Your search resulted in 334 documents. Displaying 25 entries per page.
Mechanical properties of CCA-treated southern pine after post-treatment kiln drying
1989 - IRG/WP 3543
This report reviews current research dealing with the effects of waterborne preservative treatment and redrying on the mechanical properties of wood. In general, waterborne preservative treatments reduce average mechanical properties. This effect is exaggerated when treated wood is kiln-dried after treatment, especially at elevated temperatures. For lumber, recently completed research at the Missi...
H M Barnes, J E Winandy
Prevention of non-microbial sapwood discolorations in hardwood lumber: chemical and mechanical treatments
1997 - IRG/WP 97-30137
Sapwood discolorations in hardwood lumber that are non-microbial in origin result from the formation of pigmented starch-like granules in ray parenchyma cells. These discolorations can be prevented by treating unseasoned lumber with an antioxidant (sodium bisulfite). Exposing unseasoned lumber to microwaves or treating logs with fumigants also will prevent these discolorations. Subjecting unseason...
T L Amburgey, S Kitchens
Effect of aqueous polymer treatments on wood properties. Part 2: Mechanical properties
1990 - IRG/WP 3611
Partially air-dried sapwood of sweetgum (Liquidambar styraciflua) and southern pine (Pinus spp.) was treated with either aqueous polyacrylate or aqueous dimethyloldihydroxyethyleneurea (DMDHEU) solutions. Tests for static bending, toughness, and hardness were conducted on matched treated and untreated pieces according to ASTM Standards. Properties of pine were not affected by treatment with the po...
Z Ashaari, H M Barnes, D E Lyon, R C Vasishth, D D Nicholas
Comparison of thermally modified wood originating from four industrial scale processes – durability
2002 - IRG/WP 02-40229
This study examined the differences in biological wood properties of heat treated wood originating from four different European industrial heat treatment plants. The manufacturers of heat treated material were: PLATO Hout B.V./Netherlands, Thermo Wood/Finland, New Option Wood/France and Menz Holz/Germany where Oil-Heat treated Wood (OHT) is produced.
The results of miniblock tests with basidiomyc...
C R Welzbacher, A O Rapp
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Physical and mechanical properties of tea (Thea sinensis L.), kanak chura (Peltophorum pterocarpum (DC.) Baker ex Heyne ) and bottle brush (Callistemon citrinus Stapf. ) - Timbers grown is Bangladesh
1999 - IRG/WP 99-40141
The physical and mechanical properties, especially the strength, density, structure, colour, natural durability, workability, seasonableness and treatability of timbers of tea (Thea sinensis), kanak chura (Peltophorum pterocarpum) and bottle brush (Callistemon citrinus) grown in Bangladesh have been found out for the first time. The tea and bottle brush are completely treatable at dry condition an...
A K Lahiry
Microwave modification of Yellow Stringybark (Eucalyptus Muelleriana) posts for impregnation with Copper-Chrom-Arsenic (CCA) preservatives
2000 - IRG/WP 00-40185
Yellow Stringybark posts with diameters ranging from 60-100 mm were microwave conditioned using a 60 kW microwave (MW) generator. A substantial improvement in heartwood penetration of preservatives and relaxation of growth stresses was indicated such that there was no split formation following drying of the posts. High preservative absorption of copper-chrome-arsenic (CCA) was achieved ranging fro...
G Torgovnikov, P Vinden
Modification of solid wood: research and practical potential
1997 - IRG/WP 97-40098
The polymeric structure of the wooden cellwall mainly consists cellulose, hemicellulose and lignin. The most reactive sites on these components are the hydroxyl groups. The cellwall polymers (and its reactive hydroxyl groups) are responsible for most physical and chemical properties of wood. By changing the basic chemistry of the cellwall polymers, it is possible to change different undesirable at...
H Militz, E P J Beckers, W J Homan
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
Three years of field tests with "Lignomer" stakes in ground contact
1981 - IRG/WP 3166
The "Lignomer" (Wood Polymer Composite) is a material obtained during the polymerisation of various monomers or its mixtures in wood. As laboratory tests have shown, this material is characterized by a high resistance against biological deteriorating agents. The laboratory investigations on the durability of various materials against biological deterioration are in many instances extended by field...
K Lutomski
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
Changes in some important mechanical and physical properties of untreated and treated mining timber after exposure to the conditions of a colliery
1996 - IRG/WP 96-20082
Each of salt treated and untreated mining timber (wedge) pairs with 5x15 cm² cross-section and 155 cm length prepared from Scots pine, Bornmüller's fir and oriental beech was cut in the small standard test specimens to determine changes in some important mechanical and physical properties, 13 month after exposure to the conditions of Kozlu Hard Coal Mines in the depth of 52 m. Thus, the...
A Bobat
Three-year field trials of polymeric formulations which provide a new basis for the invention and design of non-toxic wide-spectrum wood preservatives
1994 - IRG/WP 94-40029
Three types of non-toxic polymeric formulations invented using a new approach to wood preservation were challenged with termites and fungi in three-year ground-contact field trials in the sub-tropical climate of Natal. These formulations were copper soaps of carboxylic acid groups of unsaturated fatty acids of waxes and edible vegetable oils; of resin acids of rosin, and, of synthetic unsaturated ...
A A W Baecker, A Pizzi
Solution stability and Mechanical properties of Chitosan treated Pine
2005 - IRG/WP 05-30377
During the last years the research on chitosan as a wood preservative has been enhanced. Up to now, most of the research has been applied to the anti-fungal properties of chitosan, and no research was conducted on the solution stability of chitosan solutions in repeated trials by impregnation of wood, or on the mechanical properties of chitosan-treated wood. In this paper, the stability of high- a...
E Larnøy, M Eikenes, H Militz
Screening of the technical performance and aquatic toxicity of N-methylolacrylamide treated wood
2000 - IRG/WP 00-40166
In the course of the last decades chemical modification of wood species, with a limited natural durability, has been subjected to intensive research. As a possible alternative and supplementary treatment of non-durable wood in a range of applications it remains one of the major topics in the wood preservation world. Different modification systems have been scaled-up and are now in an industrialisi...
V Rijckaert, S De Geyter, J Van Acker, M Stevens
Development of bluestain in commercially harvested logs in Britain
1996 - IRG/WP 96-10150
In Britain, mechanised harvesting of conifer forestry crops is now the preferred method of felling where terrain and access allows. However, use of mechanised harvesters can lead to excessive debarking, loosening of the bark and wood splintering with, on average, about a third of the bark removed from the more severely damaged logs. More bark has also been observed to be lost from logs harvested e...
A Uzunovic, J F Webber, D J Dickinson
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Test methods for modifies wood: The EU-Thematic network approach
2002 - IRG/WP 02-20255
The last decade wood modification systems have become new wood treatment methods in Europe. Alongside several industrial initiatives for heat treatments also scaling up and pilot plant projects for chemical wood modification have recently been carried out. In 2000 an initiative to create a network related to these new developments was supported by the European Commission. Within the work proposed ...
J Van Acker, D Jones
Melamine resins as preservatives results of biological testing
1996 - IRG/WP 96-40061
Based on previous work of the authors on resins, the upgrading of wood with a true solution of a methanol etherificated melamine resin in low aqueous concentration was performed. For the relative assessment of the biological resistance against brown and white-rot fungi were used not only untreated controls of pine sapwood (Pinus sylvestris L.), but also heartwood of European larch (Larix decidua M...
A O Rapp, R-D Peek
CCA removal from treated wood by chemical, mechanical and microbial processing
1998 - IRG/WP 98-50101-26
Most preservative-treated wood produced and consumed in the U.S. is treated with toxic inorganic compounds containing copper, chromium, and arsenic. Because chromated copper arsenate (CCA) is fixed to the wood, treated wood has not been considered toxic or hazardous and is currently landfilled. Increasing public concern about environmental contamination from treated wood combined with increasing q...
C A Clausen, R L Smith
Characterization of wood decay enzymes by MALDI-MS for post-translational modification and gene identification
2002 - IRG/WP 02-10442
The recent sequencing of the Phanerochaete chrysosporium genome presents many opportunities, including the possibility of rapidly correlating specific wood decay proteins of the fungus with the corresponding gene sequences. Here we compare mass fragments of trypsin digests, determined by MALDI-MS (Matrix Assisted Laser Desorption Ionization-Mass Spectrometry), with predicted mass fragments derive...
T H de Koker, P J Kersten
Effects of the sulfuric acid modification of CCA treating solution
1987 - IRG/WP 3415
Sulfuric acid modification of CCA treating solution is often used to control the formation of sludges and undesirable deposits on the surface of treated wood. The consequences of sulfuric acid addition are examined in this work and negative effects are shown to far outweigh any benefits. Major risks include the loss of copper due to leaching from treated wood and the accelerated corrosion of treat...
R F Fox, H J Fry, E A Pasek, A S Ross
The potential of high pressure pulsation processes to treat white spruce lumber with water-borne preservatives
1988 - IRG/WP 3471
Laboratory work using end sealed 4x8x46 cm³ white spruce samples has been done to explore the suitability of three variants of a 2.1 MPa pulsation process for the impregnation of white spruce with CCA. The results showed that the process improved significantly the penetration of the preservatives and reduced significantly cell collapse, when compared with the results of treatment using a 2.1 MPa ...
J P Hösli, J N R Ruddick
A combined method for drying and preserving wood in a single step process
2000 - IRG/WP 00-40183
Based on a convective dryer, this process allows to dry and treat wood blocks with diffusible preservatives in the same time. A boric acid solution (heated to fix the wet temperature of the system) is pumped and introduced in the flow system through a venturi, where the air coming back from the drying cell also arrives. The role of the venturi is to create a dispersion of boric acid solution micro...
O Colin, C Dupuis, E Mougel, A Zoulalian, M-F Thévenon
Correlation between modulus of elasticity, mass losses and FTIR spectra of copper treated decayed wood
2006 - IRG/WP 06-10580
The composition of copper-based preservatives will change from copper-chromium to copper-ethanolamine, due to environmental demands. The most important drawback of copper-impregnated wood is the presence of tolerant fungal organisms that have developed an ability to degrade such preserved wood. In order to elucidate these processes, specimens (0.5×1.0×15 cm) made of Norway spruce (Picea abies) w...
M Humar, B Bucar, F Pohleven