IRG Documents Database and Compendium

Search and Download IRG Documents:

Between and , sort by

Displaying your search results

Your search resulted in 144 documents. Displaying 25 entries per page.

A standardised procedure for the treatment of timber with test chemicals
1986 - IRG/WP 2257
A procedure is described which allows the standardisation of sample handling and data manipulation during trials invastigating the treatability of timber with test chemicals. The use of computer software allows the data to be handled efficiently.
J Norton, A Zosars, L E Leightley

A novel guide for the determination of the physical properties of wood including kiln drying and full-cell preservative treatment
2004 - IRG/WP 04-20298
An ideal flow chart for the sequential experimental determination of a range of physical properties relevant to wood drying and subsequent preservation was designed as a novel guide to assist wood scientists. In this manner, data assembly and experimental processing are shown. This was designed according to experience and published literature. Aspects emphasised in this review were the physical properties which effect the manner of processing particularly in respect to preservative treatment of wood. For this purpose a total of 93 references covering 8 topics (descriptive wood anatomy, physical properties of wood, shrinkage and swelling, wood density, moisture content, fibre saturation point, wood drying (by oven and kiln) and liquid permeability) were reviewed.
I Usta, M D C Hale

Computerized axial tomography. A non-destructive method for three-dimensional wood density/moisture content measurement
1987 - IRG/WP 2285
Computerized Axial Tomography (CAT-scanning) - used for medical investigations of the brain - has been evaluated as a nondestructive method of three-dimensional wood density/moisture content measurements. Density can be measured with an accuracy of ±3 kg/m³, and the accuracy in average moisture content is ±1% below and above fibre saturation point. It is theoretically possible that measurements can be made in a randomly chosen volume element of 2 x 2 x 10 mm³ within a wooden testpiece. CAT-scanning has also possibilities for evaluating: - the development of fungal attack on wood; - the development of attack by marine borers on wood; - the distribution end penetration rate of preservatives in wood; - wood drying after impregnation.
L O Lindgren

Thermally modified timber (TMT) for decking applications – determination of relevant surface properties
2011 - IRG/WP 11-40544
In recent years thermally modified timber (TMT) entered various market segments. It is used for facades, horticultural equipment, garden furniture, and also for kitchen and bathroom cabinets. However, flooring turned out to be the most important application for TMT, either as interior parquet or as exterior decking. Besides durability and dimensional stability, which had been the initial target properties of TMT, research activities need to focus also on flooring relevant properties. The performance of flooring is mainly characterized by its optical appearance, thermal behaviour and different mechanical properties, e. g. hardness and bending strength. Consequently, in the frame of a worldwide inter-laboratory test on quality measures for TMT, which was initiated in the frame of IRG in 2008, studies on the sensitivity of TMT on typical flooring loads were considered. Within this study color and heat flux density measurements were conducted to determine the suitability of TMT in terms of thermal comfort. The heat flux density was barely affected by the heat treatment, because it is mainly determined by the material density. Thermal modification did not lead to a remarkable loss, neither in density nor in heat flux. However, timber turned out to be preferential compared to mineral or polymer-based flooring materials suffering from less thermal comfort. The most important mechanical load for flooring was regarded in static and dynamic hardness tests. As TMT is known to be especially susceptible to dynamic loads, a method for determination of dynamic hardness was developed and applied to differently severe treated TMT. The development based on the Brinell hardness principle and aimed on examining differences between static and dynamic loads on hardness as well as on the possibility to convert both hardness values into each other. Extensive hardness tests with 24 different native wood species and TMT were conducted. The dynamic hardness decreased with increasing treatment intensity (in maximum by 20 %), whereby the axial hardness was significantly less affected compared to radial hardness. Furthermore, the reduction in hardness was found to be reliably predictable by color measurements.
L Meyer, C Brischke, C R Welzbacher

Determination of the preventive efficacy against wood destroying basidiomycetes fungi, EN V 839 - CEN/TC 38 WG 9
1993 - IRG/WP 93-20015
The WG 9 of CEN TC/38 has presented to EC a mycological test to assess efficacy of preservatives applied by surface process. This method is now an experimental standard (EN V 839) which has to be approved by the different european delegations. The following paper is not the standard as it has been proposed but is a presentation of the principle of the method. The experimental standard specifies a laboratory method of test which gives a basis of the assessment of the preventive action of a wood preservative when applied as a surface treatment against Basidiomycetes fungi. This method is applicable to formulations of preservatives in a ready to use form (organic formulations, organic water-dispersible formulations, water-soluble materials). Series of susceptible wood species specimens are treated on longitudinal faces whith the preservative in test using brushing as surface procedure. Test specimens are then exposed by an intermediate mesh to feeder blocks infestedby pure culture of Basidiomycetes fungi in sterile conditions and penetration of fungi is assessed on cross section sawn in the samples at the end of the test.
D Dirol

On site test for indicative determination of leaching of components of preservatives from treated timber. Part 2: New data on CCA-C, CC and CCB treated timber
1994 - IRG/WP 94-50025
The 'on site test' was published at the IRG meeting in Cannes in February 1993 (IRG/WP 93-50001/12). Since this publication many on site tests were performed parallel to so-called shower tests. The correlation between the test results of the on site tests and the shower test has been established more clearly. For chromium the correlation between both tests is indistinctive of preservative formulation. For copper the correlation differs for CCA on one side and CC's and CCB's on the other side. In some cases the on site test does not correcty predict shower test results. The reasons for this phenomenon are discussed. It can be concluded that the on site test is a roughly indicative test for assessing the leaching of components of preservatives from treated timber. The correlation figures, however, are formulation dependent.
W J Homan

Quantitative determination of Chromium: A comparison of three instruments
1995 - IRG/WP 95-50053
A comparison is made between three instruments for measuring levels of chromium in the leachate of copper-chrome-arsenic (CCA) treated timber. These include an atomic absorption spectrophotometer, an inductively coupled plasma spectrometer and the RQflexâ. The RQflexâ is a new hand-held instrument which measures chromium by dipping a ReflectoquantÒ strip into the leachate and inserting the strip into the RQflexâ. Readings are determined reflectometrically following a reaction between chrome and the Reflectoquantâ strip. It provides an inexpensive and quick technique which is used in this paper to determine the degree of preservative fixation prior to the removal of CCA treated timber from drip pads of wood treatment sites. The results indicate that RQflexâ is a suitable instrument for the rapid assessment of chromium levels in rain wash off from treated timber. A comparison is given of the economics and accuracy of the instruments for measuring chromium.
S Walley, P R S Cobham, P Vinden

The effects of density on vertical variation of permeability of Sitka spruce within tree
2000 - IRG/WP 00-40156
Tree improvement of Sitka spruce is a combination of silviculture and tree breeding aimed at producing higher quality products including increased growth rate and timber yield, and wood density. It is useful to know annual ring structure and density distribution when studying the quality of wood, grading it, or determining how the wood structure affects residual flow in softwoods. Since density is a factor under genetic control, the study in this article details the effects of density on longitudinal and radial permeability of Sitka spruce from base to apex. Comparison of overall means of both longitudinal and radial void volume filled (%) suggest that longitudinal permeabilities were almost the mirror image of those for the radial permeability along the tree trunk.
I Usta.

Natural resistance of twenty-six Guianese wood species against marine borers
1988 - IRG/WP 4144
This note is a contribution on the study of the natural resistance of some wood species from French Guiana, some of which could be found too in the neighbourhood. Here are presented the results after one year exposure in the marine environment.
L N Trong

Absorption of inorganic salts solutions. Retentions of inorganic salts. Fire retardants
1990 - IRG/WP 3625
The study aims evaluated the impregnation capacity using fire retardants on woods with differents densities. At the same time, impregnation with several fire retardant salts were carried out in order to obtain their absortion and retention in wood.
A Garcia, J Navarro

A summary of tests and practical experiences with the Pilodyn wood testing instrument
1980 - IRG/WP 282
This paper presents a summary of the reports, tests and practical experiences with the Pilodyn wood tester not only, however, concerning poles but also in other fields such as standing trees, sawn timber etc. The principle of the Pilodyn is a spring-loaded pin which is fired into the object and the depth to which the pin penetrates is correlated to physical and mechanical properties of the object.
H Friis-Hansen

Implications for comparability of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1196
(Summary of paper 1193) Groups of Coptotermes acinaciformis, originating from six colonies, three taken from each of two localities, 1500 km apart, in northern Australia (Townsville, Darwin) were kept at population densities of 0.005, 0.01 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at the lowest population density; their performance reached a maximum at a population density of 0.01 g/mL. The subsequent decline in vigour was less marked as the highest population density was approached. However, the actual values for survival and wood consumption varied widely between colonies, irrespective of their origin. It is recommended that in all laboratory experiments which use survival and wood consumption as indicators of termite vigour, controls of a favourable as well as an unfavourable food type are included which would serve to monitor the vigour of the termites. Results from termite sources whose vigour falls below a certain threshold value would have to be treated with caution and could not be used in definative data, as e.g. in defining critical retentions of wood preservatives.
M Lenz

The Pilodyn instrument as a non-destructive tester of the shock resistance of wood
1978 - IRG/WP 2107
A new non-destructive shock resistance tester, the PILODYN, has been developed. The instrument measures the fracture surface area created by a constant amount of energy. It operates by shooting a blunt pin into wood by an exact amount of energy. The penetration depth is read on a scale. A wide field of application is open to a non-destructive shock resistance tester such as: 1) assessment of the residual strength of poles decaying from the outside; 2) laboratory evaluation of biodeteriorated wood; 3) the state of wood foundations and woody pilework; 4) degree of chemical decomposition of wood; 5) degree of thermal decomposition of wood; 6) measurement of the density (strength) of standing trees; 7) measurement of the density (strength) of sawn timber; 8) production control of wood based panel boards. A review of existing test results as well as new results are presented containing items 1, 6 and 7. An evaluation of the potential of the PILODYN is attempted.
P Hoffmeyer

Statistically stable models for determination of PEC
1999 - IRG/WP 99-50135
In June 1998 the European Wood Preservative Manufacturer's Group prepared a document to support the Technical Guidance concerning the placing of products on the market with respect to the Directive 98/08/EC (BPD). The essentials of this document were presented at the COST E2 meeting in Cannes last year and at the following IRG conference (Baines and Davis, 1998; IRG/WP/98-50101/20). The document presented a protocol in which a "tiered" approach is followed. The key-factors in this approach are the PNEC (predicted no effect concentration) and the PEC (predicted environmental concentration). The PNEC is calculated from eco-toxicity test results and a safety factor is introduced. In the case of metals which may also be essential trace elements, the background level is suggested as the PNEC, if this level is above the level derived f rom eco-toxicity tests. The calculation of the PEC uses different models. The focus of this paper is the reliability of the models used to determine the PEC, while pointing out that only data and models relevant to the field situation may be used. In the EWPM protocol, initially the environment has to be defined by going through flowcharts and providing an answer of "YES or NO" to each of the questions. In the first tier of the questions there are two options for the treated wood, which is likely to be treated with the candidate wood preservative. It can be assessed as presenting either: a) No risk to the environment, or b) Additional information is required and the next "tier" of questions or tests is involved. In this paper the model for a fresh water environment is presented as an example. However, the models and the systern, can also be applied to other environments. In the above mentioned flowcharts the following assumptions are made: 1.Yes, the substance is toxic and harmful, 2. Yes, if all of the substance in the treated wood entered the water, its concentration would probably be > the PNEC, 3. Yes, the treated wood is in a situation where some of the substance is likely to get into the water. For this reason a simulated exposure test would be carried out and: 4. Yes, the chemical analysis of the wash-off water would be possible and relevant. Therefore PECwater values would need to be calculated to solve the question whether PECwater> PNECwater. By definition, the PEC must be based on the same principle as the PNEC. This implies that the PEC must be relevant for long term exposition, as the PNEC is a long term value, derived from chronic studies.
W J Homan, A L Van Oosten Van

Determination of toxic limits of wood preservatives towards wood-destroying Basidiomycetes. Investigation on the effect of the use of two impregnated wood blocks and of one impregnated and an untreated block respectively in Kolle jars on the toxic limits of wood preservatives
1973 - IRG/WP 225
O Wälchli

Determination of physical properties of wood by Novel Guide
2006 - IRG/WP 06-40345
In empirical and theoretical determination of physical properties of wood, a schematic guide has been developed (as a novel guide) for the purpose of bringing facilities to researchers with a processing quantity in terms of data compilation. In this article physical properties of wood have been briefly described in respect to their effect on impregnation process, and technical information has been provided on usage of novel guide.
I Usta, M D Hale

Some relationship between physical characteristics and treatability of Bolivian woods
1987 - IRG/WP 3434
Using the available data on physical characteristics of 25 Bolivian woods, some relationships between porosity, specific gravity and treatability (hot and cold open tank process with 5% pentachlorophenol) were analysed. The aim of this report is to give information on technical characteristics of Bolivian hardwoods which have been studied in this country by Centro de Desarrollo Forestal and in Peru by Junta del Acuerdo de Cartagena.
A S Viscarra

Ancillary properties of vapor boron-treated composites
2001 - IRG/WP 01-40210
This paper discusses the water absorption, thickness swelling, and internal bond strength of North American composites treated using a vapor boron treatment process. For oriented strandboard, high boron loadings led to lower internal bond strength and lower thickness swelling. Water absorption results were variable but no deleterious effect of treatment was noted. For medium density fiberboard, the highest loadings led to reduced internal bond strength. Thickness swelling decreased with increasing boron level, but not significantly. As with OSB, water absorption results varied.
W A Jones, H M Barnes, R J Murphy

Methods for testing fumigant efficacies against termites
1986 - IRG/WP 1297
Methodologies for testing fumigants against termites are reviewed and factors needed to be taken under consideration for standardization listed. Toxicity should be defined by both direct exposure to the gas and under more practical "barrier" conditions which include test enclosures simulating abiotic surroundings of the termites, i.e. wood, nest material, etc. To observe latent effects, mortality should be recorded periodically after exposure until rates decrease to control levels. Fumigant efficacy should be reported as a function of concentration and exposure time, termed lethal accumulated dose (LAD).
N-Y Su, R H Scheffrahn

Treating Eucalyptus tereticornis wood with boron: Optimizing treatment conditions
2005 - IRG/WP 05-40309
Even though Eucalyptus tereticornis wood is suitable for small timber purposes, being non-durable, it needs to be treated with preservative chemicals. As it is a heavy, hard and difficult to treat species, the possibility of using diffusible boron compounds was investigated. The present study explored the effect of impregnation conditions such as treatment schedule, concentration of treatment solution and the moisture content of wood on the achievement of desired dry salt retention (DSR) of the preservative in the treated wood by conducting a commercial scale trial. The study revealed that wood density and moisture content adversely affected the boron impregnation. It was clear that even E. tereticornis wood in green condition could be effectively boron impregnated using appropriate treatment schedule. Only long duration treatment schedules were found to yield the desired DSR levels. A solution concentration of 8% boric acid equivalent (BAE) was found to be required. Application of an initial vacuum of 760 mm Hg (- 85 kPa) for 15 minutes followed by a pressure of 1300 kPa for a minimum period of 60 minutes and a final vacuum of 760 mm Hg(- 85 kPa) for 5 minutes was found to be an appropriate treatment schedule.
T K Dhamodaran, R Gnanaharan

Laboratory determination of the natural decay resistance of some lesser-utilized timbers from Tanzania against wood decay fungi
2004 - IRG/WP 04-10517
Four lesser known/utilized timber species (sap and heartwoods) from Tanzania, namely Albizia lebbeck, Zanthoxylum gilletii, Faurea saligna and Parinari curatellifolia were exposed to the brown rot fungi (Gloeophyllum trabeum and Coniophora puteana) and the white rot fungus (Coriolus versicolor) to determine their natural decay resistance according to the EN 113 standard procedure. The timbers were also ranked into natural durability classes according to EN 350-1. Albizia lebbeck, Faurea saligna and Parinari curatellifolia timber species (heartwood) were found to be very resistant while Zanthoxylum gilletii was heavily decayed by all the fungi. The durability ratings of the timbers were; Albizia lebbeck (1), Faurea saligna (1), Parinari curatellifolia (1) and Zanthoxylum gillettii (5). It is suggested that the durable timbers, Albizia lebbeck, Faurea saligna and Parinari curatellifolia should be promoted as alternatives to the well known durable timber species in Tanzania such as Tectona grandis, Afzelia quanzensis, Blachylaena hutchinsii and Pterocarpus angolensis which are currently being over-exploited.
P R Gillah, R C Ishengoma, E Julias, S A Amartey, D H Kitojo

Effect of incising depth and density on treatment of Douglas fir, hem fir and spruce-pine-fir lumber with CCA, ACZA or ACQ
1997 - IRG/WP 97-40093
Incising markedly improves both the depth and uniformity of preservative treatment of refractory wood species, but there are few studies directly comparing the effects of incising depth and density on penetration and retention of commonly used waterborne preservatives in wood species from the western United States. The effects of two incision densities (7300 and 8900 incisions/square meter) at two depths (5 and 7 mm) were investigated using two strength classes of Douglas fir, hem fir and spruce-pine-fir lumber. In general, grade or strength class had no significant effect on treatability. Treatability markedly improved with increasing incision depth, while increased incision density produced less tangible results. Ammonia-based treatments were associated with deeper penetration reflecting the ability of the heat and/or ammonia to improve preservative penetration. Further studies are underway to evaluate the effects of incising and subsequent preservative treatment on strength properties.
M Anderson, J J Morrell, J E Winandy

Examination of the Pilodyn as a non-destructive test method for detecting decay in CCA treated eucalypt poles
1982 - IRG/WP 2177
Below groundline condition of 274 CCA treated eucalypt poles comprising 13 different species was examined using 6 and 12 Joule Pilodyn units with 2 and 2.5 mm diameter pins. The data obtained was used to calculate regressions of density on pin penetration. A decrease in density was accompanied by an increase in pin penetration. The best correlation was found using the 6 Joule, 60 x 2.5 mm² diameter pin. The results are discussed with comments on future work with the Pilodyn.
L E Leightley

A study of wood quality of Juglans nigra and hybrid walnut (MJ 209xRA) : durability against Coriolus versicolor, density and MOR
2004 - IRG/WP 04-10522
The study investigated possible effects of harvesting season on some wood properties of Juglan nigra (JN) and a hybrid walnut (MJ209xRA). The samples were taken from trees which were harvested in June July, August, November of the same year, and March in the year after to determine whether there were any significant differences in wood properties as regards the harvesting seasons. In order to test the durability of the 648 wood samples white rot fungus Coriolus versicolor challenge test (EN113 (AFNOR 1994) was applied by using agar culture medium. The bending strength was also determined after a sixteen-week exposure to the above mentioned fungus. The data obtained clearly indicated that the heartwood of JN was more durable than its sapwood. JN sapwood was more durable than MJ209xRA sapwood. The same trend was observed with the Modulus of rupture (MOR : EN 310): the heartwood displayed higher MOR value than the sapwood. Wood density measurements also demonstrated that the wood density values of the sample heartwoods were much higher than those of the sapwoods. Results also illustrated that, from the wood durability point of view, March is the least interesting period for harvesting. June and November, on the other hand, proved to be more favourable periods as regards harvesting. This study clearly indicates that the durability and the strength of the hybrid walnut (MJ209xRA) are lower than those of the walnut (Juglans nigra), and this fact should be considered in the exploitation of hybrid wood.
B Charrier, F Charrier, D P Kamdem, J B Aurel, G Janin

Determination of total fluoride in preservative-treated wood by ion selective electrode, without steam distillation
1996 - IRG/WP 96-20086
An analytical method was developed to determine total fluoride in wood treated with aqueous fluoride or borate-fluoride formulations. Ground wood was mixed with 60% sodium hydroxide solution and oven-dried overnight before furnacing at 600°C. The cool fused product was dissolved in warm water before adding a powerful complexant/buffer solution containing sulphosalicylic acid and EDTA. Fluoride was measured by ion-selective electrode (ISE) against appropriately matrix-matched calibration standards containing 1, 10, or 100 ppm F. The method compared favourably with two alternatives; one employed the time-consuming distillation step included in the AWPA A2 1994 method, with a titration finish, and the second employed a double fusion and ISE finish, using TISAB buffer. The chosen buffer system exhibited better capacity than TISAB to complex excesses of model interferant Al. B and Si were also accommodated. Recovery from spiked Eucalyptus maculata (at 0.05-0.5% m/m F) was 94-96%. Precision when analysing Alstonia scholaris containing 0.35% m/m F was about 2%. The method enables better throughput than the AWPA A2 94 method
M J Kennedy

Next Page