Your search resulted in 26 documents. Displaying 25 entries per page.
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
Early detection of colonisation by blue stain and mould on modified wood using PCR technique
2010 - IRG/WP 10-10730
The aim of this research was the early detection of fungal attack on the surfaces of modified and unmodified wood after natural weathering. The investigation was carried out by molecular techniques and the development and establishment of genus/species specific PCR for important moulds and sapstain fungi was part of this work. After adaption of the method, a monitoring of the succession of Ascomyc...
A Steitz, B Schmöllerl, N Pfabigan, S Bollmus, G Grüll
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
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
Basidiomycete colonization of Scots pine sapwood quantified by qPCR and TGA
2011 - IRG/WP 11-10750
Scots pine (Pinus sylvestris L.) is an important softwood species in Northern Europe and is frequently used as material for various wood protection systems. In Europe, EN 113 is the standard basidiomycete laboratory durability test method, using mass loss as evaluation criteria. In this paper quantitative real-time PCR (qPCR) and thermogravimetric analysis (TGA) was used to characterize coloniza...
G Alfredsen, S Bollmus, T K Bader, K Hofstetter
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
Decrease of stiffness properties of degraded wood predicted by means of micromechanical modeling
2011 - IRG/WP 11-40570
Wood exhibits a highly anisotropic mechanical behavior due to its heterogeneous microscopic structure and composition. Its microstructure is organized in a strictly hierarchical manner from a length scale of some nanometers, where the elementary constituents cellulose, hemicelluloses, lignin, and extractives are found, up to a length scale of some millimeters, where growth rings composed of earlyw...
T K Bader, K Hofstetter, G Alfredsen, S Bollmus
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
Statistical analysis of durability tests - Part 1: Principles of distribution fitting and application on laboratory tests
2013 - IRG/WP 13-20504
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing are therefore essential in combination with proper monitoring and analysis tools. A crucial concept is variability in testing and analysis, especially for a biological material such as wood. The larger ...
I De Windt, J Van den Bulcke, C Brischke, C R Welzbacher, A Gellerich, S Bollmus, M Humar,
Determination of the natural durability of solid wood against wood-destroying fungi - a European round-robin test
2013 - IRG/WP 13-20511
In Europe the durability of wood against wood-destroying basidiomycetes is tested according to CEN/TS 15083-1 (2005). Hitherto existing experience with this standard is quite heterogeneous and results from previous round-robin tests have stayed unreported or have been reported incompletely. In particular the need for natural pre-weathering of the test specimens to allow potential detoxification of...
C Brischke, C R Welzbacher, A Gellerich, S Bollmus, M Humar, K Plaschkies, W Scheiding, G Alfredsen, J Van Acker, I De Windt
Resistance of WPC against wood destroying fungi
2013 - IRG/WP 13-40627
The investigation of biological durability is a fundamental topic to assess the performance of Wood Plastic Composites (WPC) particularly for outdoor applications. In the last years, different test setups based on existing standards on the field of wood as well as the field of plastics were used for WPC. But the test methodologies give different information about the durability of the tested mater...
A Gellerich, S Bollmus, A Krause
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
Some comments on durability testing of WPC according to EN 15534-1
2015 - IRG/WP 15-40695
The standard EN 15534-1 (2014) gives advice for broad characterization of WPC materials and products. It contains instructions for test procedures concerning different properties e.g. mechanical properties, thermal properties, as well as durability.
In this paper some WPC materials from the market were tested for their resistance against brown rot. Furthermore, the water uptake and bending prope...
S Bollmus, A Gellerich, H Militz
How does the test methodology influence the outcome of durability testing of thermally modified wood
2015 - IRG/WP 15-40699
Thermally modified wood is commercially available on the European market since many years. Today, many production units with various production capacities and different modification processes exist. Industrial scale wood heat treatment processes, under the trade name of ThermoWood were developed in Finland. ThermoWood has two standard treatment classes with different target properties, namely Ther...
A Gellerich, S Bollmus, H Militz
Selection of most aggressive test fungi for modified wood - Practical laboratory experience
2016 - IRG/WP 16-20579
One main objective of wood modification processes is the improvement of the durability against wood destroying organisms. Therefore, investigations of the resistance against wood destroying fungi have been one of the main focus within the last years. For the interpretation of the durability results, the selection of suitable test fungi is one of the main questions. A “wrong” fungus species may...
A Gellerich, S Bollmus
Variation in moisture content in field trials according to use class 3.2 conditions
2016 - IRG/WP 16-20580
Different test methods to determine the durability of wood in use class 3 (EN 335:2013) are available. Fungal degradation of wood requires liquid water. Different Standards (EN 335-1:2006; DIN 68 800:2011) specify the risk for decay with moisture content (mc) of above 20%. EN 335 (2013) does not specify moisture content but rather defined limited wetting conditions (use class 3.1) or prolonged wet...
S Bollmus, A Gellerich, H Militz
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
Towards durability classification of preservative treated wood – first attempts using different European standards
2018 - RG/WP 18-20638
EN 350 (2016) gives guidance on methods for determining and classifying the durability of wood and wood-based material against biological wood destroying agents. “Wood-based materials are those derived from trees and include amongst others: untreated wood, heat treated wood, chemically modified wood, glue laminated wood, wood-based panels, wood polymer composites and wood treated with wood prese...
S Bollmus, A Gellerich, C Brischke, H Militz
Enhancing knowledge transfer in the wood protection sector
2018 - IRG/WP 18-50338
In order to meet the needs for the developing bio-based economy, maintaining and expanding the market potential for wood raw materials and wood products in indoor and outdoor construction uses remains a key activity for industries in the biotechnological and forestry sector respectively. A major restraint in this respect is the drastically deviating views and expectations on quality and performanc...
C Brischke, G Alfredsen, S Bollmus, M Humar, D Jones, L Meyer-Veltrup, L Nunes
Durability classification of preservative treated and modified wood
2019 - IRG/WP 19-20659
EN 350 (2016) allows formally to determine durability classes (DC) for wood products and wood-based materials, which was previously only possible for untreated wood in the form of natural durability. In a first study, the University of Goettingen carried out the durability classification of chemically modified (modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea, DMDHEU) and preservative-treate...
S Bollmus, L Bachle, C Brischke, H Militz
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
Biological durability of sapling wood
2020 - IRG/WP 20-10967
Sapling-wood products from different wood species such as willow (Salix spp.) and Common hazel (Corylus avellana) are frequently used for gardening and outdoor decoration purposes. Remaining bark is suggested to provide additional biological durability. Even for temporary outdoor use it seemed questionable that durability of juvenile sapwood can provide acceptably long service lives of horticultur...
C Brischke, L Emmerich, D G B Nienaber, S Bollmus
Impact of fungal decay on the bending properties of wood
2020 - IRG/WP 20-20671
Wood used outdoors is generally prone to fungal degradation, and its impact on the structural integrity of wood is an immanent factor for service life planning with timber. Wood decayed to very small mass losses can suffer from a significant reduction in mechanical strength and elastic properties. Hence, the latter are preferred indicators to detect decay in wood durability studies. Numerous previ...
S Bollmus, P B van Niekerk, C Brischke
The role of specimen format in wood durability testing
2020 - IRG/WP 20-20672
The experimental basis for testing the biological durability of wood are often incubation experiments with wood-destroying basidiomycetes. Numerous parameters can affect the mass loss by fungal decay (MLF) in laboratory durability tests and therefore being decisive for the resulting durability classification. Among others, the dimension of the wood specimen and the time of incubation impact on fun...
C Brischke, L K Grünwald, S Bollmus
Development of procedures for sampling, testing, and classification to determine the biological durability of wood and wood products
2020 - IRG/WP 20-20676
This paper informs about a research project, which deals with several shortcomings and a lack of clarity within EN 350:2016. The project started in January 2020, will run for 3 years, and is operated by the Institute of Wood Technology Dresden (IHD) and the University of Goettingen (UGOE).
Determination and classification of durability of wood and wood products against wood-destroying organisms ...
W Scheiding, K Jacobs, S Bollmus, C Brischke