Your search resulted in 116 documents. Displaying 25 entries per page.
Characteristics of thermally modified wood in vacuum
2004 - IRG/WP 04-40287
In commercial thermal wood modification processes nitrogen, steam or oil has been used for the reduction of oxygen content in the reactor atmosphere. In present study no special heating medium, but an initial vacuuming step has been used for this purpose. Mass loss, resistance to fungal decay, dimensional stability, bending strength and modulus of elasticity of heat treated wood were evaluated and...
G Rep, F Pohleven, B Bucar
Effect of aqueous polymer treatments on wood properties. Part 1: Treatability and dimensional stability
1990 - IRG/WP 3610
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 dimensional stability were conducted on matched treated and untreated pieces. Measurement of the antishrink efficiency indicated that DMDHEU was a better stabilizer than the polyacrylat...
Z Ashaari, H M Barnes, R C Vasishth, D D Nicholas, D E Lyon
Impregnation of timber with tannin as a mean of improving its dimensional stability
1992 - IRG/WP 92-3695
The results of a joint project carried out at the Timber Division of LNEC under the 2nd research programme of the CEC DGXII - "Wood as a renewable raw material" entitled "Stabilization of wood by impregnation processes" is presented. Pieces Maritime pine timber was impregnated with tannin under pressure to see if the treatment with tannin improved the behavior of wood regarding its dimensional sta...
J S Machado
Stability of bifenthrin in a commercial phenol-formaldehyde plywood glue
2003 - IRG/WP 03-30311
Liquid phenol formaldehyde (PF) glue mixes used for plywood manufacture are strongly alkaline. At this pH insecticidal additives may not be stable for long periods. In order to establish practical working life of the synthetic pyrethroid insecticide, bifenthrin, in liquid PF glues the concentration of bifenthrin in the glue mix was measured under laboratory conditions over a 24 hour period. Glu...
M J Kennedy, P A Collins, R D Vella
A new process for in situ polymerization of vinyl monomers in wood to delay boron leaching
1998 - IRG/WP 98-40110
Efforts were accelerated on effective use of boron compounds in wood preservation owing to their environmentally safe characteristics and relatively low costs in addition to their well-known high bioactivity and fire resistant properties. Although having these unique favorable properties, they are readily leachable from treated wood at humid conditions. Therefore, they had limited market for exter...
M K Yalinkilic, W Dwianto, Y Imamura, M Takahashi
New research data confirming the suitability of bifenthrin as a wood preservative
1996 - IRG/WP 96-30116
Bifenthrin has been further tested against wood destroying insects, and its behaviour in wood has been extensively studied. Bifenthrin proved to be highly effective as a curative and preventative treatment against Anobium punctatum and Hylotrupes bajulus, after both leaching and evaporative ageing. Results of penetration tests with water and solvent based formulations, applied by brushing, dipping...
S Shires, P Héloir, B Chen, G Rustenburg
Heat treatment of less-valuable Nigerian-grown Ceiba pentandra wood for improved properties
2006 - IRG/WP 06-40332
The hardwood Ceiba pentandra locally known as “ araba “ in Nigeria is rarely used for structural and construction works due to its high dimensional instability, low strength and durability values. Samples (10 x 10 x 150mm) were removed from four green boards (25 x 200 x 3000mm) of this species originating from a natural forest stand in Nigeria and subjected to 2-hour heat treatment at 160°C a...
L Awoyemi
The Effect of Flavonoids on Colour and Spectral Changes of the Wood Surface Caused by Heat Treatment or Ultra-violet Irradiation
2006 - IRG/WP 06-40341
Both heat treatment and UV irradiation can cause discolouration and change in the spectral properties of wood surface. Some of the characteristic flavonols have significant role on colour and spectral changes, despite of their relative small quantities in wood.
Colour changes and spectral properties of natural and extracted black locust (Robinia pseudoacacia L.) and poplar (Populus nigra L.) were...
R Csonka-Rákosa, L Molnár-Hamvas, E Börcsök, J Molnár, K Németh
Effects of heat treatments on decay resistance and material properties of ponderosa pine and yellow poplar
2007 - IRG/WP 07-40374
The potential for using heat treatment to improve the properties of North American fenestration species was evaluated on ponderosa pine (Pinus ponderosa L) and yellow poplar (Liriodendron tulipifera L) treated using the ThermoWood process at various treatment temperatures and times. Soil block tests using Gloeophyllum trabeum, Postia placenta, or Trametes versicolor showed that durability was enh...
C Vidrine, C Freitag, J Nicholson, J J Morrell
Water repellency and dimensional stabilIty of wodd treated with waterborne resin acids/TOR
2007 - IRG/WP 07-40364
Wood used in above ground applications such as decking undergoes undesired dimensional changes leading to the lumber warping, cupping, splitting, etc. This is a major concern to consumers but it can be reduced by treating lumber with a water repellent. The ability of resin acids, hydrophobic compounds naturally present in southern yellow pines, was examined as a possible water repellent. A wate...
T P Schultz, D D Nicholas, J Shi
Multivariate analysis of infrared spectra for the prediction of the mechanical performance and dimensional stability of thermally modified wood
2007 - IRG/WP 07-40367
The use of calibrated mid-infrared Fourier transform (FTIR) spectroscopy for predicting the main bending strength parameters of thermally modified wood is described for the first time. The analysis is based on the handling of OSC-filtered FTIR data from control and treated wood samples, using partial least squares (PLS) regression.
Sets of Norway spruce, Scots pine and Beech wood samples were th...
M M González-Peña, M D C Hale
The Effect of Heat Treatment on Water Absorption and Dimensional Stability of Anatolian Chestnut (Castanea sativa Mill.) wood
2008 - IRG/WP 08-40407
The heat treatment of wood is an environment-friendly method for wood preservation. This process improves wood’s resistance to decay and its dimensional stability. However, mechanical properties decrease in different ration because of density loss as a result of heat treatment. In this study, the effect of heat treatment on water absorption and dimensional stability at different relative humidit...
G Gunduz, D Aydemir
Material properties of acetylated beech plywood
2008 - IRG/WP 08-40425
The effect of acetylation process on dimensional stability and mechanical properties of plywood made by Oriental beech layers (Fagus orientalis Lipsky) were studied. The layers cut into sizes of 200×200×2 mm and acetylated in 120°C for 30 and 60 min.
Thickness swelling (TS%), water absorption (WA%) and anti-swelling¬ efficiency (ASE%) of specimens were measured. Mechanical properties (MOE, MO...
A Talaei
Effectos de la intemperización artificial sobre la madera de mezquite (Prosopis laevigata)
2008 - IRG/WP 08-40430
The effects of artificial weathering on Prosopis laevigata wood were studied on eight replicates (150 x 72 x 15mm (l x t x r)) free of knots, cracks and resin. The samples were exposed tangentially to UV light and to water spray during three cycles (1 cycle corresponded 1 week of artificial weathering). The conditioning time between each cycle was thirty days. The effects were measured according t...
A Carrillo-Parra, F Hapla, C Mai
Improving the Dimensional Stability and Fire Resistance of OSB by Roller-Coating Panels with UV-Curable Finishes
2008 - IRG/WP 08-40434
Oriented strandboard was sanded and roller-coated with UV-cured finishes. The effects of these treatments on the surface roughness, dimensional stability and fire resistance of OSB were assessed. Sanding reduced the average roughness of OSB, but it had a smaller effect on maximum roughness because sanded boards still contained surface voids between some strands. Sanded boards absorbed less than ha...
P D Evans, I Cullis
Mechanical and chemical properties of blue stained wood
2009 - IRG/WP 09-10686
Discoloration of wood is frequently caused by blue-staining fungi. In the previous researches there was general opinion that blue-stain fungi do not influence mechanical properties. On the other hand, there were some opposite results reported as well. In order to elucidate this issue, specimens made of Pinus sylvestris sapwood were exposed to two the most frequent and important blue stain fungi Au...
M Humar, V Vek, B Bučar
Dimensional Stability of Nine Tropical Hardwoods from Cameroon
2009 - IRG/WP 09-10687
This study investigated the swelling behavior, rate of swelling and dimensional stability of nine tropical hardwood species from Cameroon, namely ayous (T. scleroxylon), bilinga (N. diderrichii), bubinga (G. tessmannii), iroko (C. excelsa), Makore (M. heckelii), moabi (B. toxisperma), movingui (D. benthamianus), teak (T. grandis) and zingana (M. brazzavillensis). Continuous swelling was monitored ...
S R Shukla, D P Kamdem
Evaluation of Water Repellency of Treated Wood Using Several Alternative Methods
2009 - IRG/WP 09-20419
In this study, the results of water repellency testing using a digital swellometer method for water-borne organic-preservative systems with water repellent additives are reported. The findings suggest that the traditional method of using matched untreated controls as a reference developed from historic solvent-based treatments for determination anti-swelling efficacy (ASE) may underestimate the a...
L Jin, A F Preston
Colour change monitoring of photodegradation in Scots pine (Pinus sylvestris) – a short term focus
2009 - IRG/WP 09-40442
Colour change monitoring of photodegradation is a quick and easy method for monitoring rates of photodegradation in timber. A study was undertaken to compare this technique to other monitoring methods, including microtensile strength changes and weight loss. Colour changes due to accelerated sunlight exposure were monitored using a Datacolor check spectrophotometer and compared with a set of contr...
V Sharratt, C A S Hill, D P R Kint
Weathering of Wood Modified with the N-Methylol Compound 1,3‑dimethylol-4,5-dihydroxyethyleneurea (DMDHEU)
2009 - IRG/WP 09-40467
Scots pine (Pinus sylvestris L.) sapwood boards were treated with a methylated 1,3‑dimethylol-4,5-dihydroxyethyleneurea (mDMDHEU) causing weight gains of approx. 25% and exposed to weathering for 18 months. Compared to untreated boards, treatment with mDMDHEU reduced surface discoloration mainly caused by staining fungi. Boards treated with mDMDHEU exhibited clearly lower moisture content th...
C Mai, Yanjun Xie, A Krause, K Urban, P D Evans, K Richter, H Militz
Properties of thermally modified wood of Eucalyptus globulus from Spanish plantations
2009 - IRG/WP 09-40469
This article provides the results of a study about the properties of thermally modified wood of the Southern blue gum (Eucalyptus globulus L.) from Spanish plantations. Although this specie is mainly used for chipping to obtain boards and paper pulp, its high mechanical and strength properties provide great potential for structural use or different solid wood products. A comparison of the properti...
Ó González Prieto, M C Touza
The effect of chemical changes on the wood-moisture relationships in thermally-modified wood
2009 - IRG/WP 09-40473
Small specimens of three wood species were thermally modified following twenty schedules in the 190-245°C temperature range for treatment times between 0.3 and 16 h. Five wood-moisture relations were subsequently determined, namely: anti-swelling efficiency (ASE), movement, hygroscopicity (adsorption and desorption), transversal swelling (radial and tangential directions), and equilibrium moistur...
M M González-Peña, M D C Hale
Comparison of colour change in wood clear-coating systems including inorganic and organic UV absorbers for exterior use
2010 - IRG/WP 10-40499
The aim of this work is to compare the performance of inorganic and organic UV absorbers used in a wood coating application against weathering. Our study has investigated the colour changes of selected UV absorbers; hombitec 402 RM from the Sachtleben Company as an inorganic UV absorber, tinuvin 477 DW from the Ciba Company as an organic UV absorber. The study was carried out on two wood species; ...
Ö Özgenç, B Forsthuber, A Teischinger, C Hansmann
A comparative study and evaluation of methodologies used for determining wood preservative penetration
2011 - IRG/WP 11-20475
A series of methods for determining penetration of wood preservatives into the wood structure have been developed for either quality control (QC) or research and development purposes. QC methods range from monitoring the solution uptake, applying colour indicators or sampling specific wood samples followed by wood acid digestion/atomic absorption spectroscopy (AAS) or solvent extraction/chromatogr...
R Craciun, R Moeller, J Wittenzellner, T Jakob, J Habicht
Effects of microclimate, wood temperature and surface colour on fungal disfigurement on wooden claddings
2012 - IRG/WP 12-20490
Wooden claddings are common in façades in Norway, and Norway spruce (Picea abies) is the most frequently used species. The cladding is a major part of the facade, and it has visual requirements that may define the aesthetic service life. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more of...
L Ross Gobakken, G I Vestøl