Your search resulted in 165 documents. Displaying 25 entries per page.
Bending properties of wood after its decay with Coniophora puteana and subsequent modification with selected chemicals
1999 - IRG/WP 99-40146
Mechanical properties of wood are often decreased due to decay processes caused by biotic and/or abiotic factors. Damaged wooden elements (e.g. historical structures) can be reinforced by more methods, including their modification with convenient chemicals. This paper presents influences of selected chemicals on basic bending properties (modulus of elasticity - MOE, modulus of rupture - MOR) of sound and decayed wood. Norway spruce (Picea abies L. Karst.) and European beech (Fagus sylvatica L.) samples 8.5 x 8.5 x 120 mm (RxTxL) were deteriorated with the brown-rot fungus Coniophora puteana in laboratory conditions in the interval from 2 to 10 weeks. These rot samples as well as the sound ones were subsequently modified with 5 different chemicals (shellac, epoxy resin, melamineformaldehyde resin, polybutylmethacrylate, or polyethyleneglycol) using pressure impregnation technique (p = 0.8 MPa, t = 6 h). The MOE were evaluated continually for each sample in its sound, rot and modified state (or in sound and modified state), while the MOR just for groups of sound and modified samples. An apparently positive effect on the MOE was achieved with the melamineformaldehyde and epoxy resins, while the polybutylmethacrylate and shellac had only a gentle positive effect. The MOR was increased mainly with the epoxy resin. On the other hand, the polyethyleneglycol - PEG 1000 had an apparently negative effect on both bending properties.
L Reinprecht, S Varinska
Hypoxylon species of the groups Papillata and Applanata on European beech in Serbia, Yugoslavia
1977 - IRG/WP 166
In the previous Document No: IRG/WP/165 under the title 'The most important characteristics of some species of the genus Hypoxylon found in Serbia, Yugoslavia', a contribution has been made regarding the importance of 4 species of this genus found in Serbia. In this paper the significance of the Hypoxylon species was emphasized in connection with their distribution and growth especially in European beech, having in view the fact that some of those appear primarily on recently felled timber of large dimensions. These species cause disintegration of the surface and in the deeper layers of wood. Among the species of the groups Papillata and Applanata there are species also of varying importance and this will be emphasized later in the paper.
Extraction and analysis of DNA from green and seasoned timber as basic methods for determination of wood species and origin
2013 - IRG/WP 13-20523
Against the background of the European timber trade regulation EUTR, commenced to law by March 2013, the determination of wood species and tracing of its origin is getting a great importance. A promising approach for establishing fast and reliable tracking systems for wood products is DNA analysis. A critical point is the extraction of analysable DNA from the wood and its lignified cell walls. Thus, aim of the work was the analysis of DNA content in different areas of the cross section of green and dry, well-seasoned wood from pine, spruce and beech, using quantitative, real-time PCR analysis. DNA from green timber was successfully extracted and amplified with primer set ycf3hm at all three wood species and zones of cross-section. Whereas the results with pine and spruce confirmed the expectation, that the DNA content decreases from cambium to pith, this was not observed with beech. DNA detection with 20 year old well-seasoned wood was successful only with beech. Further systematic studies are necessary to get better information about the influence of wood processing and ageing on DNA quantity and quality.
K Jacobs, H Mende, W Scheiding
Studies into the effect of soil type and soil layer on the in-ground decay of European beech
2022 - IRG/WP 22-20681
In this study, European beech (Fagus sylvatica L.) specimens were exposed to three different soil types; Podsol (Podzol), Braunerde (Cambisol), and Pararendzina (Regosol), in adapted terrestrial microcosm (TMC) tests according to CEN/TS 15083-2 (2005). Soils were sampled (250 mm deep) from field sites and separated into their constituent layers to deliver three TMC setups; mineral soil layer only (“M”), mineral and organic layers (“OM”), and mineral, organic and litter layers (“LOM”), to identify the effect of each respective soil layer on wood decay. Wood specimens (5 x 10 x 100 mm³) were measured for oven-dry mass loss (MLwood) after 16 weeks of exposure, and compared to MLwood predicted using a dose-response laboratory in-ground decay model developed by Marais et al. (2021) for European beech. To deliver predicted MLwood after 16 weeks of exposure, input variables included soil water-holding capacity (WHCsoil) and soil moisture content (MCsoil) of the sampled soils’ mineral layer, as well as soil temperature (Tsoil) and exposure time. The MCsoil of TMCs were set to 95 % of the mineral soil layers’ WHCsoil. The non-parametric Wilcoxon rank-sum test was used to compare medians between groups of measured and predicted MLwood. Simple modifying factors to account for the significant differences in MLwood groups were developed and the use of which subsequently illustrated. Overall, Podsol soils delivered the highest mean measured MLwood, while Braunerde soils the lowest. Braunerde in “M” was the only group to not register a significant difference between measured and predicted MLwood groups. Soil temperature and moisture conditions still played a dominant role in the resulting wood decay, however the need for a variable describing an additional soil property was shown. The study suggests further investigation into the development of modifying factors for different soil types, where the effect of moisture- and temperature-induced components alone cannot reliably predict wood decay in soils differing from a reference, like those used in laboratory-based TMC studies.
B N Marais, S Kovacs, M Jansen, C Brischke
Proposed method for out-of-ground contact trials of exterior joinery protection systems
1981 - IRG/WP 2157
Methods for testing the efficacy of preservative treatments for exterior joinery are described using the format of a European Standard. Commercially used treatments applied to jointed test units (L-joints) which are then protected by conventional finishes are exposed to normal outdoor hazards out of ground contact. Assessment is made a) by determining eventual failure through decay and b) by destructive examination of replicate treated and untreated units, after increasing time intervals, rating comparative performance in terms of wood permeability increase and the progress of microbial colonisation.
J K Carey, D F Purslow, J G Savory
How to Document the Performance of Super-Critical Treated Wood in above Ground Situations?
2005 - IRG/WP 05-20316
The paper presents practical experiences from the preparation of a new preservative treated wood product for introduction to the market. The product in question is Superwood™, which is treated with organic biocides using CO2 in a supercritical state as a solvent. The question is how to evaluate the performance of a new product such as Superwood™ in order to get an acceptance on the market and fulfil the formal requirements. In the European Union countries, the EN 599-1 is the standard that needs to be complied when approving a new product for the market, but it only focuses on the toxic limit against representative decay fungi according to EN 113. However, decay test, above ground and other forms of field tests are optional, this is not in line with the traditional test philosophy in the Scandinavian countries. The open question is to which extent treatment to the level of the toxic threshold value also ensures a long service life and expected performance of the treated commodity. Superwood™ is evaluated using a strategy, in which basic laboratory tests are done to get the toxic value (according to EN 599-1) and in addition a number of field tests are done including accelerated testing in the tropics. These tests are focussed on the evaluation of the performance criteria such as durability and service life and maintenance requirements. These questions must be answered by the producer without having a full record of performance test for their new products. A short status on the test performed on super-critical treated wood (Superwood™) is presented. Based on a comparison between field test in Scandinavia and in the tropical Malaysia a service life of more than 25 years for a specific supercritical treated product is estimated. It is stated that the existing European standardisation system is insufficient when it comes to service life prediction. A number of important questions need to be addressed by the European standardisation system as soon as possible because the market and the public opinion change quickly due to environmental concern.
N Morsing, A H H Wong, F Imsgard, O Henriksen
European Biocides Directive (98/8/EC): Programme for systematic examination of all active substances of biocidal products on the market on May 13, 2000 Article 16(2)
2001 - IRG/WP 01-50166-03
K Rasmussen, A B Payá Pérez
Wood preservation in Lithuania
2004 - IRG/WP 04-30363
This article is intended to give basic information on wood preservation activities in Lithuania and the main actors in wood preservations practice and research. Currently the main actors in practical Lithuanian wood preservation activity are enterprises of wood preservation industry united by the Lithuanian Wood Preservation Association. The most intensive activity in wood preservation practice and research started after 2001. The only active institution in wood preservation research currently is Lithuanian Forest Research Institute with 2 running projects. Lithuanian University of Agriculture and Kaunas University of Technology are active in standardization and have potential to start research. Main obstacles for future development of wood preservation research are: insufficient interest of industry in research and lack of skilled scientists.
Report on the activities of the European Standardization Committee CEN/TC 38 'Methods of Testing wood preservatives'
1980 - IRG/WP 279 E
Thermal treatment of wood: European Processes and their background
2002 - IRG/WP 02-40241
Recent efforts on thermal treatment of wood lead to the development of several processes introduced to the European market during the last few years. The total production capacity of heat treated wood in 2001 is estimated as approx. 165.000 m3. In the paper the different heat processes are presented. The general technology as well as scientific data on the chemical transformation of the cell wall polymers, on the biological performance, on the physical and mechanical properties of the treated wood are presented and discussed
Bioaccumulation of pentachlorophenol in rainbow trout and zebra fish muscles
1986 - IRG/WP 3372
The bioaccumulation of pentachlorophenol in Rainbow Trout and Zebra fish has been evaluated by partition coefficient n-octanol/water determination at ph 7 and measured in vivo according to the OECD guidelines and the European directive 79/831/EEC. The obtained results confirm the low bioaccumulation potential of this product in aquatic organims.
J C Palla, M Dion
Effect of medium-term degradation of beech wood by erosive (Phanerochaete chrysosporium) and lignin-selective (Ceriporiopsis subvermispora) strains of white rot fungi on its selected physical properties
2004 - IRG/WP 04-40292
At the Faculty of Wood Sciences and Technology a fungal delignification of normal and tension beech wood by erosive and lignin-selective strains white-rot fungi has been studied. The pre-treatment of both kind of wood samples was accompanied by partial delignification and apparent changes of their physical properties influencing the polar liquids penetration.
R Solár, S Kurjatko, M Mamonová, J Hudec
Interspecific variability of European oak durability against white rot fungi (Coriolus versicolor): Comparison between sessile oak and peduncle oak (Quercus petraea and Quercus robur)
2001 - IRG/WP 01-10393
The knowledge of wood natural durability against biologic predators enable its external use. The resistance of European oak wood was reported like durable according to the EN 350-2. However, some individuals may contain high durable wood. Our research was focused to understand this variability in oak population that represent the first french species (4.1 millions of ha). Natural durability of European oak heartwood (Quercus petraea and Quercus robur) against white rot fungi (Coriolus versicolor) was tested according to european standard EN 113. The experimental material consists in 23 oaks robur and 26 petraea oaks sampled from 9 French regions. For each tree, 3 twin samples were taken off from heartwood situated at 1.30 m from the bottom of the tree. Different effects were tested by hierarchic variance analysis: "species", "forest within species" and "tree within forest". The tree effect is very significant for biologic natural resistance. Variability between species was also demonstrated. Although the species effect is significant, it's relatively weak compared with tree differences (it was declared significant 5%). Durability classification was determined according European standard EN 350-1. 69.2% of petraea oak trees are classified as high durable, 19.2% durable, 7.7% moderately durable and 3.8% slightly durable. In the case of robur oak 91.3% of trees are classified as high durable and 8.7% durable.
N Ayadi, B Charrier, M Irmouli, J P Charpentier, C J Allemand, F Feuillat, R Keller
CEN Draft (38 N 460E) Standard: Test method for determining the protective effectiveness of a preservative in the marine environment
1986 - IRG/WP 4132
This European Standard describes a marine test method which provides a basis for asseasing the effectiveness of a wood preservative used to prevent attack of timber in sea-water by marine borers. The method is only suitable for testing preservatives which are intended to prevent attack by marine wood boring organisms of treated timber for use in more or less permanent contact with sea-water. It is not suitable for assessing the effectiveness of preservatives against micro-organisms. The main objective of the method described is to evaluate the relative effectiveness of a wood preservative applied by vacuum/pressure impregnation. For this reason permeable timbers are used throughout so that the protective efficacy of various retentions of the preservative can be determined. However, it is recognized that modifications of the method may be used for other purposes, e.g. to determine the relative efficacy of a preservative treatment or to determine the natural durability of the heartwood and sapwood of a selected timber species. The method is primarily intended for testing in temperate waters where Teredine and Limnoria borers dominate. However, it is also capable of being used in tropics where attack by Pholads and specific Crustacean borers may be very destructive. It has to be considered that the test has to be run for a minimum period (usually for 5 years or until the point of failure) before any interpretation of the results can be made. Variations in the test conditions can be expected from one test site to another depending on temperature, salinity, population density of the various borer species etc. This will inevitably influence the general rate of attack. However, by comparing the results obtained for samples treated with the test product with those obtained with a reference preservative and those obtained with untreated control samples, the relative protective effectiveness of the product tested can be evaluated.
Conforming to european standards for preservative-treated timber: Specifying with confidence
2000 - IRG/WP 00-20194
A four-year collaborative study between four industrial partners and BRE has assessed timber treated by current UK industrial practices in the light of current European Standards. Data were collected for CCA and creosote treated timber components, and compared with the requirements laid out in EN351-1 and -2. A number of difficulties were encountered that have been described in previous IRG papers (98-20150, 99-20156), such as the poor reproducibility of chemical analyses and variable timber density. This paper describes the conclusions of our collaboration, focusing on the application of the findings and how to overcome any difficulties encountered. The data collected allowed the calculation of figures that have been submitted for inclusion into the UK's proposed national code for preservative-treated timber (DD239). An example is the recommendation of new minimum retention figures for creosote-treated commodities. This paper describes the factors that will enable UK specifiers to use the European Standards with confidence and greater understanding of how they map onto traditional methods of specification. In addition valuable lessons have been learnt applicable to the industry world wide.
E D Suttie, R J Orsler
European standardization for wood preservation
1988 - IRG/WP 2321
European standardization for wood preservation
1989 - IRG/WP 2335
European standardization for wood preservation
1990 - IRG/WP 2359
The biocides directive
1995 - IRG/WP 95-50040-25
Draft Business Plan of CEN/TC 38 - Durability of wood and wood-based products - Introduction
2000 - IRG/WP 00-20207
CEN Technical Committees and Business Planning. The extension of formal business planning to CEN Technical Committees (CEN/TCs) is an important measure which forms part of a major review of business processes (known as 'Optimization'). The aim is to align the CEN work programme with expressed market needs and to ensure the adequate resourcing of projects through their development stages in the CEN/TCs. Your role in the implementation of the Business Planning concept will contribute significantly to the overall effectiveness of European standardization. We express our sincere appreciation and thanks for your time in reviewing this Business Plan.
The effects of heat treament on the specific gravity of beech and spruce wood
2003 - IRG/WP 03-40254
The effects of heat treatment on specific gravity of beech (Fagus orientalis) and spruce wood (Picea orientalis) naturally grown and intensively used in forest products industry in Turkey were studied. The wood samples were cut into 2 x 2 x 3 cm. Heat treatment was than applied to the wood samples at four different temperatures (130 °C, 150 °C, 180 °C and 200 °C) and three different durations (2 h, 6 h and 10 h) under air atmospheres. The results indicated that the specific gravity values treated by heating generally exhibited a decrease with increasing the exposure durations and temperatures compared to the untreated wood samples.
S Yildiz, Ü C Yildiz, G Colakoglu, E D Gezer, A Temiz
Research on the effects of wood preservatives on the physical and mechanical properties of Iranian beech (Fagus orientalis Lipsky)
1985 - IRG/WP 3351
This research work was conducted with the aim of using preservatives such as Basilit and Wolman Salts with Iranian beech and to study any physical and mechanical changes these might have on the beech species of Iran. Samples were divided into three groups; one group were used as untreated controls, the second group was treated with Basilit and the third group was treated with Wolmanit. Results obtained according to the AFNOR French system of standards were: (1) After 140 days the moisture content of each group had reached 7.3%. (2) Samples with Wolmanit absorbed twice as much as those with Basilit and the two groups has some differences in specific gravity. (3) The volumetric shrinkage of wood preserved with Wolmanit was one fifth of that treated with Basilit. (4) In bending tests the samples treated with Wolmanit had more strength up to point of rupture than those preserved with Basilit. (5) The modulus of elasticity was more in samples preserved with Basilit than in those preserved with Wolmanit. (6) In compression parallel to the grain the samples impregnated with Basilit had more resistance than in those impregnated with Wolmanit. (7) In tension tests, the samples preserved with Basilit were stronger than those treated with Wolmanit. (8) In impact bending tests, the Basilit samples were stronger than the the Wolmanit ones. (9) In hardness tests, the resistance to indentation was less with the samples treated with Basilit than with those treated with Wolmanit; the Basilit seems to make the wood softer and from this result this type of treated wood could be recommended for use by carpenters and in woodworking shops.
The effects of heat treatment on the toughness of beech wood
2004 - IRG/WP 04-40283
The effects of heat treatment on toughness of beech (Fagus orientalis) wood naturally grown and intensively used in forest products industry in Turkey were studied. The wood samples were cut into 5 x 5 x 5 cm. Heat treatment was than applied to the wood samples at three different temperatures (130 °C, 150 °C and 180 °C) and three different durations (2 h, 6 h and 10 h) under air atmospheres. The results indicated that the toughness values treated by heating generally exhibited a decrease with increasing the exposure durations and temperatures compared to the untreated wood samples.
S Yildiz, Ü C Yildiz, E D Gezer, Ali Temiz, E Dizman
Wood preservation in East European countries
1989 - IRG/WP 3527
The paper discusses the main problems of wood preservation in Bulgaria, Czechoslovakia, German DR, Hungary, Poland, Rumania and the USSR. The main types of wood preservatives produced have been presented, as well as the state of standarization to test their properties. There have been considered methods of wood treatment in use and application range of treated wood.