Your search resulted in 486 documents. Displaying 25 entries per page.
Bending properties of wood after its decay with Coniophora puteana and subsequent modification with selected chemicals
1999 - IRG/WP 99-40146
Mechanical properties of wood are often decreased due to decay processes caused by biotic and/or abiotic factors. Damaged wooden elements (e.g. historical structures) can be reinforced by more methods, including their modification with convenient chemicals. This paper presents influences of selected chemicals on basic bending properties (modulus of elasticity - MOE, modulus of rupture - MOR) of so...
L Reinprecht, S Varinska
Facts or feelings to decide on wood preservation
1988 - IRG/WP 3480
Feelings against the use of chemicals in general and of wood preservatives in special get increasing importance within the population. They are based mainly on an uncertain fear for unknown health risks and vary between different countries and regions. No straight line can be traced. Nevertheless feelings often will influence a decision against chemical wood preservation. Therefore they have to be...
H Willeitner
Properties of particleboard made from recycled CCA-treated wood
2000 - IRG/WP 00-50146
Recovery of chromated copper arsenate (CCA)-treated wood for reuse ha s been the focus of several international research groups due to the imminent disposal problem created when large quantities of CCA-treated wood ultimately come out of service. Bioleaching with Bacillus licheniformis CC01 and oxalic acid extraction are two methods known to remove significant quantities of metals from CCA-treated...
C A Clausen, S N Kartal, J H Muehl
Preservation of wood composites with zinc borate
1995 - IRG/WP 95-30074
Inorganic borates such as boric acid, borax, disodium octaborate tetrahydrate, and zinc borate can be incorporated into wood composites such as waferboard to impart decay and insect resistance to the final product. Zinc borate is especially well suited for this application due to its efficacy and leach resistance. The paper summarizes the work performed to date in this area. The effects on strengt...
P E Laks, M J Manning
Chemical and biological investigations of double-vacuum treated windows after 5 years in service
1983 - IRG/WP 3219
In 1980 The Swedish Wood Preservation Institute initiated an investigation to study the degradation of TBTO and possible fungal attack in double-vacuum treated window joinery in service during 5 years. A hospital in Gothenburg was chosen that was built during 1969 to 1976. Both untreated and double-vacuum treated windows of Pinus sylvestris were used. A brown alkyl oil type paint (Nordsjö system ...
J Jermer, M-L Edlund, B Henningsson, W Hintze, S V Ohlsson
The influence of causing primary blue-stain fungus Ceratocystis imperfecta on selected properties of Scots pine wood
2002 - IRG/WP 02-10425
The effects of development in wood the fungi causing blue-stain on the wood properties are not univocal. There were been undertaken investigation to clear the influence of such fungi on selected physical and mechanical properties of Scots pine wood.
Wet sap wood samples of fresh cut Scots pine wood (Pinus sylvestris L.) were infested with pure culture of Ceratocystis imperfecta Mill. et Grenz and...
A Fojutowski
Chemical Analysis of Southern Pine Pole Stubs Thirteen Months Following Treatment with Three Methylisothiocyanate Based Commercial Fumigants
2002 - IRG/WP 02-30294
Agricultural fumigants have been commercially used in the United States for over 20 years to control internal decay in utility poles and other wooden structures. Of the four fumigants which are currently used in the remedial treatment of utility poles, three are based on methylisothiocyanate (MITC) as being the principal fungitoxic component. Two of these MITC based fumigants, liquid metham sodi...
R J Ziobro, T C Anderson, D J Herdman, J Guzzetta, T Pope
Glass splinters as physical termite barriers: Optimized material properties in use with and without insecticidal pretreatment minimizes environmental contaminations
1991 - IRG/WP 1476
The major advantage of physically acting barriers against termites using sand or cinder is to be impenetrable for a number of termite species by showing environmental compatibility in a high degree. The major disadvantage of these barriers is the ability of termites to build galleries over them. Glass or glass-like materials are showing optimum material properties: crushed to a particle size from ...
M Pallaske, A Igarashi
Biological and physical properties of phenolic-resin treated wood before and after natural weathering
1999 - IRG/WP 99-40132
Biological and physical properties of phenolic resin-treated particleboards, which were made from fast growing tress and agrowaste as raw materials, were evaluated before and after natural weathering in tropical climate. The particles were sprayed with a mixture of a low molecular weight phenol-formaldehyde resin (5.0, 7.5 and 10% loading) and the adhesive phenol resin (8% loading). Results with l...
S Yusuf, Y Sudiyani, H Kajita, Y Imamura, M Takahashi
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
Subterranean termite foraging behaviour and the development of baiting methods used for termite control by the Division of Forest Products
1994 - IRG/WP 94-10058
Given the premise that alternatives to current subterranean termite control measures using organochlorine insecticides and arsenic trioxide have been actively researched by our Division for over ten years, emphasis on baiting methods in controlling these termites has been a major facet of our research. Recently, the new Australian Standard (AS 3660 -1993) was released which outlined the use of phy...
J R J French, J W Creffield, B M Ahmed
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
The effect of heat treatment on the properties of spruce
1994 - IRG/WP 94-40032
The effect of high temperature treatment (above 150°C) on the wood quality is studied at the VTT. Improved dimensional stability, lower equilibrium moisture content and increased durability against biodeterioration is achieved, depending on the environmental factors. The biodeterioration resistance of spruce is improved due to changes in chemical composition and lower equilibrium moisture content...
H Viitanen, S Jämsä, L Paajanen, A J Nurmi, P Viitaniemi
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
Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell
Effects of soil physical and chemical characteristics on adsorption of leached CCA and ACQ preservative components
2003 - IRG/WP 03-50200
The objective of this study was to examine the effect of soil characteristics on adsorption of wood preservative components from CCA and ACQ preservative systems. Adsorption of leached CCA and ACQ preservative components in soils with different characteristics were studied. Three soils (clay, sandy and organic) were investigated using different concentrations of leach water of CCA and ACQ wood pr...
S Stefanovic, P A Cooper
Biological and chemical investigations for the assessment of the environmental impact of wood preservative components
1999 - IRG/WP 99-50127
This study was carried out in order to investigate the suitability of biological and chemical techniques to evaluate the environmental impact of wood preservatives depleted from impregnated wood. Small specimens (15*25*50 mm3) of Scots pine sapwood (Pinus sylvestris) were treated with a CCB salt. After fixation the treated and untreated samples were washed-out according EN 84, and the different le...
E Melcher, H-W Wegen
Antagonistic properties of Gliocladium virens against wood attacking fungi
1996 - IRG/WP 96-10162
Gliocladium virens has shown good antagonism against decay fungi in agar medium and in wood blocks. Gliotoxin produced by Gliocladium virens is associated with biocontrol of some plant diseases, but its importance to biocontrol of wood-attacking fungi is unknown. We investigated the ability of gliotoxin-producing (GLT+) isolates of Gliocladium virens and gliotoxin-deficient (GLT-) mutants of Glioc...
T L Highley, H S Ananthapadmanabha, C R Howell
Anti-fungal properties of pyrolytic oils derived from softwood bark
2000 - IRG/WP 00-30218
Thermal decomposition of balsam fir and white spruce mixed bark residues at 450°C and under vacuum (< 20 kPa abs.) results in high yields of pyroligneous liquors rich in phenolic content. This vacuum pyrolysis process has been scaled-up to a pyrolysis plant with a feed capacity of 3.5 t/h of softwood bark, which is the largest plant of this type in the world. The pyrolytic aqueous condensates ...
D Mourant, Dian-Qing Yang, Xiao Lu, C Roy
Biological test, AAS and EPR study of copper monoethanolamine complex with quaternary ammonium compounds as a wood preservative
2003 - IRG/WP 03-30321
Experiments were carried out on the wood preservative with a strong fungicidal activity based on Cu(II) carbonate, 2-aminoethanol (monoethanolamine) and quaternary ammonium compound (QAC). The object of the performed investigations was sapwood of Scots pine (Pinus sylvestris L.) treated with Cu-EA-QAC formulation. Mycological investigations were carried out according to EN 113 and EN 84 standards....
B Mazela, I Polus, S K Hoffmann, J Goslar
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
Chemical treatment of chips for outdoor storage. Evaluation of sodium N-methyldithiocarbamate + sodium 2,4-dinitrophenol treatment
1980 - IRG/WP 2134
Fresh slash pine chips were treated by spraying them with a dilute aqueous solution of sodium N-methyldithiocarbamate and sodium 2,4-dinitrophenol. The were then formed into an experimental chip file 10 feet high, and the pile was maintained for seven months. The treatment effectively slowed heat release and retarded losses in wood substances, tall oil, pulp yield, and pulp strenght. Under certain...
E L Springer, M Benjamin, W C Feist, L L Zoch, G J Hajny
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