Your search resulted in 576 documents. Displaying 25 entries per page.
Leachability of borate-modified oriented strandboard: A comparison of zinc and calcium borate
2002 - IRG/WP 02-40232
The leachability of boron in zinc and calcium borate-modified oriented strandboard (OSB) was investigated in this study. The leaching experiments were conducted by exposing edge-sealed OSB samples under running water for 8, 24, 72, and 216 hours. The results were compared with those from the unleached controls. Boron leaching of the modified OSB occurred upon the initial water exposure, and the le...
S Lee, Q Wu
Highly virulent wood-rotting Basidiomycetes in cooling tower timbers
1995 - IRG/WP 95-10125
Over the past ten years most industrial cooling towers changed their water treatment systems in order to meet environmental requirements. Since this alterations wood rot attack has been reported more frequently. Several Basidiomycete fungi were isolated and determined. Amongst the most important ones are strains of Physisporinus vitreus (Pers.:Fr.) P. Karst., Phellinus contiguus (Fr.) Pat. and Don...
J Van Acker, M Stevens, V Rijckaert
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 20: Report on the inspection of specimens at Sekondi, Ghana after 48 months
1985 - IRG/WP 4116
The results of the second inspection of CCA- and CCB-treated test panels exposed at Sekondi, Ghana, in June 1980, are presented. The panels of Pinus sylvestris treated with 3% CCA are stil unattacked after 48 months. Panels treated with 10% CCA and still in test (Fagus sylvatica, Pinus sylvestris and Alstonia scholaris) are still free of attack. Locol species treated with 3% CCB have all been dest...
F F K Ampong, N Asare-Nyadu
The use of pyrethroids against Limnoria spp
1981 - IRG/WP 473
Synthetic pyrethroid insecticides discovered in the last fifteen years have been developed as crop sprays and used in aerosol formulations for the control of household pests. High toxicity to a wide range of arthropod pests, combined with reasonably low mammalian toxicity, confers an advantage over many other control agents. Some of the more recent pyrethroids are photostable and display residual ...
D Rutherford, R C Reay, M G Ford
Novel wood modification processes for window and cladding products
2004 - IRG/WP 04-40285
Because of the low natural durability and low dimensional stability of European wood species, the usage of wood for window frames has decreased dramatically during the last decade. In a joint project of several German research institutes and the window industry, following wood modification systems were compared.
heat treatment (3 different materials from 2 companies)
acetylation (pine sapwood an...
A Krause, C Hof, H Militz
IRG/COIPM INTERNATIONAL MARINE TEST - to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water. Progress Report 4: Report of second inspection (12 months) in Australia
1979 - IRG/WP 448
Previous reports have presented full details of the treatment and installation of the test specimens in Sydney Harbour during December, 1977, and of the results of the first (6 months) inspection made during June, 1978. At the June inspection it was apparent that the plastic tubing used to make up the frames from which to suspend the specimens was inadequate for the job and not strong enough to su...
J Beesley
Estimation of effective diffusion path lengths in wood by swelling studies
1989 - IRG/WP 3524
The effective average distance that a solute must diffuse to penetrate the cell wall matrix following pressure treatment is estimated from the rate of swelling of wood, vacuum treated with water. It is assumed that the diffusion paths are similar for water and a solute such as a wood preservative component. Since bound water diffusion coefficients for water in wood have been estimated by others, t...
P A Cooper, R Churma
Chemical analyses of IRG/COIPM INTERNATIONAL MARINE TEST (to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water) samples
1987 - IRG/WP 4114
Chemical analysis of CCA and CCB treated timber was carried out after exposure at tropical and temperate marine sites. Results indicated that losses of all elements had occurred. In particular, losses of boron were severe. Arsenic and copper were also lost. The chromium components in both formulations was the most dominant metal remaining. The results suggest that chromium modification was importa...
L E Leightley
The performance of water repellants on radiata pine exposed to the weather
1989 - IRG/WP 3553
The effectiveness and resistance to weathering of four water repellent treatments, a commercial timber stain, and an oil-based clear finish, was assessed using 20x20x6 mm³ samples of untreated, copper-chrome-arsenic (CCA)-treated, and tributyltin oxide (TBTO)-treated radiata pine exposed to the weather over a four month period. The water repellency of each preservative/water repellent combination...
D V Plackett, F M Cameron
Initial microbial colonisation of CCA-treated, creosote-treated and untreated Pinus sylvestris L. blocks in seawater
1996 - IRG/WP 96-10171
CCA-treated, creosote-treated and untreated Pinus sylvestris sample blocks were immersed in a seawater through-flow system for periods of between 1 and 265 hours. Samples were fixed immediately on removal and examined both qualitatively and quantitatively using the scanning electron microscope. This study of primary microbial colonisation showed differences between treatments in the diversity of m...
K Sturgess, A J Pitman
Acceleration of the fixation of chromated wood preservatives by UV-radiation
1989 - IRG/WP 3544
Preliminary laboratory tests demonstrated that the fixation of chromated water-borne wood preservatives may be accelerated by UV-radiation. The degree of fixation depends on the intensity of radiation and the prevailing temperature. Three hours radiation at 20°C in a device for artificial weathering diminished the leaching of chromium to 43% and of copper to 23% compared to not-radiated samples. ...
H M Illner, H Willeitner, K Brandt
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...
Gyu-Hyeok Kim, S Kumar, E S Demessie, K L Levien, J J Morrell
Soil-bed studies. Part 2: The efficacy of wood preservative
1983 - IRG/WP 2205
Various methods of decay assessment were investigated. Three stages or phases of decay were identified which could be used to describe the efficacy of a preservative system or virulence of a soil-bed testing medium. These included the lag, decay, and senescent phase. Premature senescence could arise if wood samples became waterlogged. It was concluded that time to failure was unsuitable as a metho...
P Vinden, J F Levy, D J Dickinson
Comparative moisture uptake of Douglas fir and radiata pine structural lumber when exposed to rain wetting as an indicator of relative decay resistance
2004 - IRG/WP 04-20285
Trials were undertaken to determine the relative resistance of radiata pine and Douglas-fir to wetting when exposed to the weather.
Douglas-fir samples were obtained from one Central North Island and three South Island sources and had a heartwood/sapwood mix typical for each resource. Radiata pine sapwood and heartwood samples were obtained from a Central North Island source. Material was exposed...
M E Hedley, G Durbin, L Wichmann-Hansen, L Knowles
Impregnation of roundwoods by sap-displacement in Madagasca
1975 - IRG/WP 352 E
The use of roundwoods is already very important in Madagascar and steadily increasing for the following applications: - posts, electricity and telephone line supports (medium voltage) - stakes, piles for civil engineering structures, bridges, gantries, road and port works, etc. - construction of houses (posts, frameworks, piles, etc.) and rural buildings (sheds, stables, piggeries) - fence posts, ...
M Fougerousse, P Guéneau
Anatomical Characteristics to the Distribution of Water-borne Copper Wood Preservatives in Wood
2004 - IRG/WP 04-40277
The objective of this study was to understand the micro-distribution of a copper-based preservative in wood in connection with anatomical morphology and to consider the fixation of copper in wood. Bulk specimens and semi-ultra thin sections (0.5µm) obtained from Japanese cedar were treated with a CuAz preservative solution. After fixation, SEM-EDXA was used to investigate the micro-distribution...
H Matsunaga, J Matsumura, K Oda
Moisture condition in treated wood exposed outdoors. A progress report
1989 - IRG/WP 3533
Wood treated with water-borne preservatives, mainly CCA (copper/chromium/arsenic), CCB (copper/chrome/boron) or CC (copper/chrome) is often said among users in Sweden to absorb more water than untreated wood. In laboratory tests this statement has not been confirmed but no field tests have been carried out in Sweden to study this phenomenon. In 1986 a project was started to compare water absorptio...
M-L Edlund, C E Sundman
Durability of surface preserved wood particle boards submitted to atmospherical influence
1995 - IRG/WP 95-40039
The worldwide problem of the continuously growing deficit of high quality natural wood material has caused the attempts of many research workers to find effective composites such as wood particle boards (WPBs) for replacing the massive wood for constructive purposes, depending on where the boards are exploited - in the open or under a shed, they are submitted to various climatic factors such as he...
L Valcheva
Dip-diffusion of dressed timber - Effect of drying
1989 - IRG/WP 3509
The effect of drying on dip-diffused dressed freshly sawn timber was determined by the depth of penetration of boron achieved on the two test timber species, White cheesewood (Alstonia scholaris) and Light Hopea (Hopea papuana). The results obtained showed that light density White cheesewood was completely penetrated even after 3 days drying while Light hopea, treated immediately achieved 5.2 mm p...
H C Konabe
The effect of wick action on the moisture distribution in heartwood and sapwood stakes of Pinus radiata D. Don.
1999 - IRG/WP 99-40139
The pattern of moisture distribution in stakes of Pinus radiata D. Don. subjected to "wick action" is investigated. There was incomplete saturation of the stakes even after 93 days of continual soaking. Maximum moisture absorption occurred at the base of the stake and at the air/water interface of the stake. Incomplete saturation of the stake was thought to be due to air embolism within the wood. ...
J Hann, P Vinden
The colonization of selected naturally durable timbers by marine fungi and borers
1977 - IRG/WP 439
In recent years, concrete and metal have been widely substituted for wood in contact with sea water, but wood products have not lost their usefulness under such conditions. In many cases, wood if sound and durable, may prove to be the most practical and economical of materials used in sea water exposure. Timber when immersed in the sea may be attacked by micro-organisms (bacteria and fungi) and ma...
S E J Furtado, E B G Jones
Changed permeability and surface properties of hornbeam wood due to its degradation by erosive strain of Phanerochaete chrysosporium
2004 - IRG/WP 04-40290
Specimens of hornbeam wood were submitted to a medium-term degradations by erosive fungus Phanerochaete chrysosporium. Biodegradations of specimens resulted in their apparent structural alterations, changes in permeability and increased intensity of interactions with polar liquids. Modified physical properties of biodegraded wood may significantly influence its penetration with polar media and che...
R Solár, S Kurjatko, L Reinprecht, M Mamon, V Vacek
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
Some experiences with attack of microorganisms on wooden constructions supporting foundations of houses and bridges
1997 - IRG/WP 97-10232
Reconstructions of bridges and public buildings or damage of houses during the construction of subway lines in Berlin have led to a number of inspections of wooden foundations, mostly pine or spruce piles, representing service lives of between ca. 70 and 140 years. In all cases bacterial attack was found both in wood submerged in ground water and in surface water. The extent of deterioration diffe...
M Grinda
Preservative treatments of window components with a water-based borate formulation
2000 - IRG/WP 00-40171
Factory finished window joinery components were treated with an aqueous borate preservative in order to investigate penetration and retention levels, associated drying times; and the potential impact of using a water-based treatment on finished items. It was found that by using borates applied by light double vacuum schedules, it was possible to meet standards for penetration and retention, to air...
J Jermer, J D Lloyd