Your search resulted in 560 documents. Displaying 25 entries per page.
The present status of wooden catamarans of the Indian Coast
1997 - IRG/WP 97-10231
Catamarans (a.k.a. kattumarams) are the most widely used fishing craft in India, and hundreds of thousands of poor, traditional fishermen depend on these vessels for their livelihood that are almost made entirely of wood. In recent years, acute shortages and phenomenal increases in prices of timber species used in catamaran fabrication have been reported, causing great hardship to the user communi...
K S Rao
Supply of wooden transmission and telephone poles in Tanzania: Problems and possible solutions
1987 - IRG/WP 3424
The eucalypts which have been used widely for utility poles for more than 30 years have dwindled remarkably from traditional supply areas. Consequently, pole-using authorities are considering importing poles from abroad. This alternative is considered unrealistic and costly. The aims of this paper are: - to dispel fears of pole scarcity and to show that an abundant resource of a variety of tree sp...
K K Murira, S A Diwani
Natural decay resistance of some lesser known /used timber species from the forests of Tanzania
2005 - IRG/WP 05-10557
In order to manage the Tropical forest in a sustainable manner and increase the resource base for their wood industries, many Tropical African timber producing countries including Tanzania are promoting the many lesser known/used timbers in their forests as alternative sources of wood to the over-exploited primary timber species. Four lesser known/utilized timber species from the forests of Tanzan...
S A Amartey, P R Gillah, R C Ishengoma, J Gabriel, D H Kitojo
Whitewood - An external joinery timber?
1975 - IRG/WP 253
The timber used traditionally for softwood joinery in the UK is redwood (Pinus sylvestris). In the past its ready availability in the desired sizes and quality and its durability in service encouraged little competition. However, the past decade has seen some erosion of this position, particularly through the increased proportion of sapwood in redwood supplies. Since the sapwood is less durable th...
J W W Morgan
The use of lap-joints in natural durability testing: moisture content development during 36 months outside exposure trials
2000 - IRG/WP 00-20217
Lap-joint trials (following European Standard ENV 12037) were set up with 11 different softwood and hardwood species. The main aim was to evaluate the suitability of this test standard (developed for testing wood preservative effectiveness) for natural durability testing. The moisture development has been followed during a 36 months period. In this paper, the outcomes of different moisture content...
H Militz, C J Bloom
The risk assessment process. Point of view of a biocide manufacturer [Évaluation du risque. Point de vue d'un fabricant de biocide]
1990 - IRG/WP 3568
Risk assessment is an inherent part of our everyday lives. The risk assessment equation combines Hazards and Exposure. For the Wood Preservation Industry, the hazards may be characterised by the toxicity a the ecotoxicity of chemicals and the exposure by the identification of exposed people, of the exposure routes and exposure frequency. To quantify the exposure, good co-operation is required betw...
D Baur
Co-operative tests concerning the influence of solvent and drying method on the toxic limit of wood preservatives against Coniophora cerebella
1972 - IRG/WP 216
In the working group II of the IRG it was agreed that more knowledge was necessary concerning the influence of the solvent on the toxic limit of organic solvent types of wood preservatives against Basidiomycetes. A test program was drawn up and after discussion in the mentioned working group the final program was accepted by the co-operating institutes in 1969. In the test program two fungicides, ...
T Hof
Pretreatment decay in poles of Pinus sylvestris
1987 - IRG/WP 1329
Storage damage by blue stain and decay in poles before impregnation has been increasingly observed during recent years and there have been reports that salt-impregnated poles today are of lower quality because of incipient decay being increasingly common. The attacks may have started at the time of cutting and then continued during the period of seasoning at the plant, which could be as long as tw...
H Lundström, M-L Edlund
Ability of heartwood extractives to inhibit the growth of a bacterial symbiont of Teredo navalis
2000 - IRG/WP 00-10369
Shipworms are important destroyers of wood in the marine environment, and wood users have long sought methods for preventing or limiting their attack. While heavy -duty wood preservatives are highly effective against these organisms, there is increasing concern about risks to non-target organisms. This has resulted in a gradual shift away from broadly toxic materials to either alternative material...
C S Love, A R Sipe, S C Cary, J J Morrell
Biocidal property of the phenolic fraction of ethanol extractives of Hopea parviflora heartwood
1993 - IRG/WP 93-30003
Natural resistance of some species of timber to fungal decay and insect damage (particularly termite) is ascribed toxic nature and quantity of certain chemical substances present in the cell wall of heartwood. These chemical substances generally known to be Phenolic and Polyphenolic compounds (Rao 1982). Earlier investigations on extractives were mainly in relation to resistance of timber to decay...
R V Krishnan, K S Theagarajan, H S Ananthapadmanabha, M Nagaraja Sharma, V V Prabhu, H C Nagaveni
Redistribution of boric acid in radiata pine during drying after preservative treatment
1993 - IRG/WP 93-40010
Samples of 100 x 50 mm² radiata pine were processed with a variety of options to produce dry, boron-treated wood. Concentrations of boric acid in the central one-ninth and in the whole of the wood cross-sections were determined by chemical analysis and compared. Diffusion treated material was dried by air, conventional kiln (70/60°C), or high temperature kiln (120/70°C). Four different predryin...
A J Bergervoet, D R Page, J A Drysdale
A new process for in situ polymerization of vinyl monomers in wood to delay boron leaching
1998 - IRG/WP 98-40110
Efforts were accelerated on effective use of boron compounds in wood preservation owing to their environmentally safe characteristics and relatively low costs in addition to their well-known high bioactivity and fire resistant properties. Although having these unique favorable properties, they are readily leachable from treated wood at humid conditions. Therefore, they had limited market for exter...
M K Yalinkilic, W Dwianto, Y Imamura, M Takahashi
Fixation of chromated wood preservatives through technical drying
1990 - IRG/WP 3623
Twin samples of sawn timber of Pinus sylvestris and Picea sp. were treated with copper-chromate-containing wood preservatives and subsequently kiln resp. air dried. After drying, the distribution of preservative and rate of fixation were determined. Drying of freshly treated wood in a condenser type kiln at temperatures of 60°C and 80°C and in a vacuum type kiln at 55°C with a pressure of about...
R-D Peek, H Klipp
Penetration of oil-borne preservatives in American elm
1975 - IRG/WP 355
Pressure treatment of elm posts and cants by Rueping schedules resulted in erratic penetration. Instead of the expected gradual decrease in retention from surface inward in posts, inner zones frequently contained more preservative than the surface quarter inch. Heartwood was found penetrated when sapwood was not. There were numerous skips in treated zones. The prevalence and possible causes were i...
E A Behr
The control and pretreatment decay in air seasoning Scots and Corsican pine poles in England
1990 - IRG/WP 1451
Previous work clearly showed that air-seasoned, British grown Scots and Corsican pine poles are subject to serious pretreatment decay. In order to control these infections a range of pretreatments are currently being investigated. One series of treatments is designed not only to control decay but also allow the development of mould and stain fungi in order to achieve the desired increases in poros...
D J Dickinson, A R Zahora, A P Dodson
Preliminary indications of the natural durability of Spruce bark board
1999 - IRG/WP 99-10312
A board material made from pressed bark, with no added adhesive, has been developed by Forintek's composites group and tested for durability by Forintek's treated-wood group and the University of Hawaii. This material was also manufactured with veneers in a one-step process. Since one role of bark on the tree is protection against pests and diseases, barkboard was expected to hav...
P I Morris, J K Grace, G E Troughton
The effects of accelerated drying of green Pinus radiata on its attractiveness to Anobium punctatum as an egg-laying site
1984 - IRG/WP 1199
The methods and results are given for a series of experiments in drying Pinus radiata sapwood under a variety of conditions, then exposing the material to Anobium punctatum egg-laying. The results showed very clearly that the attractiveness of the wood to gravid females was drastically reduced when dried from green at temperatures much above 35°C. Both simple oven drying and steam kilning produce...
D J Cross
Conforming to European standards on preservative treatment
1998 - IRG/WP 98-20150
New European standards require that specifications for the preservative treatment of timber are written in terms of the penetration and retention of preservative within the treated commodity that result from the treatment process. In order to check compliance with this type of specification, suitable methods of quantitative analysis must be available. This paper presents the results of a study by ...
E D Suttie, R J Orsler
The critical timing of inspections for field testing of natural durability
1994 - IRG/WP 94-20018
An overestimation of performance will almost always result if the condition of a specimen is considered to be attained at the precise time that an inspection is carried out. The time at which the condition is actually attained, referred to in this document as the "Condition time", is best considered to be halfway between two successive inspections. The requirement to obtain data that is relevant t...
J D Thornton
Assessment of untreated Papua New Guinean timbers against subterranean termites. Progress Report 1
1990 - IRG/WP 1436
Eight major commercial timber species (Intsia palembanica, Pometia pinnata, Homalium foetidum, Dracontomelon dao, Calophyllum spp., Eucalyptus deglupta, Nothofagus spp., and Alstonia scholaris) were exposed in ground contact against termites. Five replicates of heartwood stakes of 25x25x250 mm³ of each species were randomly embedded in the soil. Results after 24 months exposure showed that Kwila ...
M Rokova, H C Konabe
Susceptibility of heartwood of three Pinus species to attack by the subterranean termite Coptotermes acinaciformis (Froggatt)
1994 - IRG/WP 94-20026
Heartwood of plantation-grown Pinus elliottii (slash pine), Pinus caribaea (Caribbean pine) and Pinus radiata (radiata pine) was obtained from a range of locations throughout Australia and New Zealand for use in a field bioassey with subterranean termites. Timber stock was analysed for a number of stilbene and flavonoid heartwood extractive components which could contribute to variation in suscept...
M J Kennedy, L L Dixon, B C Peters
Multiple-Phase Pressure (MPP) Process: One-stage CCA treatment and accelerated fixation process. 3. Effect of process variables on sapwood treatment and CCA fixation.
1998 - IRG/WP 98-40114
The Multiple-Phase Pressure (MPP) Process achieves treatment and fixation as combined process using hot CCA, within a 2-3 hour time-frame. Timber is treated to saturation with hot CCA using an empty cell process. During the pneumatic pressure phase, hot solution is held in the wood in an otherwise liquid-free treatment vessel until fixation is >95% complete.
This report details a factorial des...
H Pearson, K Nasheri, J A Drysdale, G Durbin, M E Hedley
The susceptibility to sludging of sulfate and oxide CCA
1990 - IRG/WP 3599
Radiata pine sapwood was treated separately with a sulphate CCA-C and an oxide CCA in a pilot scale pressure plant using a full cell process. CCA solutions were recovered from the final vacuum phase, placed in plastic tubes, and their susceptibility to sludging determined by examining changes in solution pH, time required for sludge to form and weight and chemical composition of sludge formed. Sul...
B T Mutandadzi, P D Evans
Comparative study on the leaching of wood preservatives between natural exposure and accelerating laboratory conditions
1999 - IRG/WP 99-50134
Impregnated specimens with CCA, ACQ, and BAAC were subjected to leaching tests. Specimens of 2x2x1 cm3 in size were used for the laboratory leaching test for 10 days according to JIS K 1571. Specimens of 25x1 x1 cm3 were used for outdoor leaching test for 6 months. Total leaching amounts of boron per cm3 of specimens treated with BAAC were 325 µg in the laboratory test and 206 µg in the outdoor ...
K Yamamoto, S Motegi, A Inai
Survey of North American practice in conditioning forest products before preservative treatment
1972 - IRG/WP 308
Seasoning requirements for the wide range of forest products which are treated with preservatives and fire retardants must be capable of dealing with a very complex set of conditions which are summarized under a number of variables including type and hazard of end use, the most effective distribution of preservative, a wide range of cross sectional dimensions, the possibility of seasoning by a ran...
J Rak, T S McKnight