Your search resulted in 313 documents. Displaying 25 entries per page.
Ecological methods and products for wood protection used for restoration and conservation of built heritage cultural assets to increase natural durability and duration of exposure in open air museums
2010 - IRG/WP 10-40506
Wood is a perishable material, hygroscopic and fuel, which cause attention to selecting the wood species that is going to be exhibited in relation to humidity and soil. With variable depending on its humidity and moisture from the atmosphere or soil, wood is a good living environment for fungi and insects, but suffer biodegradation processes and dimensional changes. Observations over time on wood building behavior determined limiting actions of biodegradation phenomena, with different products with antiseptic, waterproof and fireproof properties. The development of forestry research and of chemical industry in particular, have put on the market for wood protection treatment a number of solutions which subsequently proved toxic to humans and the environment. Now the latest generation methods and products available to conservators and restorers disposal for use in preserving the old wooden racks and the new one used in restoration. The National Institute Wood throughout over 75 years of existence, helped by laboratory and in situ tests, carried out by specialists, contributed to marketing the new products and ways to protect freshly shot down wood used in construction and in the conservation and restoration of cultural goods. Attempts are made by exposure to fungi, insects and moisture under laboratory conditions or by exposure to natural climate conditions in the polygon NIW. The preventive protection can extend about 3-5 times the duration of use and reduce downgrading quality with over 30% of the wood used.
M Pruna, D Purice, D Dumitru Copacean
Subterranean termite foraging behaviour and the development of baiting methods used for termite control by the Division of Forest Products
1994 - IRG/WP 94-10058
Given the premise that alternatives to current subterranean termite control measures using organochlorine insecticides and arsenic trioxide have been actively researched by our Division for over ten years, emphasis on baiting methods in controlling these termites has been a major facet of our research. Recently, the new Australian Standard (AS 3660 -1993) was released which outlined the use of physical barriers (Granitgard and Termi-Mesh) as alternatives to soil chemical barriers. However, baiting methods have as yet not been incorporated into the standard. This paper describes the development of baiting techniques in laboratory and field experiments designed over the years to complement, and substitute for, the current soil chemical barrier approach. The goal is to bait or aggregate termites to a point source. In this situation, the termites may be fed bait toxicants that act as slow-acting stomach poisons, or dusted with toxicants that have a similar mode of action. The outcome is to affect colony destruction. Suggestions are offered to indicate the advantages of baiting techniques over soil chemical barriers. Furthermore, such techniques are used to rapidly evaluate potential termiticides and refine future termite control for the pest control industry.
J R J French, J W Creffield, B M Ahmed
Survey of practical methods for conditioning of forest products before preservative treatment
1971 - IRG/WP 39
The seasoning of forest products is undertaken for a wide range of end uses and is becoming increasingly required for applications and building construction and secondary manufacturing industries. A wide range of applications of new technology and specifically required seasoning schedules is being actively developed for such requirements, but less attention has been given to the means by which wood can be prepared for successful preservation treatments by seasoning or more general conditioning treatments. Much of the knowledge of the practical means of achieving good treatments through prior seasoning and conditioning resides in the skill and experience of larger treating companies. Although many of the pertinent means of achieving proper pretreatment seasoning are mentioned in important sets of standards, such as those of the American Wood Preservers Association (AWPA) and the Canadian Standards Association (CSA), it is often necessary for the consumer of treated forest products to develop the appropriate means of seasoning for his special case through reliance on the knowledge of the treater. In the case of a large consumer, such as the major utilities, there is often his own body of experience gained through the activities of a research and development group.
J Rak, T S McKnight
How to win friends and influence the market — Service Life Prediction and performance-based durability assessments of wood products in construction
2006 - IRG/WP 06-20348
Due to direct and implied demands from the market and from e.g. the EU Construction Products Directive, the need to supply service life estimates for building products is growing. For several years, a development of Service Life Prediction (SLP) methodologies has been going on, but the awareness of this development has hitherto reached only a very limited extent in the wood sector. For materials whose degradation in service is governed by not only physical factors but also, and in many cases to a dominating degree, by biological mechanisms, acurate service life estimates are particularly difficult. Still, in order to defend and expand the market for wood products in construction in the long run, it is of great importance that durability assessments are transformed and expressed in ways that are truly useful for specifyers and users. More clearly stated: The needs and the interests of the user should be in focus and should be the actual starting point for development of both products and durability assessment methods. An initiative to bring this discussion to the CEN Committee TC 38 “Durability of wood and wood-based products” has led to the formation of a Task Group, which will further look into the possibilities to incorporate SLP methods in European durability standards. This development has been carried into effect by the establishment in 2004 of a Task Force within the COST Action E 37 “Sustainability through new technologies for enhanced wood durability”. The Task Force has made preliminary work, making inventories of methods for testing and assessment, analysing the purposefulness of these methods, and giving some outlines for a future performance-based system of classification of wood products. The Task Force will give a final report of its work later this year.
Which are the best painting methods for the beech wood products protection?
2009 - IRG/WP 09-40477
Beech wood (Fagus Sylvatica L.) is one of the most important species of the wood in Kosovo. About 33% of the trees in our country are beech wood. The wood products in Kosovo are from the beech wood. The color difference between red heart wood and white wood of the beech is significant. The main problem for the wood companies in our country is that they haven’t adequate protection against weathering (snow, rain and low temperature) and leaching of preservative components into the environment. This problem becomes more important in the non-covered areas. The problems of the painting become apparent after one year of the weathering. The aim of our study is to assess the best way to protect beech wood products from the weathering and to maximally reduce the leaching. We tried different forms of the painting: film forming, non film forming, transparent stain and semi transparent penetrating stain. The results of our study showed that the film forming and semitransparent penetrating stain are the best painting methods for the beech wood products protection, according to weathering performance and coating properties.
Methods for Studying Penetration Depth of Wood Protection Products
2010 - IRG/WP 10-20432
EN 152 is an accepted standard in Europe for measuring how deep a wood protection product penetrates into the surface of treated pine wood. The method has provided consumers with a wide assortment of products that meet the specifications outlined in the standard. Because the test takes 8 or more months to carry out, artificial ageing procedures have evolved in order to standardize and speed up the procedure. Small changes in a formulation will often change a products physical parameters and especially its ability to penetrate into wood. It is therefore desirable to develop a method that can measure changes in a product’s penetrability quickly and accurately. A method is described where wood cores are drilled from treated wood, then sliced in 100 µm thick discs. Discs are then placed on nutrient agar plates seeded with conidia from Aspergillus niger. Plates are incubated for 24 hours and zones of inhibition are measured. It is believed that if a fungus is growing on the disc the biocide level will not exceed that of the fungus minimum inhibition concentration (MIC). In water based acrylic systems penetration depths are often less than one mm and it can impact the performance of a product if that changes. The procedure described in this study can show if penetration of a preservative product has been increased or reduced in as little as 24 hours.
K Hansen, L Sites, D D Nicholas
Durability of reaction to fire performance of FRT wood products in different end use applications – Methods and results
2015 - IRG/WP 15-40705
Fire retardant treatments (FRT) may considerably improve the reaction to fire properties of wood-based products and the highest fire classifications for combustible products can be reached, but the maintained reaction to fire performance e. g. in exterior applications needs to be addressed in order to form a basis for new and reliable wood products with improved fire performance. A European Technical Specification with Durability of Reaction to Fire performance (DRF) classes has been developed in order to assist product development and to guide potential users to find suitable FRT wood products. It is based on ASTM standards and has been further developed upon Nordic initiatives from industry and research as Nordtest methods. It consists of a classification system for the fire properties over time of FRT wood and test procedures for hygroscopicity and accelerated weathering covering both interior and exterior applications. The European system has been applied to a range of commercial FRT wood products and products under development and a long term experimental study on the maintained reaction to fire performance of FRT wood products over time has been performed. It includes accelerated ageing according to different procedures and natural weathering up to ten years. Main conclusions are: - The hygroscopic properties are unchanged compared to untreated wood for most commercial FRT wood products - The reaction to fire properties of FRT wood may be maintained after accelerated and natural ageing if the retention levels are high enough - Several FRT wood products loose most of the improved reaction to fire properties during weathering - Paint systems contribute considerably to maintain of the fire performance at exterior application The results of the long term study show that requirements for interior applications of FRT wood products often are fulfilled, while products for exterior applications with maintained fire performance over time are rare. There is thus a strong need for product development for exterior applications. In the meantime, requirements on the long term durability of the fire performance of FRT wood products should be included in the national building regulations. There is also a need to determine the relationship between accelerated and natural weathering in different climates in order to further develop the conditions for accelerated weathering.
B Östman, L Tsantaridis
Biological screening assays of wood samples treated with creosote plus chemical additives exposed to Limnoria tripunctata
1980 - IRG/WP 408
Laboratory methods for exposure of treated wood coupons to Limnoria tripunctata are described. Chemical additions to creosote were screened using this method. Three pesticides, Endrin, Kepone, and Malathion proved particularly effective. The addition of varying percentages of naphthalene to creosote using several treatment methods are currently being assayed. Results to date show that the coupons treated by the empty cell method have better performance than those prepared by the toluene dilution method. The naphthalene coupons treated by the full cell method show no attack after six months' exposure.
B R Richards, D A Webb
Field test evaluation of preservatives and treatment methods for fence posts
1985 - IRG/WP 3347
This work presents the field test results after fifteen years exposure of Eucalyptus saligna fence posts treated with six different preservatives and five treatment methods. All the combinations with oil-borne preservatives presented the best results and among the waterborne preservatives, the fence posts treated by immersion method were with the lowest performance in the field test.
G A C Lopez, E S Lepage
The applicability of life cyle analysis and alternative methods in the wood preservation industry
1994 - IRG/WP 94-50023
In the Netherlands, several case studies have been performed using the life cycle analysis method (LCA). This type of research is aimed at an inventory and classification (sometimes including also evaluation) of the environmental impacts of a product, from the raw material to waste stage ("cradle to grave" approach). In a LCA each environmental impact is assessed in terms of, for example, mass of raw material use (kg), energy consumption (MJ), emissions (COx, NOX, SOx, etc.) and final waste (in kg). The critical point in an LCA is the definition of comparable "functional units" for similar products made of different materials with different service lifes. As the LCA method has often proved to be very complex, lime-consuming, expensive and difficult to interpret and translate into practically usefull results, alternative methods are developed. Three methods are described and compared on the basis of various examples. It is hoped that this may be of use as a starting point for further discussion on the suitability of applying the LCA on (preservative treated) timber products.
P Esser, J Cramer
Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States. The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of commercially important copper-based wood preservatives were used as model formulations, namely copper/copper-HDO, ammoniacal copper/quat and CCA. The most important factors determining the extent of copper leaching in the different lab trials were the sample size (volume/surface ratio) and the fixation conditions prior to leaching. On the other hand, the wood species and the leaching protocol itself were found to have only minor influence on the copper leaching rate in the test methods included in this study.
J Habicht, D Häntzschel, J Wittenzellner
Developments in the protection of wood and wood-based products
1980 - IRG/WP 340
Technology is playing an increasingly important role in the field of wood protection. This current review highlights how modern techniques have provided greater insight into the biological and physical processes affecting the durability of wood and wood-based products. Emphasis is also given to developments in preservative testing methodology and to the encouraging changes towards both the correct use of timber and the improvement of Standards and Codes of Practice. A final section, on recent technical developments in wood preservation, considers subjects ranging from an evaluation of new specific biocides to methods of increasing the permeability of refractory timber species.
J M Baker
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
Testing of wood preservatives against marine borers (Part 1). Method of testing wood preservatives against marine borers (Part 2)
1971 - IRG/WP 37
P C Trussell, C C Walden
Report on the activities of the European Standardization Committee CEN/TC 38 'Methods of Testing wood preservatives'
1980 - IRG/WP 279 E
Comparison of the agar-block and soil-block methods used for evaluation of fungitoxic value of QAC and CCA wood preservatives
1994 - IRG/WP 94-20039
The modyfied agar-block and soil-block methods were used for comparing the fungitoxic value of QAC and CCA type preservatives against Coniophora puteana and Coniophora olivacea The mass loss and moisture contents of wood were analysed.
J Wazny, L J Cookson
A practical method to evaluate the dimensional stability of wood and wood products
1990 - IRG/WP 2342
This paper presents a new simple method to evaluate wood and wood products for their resistance to swelling and to assess wood preservatives for their ability to dimensionally stabilize treated wood exposed to water. Permeable wood of various dimensions and treated with different preserving chemicals have been measured for swelling in the radial and tangential direction during immersion in liquid water. The results indicate that a simple exponential function describing the dimension of the samples during immersion can be used to evaluate both the water-repellency and anti-swelling effectiveness of wood preserving chemicals. The results can be achieved in reasonable time, and the parameters of the function can be determined by a commercial desk-top computer program.
J P Hösli
Comparison of Different Methods for Assessing the Performance of Preservatives in the BAM Fungus Cellar Test
1998 - IRG/WP 98-20149
The fungus cellar test is a common means to get reliable data on the long term performance of treated wood in soil contact. A constantly high humidity and a suitable of water holding capacity for a range of micro-organisms provide high decay rates in untreated wood and produce intensive microbial pressures on wood treated with biocides. Presently a range of biocides are under test in the BAM fungus cellar and the results will be presented for the following types of biocides: Tebuconazole in combination with copper and boron (5 years fungus cellar), quats with copper and boron (5 years fungus cellar) and Cu-organic compound combined with copper and boron (3 years fungus cellar). Figures will be shown on the development of the Modulus of Elasticity (MOE) over the years and on an assessment of the stakes according to EN 252.
I Stephan, M Grinda, D Rudolph
Respiration methods used to follow the decay of wood and the toximetric evaluation of wood preservatives
1975 - IRG/WP 249
When wood is attacked and decayed by fungi, wood substance and oxygen (02) are consumed, while carbon dioxide (CO2), water and heat are liberated. Early in the 1960's workers from England, Canada and Sweden began studying CO2 evolution, with respect to decay and its control using chemical preservatives, while in Germany and the USA O2 utilization was being similarly examined. Oxygen consumption measurements during the decay of wood were made mainly using pressure differential closed systems and were shown to be reasonably sensitive and a suitable reflection of the rate and extent of decay. Carbon dioxide measurements were made using titration, conductivity and gas-chromatographic methods. The last method appears to be the most useful, being applicable to open and closed systems, flexible in application, very sensitive over a thousand-fold concentration range change without switching, and easily automated. Its application to evaluating the toxicity of wood preservatives has been intensively studied and shown to give chemical toxic thresholds after only one third of the normal incubation time, which are similar to those based on the much longer conventional weight loss method.
R S Smith
Durability of pine modified by 9 different methods
2004 - IRG/WP 04-40288
The decay resistance was studied for pine modified by nine methods of wood modification: 1) Acetylation, 2) Treatment with methylated melamine resin (MMF), 3) Acetylation followed by post-treatment with MMF-resin, 4) Thermal modification, 5) Furfurylation, 6) Maleoylation (using water solution of MG or ethanol solution of maleic anhydride), 7) Succinylation, 8) NMA-modification and 9) modification with reactive linseed oil derivative (UZA), Wood blocks of Scots pine (Pinus sylvestris L.) sapwood were modified in pilot plants. Methods 1-5 were performed by the authors at Chalmers University of Technology or at BFH in Hamburg. Methods 5-9 were part of a European research project (the Chemowood project, FAIR-CT97-3187) and therefore each of these modifications was performed by the project participant responsible for the method. For laboratory testing in TMCs (modified European standard ENV 807) and pure basidiomycete culture bioassays, smaller test specimens were cut from the modified wood blocks. Most of the modification methods were applied on test specimens for marine field testing (EN 275) and some methods to produce mini-stakes for field tests in five Swedish fields. Some modification methods result in modified wood with poor durability, whereas other methods (acetylation, furfurylation and MMF-treatment) seem to provide excellent resistance to microbial decay.
M Westin, A O Rapp, T Nilsson
Termite standards questionnaire survey. Second Report
1989 - IRG/WP 1395
Information contained in replies received from IRG members responding to the survey continue to be summarised. Again, highlighted in this second report are the major termite species in the various zoogeographical regions, their damage ranking to timber-in-service, the chemicals used in control methods, and the status of the termite standards in the respondent countries.
J R J French, J P La Fage
European standardization for wood preservation
1988 - IRG/WP 2321
Introduction to a field demonstration of various instruments and methods for the detection of defects in poles
1984 - IRG/WP 2228
Creosoted radiata pine by non-pressure methods
1988 - IRG/WP 3486
Posts of Pinus radiata have been impregnated with creosote by immersion for 1, 3, and 7 days, and by hot-and-cold open tank with hot bath temperatures at 40°C and 60°C. On the basis of the retention rates obtained, suitable procedures are described for wood elements that are going to be in ground contact, and an analysis is made of the way in which the variables tested affect the results.
M V Baonza Merino, C De Arana Moncada
Fungicidal combination products
1987 - IRG/WP 3426
Due to the increased pressure on some of the established fungicides used in wood preservation, possible alternative products become more interesting. The requirements for new chemicals are mainly lower toxicity and greater environmental acceptability. However the efficacy to target organisms should be as good as that of the currently used ones, preferably better. A possibility for progress in this direction could be fungicidal combination products showing broader spectrum of efficacy and synergistic effects. Mixtures of tributyltin compounds with Furmecyclox and K-HDO respectively are tested for this purpose. Toxic values with and without artificial ageing (wind-tunnel exposure and leaching) were determined. Investigations have been made with coating-formulations in order to test penetration, evaporation and the influence of UV-radiation. Aqueous formulations were tested for special purposes such as the treatment of freshly cut timber and the protection of brickwork. The results obtained are very promising, especially regarding long term durability. Further investigations mainly with the aqueous formulations including other test fungi and field trials are necessary to confirm the suggested application as wood preservatives.
H A B Landsiedel