Your search resulted in 103 documents. Displaying 25 entries per page.
The dip diffusion treatment of tropical building timbers in Papua New Guinea
1972 - IRG/WP 310
In Papua New Guinea a dip diffusion process using a multi salt preservative developed by C.S.I.R.0. has been in commercial use for 8 years. Over 200 million super feet (236,000 m³ ) of timber has been treated during this period and current rate of treatment is 34 million super feet (80,400 m³ ) of timber per year in 70 licenced treatment plants. The process has been found to be simple to apply, ...
C R Levy, S J Colwell, K A Garbutt
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
Wood preservation in Kenya
2000 - IRG/WP 00-40190
Focussing an Wood Preservation in Kenya, the Report discusses and elaborates on Education and Training, Research, Wood deteriorating organisms, Treatment Plants and Processes, Preserving Chemicals, Specifications, Markets, Health and Safety and Environmental issues. Education and Research is limited to one Institution only, other Institutions involved with the properties and utilization of wood ha...
R Venkatasamy
Threshold levels for dip treatments of chlorpyrifos for borer control
1995 - IRG/WP 95-10137
Chlorpyrifos has been used in non-pressure treatments of freshly sawn lumber and millwork for ten years or longer to control wood boring beetles. Since chlorpyrifos provides a quick kill of existing beetle larvae at the time of the treatment in solution concentrations as low as 0.05%, treaters tend to use less than recommended rates as a cost saving measure. However, laboratory studies conducted i...
R D Fears, J L Leca
Effects of surfactants and ultrasonic energy on the treatment of wood with chromated copper arsenate
1977 - IRG/WP 3108
Sugar pine stakes 1'' x 1" x 16" were treated by a hot-water bath followed by soaking in cold CCA solution for 10 to 30 minutes. A similar number of stakes were treated by a cold-cold bath. Half of the stakes were subjected to ultrasonic energy during the CCA bath. The mean absorption for stakes given the hot-cold bath was 18.52 pcf (297 kg/m³) and 4.64 pcf (74 kg/m³) for those...
C S Walters
Long-term efficacy of wood dip-treated with multicomponent biocides
2005 - IRG/WP 05-30379
Biocides designed for prevention of indoor mold growth on wood-based materials need to provide long-term protection under conditions of high humidity. Specimens of kiln-dried southern pine and unseasoned southern pine, aspen, and Douglas-fir were dip-treated with borate-dimethylcocoamine (DMCA) supplemented with voriconazole, thiabendazole, or thujaplicin and evaluated at 4-week intervals for inhi...
C A Clausen, V W Yang
Strength properties of preservative treated pine and spruce wood after super-heated steaming
1984 - IRG/WP 3313
Possible changes of strength properties of CCF pressure impregnated pine and spruce with subsequent steaming at 110°C respective 120°C for 30 min were examined. For spruce analysis of variance indicated that none of the processes had a significant effect on bending strength, compression strength and the corresponding modulus of elasticity as well as on impact bending strength and shear strength ...
R-D Peek
Limiting Conditions for Decay in Wood Systems
2002 - IRG/WP 02-10421
Hygrothermal models can predict temperature and moisture conditions in wall components subjected to real weather data, but specific data and a fundamental understanding of how temperature and wood moisture content dictate the progression of decay under these conditions is required for modellers to predict consequences of decay on building performance. It is well understood that wood will decay abo...
P I Morris, J E Winandy
Boron treatment methods for lyctid susceptible hardwoods growing in Tasmania
1998 - IRG/WP 98-30168
A survey of existing boron plants that treat to protect hardwoods from attack by lyctids in Australia showed that hot and cold bath, and vacuum pressure impregnation (vpi), were the two most common methods employed. In experimental work, two of the treatment methods, vpi and dip diffusion, were used to treat seasoned and green messmate (Eucalyptus obliqua) and blackwood (Acacia melanoxylon). The t...
L J Cookson, D Scown, K McCarthy
Dip-diffusion of dressed timber - Effect of drying
1990 - IRG/WP 3603
The effect of drying on BFCA dip-diffused, dressed, freshly sawn timber was determined by the depth of penetration of boron achieved on two test timber species, White Cheesewood (Alstonia scholaris) and Light Hopea (Hopea papuana). The results obtained showed that the light density White cheesewood was completely penetrated even after 3 days drying while Light Hopea, treated immediately achieved 5...
H C Konabe
Influence of felling time on the natural durability of norway spruce (Picea abies (L.) Karst.)
1998 - IRG/WP 98-10250
Natural durability was tested in a laboratory test according to EN 113. The test fungi were Coniophora puteana and Poria placenta. Additionally, the test method was modified by using water agar instead of malt agar, so that wood was the only nutrient source for the fungi. In a third attempt the samples were inoculated with Trichoderma harzianum before testing.
The trees were felled on the 22.7.97...
M Hirmke, K Messner, J Fellner, A Teischinger, R Wimmer
Aspects of leaching
1976 - IRG/WP 267
With respect to Document No: IRG/WP/246, and the recommendation that an economic leaching test can be based on a non-changing volume of water (500 ml/block), I would like to relate our experiences with this suggestion. Following 14 days of continuous immersion in de-ionized water it was found that blocks treated with moderate and above concentrations of a preservative gave no problems, but those b...
R S Smith
Preservative treatment of green timber by diffusion
1984 - IRG/WP 3291
The preservative treatment of green timber by diffusion is reviewed together with criteria which influence the economics of the process. New process options are described which should overcome some of the technical and economic disadvantages of double diffusion. These include the use of coagulating agents which increase the viscosity of the preservative solution and facilitate treatment by momenta...
P Vinden
Models of the critical time of humidity and temperature conditions for the development of mould fungi in pine and spruce sapwood
1995 - IRG/WP 95-20066
Regression models of the time factor for the growth of mould fungi in pine and spruce sapwood are studied. The first group of models are based on the results of exposures of mould fungi in static humidity and temperature conditions indicating the time for the start of mould growth in wood. The second group of models are based on the exposures of mould fungi in fluctuating or alternating humidity a...
H Viitanen
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative c...
S-E Dahlgren
Non-destructive detection of the presence and behaviour patterns of wood-destroying insects
1988 - IRG/WP 2302
An apparatus, designed for the automatic recognition of the presence and of specific behaviour patterns of wood-boring insects, is introduced. From a wood sample, a mixture of noise and action induced substratum vibrations is picked up, amplified, filtered and translated into a sequence of computer-readable numbers which are passed to a microcomputer-based signal-pattern-recognition. If an incomin...
M Pallaske
Preservative treatment of wood by diffusion processes - Simulation of commercial treatment processes
1988 - IRG/WP 3498
Spruce (Picea abies), Scots pine (Pinus sylvestris) and birch (Betula pendula) were preservative treated by diffusion with mixtures of copper sulphate and arsenic pentoxide. The preservative was fixed after a suitable diffusion storage period by soaking in ammonia solution. A high standard of treatment could be achieved in spruce sapwood. This was attributed to its low wood density, and high wood ...
P Vinden
Time limits for holding logs to achieve successful antisapstain treatment
1997 - IRG/WP 97-30126
The purpose of these trials was to determine the maximum time that logs can be left in winter and summer before treatment if sapstain, caused by pre-treatment infection, was to be prevented. Pre-treatment storage conditions representative of average temperature and humidity for the winter months of June, July and August, and of moderately severe summer conditions, for the Bay of Plenty, New Zealan...
D R Eden, R N Wakeling, C M Chittenden, J G Van der Waals, B Carpenter
Accelerated diffusion treatment of sawn Sitka spruce grown in the UK
1986 - IRG/WP 3395
The treatment of 'green' sapwood and heartwood of Sitka spruce by diffusion methods was investigated. Steam/dip treatment processes gave increased solution uptakes and depths of penetration of copper in comparison with a simple dip treatment. Further investigation is required to reduce diffusion gradients with copper based formulations and to improve the penetration of '...
R J Murphy, D J Dickinson
Field fencepost test of several species treated with water-borne preservatives by rural methods
1986 - IRG/WP 3385
Fencepost field results in ground-contact treated by rural methods: immersion-diffusion and sap displacement by evaporation are analyzed. Copper-chrome-arsenic and copper-fluor-chrome preservatives were used in two concentrations. The wooden species studied were: Pinus pinaster, Eucalyptus globulus and Quercus rubra. For each of the test units decay index evolution was analyzed after five years ex...
M V Baonza Merino
Potential for using dip/supercritical fluid treatments for wood impregnation
2004 - IRG/WP 04-40276
While supercritical fluid impregnation offers tremendous potential for impregnating wood species that resist conventional liquid preservative treatments, the resulting treatments are often not uniform among samples in a charge or between charges. One factor that influences treatment is the dynamic change in pressure that occurs during introduction of the biocide laden supercritical fluid into the ...
Sung-Mo Kang, J J Morrell
Appendage-mediated attachment in spores of lignicolous marine fungi
1982 - IRG/WP 487
The role of appendages in aiding attachment and entrapment of marine fungal spores to wood substrata is described in this paper. Scanning electron microscope (S.E.M.) observations indicated five different classes of attachment or entrapment response in the sixteen species examined. These responses varied -hith the degree to which appendages attached or entrapped spores to wood surfaces. In additio...
G Rees
Dip diffusion treatments in the tropics. A preliminary report
1973 - IRG/WP 316
Diffusion treatments based on the use of boric acid alone or in combination with other preservatives are widely used in Australasia (see IRG/WP/310). As part of a general survey covering both temperate and tropical countries, a survey of diffusion treatments in South East Asia, Southern Asia and the South Pacific was carried out, and the results of this survey are reported here. The survey is far ...
C R Levy
NMR T1 relaxation time as a non-destructive method for the study of decay in wood
1992 - IRG/WP 92-2406
The NMR spectroscopic technique of measuring the T1 spin-lattice relaxation times has been investigated for its potential in the detection of microbial decay in wood. The T1 NMR analyses were carried out on samples of Scots pine and European beech that had been exposed to decay and non-decay fungi representing each of the important groups colonising wood. Decay in the test material was also assess...
P W McCormack, A E G Cass, R J Murphy
The lasting dehydration of wood treated by bifluorides worked up in Diffusec noticed by a continual drying of the wood
1999 - IRG/WP 99-30196
After an immersion of sound wood in a solution of Diffusec, in which a combination of acid potassium and ammonium bifluorides = FHF- in dissociated form is present, their potassium and ammonium fluoride ions together with the bifluoride ion = (FHF-) diffuse into the wood. They make use of the woodmoisture available as O-H-O bonds directly attached to the cellulose in the wood fibres to attract the...
H F M Nijman