Your search resulted in 966 documents. Displaying 25 entries per page.
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Recent developments in the treatment of sawn spruce by double vacuum impregnation
1978 - IRG/WP 3114
The timbers used for building purposes in the U.K. and on the Continent of Europe are mainly softwoods. The two types of wood most used are redwood (Pinus sylvestris) and whitewood (Picea abies or Picea sitchensis). Other species are used to a lesser extent when considerations such as a long length requirement or width requirement demand the use of, for example, hemlock, Douglas fir or Parana pine...
C T Kyte, L D A Saunders
Serviceability of copper naphthenate-treated poles
2000 - IRG/WP 00-30214
Copper naphthenate-treated poles in service were inspected for deterioration, penetration, retention, and serviceability. The study to date has included poles in all hazard zones in the United States. Poles installed by 12 different utilities and eight different treating companies are included in the survey. Both southern pine and Douglas-fir poles and distribution and transmission poles are inclu...
H M Barnes, M H Freeman, J A Brient, C N Kerr Jr
The efficacy of remedial treatments for controlling fungal decay in window millwork used in the United States
1987 - IRG/WP 3432
Conventional window millwork was subjected to basidiomycete decay by inoculation and sampled for active growth of the decay fungus before and eight months after remedial preservative treatment with fused disodium octaborate rods (IMPEL) at boric acid levels of 1.5 and 4.0 kg/m³ or liquid bifluoride injections (IMPROSOL) at 1 kg/m³. The elimination of decay fungus after remedial treatment was nea...
M G Dietz, E L Schmidt
The effectiveness of deltamethrin against subterranean termites (final report)
1993 - IRG/WP 93-30011
Two series of block tests of Pinus sp were treated by dipping them for 1 (one) minute in a solution with 0.015 (w/w) and 0.05 (w/w) of deltamethrin, respectively. In both cases, an average retention of 47 kg/m³ (0.32 l/m) was reached. One part of the block tests remained under laboratory conditions during 9 months, and the other was stored during equal period of time in a theater basement submitt...
P A Zanotto
Attempt for developing a new method for above ground field testing of wood durability
2000 - IRG/WP 00-20199
Field testing remains the most appropriate way for evaluation of wood preservatives or natural durability of wood species. Above ground tests are designed to answer specific questions concerning the outdoor utilisation of wood. Such methods supply additional information and confirm or reject preliminary laboratory results. The European standard (ENV 12037, "lap-joint") for assessment of the durabi...
N Terziev, M-L Edlund
The chemical nature of bis(tributyltin) oxide in Pinus sylvestris sapwood
1989 - IRG/WP 3508
Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilisation of the tributyltin species in, and from, Scots pine (Pinus sylvestris) sapwood. Thus, 119 Sn nuclear magnetic resonance studies have shown that, on impregnation into this timber, bis(tributyltin) oxide ...
S J Blunden, R Hill
Evidence for wood cell wall degradation by the blue stain fungus Botryodiplodia theobromae Pat
1994 - IRG/WP 94-10077
Botryodiplodia theobromae Pat., a world wide ubiquitous polyfagus sapstain fungus, was found able to destroy the cell walls of birch fibres (Betula verrucosa Ehrh.) but not Caribbean (Pinus caribaea var. hondurensis Barr. and Golf.) and Scots pine (Pinus sylvestris L.) tracheids. The fungus caused characteristic erosion of fibre cell walls similar to soft rot type 2; destruction of the S1 - S2 int...
O Encinas, G F Daniel
A technique for determinging the efficacy of wood preservatives for partially treated timber
1988 - IRG/WP 2322
A technique is described for determining the efficacy of wood preservatives either for certain wood species where a full penetration cannot be achieved by normal vacuum-pressure methods or for more permeable species to look at efficacy of treated zone in preventing decay of an untreated core. Both sapwood and heartwood planks of spruce (Picea abies) and pine (Pinus sylvestris) were treated by CCA ...
A J Nurmi
Investigation on different variation factors in the results of mycological test and means to reduce and avoid them
1986 - IRG/WP 2264
In order to clarify the causes of the dispersion observed in the results obtained with mycological tests made in accordance with standard EN-113, different factors assumed to be sources of the variations were studied. These included the moisture content of the test samples during the test, the influence of certain technological properties of the wood, the virulence of the fungus strains, the metho...
D Dirol
A new method for the study of microbiological decay of wood in a strictly anaerobic environment
1988 - IRG/WP 2319
Recent work has suggested that strictly anaerobic bacteria may play a role in the biodeterioration of wood, particularly in aqueous environments. However, no suitable test methods exist for the investigation of this hypothesis. An aqueous minimal medium in specifically adapted conical flasks was sterilised, gassed using a 5.5% H2; 31.8% C02; 62.7% N2 gas mixture to remove oxygen and transferred to...
G M Rogers, A A W Baecker
Étude in vitro de la colonisation et de la dégradation structurale du bois d'aubier de Pin sylvestre par la Mérule: Serpula lacrymans Schum. ex Fr. S. F. Gray
1979 - IRG/WP 198
The degradation of Scots pine sapwood cell walls by Serpula lacrymans, a brown rot fungus, is observed after various periods of exposure from two weeks to twelve weeks. The observation by microscopy shows that the hyphae of Serpula rapidly invade the wood tissues as cell wall degradation starts. That deterioration is not gradual, it is observed to be very irregular as well within the whole of the ...
D Dirol
Formation of soft rot cavities in relation to concentric layers in wood fibre walls
1983 - IRG/WP 1185
A large number of timber species attacked by soft rot have been examined using light microscopy. The S2 layers in a large number of the timbers exhibited special structural features in the form of thin concentric layers. Several observations indicate that these layers may be characterised as "weak" zones by being more easily degradable than the surrounding wall layers. The chemical structure of th...
T Nilsson, G F Daniel
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
Acetylated solid wood. Laboratory durability test (part 2) and field trials
1995 - IRG/WP 95-40048
Degradation of acetylated beech, pine and poplar by soft rot fungi was related to strength loss in a laboratory test. No strength loss was noticed for poplar acetylated to a weight percent gain (WPG) of more than 11.2% and beech with a WPG of 12.8%. Several field trials were set up to determine the durability of acetylated products in practice. They included a field test to determine the durabilit...
E P J Beckers, H Militz, M Stevens
A suggestion for the improvement of the chemical protection of wooden poles
1987 - IRG/WP 3445
Insufficient drying of white poles in Sweden causes inadequate penetration of the impregnation compounds, CCA salts and creosote, in a varying proportion of the treated poles, and with pretreatment decay present, sooner or later, internal fungal attack in the ground-line zone of the standing poles is the result. The application of a diffusing fungicide in the ground-line zone in connection with th...
H Friis-Hansen
ATP assay for the determination of mould activity on wood at different moisture conditions
1992 - IRG/WP 92-2397
To determine fungal responses to fungicides and environmental conditions and for detection of microbial activity in wood, sensitive and objective methods are needed. We have developed a suitable assay based on analysis of adenosine triphosphate (ATP) by using the luciferin-luciferase reaction. With the aid of this assay the activity of Penicillium brevicompactum on wood at different RH levels was ...
J Bjurman
Test of N-tritylmorpholine in combination with synthetic pyrethroids against marine borers in tropical Australia and Panama
1991 - IRG/WP 4168
Test blocks ol Pinus sylvestris sapwood were pressure impregnated with white spirit solutions of N-tritylmorpholine, either alone or in combination with permethrin, deltamethrin or cypermethrin. They were exposed in the intertidal zone at Mourilyan Harbour, North Queensland, Australia and subtidally at either end of the Panama Canal. After 5 months' exposure at Naos Island at the Pacific ...
S M Cragg, J D Bultman
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
Contradiction between uptake of preservative in practical situation and laboratory testing
1992 - IRG/WP 92-2392
By brush treatment water- and solvent-based products were applied on boards of Scots pine and Norway spruce to achieve an uptake of 100 and 200 g/ml. In addition the scope of work to achieve the required uptake of preservative was determined under practical conditions for both product groups. EN 113 (RAL-GZ 830) tests were carried out to test the biological efficacy of products. After 18 months ex...
R Gründlinger, O Janotta, M Melzer
Accelerated decay tests to investigate postulated effects of tannins on CCA efficacy in wood
1988 - IRG/WP 3497
Five groups of blocks (10 x 10 x 5 mm³) viz., Pinus patula, Pinus patula impregnated to 4% (w/w) tannin; Eucalyptus grandis, Eucalyptus grandis with natural tannins extracted; and extracted Eucalyptus grandis with tannins returned as above; were prepared. Blocks from each group were then treated to 0, 5, 10 and 15 kg/m³ CCA and challenged in four 15-week decay tests, viz., soil burial, and expos...
U L Scherer, A A W Baecker
Influencia de la impregnación con soluciones tánicas en la estabilidad dimensional de la madera de Pinus pinaster Ait. procedente de España
1992 - IRG/WP 92-3686
En virtud de la importancia que presenta la madera de Pinus pinaster Ait. en el sector constructivo español, se ha sometido a esta a tratamientos en autoclave con distintas soluciones tánicas naturales y artificiales a fin de estudiar su incidencia en la estabilidad dimensional frente a exposiciones exteriores. En el estudio se pone de manifiesto el efecto creado por el tratamiento protector en ...
J A Rodríguez Barreal, J Cubillo Jordan de Urries, L Garcia Esteban
The degradation of wood surfaces by water
1984 - IRG/WP 3289
Thin radial/longitudinal sections (~100 µ) of Scots Pine (Pinus sylvestris) and lime (Tilia vulgaris), were exposed to deionised water over the temperature range 25-65°C. Losses in wet tensile strength and toughness occurred rapidly at temperatures from about 50°C upwards. After about 2 months' exposure pine lost some 10-30% of its tensile strength and 20-60% of its toughness. For lime...
W B Banks, P D Evans
Comparative study on leaching of CCA from treated timber: Modelling of emission data
1994 - IRG/WP 94-50027
Results of a comparative study on leaching of CCA from treated timber are reported. The study aims at investigating the applicability of prestandard leaching test methods for modelling purposes. Prestandards used are the European standard proposed by CEN/TC38/WG11 and NEN 7345 (Dutch prestandard for building materials). Parameters of study are type of fixation, wood species (pine - spruce), specim...
G M F Van Eetvelde, M Stevens, L Van der Mijnsbrugge
Essais de collage de bois traités pour la réalisation d'éléments de charpente lamellées. (+ abstract dated September 1971, Influence du traitement de préservation sur le collage d'éléments de charpente lamellés collés et efficacité vis-a-vis de larves néonates)
1971 - IRG/WP 203
Le but du travail est de vérifier les propriétés générales d'une poutre lamellée collée après traitement des éléments la composant au moyen de formulations insecticides et fongicides commerciales à solvant clair dans les conditions les plus usuelles de fabrication. Les essences utilisées ont été: Epicéa - Pin sylvestre - Sapin de Douglas en planches rabotées de 80 cm de lo...
J Guillemain-Thévenot