Your search resulted in 109 documents. Displaying 25 entries per page.
Spruce and pine heartwood treatment by means of microwave radiation
2008 - IRG/WP 08-40411
An easier penetrability and a more even uptake of wood protection agents is aimed for the two most common wood species in Europe, namely Norway spruce (Picea abies) and Scots pine heartwood (Pinus sylvestris), particularly when there is a great difference in absorption behavior of sapwood and heartwood. Microwave conditioning can improve permeability, reduce density and heat conductivity and chang...
A Treu, H Rieche, H Militz
Spruce and pine heartwood treatment by means of microwave radiation
2008 - IRG/WP 08-40411
An easier penetrability and a more even uptake of wood protection agents is aimed for the two most common wood species in Europe, namely Norway spruce (Picea abies) and Scots pine heartwood (Pinus sylvestris), particularly when there is a great difference in absorption behavior of sapwood and heartwood. Microwave conditioning can improve permeability, reduce density and heat conductivity and chang...
A Treu, H Rieche, H Militz
The efficacy of commercial silicones against blue stain and mould fungi in wood
2008 - IRG/WP 08-30471
Scots pine (Pinus sylvestris L.) wood samples were vacuum pressure impregnated with quatsilicone micro emulsion (<40 nm particle size), aminosilicone macro emulsion (110 nm) and silicone macro emulsion with alkyl modified side groups (740 nm) and the resulting material properties were studied. Quatsilicone micro emulsion resulted in maximum bulking (4.8%) and anti-swelling efficiency (21.8%) in...
S C Ghosh, C Mai, H Militz
Resistance against basidiomycetes of 1,3-dimethylol-4,5-dihydroxy ethylene urea (DMDHEU)-modified plywood of Pinus sylvestris
2008 - IRG/WP 08-40398
Plywood produced with rotary-cut veneers of Pinus sylvestris impregnated with a solution of 1.3 M 1.3-dimethylol-4.5-dihydroxyethyleneurea (DMDHEU) and glued with a phenolic resin (Prefere 4976 DYNEA) were inoculated with Coniophora puteana, Coriolus versicolor and Pleurotus ostreatus, following the European standard ENV 12038. The specimens were leached following European standard EN 84. The re...
A Dieste, A Pfeffer, S Bollmus, H Militz
Termite resistance of DMDHEU-treated wood
2008 - IRG/WP 08-40401
Chemical wood modification with dimethyloldihydroxy-ethyleneurea (DMDHEU) or its derivatives are applicable to both solid lumber and wood-based composites. Advantages of DMDHEU-based modification are an increase of dimensional stability and high durability against white, brown and soft rot fungi. At higher chemical loadings, the hardness of the wood is considerably increased. Due to the durabil...
H Militz, S Schaffert, B C Peters, C J Fitzgerald
Degradation of wood veneers by Fenton’s reagents: effects of low molecular weight phenolic compounds on hydrogen peroxide decay and tensile strength loss
2009 - IRG/WP 09-20400
Pine wood (Pinus sylvestris) veneers strips were incubated in acetate buffer containing hydrogen peroxide and iron to mimic mechanisms of brown rot decay and assess the degradation of cellulose through analysis of the tensile properties of the decayed wood. The tensile properties of thin wood strips treated with Fenton system reagents or precursors were determined and correlated to weight loss as ...
Yanjun Xie, R Well, Zefang Xiao, B Goodell, J Jellison, H Militz, C Mai
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
Weathering of Wood Modified with the N-Methylol Compound 1,3‑dimethylol-4,5-dihydroxyethyleneurea (DMDHEU)
2009 - IRG/WP 09-40467
Scots pine (Pinus sylvestris L.) sapwood boards were treated with a methylated 1,3‑dimethylol-4,5-dihydroxyethyleneurea (mDMDHEU) causing weight gains of approx. 25% and exposed to weathering for 18 months. Compared to untreated boards, treatment with mDMDHEU reduced surface discoloration mainly caused by staining fungi. Boards treated with mDMDHEU exhibited clearly lower moisture content th...
C Mai, Yanjun Xie, A Krause, K Urban, P D Evans, K Richter, H Militz
Protection mechanisms of modified wood against decay by white and brown rot fungi
2010 - IRG/WP 10-10713
The resistance of beech and pine wood blocks treated with 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) against T. versicolor and C. puteana increased with increasing WPG. Full protection (mass loss below 3%) was reached at WPGs of approximately 15% (beech) and 10% (pine). Metabolic activity of the fungi in the wood blocks was assessed as heat or energy production determined by isothermal mic...
C Mai, P Verma, Yanjun Xie, J Dyckmans, H Militz
Simulation and Investigation of Wood Degradation by Erosion Bacteria in Laboratory Experiments
2010 - IRG/WP 10-20431
A Microcosm experiment was successfully set up to establish, monitor and manipulate bacterial wood degradation under low oxygen conditions. Sound pine sticks were placed in waterlogged sediment from a heavily decayed pine pile foundation site in Amsterdam. The system was subject to different gassing treatment regimes in order to investigate the role of oxygen in the bacterial degradation process o...
J Gelbrich, E I Kretschmar, N Lamersdorf, H Militz
The Use of Micro-Tensile Testing to Assess Weathering Decay and Oxidative Degradation of Wooden Items
2010 - IRG/WP 10-20433
This paper presents a method to study the weathering performance of wooden items and to assess the oxidative degradation of wood via the Fenton reaction. Weathering resistance and photo-stability of wood was tested using pine wood (Pinus sylvestris) veneer strips measuring approximately 60 µm in thickness. The veneer strips were treated using a reactive chemical to impart surface protection. The ...
C Mai, Yanjun Xie, Zefang Xiao, P D Evans, H Militz
Hydrothermal modification for upgrading the durability properties of soft deciduous wood
2010 - IRG/WP 10-40494
To extend the application potentialities of soft deciduous wood, upgrading the durability properties, hydrothermal modification (HTM) of aspen alder and birch wood was investigated. The treatment was conducted in a multifunctional laboratory device WTT. In the previous cases it has been found that the treatment at 160oC improves the durability insufficiently. The modification at 180oC ensured a hi...
B Andersons, I Andersone, V Biziks, I Irbe, J Chirkova, E Sansonetti, J Grinins, H Militz
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
Preliminary laboratory bioassay to evaluate engineered Fibre-boards against subterranean termites C. acinaciformis (Isoptera: Rhinotermitidae)
2012 - IRG/WP 12-10768
In Australia, laboratory bioassays with subterranean termites typically contain groups of workers and soldiers in a substrate of moist mound material. This termite substrate may affect termite consumption, and the test materials create a favorable termite condition for the test. The main purpose of this test is to examine the effect of a melamine formaldehyde treatment of wood panels to evaluate t...
B M Ahmed (Shiday), H Militz, B Ozarska, I Ali, L Kloeser
Evaluation of fungal infestation and decay in a simulated use class 3 situation (block test) after some years of exposure
2012 - IRG/WP 12-20487
The so named “block test” was designed as part of the assessment methodology for testing the behaviour of natural and modified wood used under use class 3 (EN 335-2) conditions. The test was developed to expose the wood close to the ground to an environment with high humidity and high biological activity, but not in soil contact.
The present study describes the evaluation of fungal infestatio...
A Gellerich, K Röhl, S Adamopoulos, H Militz
Analyses of premature failure of utility poles
2012 - IRG/WP 12-40584
In this study a total number of 18 utility poles of Scots pine (Pinus sylvestris) impregnated with a copper-chromium containing preservative were investigated. They were part of different lower voltage transmission lines in the western part of Germany and failed before predicted minimum service life. All poles in this study were less than 15 years in use. The type of decay and fungi were evaluated...
S Bollmus, N Rangno, H Militz, A Gellerich
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
The chemistry of wood degradation by Basidiomycetes studied in a van Krevelen diagram
2013 - IRG/WP 13-10805
The atomic composition ratios of decayed wood by Basidiomycetes are mapped in a van Krevelen diagram. It is shown that the wood residue after decay is chemically reduced, rather than oxidized. A previously developed and verified theoretical model for thermal wood modification, relating atomic composition ratios to moisture sorption and fungal resistance properties has tentatively been applied to w...
W Willems, H Militz
System treatments of Pinus sylvestris - influence on moisture, decay and discoloration
2013 - IRG/WP 13-30612
Biological activity can cause challenges for the use of wood in outdoor exposure. Decay and discolouring fungi influence the service life of wooden constructions, and the moisture content of the wood is often an important factor. The aim of this study was to evaluate the performance of different combinations of preservative/modified wood protection treatments and surface treatments for wooden deck...
A Schabacker, G Alfredsen, L Ross Gobakken, H Militz, P O Flæte
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
CreoSub – New protection technology to substitute creosote in railway sleepers, timber bridges, and utility poles
2014 - IRG/WP 14-30644
Creosote oil is one of the oldest industrially used wood preservatives. Due to its toxic profile, the European Commission has restricted the use of creosote specific applications, but it is highly controversial within the European Commission. Its approval for use after 2018 is very questionable and may depend on derived research results until then, i.e., the viability of alternatives developed to ...
U Hundhausen, K-C Mahnert, A Gellerich, H Militz
Termite resistance of wood modified with short- and long-chain siloxanes
2014 - IRG/WP 14-40660
Scots pine (Pinus sylvestris L.) sapwood specimens modified with short- and long-chain amino-functional siloxane emulsions were exposed to subterranean termites (Reticulitermes flavipes Kollar). Laboratory choice and no-choice tests following the standard EN 117 (2013) were conducted for 8 weeks in order to evaluate the influence of these silicon-based compounds on the termite resistance of treate...
P Gascón-Garrido, M-F Thévenon, H Militz, C Mai
Improving dimensional stability of thermally treated wood by secondary modification – potential and limitations
2014 - IRG/WP 14-40664
The potential of treating thermally modified wood with melamine resin to improve the dimensional stabilization is tested in this research. Two different boards of poplar (Populus ssp.) were cut into two halves. One half of each board was thermally modified (T1 and T2) in a commercial process, the other half was used as untreated reference material. The material was thermally modified using the vac...
G Behr, K-C Mahnert, S Bollmus, H Militz
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
Penetration of phenol formaldehyde (PF) resin into beech wood studied by light microscopy
2015 - IRG/WP 15-20558
In this study, we examined the distribution and penetration depth of phenol-formaldehyde (PF) resin into wood specimens by light microscopy (LM). Two PF resins from different producers, of concentrations 9, 18 and 27 wt % in water, were vacuum impregnated into European beech wood (Fagus sylvatica) blocks of 15x25x50 mm³. The presence of chemical agent in the wood was carried out by way of their i...
V Biziks, S Bicke, H Militz