Your search resulted in 3291 documents. Displaying 25 entries per page.
Control of wood biodeterioration by fungal metabolites
1992 - IRG/WP 92-1527
Treating wood with different conventional preservative chemicals for protection and economic utilisation is well known. Tough some of these chemicals are toxic to skin, their use as wood preservative is unavoidable as they should be toxic to biodeteriorating organisms also. Recent advances in chemistry of natural products enabled the use of wood extractives as biocidal compounds against biodeterio...
H S Ananthapadmanabha, H C Nagaveni, V V Srinivasan
Categories in wood preservation hazard, risk, and use
1994 - IRG/WP 94-20048
In various countries hazard-, risk-, or use-categories have been established. The different terms seem to be only a sophisticated language problem, but they are rather a basic principle of the philosophy of wood preservation which is going to obtain importance with respect to the low reputation of chemical wood preservatives in an increasing number of countries. Whilst hazard signifies the fact th...
H Willeitner
Dimensational stabilisation of wood
1981 - IRG/WP 3171
A review is given of the studies on the dimensional stabilisation of wood which have been carried out in the laboratory 5.14 "Wood Technology" since 1967. All stabilisation methods known have first been compiled from the available literature. Practical studies were then started. Wood was treated with monomers (styrene, methyl metacrylate, isocyanate), formaldehyde, tannin and sugar. Despite a sati...
A Burmester
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
In vivo growth study on two gymnosperms and four angiosperms for REB wood poles
1998 - IRG/WP 98-10246
Revealed that the highest growth rates and pole yield in two plantation sites in Bangladesh are significant with 2.06 cm/y in diameter, 0.97 m/y in height and 90% pole yield within 19y in Pinus caribaea; 1.96 cm/y, 0.91 m/y and 100% pole yield within 15y in Xylia dolabriformis; 1.88 cm/y, 0.91 m/y and 22% pole yield within 13y in Dipterocarpus turbinatus; 1.64 cm/y, 0.82 m/y and 28.75% pole within...
A K Lahiry
Laboratory versus field tests for evaluating wood preservatives: A scientific view
1995 - IRG/WP 95-20076
The relative merits of field tests versus laboratory tests for evaluating wood preservatives are discussed. Many of the problems involved in interpretation of the results are similar for both types of test. One major problem is to select field sites or laboratory tests that are representative for the practical use of treated timber in ground contact. Decay tests with treated wood in unsterile soil...
T Nilsson, M-L Edlund
Northern oak wood and its damages in Iran
1988 - IRG/WP 1377
The Northern oak species of Iran designated Quercus castaneaefolia C.A.M. is distributed widely in caspian littoral. In natural conditions (healthy) has favourable quality and it is used mostly in rural construtions, sleepers, parquets, cross arms for electric and communication poles, it is used also indoor and window construction, benches and finally veneer. This wood in the case of sleepers and ...
D Parsapajouh, P Niloufari
Performance criteria for approving new wood preservatives for ground contact
1994 - IRG/WP 94-20021
Protocols for testing novel formulations prior to approval or registration as wood preservatives are being developed in a number of countries, e.g. Australia, New Zealand, USA. One aspect which must be addressed is the effectiveness in tests relative to that of currently approved formulations which would be acceptable to approving authorities. It is assumed that natural exposure testing is a prere...
M E Hedley
Investigation of temperature effect on fixation of Celcure preservative (ACC) in Hornbeam (Carpinus betulus I)
2003 - IRG/WP 03-30304
In this research, the fixation speed of Celcure 2 % (ACC) preservative salt, under temperature of 30 ºC, 40 ºC and 50 ºC on intact wood specimens of hornbeam was investigated. For this purpose, blocks of wood with 2Í 2 Í2 cm dimensions of hornbeam were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. For measuring the percentage of fixation through time, the specimens were extracted by using hydraulic pressure equipment, under 70 Mpa pressure. The PH of extraction was measured with the method of Diphenyl Carbazid and by using spectrophotometer. This measurement was done continuously and the amount of 6-valence chromium concentration present in the extract was compared with the amount of chromium concentration in the primary solution and then the percentage of fixation was calculated.
The results showed that the decrease in 6-valence chromium is accompanied with increase of PH, this due to absorption of positive hydrogen ion by 6-valence chromium for reduction to 3-valence chromium and also ion –exchange of active components with wood during the primary phase of fixation. Also, the time necessary for reaching complete fixation in intact wood in the fixation temperature conditions of 30, 40, 50 ºC were 98, 52, 24 hours, respectively. In general, the results showed that temperature has effective role accelerating of fixation process.
R Imani, R E Majdar, A Karimi
Variation in biological performance of CCA caised by preservative application method
1996 - IRG/WP 96-40072
A series of laboratory studies to investigate the influence of treatment application method on CCA performance in Cosican pine has been completed. Biological decay tests, such as serial exposures, were used to induce decay in wood at preservative retentions of up to 10 kg/m³ CCA salts. Significant differences in performance of the preservative against either brown, white or soft rot decay fungi w...
P R Newman, R J Murphy
Laser incising of spruce lumber for improved preservative penetration
1991 - IRG/WP 3646
Red spruce heartwood specimens were incised using a range of laser beam power levels and pulse durations. The penetration of CCA through these holes into the wood was monitored after pressure treatment. In addition, green and dried spruce samples were incised using two patterns with incision densities of either 16.1 holes/in² or 21.3 holes/in². Following CCA pressure treatment the samples were t...
B Goodell, F A Kamke, Jing Liu
A new preservative - A double-edged sword
1990 - IRG/WP 3573
Increasing environmental pressures on the use of pesticides throughout the world will impact more on the use of all wood preservatives. In particular the use of traditional wood preservatives and methods of application are under close scrutiny. The industry is responding to the challenge of developing alternative products and systems but faces great problems due to the excellent performance and sa...
M Connell, J A Cornfield, G R Williams
Pollution in wood preservation - Aspects and problems
1973 - IRG/WP 55
In the field of wood preservation too, pollution problems have to be considered. They originate with the wood preservatives used. The extent of pollution differs widely with the type of preservative and the treatment process used. Per unit of impregnated timber, pollution will be lower if treatment is performed in treating plants than in distributed places. It will be highest for the old type Bouc...
H Willeitner
A review of the implementation of results-based standards for preservative treated timber
1999 - IRG/WP 99-20156
European standards for the specification of preservative treated timber are written in terms of the results achieved in the commodity by the treatment process. This is described in terms of penetration and retention of preservative. Results from a study on the commercial application of this approach in the UK show the difficulties associated with applying the new European standards; particularly w...
E D Suttie, A S Hughes, R J Orsler
Specifying preservative-treated resistant timber: Conforming to European Standards
2001 - IRG/WP 01-20235
The most common construction timbers used in the UK are of low natural durability and, generally, resistant to preservative treatment. These include species of spruce, hemlock and fir. However, their characteristically limited and non-uniform uptake of preservatives may still confer sufficient protection to give satisfactory durability performance in terms of biological resistance. This paper desc...
E D Suttie, A F Bravery, T B Dearling
Isolation and identification of the fungal flora in treated wood. Revised technique
1977 - IRG/WP 159
At the 8th Annual Meeting in Wildhaus a paper was presented for discussion on the isolation of fungi from treated wood.·Since then work of this nature has been undertaken at Imperial College and as a result a revision of that document has been made and is presented here. The main alterations are: 1) To streamline the isolation procedure 2) Modification of the benomyl agar 3) The inclusion of a st...
C P Clubbe, J F Levy
Influence of the decay of spruce chips by the selected fungi on their chemical structure and the pulp properties
2004 - IRG/WP 04-10510
The paper focuses on changes in the weight and in the molecular structure of spruce chips submitted to long-term storing as well as to medium- and long-term model rotting degradation caused by some chosen fungi identified at storing processes on the pile. For the model decay of chips under laboratory conditions during 3 or 6 weeks the white-rot fungi: Phanerochaete chrysosporium, Heterobasidion an...
R Solár, L Reinprecht, A Geffert, F Kacík
Towards a unified international hazard class system
1996 - IRG/WP 96-20081
Working party 2.5 on International Standardisation has set the development of a unified hazard class system as a short-term objective. This document is intended to stimulate the discussion required to work towards such a system. Two possible approaches are discussed, the compromise approach and the development of a basic system from first principles. For the second approach, the factors impacting ...
P I Morris
Proposal for a method aiming at the quantification of the impact of wood extraction in Life Cycle Assessment
1998 - IRG/WP 98-50113
Life Cycle Assessment has been accepted as an instrument for the assessment of the environmental impact of products. Characterisation factors for impact assessment of emissions from products have been established. To date no characterisation factor exists for the extraction of biotic resources, for example wood. Since the main disadvantage of using wood as a material lies in the extraction of reso...
P Esser, E Van der Voet
Exterior wood stains
1979 - IRG/WP 3136
The use of semi-transparent exterior wood stains has grown remarkably since their development during the 1960s. This can be partly attributed to their offering a break with tradition at a time when it was being recognised that changes in the quality of timber and how it was used demanded different methods of exterior wood finishing. Information is already available on the characteristics and uses ...
E R Miller
Effects of steaming heat treatment of wood on the stimulation of termite feeding
1997 - IRG/WP 97-10212
At the 26th IRG conference, we reported that steamed Japanese larch heartwood samples were suffered a serious attack by subterranean termite, Coptotermes formosanus both in choice and no-choice feeding tests. This is possibly caused by the yield of termites stimulants in the wood samples resulting from the steaming process. Since the steaming heat treatment has often been applied to other several ...
S Doi, Y Kurimoto, M Takahashi, T Yoshimura
Ten year performance of l-joints made from borate diffusion treated wood
2000 - IRG/WP 00-30225
While there are decades of experience with borate-treated wood in coated, exterior applications in New Zealand and the UK, other countries have been more reluctant to use this process. As part of a research program on the potential use of borates by the Canadian wood products industry, Forintek set up, in 1990, an L-joint test of untreated and borate-diffusion treated hem-fir (western hemlock and ...
P I Morris
Inter-laboratory comparison of assessment methods for wood preservatives against subterranean termites: Determination of protection threshold limits for CCA
1999 - IRG/WP 99-10317
In 1996, several institutes conducted laboratory bioassays on the efficacy of unleached Pinus radiata specimens treated with copper-chromium-arsenic (CCA) and copper naphthenate (Cu Naph) at retentions of 0.5, 1.0, 2.0 and 4.0 kg/m3 (total salt for CCA; elemental copper for Cu Naph) against a range of species of subterranean termites (IRG/WP/96-10174). Each participant employed the standard test m...
J W Creffield, M Lenz
Issues Facing Wood Preservation in Australia Today
2003 - IRG/WP 03-30327
Timber and timber products are a major part of the Australian building industry and preservative treatment is a common consideration for most timber users. Despite this however, there is a major lack of awareness by the users of the various issues associated with preservative treatment.
Australian treatment specifications are logical, concise and uncomplicated. There are three agencies in Austr...
J Norton
Evaluation of wood preservatives for Nordic wood preservation class AB
2002 - IRG/WP 02-30297
In the Nordic countries there are restrictions in the use of wood preservatives based on chromium and arsenic. For above ground use, class AB according to the Nordic system, only
copper based preservatives are allowed in Sweden. Thus several new preservatives, copper based or metal free are now used. They have been approved by the Nordic Wood Preservation Council after passing laboratory tests ag...
M-L Edlund, J Jermer