Your search resulted in 176 documents. Displaying 25 entries per page.
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
Envelope treatment to protect softwood timbers from damage by subterranean termites
2003 - IRG/WP 03-30313
Two aboveground field trials were conducted in Australia to determine the effectiveness of envelope treatments of deltamethrin and permethrin for the protection of softwood framing timbers against termite damage. Radiata pine Pinus radiata D.Don and slash pine Pinus elliottii Englem., were treated with Tanalithä T (a novel solvent) to achieve 5-mm-depth envelopes. Details of a field trial against...
B C Peters, J W Creffield
SEM of wood dust particles
1997 - IRG/WP 97-50084
Dust particles from beech and oak trees have been classified in Germany as being "working materials which are definitely carcinogenic to humans". All other wood dusts, including those from softwoods, are classified as being materials "with reasonable suspicion of carcinogenic potential". The carcinogenic principle of action continues to remain unclear. The mechanical irritation is one of a number ...
U Schmitt, R-D Peek, A O Rapp
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
Dimensional stability, biological resistance, and mechanical properties of phenol-resin-treated particleboard
1990 - IRG/WP 3622
Particleboards were treated with a low molecular-weight phenol-formaldehyde (PF) resin and their enhanced properties were evaluated. Besides dipping of particles in aqeous solutions of resin, and spraying of resin solutions before spray of the conventional phenol-formaldehyde resin for adhesive binder, one step treatment by spraying of the mixture of the low molecular-weight resin and the adhesive...
Y Imamura, H Kajita
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
How to keep coated wood structures sufficiently dry to avoid damage caused by rot
1991 - IRG/WP 2376
During the last ten years, a new type of problems with wood rot has emerged in Scandinavia. Thousands of houses have been damaged by wood rot attaching to the exterior wood panel. This paper provides an overview of finished and ongoing work in order to identify the cause of these problems. In field tests, the moisture conditions were measured in panels coated with different paint systems. The infl...
S Hjort
An overview of termite control in buildings in Kenya
1997 - IRG/WP 97-10242
Termites are well known pests of wooden products and structural timber and are responsible for considerable damage in the building sector in sub-Saharan Africa. A general diagnostic survey of damaging termite species in agriculture, forestry and buildings was carried out for the first time in Kenya (1991-1992). Termite species implicated in damage to wooden materials and structural timber in build...
G R S Ochiel, W Gitonga, L Toft
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
Inhibition of wood decay and termite damage by calcium precipitation
1996 - IRG/WP 96-30111
Fungal decay of wood in service, especially brown rot, results in billions of dollars (US) of losses annually. Recent environmental restrictions, both U.S. and international, are limiting or eliminating the use of broad spectrum biocides for wood preservation, primarily due to problems with disposal. In order to design new, environmentally benign methods for control of wood decay fungi, it is esse...
F Green III, T A Kuster, L Ferge, T L Highley
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
Wooden windows, avoidance of damage via constructional measures
1990 - IRG/WP 3591
Increasing awareness of the environment reinforces the trend to use wood as a building material for windows in modern building constructions. Wood is a natural building and construction material. Under certain circumstances such as persistent humidity exceeding 30%, wood is rapidly degraded by decay fungi into CO2 and inorganic salts. The cost caused by damage (e.g. replacement of windows) represe...
R Gründlinger, K Messner
Development on Damage Functions of Wood Decay for Building Envelope Design
2005 - IRG/WP 05-10556
For the hygrothermal analyses of building envelope systems for insulation design, we tried a natural decay test of wetted wood specimens without any inoculation of fungi. Three principal experimental types: under steady-state conditions (Experiment A), at a cyclic water dripping under Non-steady conditions (Experiment B) and at a cyclic water dipping under-steady conditions (Experiment C), were ca...
H Suzuki, Y Kitadani, K Suzuki, A Iwamae, H Nagai
Survey of maintenance management of a residence
2001 - IRG/WP 01-10405
The following points were clarified from the responses to the questionnaire. Termite damage was most common in the bathroom, washroom, and entrance, in that order. Termite damage was most commonly found beneath floors, followed by floor surfaces, and inside walls, in that order. Damage in framing was minimal. Damage in all structural components was most common in the Kyushu region, with the most s...
Y Yamaguchi, M Azuma, Y Hikita, K Nishimoto
Mechanical resistance of Pinus radiata CCA treated and face jointed with PVA adhesive
1999 - IRG/WP 99-40140
Due to the increased use of Pinus radiata timber composites (laminated structural members, panels, etc), its low natural durability and the toxicity of phenol-formaldehyde type adhesives, a PVA (polyvinyl acetate) adhesive was evaluated in machined and rough CCA treated and untreated face joint samples under DIN 68602 (EN 204-205) standard for groups of requirement 3 and 4. The results showed that...
M C Rose, L Reyes, P León
Der Fall Lyctus. Skizzen über Auftreten, Bedeutung und Bekämpfung eines Holzwurms
1980 - IRG/WP 1100
Lyctus brunneus (Steph.) and allied species cause severe damage to wood throughout the world and inflict losses on producers, the trade, industries and craftsmen. Starch-containing wood is liable to attack. The history of the accidental introduction of this wood-destroyer into West-Europe and the causes for this are outlined, biological requirements for the attack as well as developments for Lyctu...
S Cymorek
Inhibition of termite damage by N'N-napthaloylhydroxyamine (NHA): Reticulotermes flavipes (Kollar) vs. Coptotermes formosanus Shiraki
2000 - IRG/WP 00-10354
The calcium precipitating agent NHA has been shown to protect southern yellow pine (SYP) from wood decay and termite damage comparable to CCA in field tests (Gulfport, MS) for two years (Crawford and Green, 1999). In a collaborative study, SYP wood blocks were vacuum treated with three concentrations of aqueous NHA and exposed in a no-choice test to Eastern subterranean termites (FPL, USA) and For...
F Green III, S T Lebow, T Yoshimura
Fungus cellar testing as an evaluation method for performance of treated timber in ground contact
2001 - IRG/WP 01-20227
A fungus cellar method for the accelerated evaluation of performance of treated wood in ground contact is described. The test soil comprised of sandy loam, vermiculite and Japanese horticulture soil "Kanumatsuchi" in a ratio of 6:2:2 by volume. The soil was inoculated with the dominant test fungus isolated with selective medium from decayed wood samples. Pairs of treated and untreated wood specime...
Y Nagano
The effect of hemicellulose degradation on the mechanical properties of wood during brown rot decay
2001 - IRG/WP 01-20219
Incipient decay of wood by brown rot fungi causes measurable strength losses in wood before measurable weight loss occurs. Previous studies have shown that the high levels of strength loss that occur during incipient brown rot decay may be related to loss in hemicellulose. This paper investigates the effect of decay on hemicellulose composition and the relationship to the mechanical properties of ...
S F Curling, C A Clausen, J E Winandy
Some observations on the damage to timbers and wooden articles in cultural properties by insects in Italy
1981 - IRG/WP 1135
The damage to cultural properties by insects, especially of wooden material, is a serious problem in Italy. We have carried out a preliminary investigation concerning the most widely distributed and dangerous insects damaging timbers and wooden articles in cultural properties. Up to now the investigation has been carried out in Toscana, Lazio and Emilia Romagna and has concerned some collections o...
A Gambetta
Evaluating the natural durability of native and tropical wood species against Reticulitermes flavip
2004 - IRG/WP 04-10539
Environmental pressures to eliminate arsenate from wood preservatives has resulted in voluntary removal of CCA for residential applications in the United States. A new generation of copper organic preservatives has been formulated to replace CCA for decking and in-ground applications but there is no guarantee that these preservatives represent a permanent solution to all related problems. There...
R A Arango, F Green III, K Hintz, R B Miller
Decrease in the mechanical resistance of blue stained and "orange stained" Pinus radiata wood
1999 - IRG/WP 99-10313
It is recognised that sapwood attacked by Ceratocystis pilifera increases its permeability to pressure preservative treatments. Since hiphae not only utilise pits, but also the cell wall for crossing from one cell to another, the mechanical resistance of the stained wood might be affected. The orange colour very commonly present in Pinus radiata logs heartwood under water sprinklers, has not recei...
M C Rose, L Reyes, J Alvarez, A Andaur, C Beltran, D Rivera
Risk of pulmonary damage as a result of an evaporation of ca. 50 ppb = 42 mg HF, evaporated from wood treated by difluorides
1987 - IRG/WP 3401
In this review of the literature the effects of fluorides and fluorine on man are described, especially the low level effects of inhaled HF on human beings. The term "fluoride" is used as a general term everywhere, where exact differentiation between ionic and moluecular forms or between gaseous and particulate forms is uncertain or unnecessary. The term covers all combined forms of the element, r...
H F M Nijman
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
Poplar wood and its damages in Iran
1987 - IRG/WP 1332
In Iran poplar planting has been used for many centuries ago specially in regions without forests. It had rural uses in ancient time, but recently many fast growing poplar species have been planted and many hybrids also have been planted; the following species had been cultivated widely in Iran: Populus nigra L. var. italica, Populus alba L., Populus caspica Bornm, Populus deltoides L., Populus X....
D Parsapajouh, P Niloufari