Your search resulted in 622 documents. Displaying 25 entries per page.
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
Resolution from IRG Working Group II Sub-group 4 'Stain in timber in service'
1984 - IRG/WP 2230
Sub-group 4 of IRG Working Group II has completed a series of studies of artificial weathering as an alternative to natural weathering in relation to testing the efficacy of chemicals in preventing blue stain in service. The Sub-group reports that within the limits of the equipments studied and described in its report Document No: IRG/WP/2215 the extent of blue stain varied little as a direct cons...
D J Dickinson
Appearance of PEC-treated poles in service
1985 - IRG/WP 3323
Poles treated with conventional high temperature creosote (HTC) are banned for use in Australia by the major union handling them. Pigment emulsified creosote (PEC) is an acceptable alternative because it provides much dryer and cleaner commodities than does HTC. More than 5000 poles have so far been treated with PEC and many are being installed into service. The brown pigmented PEC 30 B has given ...
H Greaves, C-W Chin, K J McCarthy, J B Watkins
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
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
Termite and decay resistance of particleboard composed of white cypress pine and radiata pine
1997 - IRG/WP 97-10200
Phenol-formaldehyde bonded particleboard was manufactured from blends of non-durable radiate pine (P. radiate) and heartwood of the naturally durable species, white cypress pine (C. glaucophylla). Board specimens were subjected to bioassays using two termite species, M. darwiniensis and C. acinaciformis, and the basidiomycete fungi, C. puteana and P. ostreatus, and the durability of specimens was ...
P D Evans, J W Creffield, J S G Conroy, S C Barry
International comparison of three field methods for assessing the in-ground termite resistance of materials - highlights after two years
1999 - IRG/WP 99-20157
First-year results of a comparative study, evaluating the in-ground termite resistance of a range of materials, including CCA and ACQ-treated timbers, using the below-ground exposure, ground contact and graveyard methods against diverse termite faunas were provided in IRG/WP/98-20132. Further annual inspections have confirmed early trends and identified notable differences between sites and method...
M Lenz, J W Creffield, A F Preston, B M Kard, C Vongkaluang, Y Sornnuwat
Natural decay resistance of some lesser-used tropical hardwoods from Ghana
2002 - IRG/WP 02-10438
Ghana is a tropical African country that is rich in diverse timber species. In order to reduce over-exploitation of the popular timber species and increase the resource base for the wood industry, lesser-used or lesser-known timber species are being promoted locally and for export. To do this successfully, it is essential to determine the physical, mechanical and biological properties of these tim...
S A Amartey, F R Hanson
Properties of plywood and Oriented Strand Board manufactured with an organic insecticide incorporated in the adhesive formulation
2000 - IRG/WP 00-40174
The efficacy of Fipronil as an insecticide has been established by laboratory and field experiments and commercial use against a broad range of insect pests for various crops. It can be used by either foliar or soil application. Development is underway for the non-agricultural uses of fipronil. Research is ongoing for the control of ants, cockroaches, fleas, ticks, houseflies, mosquitoes, termites...
D P Kamdem, J H Hope, A Jermannaud
Decay and mold resistance of borate modified oriented strandboard
2003 - IRG/WP 03-40260
Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified
oriented strandboard (OSB) from southern mixed hardwoods and yellow pine was investigated in this study. Tests were done with brown rot, Gloeophyllum trabeum, and white-rot, Trametes versicolar, fungi for 8 and 12 weeks, respectively. Wood species and fungus type had significant influence on the decay resistance. Decay...
Q Wu, S Lee, J P Jones
Natural exposure weathering tests: Their role in the assessment of wood preservative efficacy
1993 - IRG/WP 93-20006
Previous work has demonstrated the potential and usefulness of natural ageing procedures in e evaluation of wood preservative efficacy. This results from the combination of physico-chemical influences and microbiological interactions with both substrate and wood preservative. In this paper, results are presented for a range of biocide types. Discussions are centred on the value of natural exposure...
G R Williams, J Brown
A new technique for testing decay resistance of framing lumber
2002 - IRG/WP 02-20247
Model house frame units (two studs, top and bottom plates and a central “dwang”) were constructed using short (500-600 mm) lengths of framing timber. Constructed frames were impregnated with water using a mild pressure schedule to raise the initial moisture content to 35-40 % mc. The back face of each unit was then covered with black polyethylene. Two locations at the stud/dwang and stud/botto...
M E Hedley, D Page, B E Patterson
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
Correlation between changes in colour and chemical composition during photo-degradation of wood surfaces
2005 - IRG/WP 05-40301
Changes in colour of wood (yellowing) during photo degradation or weathering reflect chemical changes in wood. Therefore, the relationship between changes in chemical composition and CIELAB colour parameters is very important to characterize photodegradation of lignocellulosic surfaces. In this study, the changes in chemical composition and yellowing due to photo-degradation was studied by expos...
K K Pandey
Evaluating the natural durability of native and tropical wood species against Reticulitermes flavip
2004 - IRG/WP 04-10539
Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to all related problems. There...
R A Arango, F Green III, K Hintz, R B Miller
Improvement of some technological and biological properties of poplar wood by impregnation with aqueous macromolecular compounds
1992 - IRG/WP 92-3721
Poplars (Populus spp) belong to the most important tree species in afforestation programs of the Netherlands. Due to their rapid growth, the wood quality is usually low. Therefore, studies were performed to elucidate whether some technological properties and the resistance against fungal attack could be improved by impregnation with water-soluble resins. The results showed that swelling and shrink...
R D Peek, H Militz, J J Kettenis
Improvement of wood decay resistance by tannin impregnation
1991 - IRG/WP 2380
The fungical effect of tannins is appraised after exposure of treated woods samples to wood rotting fungi. A screening-test is carried out with several solutions containing extracts of two kinds of tannins; a condensed tannin derived from Quebracho heartwood (Schinopsis sp.) and a hydrolyzable one extracted from chestnut heartwood (Castanea sativa Mill). If a fungicidal action was indeed found it ...
D Dirol, A Scalbert
Decrease in the mechanical resistance of blue stained and "orange stained" Pinus radiata wood
1999 - IRG/WP 99-10313
It is recognised that sapwood attacked by Ceratocystis pilifera increases its permeability to pressure preservative treatments. Since hiphae not only utilise pits, but also the cell wall for crossing from one cell to another, the mechanical resistance of the stained wood might be affected. The orange colour very commonly present in Pinus radiata logs heartwood under water sprinklers, has not recei...
M C Rose, L Reyes, J Alvarez, A Andaur, C Beltran, D Rivera
Fungal-termite associations in the natural resistance of selected eucalypt timbers
1978 - IRG/WP 173
Butt billets of Eucalyptus regnans F. Muell., Eucalyptus grandis W. Hill ex Maiden, and Eucalyptus camaldulensis Dehnh., showing no visible signs of decay, were examined for the presence of fungi in outer, middle and inner heartwood. Fungi obtained in pure culture were characterized. Eucalyptus regnans yielded Cytospora eucalypticola van der Westhuizen, Trichoderma harzianum Rifai and Penicillium ...
D B A Ruyooka
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Biological resistance of aldehyde-treated wood
1994 - IRG/WP 94-40018
Biological resistance of wood treated with aldehyde cross-linking agents such as glyoxal, glutaraldehyde and dimethylol dihydroxy ethyleneurea (DMDHEU) were investigated. Sapwood blocks of Japanese cedar and Japanese beech, measuring 20 x 20 x 10 mm³ (T x R x L), were vacuum-impregnated at room temperature with 5-25% of aldehyde solutions. Blocks were kept in the solution for 1 week to gain the o...
S Yusuf, Y Imamura, M Takahashi, K Minato
Marine exposure assessment of the natural resistance of a number of lesser known species of tropical hardwoods to teredinid and limnoriid borers
2004 - IRG/WP 04-10520
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, candidate timber species were selected for testing in the sea on the basi...
J R Williams, S M Cragg, L M S Borges, J D Icely
The influence of copper (II) chemicals on the weathering of treated wood. Part 1: ACQ treatment of wood on its weathering
1994 - IRG/WP 94-30040
Wood weathering can be accelerated by alkylammonium compound (AAC) treatment, and slowed by ammoniacal copper quat (ACQ) treatment. This study aims at investigating the influence of ACQ treatment of wood, especially the present of copper (II), on its weathering. ACQ, CCA and DDAC treated microtomed sections of southern yellow pine earlywood were prepared and naturally weathered for five periods, t...
Ruiying Liu, J N R Ruddick, L Jin
Effect of Scytalidium lignicola on decay resistance and strength of wood
1994 - IRG/WP 94-10061
We reported previously that in laboratory tests, pretreatment of Douglas-fir and Southern Pine blocks with Scytalidium lignicola prevented decay. In the present work, we determined 1) the ability of Scytalidium lignicola to colonize and survive in wood exposed in the field, 2) the decay resistance of blocks removed from previously treated Scytalidium lignicola wood and 3) the effect of Scytalidium...
T L Highley
Preliminary results of the treatment of wood with chlorosilanes
1981 - IRG/WP 3172
It is clear from the initial data reported here that the treatment of pine sapwood with chlorosilanes under the reaction conditions employed did not significantly reduce the decay by both white rot and brown rot fungi. Only the dichlorosilane compounds showed to possess some protective action against fungal attack. Before drawing conclusions on the application of organosilicon compounds as potenti...
M Stevens