Your search resulted in 781 documents. Displaying 25 entries per page.
Microwave conditioning of Pinus radiata D. Don for preservative treatment
2000 - IRG/WP 00-40182
This paper reviews the effect of pressure steam conditioning on the permeability and treatability of green radiata pine heartwood and the potential for substituting microwave conditioning for steaming. The penetration of liquids into radiata pine occurs mainly in the radial tissue. The permeability of green radiata pine improves following steam conditioning by blowing out the soft radial tissue. T...
P Vinden, G Torgovnikov, J Romero
Sampling rates and the probability of detecting defective treatment in the sampling of preservative treated timber
1987 - IRG/WP 2277
When attempting to enforce standards of penetration and retention set for treated timber, the regulating authority must establish a sampling or inspection scheme which will prevent large quantities of substandard product entering the market. On the other hand, the scheme should not penalise treaters for the small quantities of such material which are inevitably produced by any industrial process. ...
M J Kennedy, L E Leightley
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
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
Resistance of painted wood to mould fungi. Part 2. The effect of wood substrate and acrylate paint systems on mould growth
1997 - IRG/WP 97-10234
Resistance of acrylate paint systems on different types of pine and spruce sapwood to mould fungi was studied. Dipping into the preservative prior to painting, a primer with and without a fungicide (propiconazole + IPBC 0.50 + 0.2%) and a topcoat with and without a fungicide (propiconazole + IPBC 0.25 + 0.12%) were combinations of the treatments studied. The efficacy of the treatment systems varie...
H Viitanen, P Ahola
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Practical consequences of the clarification of the chemical mechanism of CCA fixation to wood
1983 - IRG/WP 3220
Practical consequences derived from the chemical investigation of the mechanism of fixation of CCA to the wood constituents are discussed. Among these, formulas for the calculation of the time of hexavalent chrome fixation are presented. Furthermore, three parameters are shown to be important to the long-term effectiveness of CCA-treated timber: (i) the temperature of treatment, (ii) the initial p...
A Pizzi
Serviceability modeling-Predicting and extending the useful service life of FRT-plywood roof sheathing
2000 - IRG/WP 00-20210
One of the most, if not the most, efficient methods of extending our existing forest resource is to prolong the service life of wood currently in-service by using those existing structures to meet our future needs (Hamilton and Winandy 1998). It is currently estimated that over 7 x 109 m3 (3 trillion bd. ft) of wood is currently in service within the United States of America (PATH 1999). Research ...
J E Winandy
Recent developments in the treatment of sawn spruce by double vacuum impregnation
1978 - IRG/WP 3114
The timbers used for building purposes in the U.K. and on the Continent of Europe are mainly softwoods. The two types of wood most used are redwood (Pinus sylvestris) and whitewood (Picea abies or Picea sitchensis). Other species are used to a lesser extent when considerations such as a long length requirement or width requirement demand the use of, for example, hemlock, Douglas fir or Parana pine...
C T Kyte, L D A Saunders
The treatment of sawn whitewood with organic solvent wood preservative
1982 - IRG/WP 3192
The impregnation schedules approved in the UK for the treatment of sawn European whitewood (Picea abies) with organic solvent borne preservatives result in comparitively high loadings relative to the limited depth of penetration they achieve. Results are presented, which show how substantial reduction in the overall loading may be achieved without concomitant reduction in penetration. A model for ...
L D A Saunders
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
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples...
P D Evans, P D Thay, K J Schmalzl
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
Incorporation of phenyl boronic acid treatment with vapor phase formalization
1997 - IRG/WP 97-40083
Phenylboronic acid (PBA) treatment was incorporated with vapor phase formalization (VPF) in order to increase dimensional stability and boron fixation as well as enhancement of biological resistance. Five and ten hours VPF were applied after PBA treatment as 0.34, 0.50, 1.00 and 2.00% concs. aqueous solutions. Anti swelling efficiency (ASE) attended to 71% in specimens impregnated with 0.50% PBA s...
M K Yalinkilic, S Yusuf, T Yoshimura, W-Y Su, K Tsunoda, M Takahashi
Surface Barriers for Protection of Culture and Heritage Wooden Objects from Insect Attack
2004 - IRG/WP 04-20286
Anoxic treatment is an environment friendly procedure for eradication of wood boring insects in wooden objects of cultural and historical heritage. However, after the anoxic treatment, wooden antiques remain susceptible to further insect attacks. Possible protection against insects could be provided by the so-called post-repression protective barriers. Potential coating materials for such barriers...
M Petric, M Pavlic, B Kricej, M Humar, F Pohleven
Safe application of copper-chrome-arsenate preservatives
1975 - IRG/WP 377
All wood preservatives contain biologically active substances and must, by design, be in some measure toxic to man. There is nothing fundamentally difficult, however, about using a wood preservative with complete safety. It depends on knowing the risks to health and/or the environment, which the preservative may present, and planning application accordingly. In this paper we examine these and othe...
I N Stalker, P B Cornwell
Development of a turbidity method for the determination of water repellent in CCA treatment solutions
2000 - IRG/WP 00-40177
The use of aqueous water repellent emulsion formulations has increased significantly in the wood treatment industry. These are primarily used to enhance the weathering characteristics of wood products treated with water borne preservatives systems used in exterior above ground exposures. However, they are also used in pole treatments to improve the climbing characteristics and in low VOC millwork ...
P J Walcheski, L Jin
Improving the weather resistance of glue-laminated jarrah and karri
1994 - IRG/WP 94-40017
Surface modification and dimensional stabilisation significantly increased the dry and wet shear strength of karri and jarrah lap-shear specimens (laminates) bonded with resorcinol formaldehyde. The combination of surface modification (sanding/sodium hydroxide treatment), and furfurylation produced the highest dry and wet shear strengths. Acetylated laminates had the lowest dry bond strength, but ...
J Balfas, P D Evans
Laboratory evaluation of borate formulations as wood preservatves to control the subterranean termite coptotermes acinaciformis (isoptera: Rhinotermitidae) in Australia
2001 - IRG/WP 01-30266
The termiticidal efficacy of Borocol (sodium octaborate tetrahydrate), boric acid, bore-ester-7 and tri- methyl borate was evaluated in laboratory bioassays against Coptotermes acinaciformis (Froggatt). Seasoned sapwood blocks of Pinus radiata D. Don, and Eucalyptus regnans (F. Muell) were impregnated with the various borate compounds. There were marked differences in mass loss and mortality rate ...
B M Ahmed, J R J French, P Vinden
An inclination incising technique for the preservative treatment of refractory timbers
1991 - IRG/WP 3664
An inclination incising technique for preservative treatment of refractory timbers was examined by changing cutting angle to the longitudinal direction of test specimen and by using different types of knife edge. Incised wood were impregnated locally into incisions with CCA solution by the specified local pressure process. Width and length of penetration areas of CCA solution were measured on long...
Y Nakamura, K Nishimoto
A technique for determinging the efficacy of wood preservatives for partially treated timber
1988 - IRG/WP 2322
A technique is described for determining the efficacy of wood preservatives either for certain wood species where a full penetration cannot be achieved by normal vacuum-pressure methods or for more permeable species to look at efficacy of treated zone in preventing decay of an untreated core. Both sapwood and heartwood planks of spruce (Picea abies) and pine (Pinus sylvestris) were treated by CCA ...
A J Nurmi
The efficacy of Sentry® as a treatment for the control of sapstain in pre-infected radiata pine
2001 - IRG/WP 01-30260
Experiments were conducted to determine the efficacy of Sentry® when used to control sapstain fungi on radiata pine branch billets stored under high fungal hazard conditions. Prior to antisapstain treatment, the billets were pre-infected with a mixed inoculum of staining fungi and held from zero to 10 days at 25°C and 75% relative humidity. This was done to produce billets with different degrees...
C Chittenden, J G van der Waals, B Kreber, R N Wakeling
Investigation on different variation factors in the results of mycological test and means to reduce and avoid them
1986 - IRG/WP 2264
In order to clarify the causes of the dispersion observed in the results obtained with mycological tests made in accordance with standard EN-113, different factors assumed to be sources of the variations were studied. These included the moisture content of the test samples during the test, the influence of certain technological properties of the wood, the virulence of the fungus strains, the metho...
D Dirol
Treatability problems - Relationships between anatomy, chemical composition and treatability
2001 - IRG/WP 01-40213
This report documents the results of phase 1 and 2 of a 3-phase research program. In phase 1, two hundred and fifty-six (256) Southern pine (pinus spp.) nominal 2 x 6's (38 mm x 140 mm) from a single mill in Georgia (southeastern US) were evaluated for treatability with CCA preservative. After treatment, 128 pieces representing a broad range of treatment characteristics were selected and ...
J E Winandy, F Green III, D Keefe
Durability of Wood Plastic Composites Relative to Natural Weathering and Preservative Treatment With Zinc Borate
2005 - IRG/WP 05-40316
Wood-Plastic Composites (WPCs) used for decking have experienced dramatic increases in North America, averaging 25% growth per annum since 1998. A key factor contributing to this growth has been the successfully communicated message that they are "virtually maintenance free". The common perception being that the wood fiber is completely encapsulated by the thermoplastic resin, minimizing the pot...
M E Mankowski, F M Ascherl, M J Manning