Your search resulted in 69 documents. Displaying 25 entries per page.
A review on prediction methods of wood natural durability
2017 - IRG/WP 17-10892
Natural durability of timber may be defined as “inherent ability of timber to attack by wood destroying organisms (bacteria, fungi, insects, marine borers) without preservative treatment. On the base of biological tests, EN-350-2 standard (Afnor, 1994), describe the classification of wood species according to their natural durability. But these specifications are not adapted in the case of wood ...
N Amusant, C Flora, J Beauchène, E Houël, C Duplais
UV-microspectrophotometry of lignin and accessory compounds in wood cell walls of conifers
1999 - IRG/WP 99-20171
The distribution of lignin in the cell wall of conifer tracheids was determined by UV-VIS microspectro-photometer. Wood sections of one micron thickness were measured between the wavelength 240 and 700 nm. Spectral analyses revealed that the conifer lignin associated with the tracheid secondary wall and middle lamella is composed of guiacylpropane units which exhibit a characteristic UV absorption...
G Kleist, G Koch, J Bauch
Photostabilization of Wood with Higher Molecular Weight UV Absorbers
2010 - IRG/WP 10-30524
Higher molecular weight UV absorbers were created by reacting the epoxy-functionalized UV absorber 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) with maleic, phthalic or succinic anhydride. The ability of the UV absorbers to photostabilize wood was then examined. FTIR-spectroscopy confirmed that HEPBP reacted with phthalic anhydride to create a polyester that preserved the UV-absorbing benzop...
P D Evans, M J Chowdhury
Effect of acetylation on decay resistance of wood against brown-rot, white-rot and soft-rot fungi
1989 - IRG/WP 3540
Effect of acetylation on decay resistance of wood was investigated using wood blocks of Cryptomeria japonica, Pinus densiflora, Albizia falcata and Fagus crenata. Blocks were treated with uncatalyzed acetic anhydride for different lengths of time and exposed to Tyromyces palustris, Serpula lacrymans, Coriolus versicolor and unsterilized soil. The action of OH-radical on acetylated wood was also ex...
M Takahashi, Y Imamura, M Tanahashi
Relationship between stacking, location and antisapstain preservatives on visible degrade of Eucalyptus regnans and Pinus radiata boards
1999 - IRG/WP 99-20162
An antisapstain trial was established at a Eucalyptus hardwood sawmill in Victoria, Australia. The trial incorporated two commercial formulations of antisapstain preservatives, used at four different concentrations on both hardwood (Eucalyptus regnans F. Muell) and softwood (Pinus radiata D. Don) boards. The trial also utilised different stacking methods (block-stacked, sticker-stacked, and block-...
J Snow, P Vinden, S M Read
Microscopic characteristics of Pinus radiata wood veneers weathered outdoors for one yea
1993 - IRG/WP 93-10018
Radiata pine (Pinus radiata) wood veneers glued to solid wood hacking strips were exposed outdoors at 45° north-facing for one year and then examined by light microscopy (LM) and transmission electron microscopy (TEM). As expected, the exposed wood surfaces were colonised by a variety of microorganisms; however, wood decay was not observed. Ultlaviolet (UV light) radiation and water were the main...
A P Singh, R A B Sweeney, E A Dunningham, D V Plackett
Influence of storage on mould susceptibility of wood at relative humidity values lower than 100%
1989 - IRG/WP 1413
It is well known that wood material changes with time because of different environmental influences. The effects of such changes on the subsequent mould susceptibility are less known. In this paper we report on increased mould susceptibility of pine wood after storage. Mould growth was detected by indirect methods....
J Bjurman
An insight into brown rot decay of timber as revealed by 13C CP/MAS NMR
1985 - IRG/WP 1259
L E Leightley
Fungal degradation of wood treated with metal-based preservatives. Part 2: Redox states of chromium
1996 - IRG/WP 96-10164
Concerns have arisen about the leaching of heavy metals from wood treated with metal-based preservatives, such as chromated copper arsenate (CCA). Of particular concern is the toxic redox state of chromium and arsenic in aging and decayed CCA-treated wood. Generally, hexavalent chromium is more toxic than trivalent chromium and trivalent arsenic is more toxic than pentavalent arsenic. The desired ...
B Illman, S Bajt, T L Highley
The use of ESR spectroscopy to assess the photostabilising effects of wood preservatives
2000 - IRG/WP 00-20186
The degradation of wood surfaces exposed to UV light which leads to poor performance of clear coatings is understood to be due to delignification via a mechanism involving free radicals. Certain wood preservatives most notably CCA are able to photostabilise wood and therefore they may reduce the concentration of free radicals formed when treated wood is exposed to ultraviolet light. As a first ste...
S Schmid, R D Webster, P D Evans
Effects of artificial UV weathering and soft rot decay on heat treated wood
2005 - IRG/WP 05-40302
Oil and inert gas oven heat treated pine wood strips 100 µm thick were mildly heat treated (200°C, 30 mins linseed oil, 120 mins oven). Following treatment, specimens were exposed to UV weathering (300 hours) and decay by the soft rot fungus, Chaetomium globosum. The effects of each treatment were assessed by zero span tensile testing, microscopy and by FTIR.
Tensile testing of heat treated s...
M D C Hale, S C Ghosh, M J Spear
Acceleration of the fixation of chromated wood preservatives by UV-radiation
1989 - IRG/WP 3544
Preliminary laboratory tests demonstrated that the fixation of chromated water-borne wood preservatives may be accelerated by UV-radiation. The degree of fixation depends on the intensity of radiation and the prevailing temperature. Three hours radiation at 20°C in a device for artificial weathering diminished the leaching of chromium to 43% and of copper to 23% compared to not-radiated samples. ...
H M Illner, H Willeitner, K Brandt
EELS (Electron Energy Loss Spectroscopy) - a technique for quantification of nitrogen and other light elements in the cell wall
1999 - IRG/WP 99-20163
A literature survey was performed to find progress in techniques for monitoring penetration of synthetic resins in wood cell walls. Electron energy loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM) was successfully applied for the high resolution examination of the distribution of a partly methylated hydroxymethyl melamine resin in Norway spruce (Picea abies Karst...
A O Rapp, H Bestgen, W Adam, R-D Peek
An investigation of organotin compounds in treated wood using Mössbauer spectroscopy
1983 - IRG/WP 3249
The influence of sample preparation on the 119mSn Mössbauer spectrum of tributyltin chloride in ponderosa pine was investigated. Initial studies with sawdust and compressed discs concluded that the latter were clearly superior. Further studies showed that compressed discs prepared from 0.4 g of treated wood and 0.1 g of cellulose were robust and gave excellent Mössbauer spectra. The possibility ...
J N R Ruddick, J K Ingram
Prediction of Weight Percent Gain (WPG) of furfurylated wood by FT-NIR spectroscopy
2004 - IRG/WP 04-20295
Wood modification based on furfuryl alcohol improves several important wood properties, such as the resistance to fungal decay and insect attack, hardness, dimensional stability, bending strength and stiffness. The improvements of wood properties depend on the weight percent gain (WPG) due to furfurylation. Fourier transform near infrared (FT-NIR) spectroscopy was used to calibrate PLS-regression ...
M Eikenes, P O Flæte, E Ystrøm Haartveit, S Lande
A comparison of inductively coupled plasma spectroscopy and neutron activity analysis for the determination of concentrations in wood
1993 - IRG/WP 93-10048
As wood decays the ionic composition changes, with increases often being seen in the concentrations of Ca, Mg, Fe, Mn and sometimes K. The concentration of eight cations in red spruce sapwood and heartwood samples was determined independently by inductively coupled plasma spectroscopy (ICP) and by neutron activation analysis (NAA) as part of an effort to standardize our analytical procedures and c...
J Jellison, J Connolly, K C Smith, W T Shortle
The compatability of tributyltin fungicides and synthetic pyrethroid insecticides as wood preservatives
1987 - IRG/WP 3414
The stability of three synthetic pyrethroids, cypermethrin, deltamethrin and permethrin, to selected tributyltin compounds, Bu3SnX {where X = OSnBu3, Cl, 02CC6H5, O2C (Naphthenyl), OSO2Et}, (Bu3SnO)3PO and {NBu4} {Bu3SnCl2}, in toluene solution was investigated by infra-red spectroscopy over a six month period. It was found that only (Bu3Sn)2O reacted with the pyrethroids and that their order of r...
S J Blunden, R Hill
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
A technique for the rapid assessment of wood surface degradation during weathering
1987 - IRG/WP 2281
Radiate pine (Pinus radiata D. Don) sapwood samples taken from four trees were converted into thin strips 100 x 10 x 0.085 (85 µm) mm³, (longitudinal x radial x tangential) in size and exposed in preweighed hatches to the weather inclined at 45° facing equatorially for 10, 20, 40, 60, 80 and 100 days. Significant (P < 0.001) weight losses occurred with time over the exposure period. Differen...
P D Evans, D Abbott, S Thein
NIR spectroscopy for rapid estimation of decay resistance
2004 - IRG/WP 04-20294
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta. In general outer heartwood was more resistant than inner heart...
P O Flæte, E Ystrøm Haartveit
Permanence of permethrin and bifenthrin in framing timbers subjected to hazard class 3 exposure
2005 - IRG/WP 05-30383
End-sealed Pinus radiata specimens measuring 235 x 90 x 35 mm were treated using a modified Lowry schedule with permethrin or bifenthrin in white spirit to Hazard Class 2 (H2) retentions. After conditioning, the specimens were exposed at 45o on north facing racks near Melbourne (Australia). Samples of the specimens were taken before installation, and after three and six months exposure. Analyses o...
A C Hunt, D G Humphrey, R Wearne, L J Cookson
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Artificial weathering exposure as an alternative for standard ageing according to EN 84 (leaching) and EN 73 (evaporation)
2002 - IRG/WP 02-20254
In order to verify potential weaknesses of wood preservatives fungal tests are carried out after ageing of wood preservative treated test blocks. The European standard EN 599 as a framework for efficacy assessment of wood preservatives includes the use of two ageing methods prior to fungal testing, namely a leaching method (EN 84) and an evaporation method (EN 73). The European research project "F...
J Van Acker, M Grinda, D J Dickinson
Differentiation of Scots pine heartwood and sapwood by near infrared spectroscopy
2003 - IRG/WP 03-10459
In Scandinavia Scots pine heartwood has, in recent years, gained popularity as material for external structures exposed to moderate risk of decay. As non-durable sapwood surrounds the heartwood in pine trunks it is of crucial importance to separate this wood from the heartwood during log processing into heartwood products. Heartwood and sapwood can be differentiated by visual evaluation of colour ...
P O Flæte, E Ystrøm Haartveit
Accelerated weathering test for the evaluation of wood preservative efficacy
2003 - IRG/WP 03-20262
Wood samples treated with ammonium copper quat (ACQ-1900 and ACQ-2200), Chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments.
The weathering experiment was performed by cycles of 2 hours UV-light irradiation followed by water spray for 18 minutes. The changes on the surface of the weathered samples were characterized by FTIR Sp...
A Temiz, M Eikenes, Ü C Yildiz, F G Evans, B Jacobsen