Your search resulted in 3057 documents. Displaying 25 entries per page.
Mould growth on wood-based materials – a comparative study
2010 - IRG/WP 10-20455
Ten different wood-based materials - preservative-treated wood, fire retardant-treated wood, modified wood, WPCs and untreated references of pine sapwood and spruce - were tested for mould growth according to SP method 2899 during 42 days at 90% RH and 22°C.
Even though the results must be interpreted carefully, they indicate significant differences in mould resistance between the materials tes...
P Johansson, J Jermer
Direct estimation of the durability of high-pressure steam modified wood by ESR-spectroscopy
2010 - IRG/WP 10-40508
Heat generated persistent free radicals have been detected by electron spin resonance measurement of thermally modified wood, prepared by high pressure superheated steam treatment. The specific density of these radicals have been correlated with the durability against basidiomycetes, as measured by the European standard EN113 test. In the lower range of specific radical densities, the found correl...
W Willems, A Tausch, H Militz
Performance of selected types of coated and uncoated modified wood in artificial and natural weathering
2010 - IRG/WP 10-40510
The objective of the present work was to investigate the influence of commercial wood modification methods on weathering behaviour and coating performance. It was aimed to compare modification methods and to set up maps of weathering behaviour for these methods with and without a semi-transparent wood stain. Artificial and natural weathering trials were carried out with a selection of different ty...
G Grüll, L Podgorski, M Truskaller, I Spitaler, V Georges, S Bollmus, A Steitz
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
Acquisition of sorption isotherms for modified woods by the use of dynamic vapour sorption instrumentation: Principles and Practice
2010 - IRG/WP 10-40518
The complex wood-water relationship has been the topic of numerous studies. Sorption isotherms – in particular – have been derived for hundreds of wood species, their sap- and heartwood sections as well as for decayed, engineered and modified wood materials. However, the traditional methods for obtaining sorption isotherms are very time consuming. With new dynamic vapour sorption (DVS) instrum...
E T Engelund, M Klamer, T Mark Venås
Testing of decay resistance of sapwood and heartwood of thermally modified Scots pine and Norway spruce
2010 - IRG/WP 10-40523
Thermal modification at elevated temperatures changes the chemical, biological and physical properties of wood. One of the main targets of thermal modification is to increase the biological durability and decay resistance of wood. Although the effects of thermal modification on wood have been widely studied, the significance of sapwood and heartwood on the resistance of thermally modified wood has...
H Viitanen, S Metsä-Kortelainen
Wet and dry adhesion of coatings on modified and unmodified wood: comparison of the pull-off test and the cross-cut test
2010 - IRG/WP 10-40524
The objective of this paper is to study the influence of several types of modification (acetylation, furfurylation, thermal modification) on coatings adhesion and to compare two methods of assessing the adhesion: the cross-cut test and the pull-off test both tested in dry and wet conditions. The study also investigates the effect of other parameters of the wood substrates on adhesion like the ring...
L Podgorski, G Grüll, M Truskaller, J D Lanvin, V Georges, S Bollmus
Molecular investigation of Postia placenta growing in modified wood
2011 - IRG/WP 11-10756
Brown rot is the most common and destructive type of fungal decay for wood in service. These fungi depolymerize preferentially the structural carbohydrates, cellulose and hemicellulose in the cell wall leaving oxidized lignin behind. Modified wood can provide protection against a variety of wood deteriorating organisms, including decay fungi. However, there is still little known about the mode of ...
B Schmöllerl, G Alfredsen, C G Fossdal, M Westin, A Steitz
Aesthetic service life of coated and uncoated wooden cladding - influencing factors and modelling
2011 - IRG/WP 11-20470
Mould growth on exterior coated cladding façades is an undesirable element and will often shorten the aesthetical service life. Mould growth on painted surfaces is influenced by type and concentration of film fungicides, the paint formulation and the wood substrate itself, and wooden cladding may experience exponential fungal deterioration caused by variation in the climatic factors, often within...
L Ross Gobakken, O A Høibø
Slice - Cut and Analyze Laser Microdissection (LMD): A method to produce sample material from modified wood for chemical quality analysis
2011 - IRG/WP 11-20478
Wood modification with its various systems is an established way to enhance a wood products’ service life in outdoor applications. Per definition, selected material properties are enhanced by means of modification without producing toxic substances or residues during service life and combustion afterwards. The systems of impregnation modification include a physical and often chemical alteration ...
K Zimmer, E Larnøy, A Treu, M Fongen
Effect of P/F ratio, PF concentration and treating method on boron leaching from wood treated with PF modified boron compounds
2011 - IRG/WP 11-30559
In order to immobilize boron in wood, three kinds of resol-type phenol-formaldehyde (PF) resin with different P/F ratios were synthesized in laboratory and incorporated with three types of boron compounds to treat wood. The used boron compounds included boric acid (BA), borax (BX) and disodium octaborate tetrahydrate (DOT). The leaching test of boron from wood blocks was performed according to the...
Liping Yu, Jinzhen Cao
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
Physical properties of Pinus radiata veneers modified with hexamethoxymethyl melamine prepolymers
2011 - IRG/WP 11-40551
Prepolymers containing hexamethoxymethyl melamine and either sucrose (Suc-HMMM) or polyvinyl alcohol (PVA-HMMM) were prepared by acid catalysis under reaction conditions optimised with respect to stiffening effect when introduced into Pinus radiata veneers by vacuum impregnation and cured by hot pressing at 150C. Maximum increases in MOE were 20% for Suc-HMMM (50% WPG), 22% for PVA-HMMM (...
C Molloy, W Rae, S Connor, T Henderson, A Siraa
Biological properties of Pinus radiata veneers modified with hexamethoxymethyl melamine
2011 - IRG/WP 11-40552
An investigation of the effects on decay and termite resistance of a wood modification process involving prepolymers of hexamethoxymethyl melamine (HMMM) was conducted using LVL as a model engineered wood product. Dry Pinus radiata veneers were vacuum-impregnated with a wood modification formulation containing a mixture (P-H:S-H) of two separate prepolymerisation reactions containing polyvinyl al...
A Siraa, S Millward, C Molloy
Durability of modified wood in UC3 and UC4. Results from lab tests and 5 years testing in 3 fields
2011 - IRG/WP 11-40562
In 2005 an extensive test program including field tests was set up in order to obtain more data on the durability and long term performance of modified wood and semi-durable wood species. One of the main challenges for modified wood is to predict accurate service life time in UC3 (use class 3, above ground) and UC4 (use class 4, in soil or fresh water contact). So far, data from in-service condi...
M Westin, G Alfredsen
Wet and dry adhesion of coatings on modified and unmodified wood: influence of 18 months of natural weathering on the pull-off test and cross-cut test results
2011 - IRG/WP 11-40569
The objective of this paper is to study the influence of several types of modification (acetylation, furfurylation, heat treatment) on coatings adhesion after 18 months of natural weathering according to EN 927-3 in Vienna (Austria).
The paper compares two methods for assessing the adhesion: the cross-cut test (EN ISO 2409) which is the conventional method used and recommended in EN 927-3 and th...
L Podgorski, G Grüll, M Truskaller, J D Lanvin, S Bollmus
The resistance of thermo and thermo-oil modified black poplar wood (Populus nigra L.) to Basidiomycetes fungi
2012 - IRG/WP 12-40585
The share of area taken by poplar tree species in Poland account for 2.0% of the area of state forests, 4.8% of national parks and for 2.3% in the privately-owned forests. It is shown and expected an increase in the share of poplar stands connected with plantation of fast growing trees. The poplar wood is not resistant to Basidiomycetes fungi, easy attacked by insects and in consequence is regarde...
A Fojutowski, A Kropacz, A Noskowiak
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
Mould growth on wood-based materials – a simulated in-service study
2012 - IRG/WP 12-20503
Ten different wood-based materials including preservative-treated wood, fire retardant-treated wood, modified wood, WPCs and untreated references of pine sapwood and spruce were placed in three different environments (an attic and two crawl spaces) for a period of 26 months. Mould growth was analysed at five to seven month intervals in an effort to map the growth development. The relative humidit...
G Bok, P Johansson, J Jermer
Termite resistance of wood impregnated with phenol-formaldehyde (PF) modified boron compounds
2012 - IRG/WP 12-30604
In order to investigate the effect of phenol-formaldehyde (PF) modified boron compounds on termite resistance of two main plantation-grown wood species, namely, Masson pine (Pinus massoniana Lamb.) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), laboratory termite tests and field tests were carried out according to AWPA standard E1-97 and AWPC protocols/2007. Different concentrations of b...
Jinzhen CAO, Liping YU, Xuexiang HE
Virulence of two Laboratory Test Strains and one Natural Isolate of Rhodonia (Oligoporus) placenta against Thermally Modified Pine and Beech Wood
2013 - IRG/WP 13-20524
Rhodonia (Oligoporus) placenta is known as a relative aggressive basidiomycete fungus against thermally modified timber. In durability lab tests, this often results in a lower durability class, compared to other test fungi. In the reported work, the virulence of three different strains of Rhodonia placenta for untreated and thermally modified timber was determined and compared. Therefore, two lab ...
K Plaschkies, W Scheiding, K Jacobs, N Rangno
Surface energy characterization of thermally modified wood using inverse gas chromatography
2013 - IRG/WP 13-20532
The objective of this work is to characterize surface energetics of thermally modified wood. Such information may be useful for a better understanding and predictions of adhesion properties between the modified wood and other material systems, e.g. coatings, adhesives or matrices in composites. Inverse gas chromatography (IGC) was used to study the surface energy characteristics of thermally modif...
S Källbom, K Segerholm, D Jones, M Wålinder
Report on COST E37 Round Robin Tests – Comparison of results from laboratory and field tests
2013 - IRG/WP 13-20535
A round robin involving 15 European participants was set up in 2006. The round robin consists of both a field test according to the double layer test method and a laboratory test with two different preconditioning methods. When comparing EN 84 preconditioning (two weeks water leaching) with natural preconditioning (1 year in field, above ground) according to CEN/TS 15397, no significant difference...
M Westin, E Conti, J Creemers, P-O Flæte, A Gellerich, I Irbe, M Klamer, B Mazela, E Melcher, R Möller, L Nunes, S Palanti, L Reinprecht, E Suttie, H Viitanen
Performance testing of DMDHEU-modified wood in Australia
2013 - IRG/WP 13-30613
Chemical wood modification with dimethyloldihydroxy-ethyleneurea (DMDHEU) or its derivatives has been researched for many years and shown to be applicable to improve certain wood properties to both solid lumber and wood-based composites. Earlier research proved a high biological resistance of DMDHEU-modified wood against biological degradation in laboratory and field tests in Europe. Due to the ve...
H Militz, J Norton