Your search resulted in 153 documents. Displaying 25 entries per page.
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
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
Three-Dimensional Digital Image Correlation of Strains in Profiled Wood Decking Exposed to Wetting & Drying
2017 - IRG/WP 17-20611
We use three dimensional digital image correlation to measure the strains that develop at the surface of profiled radiata pine (Pinus radiata D. Don) deck boards subjected to a wetting and drying cycle. We hypothesise that surface profiling will change the pattern of strain distribution at the surface of deck boards by concentrating stresses at the base of profile grooves. Five groups of three deck board samples were produced from five different pieces of machine stress-graded radiata pine wood. Two wavy profiles, ribble or ripple, were tested. Flat unprofiled boards acted a control. Each board was fixed to a rigid frame and subjected to a wetting and drying cycle. Full field surface strain data was collected using 3D digital image correlation. Strains varied across the surface of both flat and profiled boards. Profiling changed surface strain patterns; strain maxima and minima developed in the profile ridges and grooves during wetting, respectively, but this pattern of strains reversed during drying. Such a pronounced reversal of strains was not observed when flat boards were exposed to wetting and drying, although there was a shift towards negative strains when flat boards were dried. We conclude that profiling changes surface strain distribution in deck boards exposed to wetting and drying, and causes high strains to develop in the grooves of profiled boards. These findings help explain why checks in profiled deck boards are mainly confined to profile grooves where they are difficult to see, and the success of profiling at reducing the negative effects of checking on the appearance of wood decking.
J Mallet, S Kalyanasundaram, P D Evansa
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
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
Aesthetic changes of coated thermally modified wood after artificial weathering
2017 - IRG/WP 17-40819
The thermal modification process affects the chemical configuration of the wood matrix improving some physical properties and durability. In addition, the distinctive dark tones of thermally modified timber increase the economic value of several light-coloured species. However, heat-treatment alters the substrates and it could influence in the application of coating products, necessaries to mainta...
R Herrera, J Sandak, E Robles, J Labidi
Wood Hydrophobic Modification by Mixed Wax Emulsions
2018 - IRG/WP 18-40839
An environmental-friendly, economical and facile method to construct hydrophobic system for improving wood repellency was applied in this study. Using paraffin wax and carnauba mixed wax O/W emulsions can simultaneously fabricate continuous wax films and rough structures in wood internal and external surface under appropriate heat treatment. In the study, single and mixed wax emulsions of 4% solid...
C Chen, W Wang
Visual appearance of unpainted wooden claddings during the first year of outdoor exposure: Evaluation of surface mould growth, lightness (L*) and wasp attack
2018 - IRG/WP 18-40841
This study addresses changes in visual appearance of unpainted wood materials exposed outdoors. Specimens of Norway spruce (Picea abies) Scots pine (Pinus sylvestris), aspen (Populus tremula), acetylated Radiata pine (Pinus radiata) and DMDHEU-modified Scots pine sapwood were exposed facing south in Ås, Norway for 60 weeks. During this period, surface mould growth development and wasp attack were...
S Karlsen Lie, L Ross Gobakken, G I Vestøl, O Høibø
Charring of Norway spruce wood surface – an alternative surface modification technique?
2019 - IRG/WP 19-40870
Charring is an old wood surface treatment technique, mainly performed on wooden façade elements with the aesthetical aims, but also with the purpose of protection. This flame treatment method can be grouped into heat treatment processes. Below the top charred layer of damaged wood there is a layer which is during flame treatment exposed to high temperatures in anoxic or semi-anoxic conditions. Th...
M Petric, M Pavlic, J Zigon
Improvement of wood decay and termite durability resulting from combined treatments based on borax/phenol-formaldehyde impregnation followed by thermal modification
2019 - IRG/WP 19-40871
This study determined the factors influencing the boron content after leaching of pine blocks impregnated with aqueous solution of phenol-formaldehyde (PF) resin with or without borax and subjected to heat treatment by response surface methodology. An experimental design permits to analyze the effects of heat treatment temperature (150, 185 and 220°C), curing time (5, 12, 5 and 20 hours), resin c...
S Salman, M-F Thevenon, A Petrissans, S Dumarcay, P Gerardin
Application of diverse hyperspectral imaging systems for evaluation of heritage objects
2020 - IRG/WP 20-10971
Advanced imaging techniques are able to non-invasively characterize, monitor and evaluate the impact of conservation treatments on cultural heritage (CH) objects. In this specific field, hyperspectral imaging (HI) allows non-destructive characterization of materials by identifying and characterizing colouring agents, binders and protective coatings as constituents of an object’s original constru...
J Sandak, A Sandak, L Legan, K Retko, M Kavčič, J Kosel, F Poohphajai, R Herrera Diaz, V Ponnuchamy, N Sajinčič, Č Tavzes, P Ropret
Biofinish: A Functional Wood Surface Treatment based on Aureobasidium
2020 - IRG/WP 20-40903
Xyhlo Biofinish is a natural and environmentally friendly wood protection concept based on linseed oil impregnation and a fungal-based coating. It emerged in the late 1990s and has been developed over the past 15 years into an industrially applicable process in the Netherlands. The combination of linseed oil impregnation and a surface treatment with the living fungus Aureobasidium extends the serv...
S Rensink, M Sailer, S Roukens, J Gerber, H van der Mel, K Potgieter, J Spit, R Bulthuis, C Struck, M Bennink
The influence of chemical compounds on wood cell wall to surface cracks
2020 - IRG/WP 20-40908
Degradation due to cracking and dimensional changes caused by drying, have a significantly negative impact on the preservation and durability of wood. Therefore, the prevention of surface cracking, which tends to occur during the drying process, is vital. High temperature set drying is one of the most effective methods for preventing wood surface cracking. It begins with softening the wood at a hi...
R Suzuki, Y Mori, K Yoshihiro, K Yamashita, M Kiguchi
Plasma treatment of wood - a review of 15 years of research in Göttingen
2021 - IRG/WP 21-40913
Wood is an important renewable resource and can be found omnipresent in everyday life. Its natural properties offer numerous advantages regarding physical, mechanical but also aesthetic aspects, but also challenges that one has to address with various modification methods.
Driven by the desire to promote the use of promising new technologies using plasmas, there has been a close research network ...
P Sauerbier, R Köhler, G Avramidis, W Viöl, H Militz
Influence of weathering on surface roughness of thermally modified wood
2021 - IRG/WP 21-40915
Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to weathering, its moisture performance might decrease fairly fast. The aim of this study was to determine whether this phenomenon is associated with crack formations or roughness. Norway spruce, thermally modified spruce, wax-treated th...
E Kerzic, B Lesar, M Humar
Surface morphology and short-term water uptake of charred and coated wood
2021 - IRG/WP 21-40916
Charring of the wood surface represents a traditional alternative surface treatment technique with the purpose of aesthetics and protection. By the treatment with flame the surface of wood becomes carbonized and a few millimetres thick charred layer is formed on the top of the wooden element. Further, the charred layer can be removed by brushing, which accentuates the structure of the surface. Add...
J Zigon
Dynamics of fungi colonization on the surface of Scots pine wood during natural weathering in different European climate zones
2022 - IRG/WP 22-10984
Wood The presence of fungi leads to biomaterial decay and/or changes in aesthetical appeal. The start of fungi colonization as well as the following growth on wood are primarily influenced by four factors: ambient temperature, moisture history of the object, access to oxygen, and intrinsic properties of the exposed wood, considered here as a source of nutrients for microorganisms. A prevalence of ...
F Poohphajai, O Myronycheva, O Karlsson, L Rautkari, J Sandak, A Sandak
Impact of wetting agents on polyelectrolyte complex impregnation for wood fire-retardancy
2022 - IRG/WP 22-30768
Wood fire performance is a great concern in interior finishing due to the high risk of flame spread. To increase the use of wood in high building while ensuring the safety of building occupants, fire retardant (FR) treatments are required. Traditionally, two fireproofing strategies are employed: impregnation and coatings. They have been widely studied but they, respectively, are time and chemicals...
M Soula, J B Grenier, S Duquesne, F Samyn, V Landry
Surface chemical wood densification through in situ electron beam polymerization: description and dose study
2022 - IRG/WP 22-40933
Traditional wood chemical densification processes can be used to improve wood mechanical properties by increasing density of the material throughout its thickness. While mechanical surface densification has heavily been investigated, surface treatments involving impregnation of monomers remain unexplored. This study describes a new material, surface densified through lateral impregnation of acryla...
J Triquet, P Blanchet, V Landry
Comparative study of the properties of silicate coatings with different mineral pigments (titanium dioxide, iron (III) oxide, copper (II) oxide) on the surface of wood
2022 - IRG/WP 22-40936
Silicate coatings are attractive alternatives to conventional organic-based coatings for wood protection. In this work, silicate coatings were prepared with a potassium silicate binder modified with a methyl siliconate solution, and three types of mineral pigments titanium dioxide, iron (III) oxide and copper (II) oxide. The coatings were applied on beech wood and cured under ambient conditions. T...
A M Cheumani Yona, M Petrič
Effect of nano-particle characteristics and concentration on UV protection of timber: A field exposure test
2022 - IRG/WP 22-40941
Wood has a well-known susceptibility to ultra-violet light degradation, leading to premature replacement. A variety of products have been developed to protect against this damage, but most provide less than 12 months of protection and must be regularly reapplied. Developing improved coatings would help reduce wood losses and reduce maintenance costs. Nano-particles have a variety of attractive pro...
T Yi, J J Morrell
The influence of thermal modification and surface charring to different levels on wettability of Norway spruce wood
2022 - IRG/WP 22-40942
The wood can alternatively be protected from water absorption by thermal modification and charring. Both techniques cause certain chemical and physical changes in the wood, the extent of which depends on the level of temperature applied. The objective of this study was to determine how the combination of charring to different levels and thermal modification affects the chemical, morphological, and...
J Žigon, C Gerardin, M E P Wålinder, P Gerardin
Accelerated surface mould testing for exterior wood treatment in Temperate, Tropical and Laboratory environments
2023 - IRG/WP 23-20699
Mould attack is a very common cause of discoloration on wooden surfaces and can subsequently promote development of wood decay by other organisms. Prevention of mould growth is relevant for both pigmented wood paints as well as more transparent systems with a high or low amount of binder. The use of commercial biocides has led to effective microbiological inhibition in many contexts, but the incre...
A Nazeri, J Stenbaek, T R Laursen, A H H Wong, B M Hasnul
Effects of preservative impregnations on wettability and surface free energy properties of Eucalyptus grandis wood
2023 - IRG/WP 23-40978
Wettability and surface free energy (SFE) are crucial parameters for evaluating the adhesion thermodynamics of solid surfaces. Hence, this study investigated the effects of copper azole (CA) and disodium octaborate tetrahydrate (DOT) preservative impregnations on Eucalyptus grandis wood wettability and SFE. Wettability was determined in terms of contact angles with polar (water) and non-polar (dii...
A A Alade, C B Wessels, H Stolze, H Militz
Starch modified with silanes – high hydrophobic surface treatment for wood protection
2023 - IRG/WP 23-40981
The great potential of silanes for starch modification and their utility as surface wood protection is still not sufficiently assessed. The work aimed to analyze the crosslinking process's effect on starch modification with silane and tested the hydrophobic properties of surface-treated wood. The starch treatment was modified with methyltrimethoxysilane or N-octyltriethoxysilane. SEM-EDX with a cr...
W Perdoch, M Bajstok, B Mazela, I Siemińska, B Peplińska