Your search resulted in 154 documents. Displaying 25 entries per page.
Effects of microclimate, wood temperature and surface colour on fungal disfigurement on wooden claddings
2012 - IRG/WP 12-20490
Wooden claddings are common in façades in Norway, and Norway spruce (Picea abies) is the most frequently used species. The cladding is a major part of the facade, and it has visual requirements that may define the aesthetic service life. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more of...
L Ross Gobakken, G I Vestøl
The effect on moisture content of water trapped in wood joints
2012 - IRG/WP 12-40613
To predict the service life of a structure, a model where the exposure of a structure is compared to its resistance can be used. Which exposure and resistance parameters that are relevant depend on which materials the structure consist of. This approach, with an exposure and a resistance parameter, is similar to the one used in structural engineering where a load (exposure) is compared to the bear...
M Fredriksson, L Wadsö, P Johansson
Influence of a pulsed electric field on the growth of surface fungi
2013 - IRG/WP 13-10795
The colonization of mold and staining fungi are not only an aesthetical problem. Blue stain fungi are able to penetrate paint films. Maintenance of coatings on wood are time consuming and costly. A new approach uses a pulsed electric field (PLEOT) in order to protect wood against surface fungi. This technology is evaluated in non-sterile laboratory conditions on different coated and uncoated Scots...
M Starck, A Treu
Surface moulds and staining fungi on acetylated wood – effect of increasing acetyl content
2013 - IRG/WP 13-10797
Wood used in outside applications is susceptible to weathering and photo degradation, which often leads to surface discoloration, loss of brightness and surface deterioration. Research has shown that acetylated wood is more resistant against brown rot, white rot and soft rot, and more dimensionally stable than untreated wood. However, acetylated wood seems still to be disfigured by surface moulds ...
L Ross Gobakken, S Bardage, C J Long II
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
Moisture distribution in glulam beams with natural cracks observed with CT Scanning before and after rain
2013 - IRG/WP 13-20534
The way cracks in outdoor wooden constructions affect durability is an interesting topic, since a certain amount of cracks can always be found naturally in wood and glued laminated wood. The question in this was, can cracks lead water into the wood and thereby increase the risk for decay and reduce strength and service life. Moisture balance, i.e., water absorption and water distribution were stud...
K Sandberg
Performance of biocide-free preservative-protective systems modified with organosilicon compounds
2013 - IRG/WP 13-30628
The objective of the research was to determine the influence of organosilicon compounds in preservative-protective systems on the selected properties of pine wood aimed for outdoor use. The investigations were made for biocide-free systems based on alkyd resin and natural oils modified with alkylalkoxy-, amino- and glycidoxysilanes. The special attention was paid on the influence of hydrophobic pr...
B Mazela, P Hochmańska, T Krystofiak
Preparation and characterization of activated carbon fibers prepared from liquefied wood
2013 - IRG/WP 13-40636
Activated carbon fibers were prepared from liquefied wood through stream activation. The effects of activation temperature and time on the microstructure and surface functional groups of the liquefied wood activated carbon fibers (LWACFs) were studied using analysis of burning behavior, X-ray diffraction, nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy, and SEM. The resu...
Wenjing Liu, Guangjie Zhao
Using hyperspectral imaging to detect and quantify mould and blue stain on coated and uncoated wood
2014 - IRG/WP 14-10822
Hyperspectral imaging has been applied on the surface of samples of coated and uncoated Norway spruce (Picea abies) as a new technique to detect and quantify growth of mould and blue stain fungi. Principal Component Analysis of the hyperspectral images resulted in a clear visualization of the fungi and the amount of mould coverage could be estimated. This indicates that NIR hyperspectral imaging c...
L Ross Gobakken, I Burud, A Flø, K Kvaal, T K Thiis
Visualization of gold/silver nanostars in wood by surface enhanced Raman spectroscopy
2014 - IRG/WP 14-30653
Nanotechnology is a fast growing up-to-date technology and ventures expeditiously in the wood preservative market. However, there is still a huge lack of understanding about the interaction and incorporation of nanoparticles (NSs) in wood. Surface-enhanced Raman scattering (SERS) offers unique advantages as an analytical tool with a high selectivity and sensitivity without matrix interference. Her...
C Geers, L Rodríguez-Lorenzo, M Placencia Peña, P Brodard, T Volkmer, B Rothen-Rutishauser, A Petri-Fink
VOC-free remedial treatment agent on organic solvent basis with surface cleaning by photocatalysis using titanium dioxide
2014 - IRG/WP 14-40651
Due to the EU Regulations according to the harmonisation of the European market of biocidal products and the EU Regulations regarding emissions of volatile organic compounds in residential properties a new VOC free yet organic solvent based remedial treatment agent is introduced including a potential method to clean up the wooden surface of remaining biocides after a remedial treatment using photo...
H Ahl, J Fromm, P Jüngel, E Melcher, M Pallaske
The effect of UV irradiation on some technological properties of different polyurethane varnishes coated plywood panels from veneers dried at different temperatures
2014 - IRG/WP 14-40661
In this study, the effect of UV irradiation on some technological properties of three different polyurethane varnishes coated plywood panels produced from Scots pine (Pinus sylvestris L.) and Maritime pine (Pinus pinaster L.) veneers manuactured and dried at different temperatures was studied. Accordingly, 32°C log peeling temperature and three different veneer drying temperatures (110, 140 and ...
Ö Özgenç, C Demirkir, Ü C Yildiz, G Çolakoğlu
The role of hydrophobins in surface growth by the Blue Stain fungi Aureobasidium pullulans
2015 - IRG/WP 15-10837
Hydrophobins are small proteins found exclusively in filamentous fungi. These proteins are able to assemble spontaneously into amphiphilic monolayers at hydrophobic–hydrophilic interfaces. Hydrophobins have a diverse role, e.g. allowing the fungi to break through interfaces during aerial hyphae formation, sporulation, fruit body production and cell penetration. In this ongoing study, we are look...
J Stenbæk, L Riber, J Blæsbjerg Nielsen, C Møller Hansen, B Jensen
Effects of UV Radiation on Melanization and Growth of Fungi Isolated from Weathered Wood Surfaces
2015 - IRG/WP 15-10842
This research tests the hypothesis that fungi isolated from weathered wood will respond to elevated levels of UV radiation by increasing their melanin production. To test this hypothesis, we measured the melanin production and mycelial color of Aureobasidium pullulans and Cladosporium cladosporioides, before and after the fungi were grown under artificial UV, visible light and complete darkness. T...
V A Hernández, P D Evans
Acceptance levels of surface disfigurement - tolerance to defects of coated wood
2015 - IRG/WP 15-20564
Service life planning (PSL) has become an important issue in performance based building and substantial progress has been made in recent years. The role of predicting the aesthetical service life of wooden building components has been underestimated for quite long time but is recently attracting more and more notice. It is influenced by numerous factors such as discoloration, fading, flaking, crac...
C Brischke, P Kaudewitz
Indentation and pendulum hardness tests: two convenient assessment methods of the performance of exterior wood coatings
2015 - IRG/WP 15-40689
Developing formulations of exterior wood coatings with long service life is a big challenge. For many years in Europe the performances have been mainly evaluated through weathering tests (within the EN 927 series) followed by visual assessment (blistering, flaking, mould growth, chalking and cracking), colour and gloss measurements, and adhesion tests. Very recently the importance of the mechanica...
L Malassenet, L Podgorski, M Truskaller, G Grüll
Termiticide Residues in Building Foundation Aggregate Fills After Trench and Surface Applications
2015 - IRG/WP 15-30679
Termiticide concentrations (ppm) in aggregate fill were determined by measuring active ingredient (a.i.) residues of two pyrethroid termiticides, Up-Cyde Pro® 2EC-cypermethrin, and BaseLine® EC-bifenthrin, at 24.0 hours, and then at 6.0- and 12.0-months after ‘horizontal’ surface applications, perimeter ‘trenching and rodding’ applications, or ‘rodding only’ trench applications at lo...
B M Kard, C E Koneman, K T Shelton, C C Luper, R A Grantham
Simulation of surface climate and mould growth on wooden façades
2016 - IRG/WP 16-20585
The weathering of wooden surfaces is normally caused by mould growth, lignin deterioration and leaching of extractives. For well insulated buildings, the effect of the interior climate on the outer surface is small and sometimes negligible. This paper describes simple models for surface temperature and moisture conditions on a wooden façade that can further be used to model weather degradation an...
T K Thiis, I Burud, D Kraniotis, L Ross Gobakken
Increasing the hardness of wood-composite panels by nanosilver
2016 - IRG/WP 16-40715
Effect of silver nanoparticles on hardness in medium-density fiberboard (MDF) was studied here. A 400 ppm aqueous nanosilver suspension was used at three consumption levels of 100, 150, and 200 mL/kg, based on the dry weight of wood fibers; the results were then compared with the control panels. The size range of silver nanoparticles was 30-80 nm. Composite mats were hot-pressed for 6, 8, and 10 m...
H R Taghiyari, J Norton, K Heidarhaee
Formation of hydrophobic wood surface by means of thermal treatment and surface modification with alkyl ketene dimer (AKD)
2016 - IRG/WP 16-40738
One of the major shortcomings of wood-based materials compared to technical materials is attributed to their poor dimensional stability in changing climates and in contact with liquid water. Heat treatment induces chemical change with a consequent decreasing of reactivity of the material showing unwanted surface inactivation. Alkyl ketene dimer (AKD) is a widely used sizing agent in papermaking, w...
T Lovaglio, T Meints, L Todaro, W Gindl-Altmutter
Variation in coating hardness during the EN 927-6 weathering test: influence of pigmentation
2016 - IRG/WP 16-40739
The objective of the SERVOWOOD project is to develop and establish European Standards that will facilitate the prediction of service life for exterior wood coatings. Within this project an extensive round robin exercise has been carried out by five partners to establish the repeatability and reproducibility of the EN 927-6 artificial weathering test. This round robin included the exposure of the I...
L Podgorski, L Malassenet, C Reynaud
The influence of log soaking temperature and thermal modification on the properties of birch veneers
2016 - IRG/WP 16-40749
In veneer manufacture the logs are routinely soaked in heated water baths in order to soften the wood prior to peeling. The temperature of the water may vary greatly between batches; however, the influence of log soaking temperature on veneer properties has had little research attention. Uncontrolled moisture is known to cause problems in wood-based materials, while thermal modification offers a m...
S Källbom, K Laine, M S Moghaddam, A Rohumaa, K Segerholm, M Wålinder
Evaluation of surface cracks on wood – physical assessment versus subjective sensation
2017 - IRG/WP 17-20617
In the presented studies from the University of Goettingen (Study I) and the University of Hannover (Study II), the assessment of cracks with different methods and their acceptance in general as well as depending on different target groups are investigated. The aim was to determine which factors are relevant for a crack evaluation and which visual impression of a wooden surface is tolerable for co...
A Gellerich, C Brischke, L Emmerich, L Meyer-Veltrup, P Kaudewitz
Weathering protection of European hardwoods through double modification
2017 - IRG/WP 17-30715
Beech and poplar were thermally modified, treated with melamine resin and both treatments were combined. The weathering performance (cracks and general appearance) of modified beech and poplar was assessed in natural weathering and correlated to material properties such as work in bending (WB) and Brinell hardness. In addition, the equilibrium moisture content after exposure of 12 months and subse...
G Behr, A Gellerich, S Bollmus, H Militz
Surface Protection of Wood with Metal Acetylacetonates
2017 - IRG/WP 17-40802
Metal acetylacetonates are coordination complexes of metal ions and the acetylacetonate anion. They have diverse uses as catalysts, cross-linking and curing agents and adhesion promotors. Some metal acetylacetonates can photostabilise polymers whereas others are photocatalysts. We hypothesise that the ability of metal acetylacetonates to photostabilise wood will vary depending on the metal in the ...
Yuner Zhu, P D Evans