Your search resulted in 348 documents. Displaying 25 entries per page.
Improvements of stability and durability of beechwood (Fagus sylvatica) by means of treatment with acetic anhydride
1991 - IRG/WP 3645
In the present investigations, beechwood (Fagus sylvatica) was treated with non-catalysed acetic anhydrid at 120°C and some physical- and biological parameters of the treated wood were compared with those of non-treated wood. The radial and tangential shrinkage and swelling, respectively, and the absorption capacity of the acetylated wood against moisture is considerably lower. The durability aga...
H Militz
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
Laboratory tests on artificial weathering of Quercus rubra crossties
1986 - IRG/WP 2252
Clear red oak (Quercus rubra) blocks were used to evaluate various types of accelerated aging tests including boil, steaming, and cyclic weathering. It was found that the repeated vacuum and pressure treatment of wood in water, steaming, oven-dry, and freezing appeared to be most effective in reducing the MOE in compression and hardness modules of wood specimens. Red oak crossties which were press...
P Chow, A J Reinschmidt, E J Barenberg, S L Lewis
Chemical evaluation of borate treated pine sapwood attacked by the subterranean termite Coptotermes acinaciformis
1993 - IRG/WP 93-20003
Sapwood of hoop (Araucaria cunninghamii Ait. ex D. Don) and slash (Pinus elliottii Englem.) pines were treated by Vacuum Pressure Impregnation (VPI) to provide test specimens. The concentration of boron was defined by chemical analyses of the timber, in the zone of primary attack by the termite being bioassayed. A common method of definition of preservative retention, weight uptake of preservative...
A R Moffat, B C Peters
Influence of concentration, catalyst, and temperature on dimensional stability of DMDHEU modified scots pine
1998 - IRG/WP 98-40119
Dimethyloldihydroxyethyleneurea (DMDHEU) is being used in textile industry to improve wrinkle recovery. Trials on solid wood have been performed to minimise swelling of the wood. This paper focuses on the effect of various types and concentrations of catalyst and reaction temperature on the dimensional stability of Scots pine. Three different catalysts, NKS (based on magnesium chloride), 3282 (bas...
M Van der Zee, E P J Beckers, H Militz
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper/chrome/arsenic preservative
1981 - IRG/WP 3180
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. The growth characteristics of spruces (Picea spp) make them attractive candidates for forestry schemes. In 1975 the UK Forestry Commission had about 400 000 hectares, about 20% of total UK forest area, planted with Sitka spruce (Picea sitchensis)...
C R Coggins
Modified Wood – Methods, testing and applications: Outcomes of the EU-Thematic Network
2003 - IRG/WP 03-40268
In the last decade, interest in the development of wood modification systems has increased in Europe. Alongside several industrial initiatives for heat treatments, there have also been scaling up and pilot plant projects for chemical wood modification. Between 2000 and 2003, the European Commission funded the "Thematic Network on Wood Modification". This paper will feature the modification process...
D Jones, W Homan, J Van Acker
Fenton's reagent as a modification tool in brown-rot decay
1996 - IRG/WP 96-10155
A biomimetic approach was used to clarify the role and importance of the Fenton-type reaction in the carbohydrate degradation by brown-rot fungi. Spruce sawdust and microcrystalline cellulose were modified in the H2O2/Fe(II) treatment. The degree of hydrolysis of the pretreated spruce sawdust was clearly increased with the complete cellulase (Econase), purified endoglucanase from Trichoderma reese...
M Rättö, A-C Ritschkoff, J Buchert, L Viikari
Copper linoleate: A new low toxcity wide spectrum, heavy duty wood preservative
1995 - IRG/WP 95-30082
Copper linoleate, a "fixed" copper soap has been developed and evaluated in South Africa over a 30-year period. The initial product, an organic solvent based preservative has been tested in pine poles against termites and fungi. Results indiate that the product has performed well against existing heavy duty wood preservatives such as CCA and creosote in long term field trials (30 years). The paper...
D Conradie, P Turner, W E Conradie, A J Pendlebury, T Pizzi
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
Steam/hold/APM boron treatment - Treatability trials with green gauged radiata pine
1987 - IRG/WP 3439
Freshly sawn 100 x 50 mm radiata pine was green gauged, steam conditioned and preservative treated with a mixture of borax and boric acid using a modified Alternating Pressure Method (APM) treatment schedule. A 12 hour holding period between steam conditioning and treatment resulted in the necessary moisture loss and moisture re-distribution to facilitate treatment to NZ Timber Preservation Author...
P Vinden
Studies on the resistance of DMDHEU treated wood against white-rot and brown-rot fungi
2005 - IRG/WP 05-10566
Beech wood (Fagus sylvatica) modified with the textile finishing agent 1,3 dimethylol-4,5-dihydroxyethylen urea (DMDHEU) has shown to improve durability against the white-rot fungus Trametes versicolor. In a mini-block test, the weight loss over eight weeks of incubation decreased with increasing weight percent gain (WPG) of DMDHEU. At 25% WPG, no significant weight loss was observed, while untrea...
P Verma, C Mai, A Krause, H Militz
A study on the pressure impregnation of Eucalyptus globulus fence-posts with CCA preservatives. Part 2
1989 - IRG/WP 3514
This paper describes the second part of a study on pressure impregnation of Eucalyptus globulus fence-posts with CCA preservatives presented at the IRG 19th Meeting. Fence-posts of three diameter classes, were treated, considering only one treatment schedule. The results show possibility of vacuum-pressure impregnation of blue gum fence-posts, with diameter less than 9 cm, though mainly by longitu...
L Nunes, D De Sousa Castro Reimão
Efficacy of anhydrides as wood protection chemicals
1997 - IRG/WP 97-30162
Wood samples treated with anhydrides of various compositions have been examined for their decay resistance and moisture behaviour. For this purpose two brown rot fungi (Coniophora puteana and Gloeophyllum trabeum) and two white rot fungi (Trametes versicolor and Pycnoporus sanguineus) were used in conventional and modified soil block tests. The modified soil block tests conformed to the method as ...
S C Forster, M D C Hale, G R Williams
Development of wood retification process at the industrial stage
1998 - IRG/WP 98-50101-16
Wood is a natural composite material which exhibits outstanding properties from the technical as well as from the ecological point of view. However, it is an anisotropic, hygroscopic material sensitive to biological attacks. We have to stabilise and preserve it if we want to ensure its market shares faced with competing synthetic material, whilst taking the new environmental rules into account.
T...
P Gohar, R Guyonnet
The effects of chemical modification on the physical properties of alder and spruce particleboards
2005 - IRG/WP 05-40300
In this paper, it was aimed to improve some physical properties of chemically modified particleboard, made from spruce and alder species, spreading widely at Black sea region in Turkey. Spruce and alder chips were reacted with acetic, succinic, maleic and phthalic anhydrides at constantly heat for 3 hours then, hot pressed at 150 °C by using Phenol formaldehyde (PF) resin. Target board density wa...
E Dizman, Ü C Yildiz, H Kalaycioglu, S Yildiz, A Temiz, E D Gezer
Sphaeroma terebrans Bate: A note on distribution and preservative tolerance in Florida coastal waters
1987 - IRG/WP 4135
Treated test panels were installed in January 1984 in a Florida estuary where Sphaeroma terebrans had severely damaged pilings treated with copper chromate arsenate (CCA). Test treatments were CCA at three retentions, coal-tar creosote at three retentions, creosote with chlorpyrifos, dual treatment with CCA and creosote, and three types of chemical modification of the wood test panels. We describe...
B R Johnson, E D Estevez, S A Rice
Collaborative field trial out-of-ground contact
1982 - IRG/WP 2179
At the 12th meeting of the IRG in Sarajevo, Yugoslavia it was decided after considerable discussion that the best way to proceed with the work of the subgroup was to centre it around a co-operative field trial based on the L-joint test detailed in IRG/WP/2157. At the same time it was agreed that interested laboratories would also conduct their own methods, particularly the German planner test and ...
D J Dickinson, A F Bravery, J K Carey
Determination of N-cyclohexyl-diazeniumdioxide (HDO) containing compounds in treated wood using GC-MS
2000 - IRG/WP 00-20201
Beside the biological effectiveness the approval of a chemical wood preservative requires also techniques for the analytical determination of active ingredients in different matrices. Fulfilling of the last requirement is particularly difficult in the case of impregnated timber treated with wood preservatives containing organic compounds. This paper describes a procedure for the determination of t...
P Jüngel, J Wittenzellner, E Melcher
The biological effectiveness of wood modified with heptadecenylsuccinic anhydride against two brown rot fungi: Coniophora puteana and Gloeophyllum trabeum
1992 - IRG/WP 92-3705
A modified soil block test was carried out using wood samples reacted with heptadecenylsuccinic anhydride (ASA). This modification gave good resistance to decay brought about by the brown rot fungi Coniophora puteana and Gloeophyllum trabeum during the twelve week exposure period. Results indicated that there was a good correlation between increased loading of modifying reagent and an increase in ...
C Codd, W B Banks, J A Cornfield, G R Williams
Temperature and pressure inside wood during creosote impregnation
1991 - IRG/WP 3649
Creosote gives the best protection against decay for sleepers and poles. However, it has a major drawback - bleeding. Modified impregnation processes to reduce bleeding have been tried. For developing such processes it is important to know the actual temperature and pressure inside the wood. This paper describes measurement of temperature and pressure inside wood during creosote impregnation. The ...
Ö Bergman
Modification of wood by graft treatment
2003 - IRG/WP 03-40257
New water-repellent systems for wood are needed to improve the weathering characteristics. This study found that treatment of wood with chemical grafting systems imparted substantial water repellency. Different direct oxidative grafting systems were examined. Specifically, KMnO4, Fe(NH4)(SO4)2·12H2O, Fe2(SO4)3·5H2O, and (NH4)2Ce(NO3)6 were used as initiators and styrene as the monomer. All the...
M M Morshed, D D Nicholas, C Pittman Jr, T Schultz
Durability aspects of (hydro)thermal treated wood
2000 - IRG/WP 00-40160
Samples of several wood species were treated in a two steps process, subsequently hydrothermal and dry heat-treated, by the so-called PLATO-process and analysed for their resistance against fungal attack. Both PLATO-treated and dry heat-treated specimen were prepared and analysed, in order to study the influence of moisture during hydrothermal treatment of wood. The resistance against all of the s...
B F Tjeerdsma, M Stevens, H Militz
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Tunnelling bacteria
1983 - IRG/WP 1186
The micromorphology of decay in wood caused by a certain group of single-cell bacteria, called tunnelling bacteria (TB), is described. TB are characterised by their tunnelling ability within the secondary cell walls of wood fibres. Pure cultures of TB have not yet been obtained although the typical decay patterns can be reproduced using mixed bacterial cultures. Some indications of lignin degradin...
T Nilsson, G F Daniel