends of 50% western pine wood flour (WF) and high-density polyethylene (HDPE), and untreated pine solid wood. The study in...
R E Ibach, Y S Hadi, C M Clemons, S Yusuf
Recent findings clarifying the mechanism of brown-rot decay protection in acetylated wood
2018 - IRG/WP 18-40827
This paper summarizes the findings obtained during my PhD research over the past three years. The results provide insights which help to understand the enhanced brown-rot decay resistance of acetylated wood with particular emphasis on the role of water. The protection acetylation provides is derived from moisture exclusion within the acetylated cell wall, but the exact mechanism by which water is ...
G Beck
Study on the ability of wood-destroying fungi to grow through chemically modified wood
2019 - IRG/WP 19-40858
Over the last decades, chemical wood modification technologies were developed to increase the resistance against attack by wood-destroying organisms without using biocides. Most of those technologies are based on an impregnation step initially. In most treated wood products, mainly by using solid wood in thicker dimensions as in posts, poles, sleepers, deckings etc. it is known that wood impregnat...
L Emmerich, S Strohbusch, C Brischke, S Bollmus, H Militz
Different levels of acetylation lead to groupwise upregulation of non-enzymatic wood degradation genes of Rhodonia placenta during initial brown-rot decay
2020 - IRG/WP 20-10958
Rhodonia placenta, often used as a model fungus to represent brown rot fungi, uses a two-stepped degradation mechanism to degrade wood. Regarding the overcoming of wood protection systems the initial degradation phase seems to be the crucial point. A new laboratory test enables the separation of the non-enzymatic oxidative and the enzymatic degradation phases, which has previously been proven chal...
M Kölle, R Ringman, A Pilgård
Elucidation of reactive sites of wood modified with acetic anhydride: Insights from density functional theory calculations
2020 - IRG/WP 20-40892
Density functional theory (DFT) was employed to investigate the interaction of cellulose and lignin with acetic anhydride for explaining the wood modification process. Atoms in molecules (AIM) and reduced density gradient (RDG) along with non-covalent interaction (NCI) plots were used to analyse the intermolecular bonding characteristics. Cellulose was modelled with a cellobiose unit (dimer of glu...
V Ponnuchamy, A Sandak, J Sandak, R Herrera Diaz
Longterm Performance of Treated Timbers in Marine Exposures
2020 - IRG/WP 20-10969
The performance of preservative-treated or modified woods in marine exposures was evaluated at test sites in Newport, Oregon, USA and Brisbane, Queensland, Australia. All samples have exhibited excellent performance at the Newport, Oregon site, while attack was more aggressive at the sub-tropical Brisbane site. Acetylated wood as well as samples treated with 7.3% chromated copper arsenate (CCA-T...
M Konkler, A R Zahora, J Norton, J J Morrell
Durability of acetylated Radiata pine: Laboratory tests and performance in practice
2020 - IRG/WP 20-40899
Wood acetylation is an established process to enhance biological durability and dimensional stability of lower valuable wood species without the use of biocides. Acetylated Radiata pine (ACCOYA® wood) has been on the market for more than 10 years now, starting in 2007.
Numerous lab tests have confirmed the high durability of acetylated Radiata pine. Here, additional data with four Radiata pine ...
K Jacobs, W Scheiding, B Weiß
Results of the resistance of acetylated wood against marine borers at three Italian sites after five years of sea immersion
2022 - IRG/WP 22-10994
The aim of this research was the determination of resistance of acetylated wood against marine decay in use class 5 (EN 335) in temperate sea waters. The resistance of acetylated Pinus radiata (radiate pine) in solid and medium density fibreboard (MDF) panels is compared with that of the untreated Scots pine, radiata pine and other untreated wood of European species such as Fagus sylvatica (Europe...
S Palanti, F Stefani, M Andrenacci, M Faimali, I Guarneri, M Sigovini, D Tagliapietra
Acetylation of pine wood in Uruguay
2022 - IRG/WP 22-40927
As a renewable material, wood is susceptible to decay by biologic (fungi, insects) and non biologic (water, radiation, mechanical wear, etc) agents. Such agents are controlled by using wood species of high natural durability, or by protecting the wood through drying, construction design, or the application of preservatives. The latter method has been and still is the most used in Uruguay, usually ...
C M Ibáñez, L Castillo
Steam Pre-conditioning Treatment Prior to Acetylation: Impact on Dimensional Stability, Moisture Response Behaviour, and White-Rot Fungal Resistance of Hevea brasiliensis and Mitragyna ciliata Wood
2022 - IRG/WP 22-40930
The effect of steam pre-conditioning treatment on the dimensional stability, moisture response behaviour, and durability against white-rot fungus P. chrysosporium of acetylated Hevea brasiliensis and Mitragyna ciliata wood species were assessed. Defect-free specimens of both species from the top, middle, and base positions were selected, prepared according to ASTM D143-09 & ASTM D-2017 standards a...
E Uchechukwu Opara, J Mayowa Owoyemi, J Adeola Fuwape
Chemical modification of cellulose nanofibrils for tailoring properties of composites
2022 - IRG/WP 22-40934
Due to its natural abundance, complete biodegradability and excellent properties, cellulose is one of the most promising materials for the production of bio composites, as well as one of the most promising fillers for biodegradable polymer composites. This is also true for nanocellulose. A large number of hydroxyl groups on the surface of fibers or fibrils enables a whole series of chemical reacti...
I Poljanšek, J Levanič, V Ž Bogataj, V Vek, P Oven
Failure characteristics of thermally modified poplar wood subjected to mechanical tests
2023 - IRG/WP 23-40983
Poplar (Populus spp.) are among the fastest growing timber species and have been widely planted for use in plywood, composites, pallets, furniture components and paper production. However, the low density of the wood limits many structural applications and the wood has little resistance to biodegradation. Thermal modification represents one approach to improving durability by changing the moistur...
E Bari, M Ghorbanian Far, N Moradi, J J Morrell, G Daniel, B Mohebby, R Hosseinpourpia, M Humar