IRG Documents Database and Compendium


Search and Download IRG Documents:



Between and , sort by


Displaying your search results

Your search resulted in 126 documents. Displaying 25 entries per page.


New developments in wood preservation
1974 - IRG/WP 335
Most of the developments in wood preservation in recent years have been stimulated by changing circumstances, particularly the increasing interest in reducing hazards and environmental, pollution but also the serious difficulties that are now being encountered in obtaining economic supplies of established preservatives. There is perhaps a danger that new controls to reduce pollution dangers may be too severe.
B A Richardson


Pinus and Eucalyptus fenceposts treated with creosote and solvex tar by hot and cold open-tank process
1987 - IRG/WP 3455
A comparative study of the behaviour of two different wood preservatives, creosote and solvex-tar, was made, using two wood species, Pinus pinaster Ait and Eucalyptus globulus Labill, by the hot and cold open-tank process. Results showed that the creosote behaved better in relation with the uniformity of its distribution in wood. On the other hand, better results were obtained on Pinus for both preservatives.
M V Baonza Merino


Comparison of cubic and plug samples for preparation and data assembly in permeability study
2000 - IRG/WP 00-20197
In order to determine if plug experimental samples (PES: 30 x 15 mm2 diameter) could be used for inspection of wood permeability characteristics, radial and longitudinal flow directions were prepared according to either PES or cubic experimental samples (CES: 100 x 20 x 20 mm3) from the sapwood zone of Sitka spruce and treated by tanalith-C according to full-cell process. Results from the two preparation techniques agreed in the test to determine the mean percentage of void volume filled by liquid both radially and longitudinally, while the preparation process (i.e. machining, sealing, etc.) of the experimental samples and the period of the data collection was quite longer in CES than that for PES in either flow direction.
I Usta


The use of pressure cycling to improve heartwood penetration in Pinus radiata (D. Don)
1995 - IRG/WP 95-40050
This study investigates the effect of cycling pressure on the treatability of radiata pine heartwood. The results indicate that liquid penetration into the heartwood is affected by the preconditioning method used and pressure treatment time. There is no significant improvement in the penetration of Pinus radiata (D. Don) heartwood when a cycling or pulsation process is used.
P R S Cobham, P Vinden


Wood furfurylation process and properties of furfurylated wood
2004 - IRG/WP 04-40289
The first processes for “furfurylation” of wood (wood modification with furfuryl alcohol) were developed several decades ago. Furfuryl alcohol is a renewable chemical since it is derived from furfural, which is produced from hydrolysed biomass waste. Over the last decade modernised processes for furfurylation of wood have been developed. These new processes are based on new catalytic systems and process additives. Two main processes for production of furfurylated wood have been developed for WPT (Wood Polymer Technology ASA) by the authors – Kebony 100 for high modification levels of hardwoods and VisorWood for lower modification levels of pine. Commercial production according to the Kebony process has been running since August 2000, mainly for flooring. A small Kebony production plant is now in operation in Lithuania. A larger Kebony/VisorWood production plant started up in September 2003 in Porsgrunn, Norway. Several new plants operating according to the VisorWood process, each with an annual capacity of 10 000 m³ or more, are under construction. The properties of furfurylated wood depend on the retention of grafted/polymerised furfuryl alcohol (PFA) in the wood. At high modification levels (high retention of PFA) the enhancement of a wide variety of properties are achieved: an exceptional hardness increase, exceptional resistance to microbial decay and insect attack, high resistance to chemical degradation, increase in MOR & MOE, and high dimensional stability. At lower modification levels many property enhancements also occur, however to slightly lower extent. Notable are resistance to microbial decay and insect attack, increase in MOR & MOE, and relatively high dimensional stability.
M Westin, S Lande, M Schneider


Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 5. Treatment of Sitka spruce and Scots pine
1999 - IRG/WP 99-40136
The suitability of the MPP Process for CCA treatment and accelerated fixation of species other than Radiata pine was assessed by pilot plant trials on UK-grown Sitka spruce (Picea sitchensis) and Scots pine (Pinus sylvestris). Pressure and vacuum kickbacks of spruce (14 l/m3) and Scots' pine (122 l/m3) were both substantially lower than that generated during treatment of radiata pine (369 1/m). Total Organic Carbon (TOC) in kickback from spruce treatment (~ 750 ppm) was approximately half that in Scots pine kickback (~ 1400 ppm), and were substantially less than TOC generated during treatment of radiata pine (~ 2000 ppm). Extent of CCA fixation (spruce: 93%, Scots pine: 97%) was similar to that obtained with radiata pine (97%). To reduce post-treatment drippage, caused particularly by the refractory nature of spruce, a modified Bethell process was found most appropriate for MPP treatment rather than modified Lowry schedules used with radiata pine. Use of hot CCA solutions did not improve penetration into spruce and some collapse (washboarding) of early wood was a feature of its treatment.
M E Hedley, K Nasheri, G Durbin


An effective preservative treatment of borak bamboo (Bambusa balcoona Roxb.)
1996 - IRG/WP 96-40070
Adequate penetration and retention of CCA and CCB has been obtained in predried Borak Bamboo (Bambusa balcooa Roxb.), aboundantly grown in Bangladesh, with Full Cell Pressure Process. The treated bamboo can be used as building materials, the sufficient treatability ensured its long term best utilization at ground contact and indoors. Which will keep the environmental & socio economical conditions of Bangladesh more viable and normal.
A K Lahiry, S Begum, G N M Ilias, M A Matin Sheikh, M A B Fakir, M I Hossain


Steam conditioning of partially dried radiata and Corsican pine roundwood
1988 - IRG/WP 3499
The effect of partial air drying prior to steam conditioning and its effect on subsequent preservative treatment by the Bethell treatment process was investigated. A high standard of preservative treatment was obtained in both radiata and Corsican pine, irrespective of whether a period of partial drying was imposed before or after steam conditioning.
P Vinden, D R Page, K Nasheri


The internal-external diffusion process: Table salt treated poles
2005 - IRG/WP 05-50224-25
This new technique of preservation of wooden poles consists of keeping preservative in stock, in a reservoir drilled inside the pole, in its whole length. This permits the use of non toxic, common products such as table salt, grease, etc, in the preservation of utility poles, building columns, or the like. Some major obstacles to a good implementation of a good preservation with the classical processes become advantages with the new technique, notably the low permeability of some sorts of wood, and inaptitude to the fixing of a big number of chemicals aimed to provide a durable protection to wood submitted to weather.
L Nitunga


Analysing the characteristic role of moisture content for drying and fluid flow in Sitka spruce. - Part 1: The drying process of sapwood and heartwood of two different thickness of Sitka spruce using a kiln. - Part 2: Effects of moisture content on longitudinal permeability of Sitka spruce in vertical variation of the tree
2000 - IRG/WP 00-40173
The characteristic role of the moisture content in Sitka spruce (Picea sitchensis (Bong.) Carr.) that grown in the United Kingdom was examined by this study on the basis of (1) the reduction of moisture content in two different thickness of sapwood and heartwood by kiln drying process, and (2) the effects of moisture content to the longitudinal void volume filled of tanalith-C by the full-cell process from base (1 m) to apex (3 m) of the tree in sapwood zone. Accordingly, conclusions on indication of the drying process of sapwood and heartwood, and vertical variation of longitudinal flow with effects of moisture were listed separately: (1) Comparison of Drying Characteristic of Sapwood and Heartwood: The two different thickness (300x30x30 mm3 and 300x20x20 mm3) of sapwood and heartwood of Sitka spruce was dried using the suggested drying schedule in kiln. The reduction of moisture was schematically diagrammed according to sapwood and heartwood stakes. The reduction of moisture followed the same downward trend that sapwood (S) loses more moisture than heartwood (H) although the small stakes of S and H lost moisture rapidly compared with the large ones. (2) Vertical Variation of Moisture Content and Longitudinal Permeability: The 90 kiln dried defect free sapwood stakes (150x25x25 mm3) of Sitka spruce was taken from base to apex of the trees at 1, 2 and 3 m above ground level. After having the determination of moisture content in each experimental stake, the treatment was carried out by the full-cell process with CCA preservative (Tanalith-C) using a model pressure treatment plant. Significant differences observed among the tree heights from 1 to 3 m showing that slightly increases of moisture content from base to apex and conversely decreases of longitudinal void volume filled by preservative fluid.
I Usta


Wood preservatives ecotoxicology on Gammarus pulex (L.) - toward an environmental monitoring method and a getting rid of pollution process
2005 - IRG/WP 05-50224-9
Wood preservatives can have a strong impact on freshwater invertebrates when used close to aquatic ecosystems. It has been reported in Jura that different arthropod taxa, specially crustaceans, have disappeared along several kilometers downstream from factories using insecticides and fungicides as wood preservatives. The crustacean Gammarus pulex (L.) is a relevant bioindicator to characterize the impact of wood preservatives on freshwater community. It presents a high sensitivity to wood preservatives but a relative tolerance to organic and nutrimental pollution. This abundant and ubiquitous crustacean has a key role in numerous aquatic ecosystems particularly in the decomposition of cellulose and as a prey for several fish species susceptible to be eaten by humans. In this study, we aim on the one hand to determine the adsorption capacity of different substrates of propiconazole, a fungicide widely used in the wood treatment, and on the other, to evaluate the toxicity of wood preservatives for G. pulex in controlled conditions. We hypothesize that the fungicide toxicity may be influenced by different types of substrate used in the test containers, i.e., coarse organic matter and gravel. These results should allow us to go, firstly toward the elaboration of sensors in order to detect product emissions in the aquatic environment, and secondly toward a depuration process in order to decrease the impact on the aquatic communities. These experiments should also allow us to develop a new biological monitoring method for the assessment of the impact of wood preservation on the aquatic ecosystems.
O Adam, F Degiorgi, G Crini, P-M Badot


Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed.
H M Barnes, T L Amburgey, R W Landers


A behaviour of CCA penetration of fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications
2006 - IRG/WP 06-40346
A behaviour of CCA penetration of Bornmulleriana fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications was illustrated for the main flow directions by the experimental pictures.
I Usta, R Despot, M Hasan


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.


Technique for monitoring absorption during a vacuum pressure process
1992 - IRG/WP 92-3696
A laboratory technique was developed and an apparatus constructed which allowed for the direct and continuous measurement and observation of volumetric uptake of water-borne preservative into wood samples throughout a controlled vacuum-pressure treatment process. Fractional filling of void space was calculated. Graphing (fractional saturation) against time allows prediction of optimum cycle lengths with respect to achievable saturation values. Treatability evaluations using this technique were carried out on heartwood samples of six Malaysian hardwood species, kapur, kempas, keruing, punah, rubberwood, simpoh and on sapwood samples of Scots pine as a control. Generally the graphs exhibited two quasi-linear zones showing rapid initial absorption followed by slow absorption over a long period.
A J Pendlebury, J A Petty


Improvement of liquid penetration of wood by precompression under appropriate conditions and recovery process
1993 - IRG/WP 93-40014
A new system for enhancing the penetration of liquid into wood using a precompression treatment was designed, and the effects of compressive deformation and recovery on liquid uptake were evaluated. Precompression of up to 60% under appropriate moisture and heat conditions effectively increased the penetration of liquid into refractory wood samples of practical sizes without producing any strength reduction. Water-saturated wood was compressed perpendicularly to the grain at temperature of 30 to 80°C, and two types of pretreated wood were prepared; i.e., set-recovered wood in which loading was released immediately after precompression, and preset-fixed wood which was dried under the influence of a decompressive force. The amount of liquid taken up by set-recovered wood was 2-3 times that taken up by untreated wood. When preset-fixed wood was dipped in liquid and the deforming force was released, liquid penetration was more than 25 times that seen in untreated softwood heartwood. Liquid effectively penetrated even long samples when pressure impregnation was applied to precompressed and preset-fixed wood. No significant reduction of strength was observed for treated wood except for that which had been precompressed up to 60%. Fracture of pit membranes during compression with little damage to unpitted cell-walls and an elastic recovery process were believed to improve liquid penetration with negligible compression defects.
I Iida, Y Imamura


Biocontrol of Reticulitermes santonensis by entomopathogenic fungi - Improvement of the contamination process
2000 - IRG/WP 00-10359
The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were selected for their potential to control the subterranean termite Reticulitermes santonensis. The research work aims to increase the mortality of termites by improving the contamination process inside a termite colony. The transfer of fungal spores from contaminated termites to a whole colony of termites was thus studied. In a first step, termite workers were contaminated by spores. Then they were introduced in a population of healthy workers at 10%, 25% and 50%. The tests showed that 25% and 50% of initially contaminated termites was sufficient to spread the spores among the healthy termites. The total mortality reached 100% within a few weeks. Experiments were carried out using the two entomopathogenic fungi and different methods of contamination. Results are discussed taking into account the possible development of a bait in the future.
I Le Bayon, D Ansard, C Brunet, S Girardi, I Paulmier


Innovations in the treatment of Southern pine heartwood
2000 - IRG/WP 00-40172
Whereas the sapwood of southern yellow pine (Pinus spp.) is readily treatable, the heartwood is essentially impermeable to preservatives such as chromated copper arsenate (CCA). Preliminary studies at the Mississippi Forest Products Laboratory indicate that increases in penetration and retention of preservative in pine heartwood can be obtained by subjecting kiln dried dimension stock to varying mechanical stresses using the patented TASK Process machine. The TASK Process machine incorporates varying levels of compression and/or vibration to mechanically stress lumber.
M G Sanders, T L Amburgey, H M Barnes


Methods of treatment of wood preservatives. The selection of appropriate preservation process with particular reference to mixed tropical forest resources. A key address
1982 - IRG/WP 3177
All wood is biodegradable. Many timber species have, however, sufficient natural durability to permit their use, particularly in protected situations, without any special precautions. Many others, of course, are readily attacked by insects and where there is sufficient moisture and air, by wood-decaying fungi. It is these timber species which benefit most from treatment with wood preservatives. Even the so called durables may also benefit so since all sapwood is perishable and durable heartwood in the sea or in ground contact eventually fails from attack by animals and/or micro-organisms. In recent years it has become apparent that for high hazard end uses it is necessary to consider the timber species/preservative type/treatment method as a single unit. It is of course possible, after accumulation of experience and test data, to group certain timber species into classes which can be processed together but until this has been established it is necessary to consider each and every timber species as a distinct biological entity which will respond differently to other timber species to preservative treatment. It has also been found that the most widespread treatment process, vacuum/pressure treatment, is inappropriate for many of the timber species available from the world's forests, particularly hardwoods. In ground contact, the commercially available preservatives do not provide the needed protection against fungal decay and in low hazard uses other preservatives and processes may be used more cost effectively for at least equally satisfactory results. In many temperate countries depletion of durable hardwoods led to wide use of perishable conifers in high hazard sites; wood preservation using tar oils or water-borne fixed preservatives applied by pressure improved these conifers so that in many uses they outlasted the best of the durable hardwoods. Thus, and rightly so, emphasis has been placed in most temperate countries on this approach, non-leachable preservatives applied by pressure to permeable coniferous wood. It is thus reasonable to assume that wood preservation has been very successful. Or has it? It depends on the approach made, and whether the objectives of those using wood preservation have been met. The selection of treatment methods depends heavily upon the objectives and the way successful wood preservation is gauged.
C R Levy


TBTO absorption and penetration in pine joinery treated by various processes
1989 - IRG/WP 3523
Matched sections of several White pine (Pinus strobus) and Ponderosa pine (Pinus ponderosa) mouldings were treated with TBTO by Double vacuum, modified empty-cell, 15 second dip and several preheating treatments followed by a 15 s dip treatments. As expected the double vacuum and empty-cell (batch) treatments resulted in much greater retentions and penetrations than the dip treatments. The absorptions by the 15 s dip treatments could be improved significantly by preheating the wood to 60-90C° by microwave, radio-frequency or infra-red techniques. Since this approach is amenable to a continuous treatment process, it is being evaluated for potential commercial application.
P A Cooper, Y T Ung


Resin bleed after light organic solvent preservative treatment - the effect of drying method and process type
1986 - IRG/WP 3378
The effects of drying method and treatment process type on resin bleed were investigated. High-temperature drying of resinous radiata pine (Pinus radiata D. Don) heartwood resulted in improved wood permeability, higher preservative uptake, and greater resin bleed when treated by the Rueping process. Resin bleed was reduced substantially when timber was treated by the Lowry process, and totally eliminated when Bethell-treated. The incorporation of 2% wax into the preservative formulation may control resin bleed after Rueping treatment.
P Vinden


Leaching of copper, chromium and arsenic from CCA-treated slash pine heartwood
1994 - IRG/WP 94-50020
Drying green slash pine with any of three high temperature drying schedules produced a product in which both the sapwood and the heartwood could be penetrated with CCA using a modified Bethell treatment schedule. Required H3 retentions were achieved in both sapwood and heartwood, from 200 litres per m³ charge uptake. Post-treatment fixation/drying was accomplished by three different regimes, including an accelerated fixation. Although acceptable preservative penetration and retention was achieved in the heartwood, arsenic fixation (as determined by both AWPA procedure E11-87 and U.S. EPA TCLP procedure) was inferior to that attained in the sapwood. TCLP leachates from 1 cm³ heartwood blocks contained up to 4.5 mg/l arsenic, very close to the maximum value (5.0 mg/l) currently permitted in Australia for arsenic waste disposal. Though there are clear advantages in achieving heartwood penetration, caution must be exercised to ensure that this step does not compromise the accepability of the product. No process modification could be accepted if it introduced possibilities of exceeding safe disposal limits for sawdust and offcuts, or building site contamination.
M J Kennedy, G Palmer


Preservative treatement of muli bamboo (Melocanna baccifera) by pressure process
2001 - IRG/WP 01-40194
This study was carried out in order to investigate the possibility of preservative treatment of split bamboo by pressure process. Whole bamboo is very difficult to treat by pressure process, which is the best and most dependable of all treating processes. Because it surface has a coat of impervious cutiular which make it very resistance to the penetration of liquid. Beside this it is prone to develop cracks under high pressure reducing strength to a greater extent. Split bamboo is used for different purposes. Generally muli bamboo (Melocanna baccifera) is used in splitting condition due to its strength and thickness. To find out the optimum schedule for the treatment of split bamboo, a number of schedule were carried out varying pressure and period. It was found that there was no significant variation with increasing pressure and period. It was observed that split bamboo can be satisfactorily treated by pressure process following a moderate treatment schedule with conventional water-borne preservatives.
K Akhter, M Younusuzzaman, M H Chowdhury


Effect of treatment process on performance of copper-chrome-arsenate. Part 2: Field stake tests
1995 - IRG/WP 95-40046
Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation stakes were installed in a randomised plot in the Whaka graveyard located on the FRI campus. Stakes were inspected at yearly intervals using AWPA M-10 standard procedure. After 5 years' exposure performance was strongly correlated with preservative retention expressed either as copper retention or total element (Cu+Cr+As) retention. Treatment process had very little effect on performance and confirmed results obtained from similar material exposed in fungus cellar tests. Implications of these results for commercial treatment operations are discussed.
M E Hedley, J Anderson, J B Foster, B E Patterson


Bending properties of TCMTB-treated Southern pine sapwood using supercritical carbon dioxide impregnation process
1997 - IRG/WP 97-40080
The effects of elevated pressure and treatment with thiocyanomethylthiobenzothiazole (TCMTB) on the bending properties of Southern pine sapwood were evaluated at pressures ranging from 1,800 to 3,600 psi. All bending properties were affected to some extent by supercritical fluid treatment. Modulus of elasticity and work to maximum load were not significantly affected by pressure levels. Modulus of rupture differed among individual pressure levels, but the effects on bending strength were less definitive. TCMTB retention had little or no effect on properties, suggesting a lack of chemical interactions between the lignocellulosic matrix and this biocide. The effect of treatment on bending properties was unexpected as previous trials on smaller specimens and selected composite panels had shown no negative effects. Further trials of other wood samples with increased replication are planned to more fully understand potential treatment effects on strength properties.
Gyu-Hyeok Kim, S Kumar, E S Demessie, K L Levien, J J Morrell


Next Page