Your search resulted in 739 documents. Displaying 25 entries per page.
Markers of quality in self-bonded beech boards
2017 - IRG/WP 17-40820
A self-bonding phenomenon takes place when five layers of beech (Fagus Sylvatica L.) veneers are pressed at temperatures higher than 200ºC. If the pressing temperature between veneer surfaces reaches at least 225ºC during pressing and if the pressure applied is optimal, water-resistant bonds are formed between veneers. This study investigates the relation of thickness reduction (marker of compre...
C Cristescu, D Sandberg, O Karlsson
Heat treatment of bamboo
2001 - IRG/WP 01-40216
Bamboo is a fast growing material with remarkable mechanical properties. In many tropical and subtropical countries bamboo is available in suitable dimensions for a reasonable price. Therefore it is used for many purposes which range from the basket production up to the industrial production of parquet or paper. However, bamboo is known as susceptible to fungal or insect attack and it is difficult...
H Leithoff, R-D Peek
Innovations in the treatment of Southern pine heartwood
2000 - IRG/WP 00-40172
Whereas the sapwood of southern yellow pine (Pinus spp.) is readily treatable, the heartwood is essentially impermeable to preservatives such as chromated copper arsenate (CCA). Preliminary studies at the Mississippi Forest Products Laboratory indicate that increases in penetration and retention of preservative in pine heartwood can be obtained by subjecting kiln dried dimension stock to varying m...
M G Sanders, T L Amburgey, H M Barnes
Heat treatment of wood strands for OSB production: Effect on the mechanical properties, water absorption and dimensional stability
2002 - IRG/WP 02-40238
The effect of heat treatment on the mechanical and physical properties of commercial OSB strands was evaluated. Heat treatment was applied under inert atmospheric conditions to wood strands. The aim of this study was to examine the heat treatment parameters to achieve significant reduction of thickness swelling (upon exposure to moisture in service) without causing excessive
reductions in stren...
G J Goroyias, M D C Hale
Vapour boron treatment of wood based panels: Further studies on mechanical properties
1993 - IRG/WP 93-30028
Samples of medium density fibreboard, chipboard and oriented strandboard were treated to two retentions of boric acid by vapour phase methods. The results of short term mechanical tests on this material were discussed by Hashim et al. (1992). The present paper discusses results with long term studies on bending and impact resistance with panel types. Long term tests of impact resistance showed no ...
R Hashim, R J Murphy, D J Dickinson, J Dinwoodie
Bending properties of treated western hemlock plywood
1996 - IRG/WP 96-40064
This study investigated the mechanical properties of western hemlock plywood after treatment with waterborne preservatives and redrying. Unlike previously reported results for southern pine plywood, western hemlock plywood was more sensitive to redrying temperature than to preservative treatment. Generally, western hemlock plywood was affected by temperature and other variables. Losses in mechanic...
H M Barnes, A Khouadja, D E Lyon
Effects of a formaldehyde and sulphur dioxide treatment on decay and mechanical properties of aspen waferboard
1983 - IRG/WP 3242
Aspen wafers were sequentially treated under vacuum with formaldehyde and sulfur dioxide gas and pressed into waferboard bonded with powdered phenol formaldehyde resin. Decay resistance and strength properties were determined before and after simulated weathering. The water resistance of the phenol bonding system was lost in board made from the gas-treated wafers. This white rot fungus Coriolus ve...
E L Schmidt
Effects of alkali treatment on some mechanical and chemical properties of creosote treated oaks
1991 - IRG/WP 2366
To date, there is a lack of information on the effects of chemical treatment on the performance of creosote preservative treated oak sleepers. This factorial experiment was designed to analyze three main effects: species (Quercus alba and Quercus rubra) creosote treatment (treated and untreated), and alkali (NaOH) soaking (0, 1, and 10 percent). The modulus of elasticity (MOE) and fiber stress at ...
P Chow, A J Reinschmidt, E J Barenberg, L C Chang
Effect of vapour boron treatment on mechanical properties of wood based board materials
1992 - IRG/WP 92-3727
The mechanical properties of Medium density fibre board, Chipboard and Oriented strand board were investigated after treatment to two retention levels of boric acid applied as a vapour phase system. A range of mechanical properties were investigated. The vapour boron treatment does not have any significant effect on most of the mechanical properties of the boards. The exception is a reduction in i...
R Hashim, D J Dickinson, R J Murphy, J Dinwoodie
Supercritical fluid treatment: Effects on bending strength of white spruce heartwood
1993 - IRG/WP 93-20008
The effects of supercritical carbon dioxide on wood strength were evaluated using white spruce heartwood, a species known to be especially susceptible to collapse during exposure to higher pressures. The effects of pressures of 2000 or 3600 psig and temperatures of 40 or 80°C were evaluated using 30 or 60 minute exposure periods. No significant differences were noted in modulus of rupture or modu...
S M Smith, J J Morrell, E Sahle-Demessie, K L Levien
Effect of point of preservative addition on the mechanical and physical properties of strandboard treated with Tanalith 3485
2000 - IRG/WP 00-40152
Preservative has been added to a PF bonded strandboard at various different stages in the manufacturing cycle and the physical and mechanical properties of the boards have been evaluated (modulus of elasticity, modulus of rupture, thickness swelling, water absorption, internal bond strength, and shear strength). Preservative addition has been examined at five different stages namely green strand d...
G J Goroyias, M D C Hale
The effects of preservative treatment and exposure to wood degrading fungi on fiber reinforced polymer (FRP) materials used for structural wood reinforcement
2001 - IRG/WP 01-40204
Glass fiber reinforced phenolic (GFRP) composite materials are becoming increasingly accepted for use in the construction industry because they combine advantages of both wood and advanced polymeric materials. Addition of only 1-3% FRP in the tension zone, for example, can typically improve the strength of the hybrid system by 200%. As more applications are found for wood/FRP hybrids, (e.g. lamina...
C Tascioglu, B Goodell
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
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
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
High-energy multiple impact (HEMI)-test – Part 2: A mechanical test for the detection of fungal decay
2006 - IRG/WP 06-20339
The suitability of the high-energy multiple impact (HEMI)-test for detection of early fungal decay was examined. The HEMI – test characterizes the treatment quality of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are expressed by structural changes of the wood. Simil...
C R Welzbacher, C Brischke, A O Rapp
Wood plastic composites from modified wood; Part 1 - Conceptual idea, mechanical and physical properties
2006 - IRG/WP 06-40338
Wood plastic composites, WPCs, are rapidly taking shares from preservative treated wood on the decking market. However, the long term performance of the WPC products in this application is uncertain. Therefore, in an attempt to increase the long term performance and durability, the substitution of the unmodified wood component with modified wood has been studied in the work presented in this paper...
P Larsson Brelid, B K Segerholm, M Westin, M E P Wålinder
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
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
Changes in hygroscopic, mechanical and surface properties of Scottish-grown Sitka Spruce (Picea sitchensis) wood subjected to dry heat treatment
2008 - IRG/WP 08-40415
Heat-treatment is a wood modification method which has been used to some extent in improving timber quality. However, the main limitation in the use of this technique despite its numerous advantages is the adverse effects on the various properties associated with the use of wood as an engineering material. Dry heat treatment of Scottish-grown Sitka spruce (Picea sitchensis) wood was carried out at...
L Awoyemi, M C Jarvis, A Hapca
The effects of zinc borate treatment of wood strands on some technological properties of oriented strandboard (OSB)
2008 - IRG/WP 08-40419
In this study, influences of zinc borate treatment on some technological properties of oriented strandboard (OSB), from aspen wood (Populus euroamericana cv.) were evaluated. Therefore, a total of nine panels with dimensions of 40 cm by 40 cm by 1.8 cm and with an average target density of 0.65 g/cm3 were manufactured under the laboratory conditions. Experimental panels were manufactured at two di...
A D Çavdar, H Kalaycioglu, G Nemli
Differential response of wood to dry air thermal treatment (DATT) and soy oil thermal treatment (SOTT)
2009 - IRG/WP 09-40446
Thermal treatment is an alternative to chemical modification method which has been used to some extent in improving timber quality. In order to get the maximum benefits possible without compromising the various end-use quality requirements of timber, several possibilities have been and are still being investigated in relation to this technique. Clear wood samples (19 x 19 x 150mm) of kiln-dried re...
L Awoyemi
Bioresistance of Poplar Wood Compressed by Combined-Hydro-Thermo-Mechanical Wood Modification (CHTM) Process
2010 - IRG/WP 10-40532
Bioresistance of treated Poplar wood by CHTM process (Combined-Hydro-Thermo-Mechanical Wood Modification) was studied in the current research work. Resistance against brown rot fungus Gloeophyllum trabeum as well as the soft rot decay was the main concern of this work. Poplar wood blocks were hydrothermally treated at temperatures of 120,150 and 180°C for holding time of 0, 30 and 90 min. afterwa...
L Khademi-Bami, B Mohebby
Effects of nano-silver on brittleness of heat-treated solid woods
2011 - IRG/WP 11-40572
The present study is aimed at the effect of heat-treatment of normal as well as nano-silver-impregnated Populus nigra, Populus deltoides, and Fagus orientalis on brittleness. Specimens were impregnated with 200 ppm water-based solution of nano-silver particles under 3 bars in a pressure vessel using empty-cell process. For heat treatment, both nano-silver-impregnated and normal specimens were kept...
H Reza Taghiyari, B Moradi Malek, A Karimi
Mechanical Properties of Hydrothermally Treated Beech Wood in Buffered Mediums
2012 - IRG/WP 12-40597
Hydrothermal treatment of beech wood in buffered mediums was carried out by aim of controlling the destructive effect of acids formed by degradation of carbohydrates on strength properties. Different mediums (water, buffer5, 7 and 8) and temperatures (160 and 180 °C) were used. Mechanical properties of specimens including modulus of rupture (MOR), modulus of elasticity (MOE) and toughness were de...
A Talaei A Karimi, K Yaghoobi, A Talaei