Your search resulted in 177 documents. Displaying 25 entries per page.
An experimental method to simulate incipient decay of wood by basidiomycete fungi
2000 - IRG/WP 00-20200
At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed progressive removal of samples ...
S F Curling, J E Winandy, C A Clausen
Ancillary properties of vapor boron-treated composites
2001 - IRG/WP 01-40210
This paper discusses the water absorption, thickness swelling, and internal bond strength of North American composites treated using a vapor boron treatment process. For oriented strandboard, high boron loadings led to lower internal bond strength and lower thickness swelling. Water absorption results were variable but no deleterious effect of treatment was noted. For medium density fiberboard, th...
W A Jones, H M Barnes, R J Murphy
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
A deflection test for monitoring decay in miniature beams
1986 - IRG/WP 2269
A laboratory apparatus for assessing decay in small stakes is described. It involves the measurement of deflection in a static bending apparatus using a displacement transducer linked to a microcomputer. Measurements are non-destructive, rapid, accurate and automatic and decay can be assessed repeatedly over long time periods....
S M Gray
Methods of assessing decay in poles in service with the Pilodyn wood tester
1978 - IRG/WP 2107 A
H Friis-Hansen
Use of the Pilodyn to assess deterioration of treated aspen waferboard after 30 months of outdoor exposure
1986 - IRG/WP 2254
Samples of preservative treated aspen waferboard exposed outdoors for 30 mo. were compared using pin penetrations of the 6 Joule Pilodyn. These results correlated well with rankings of treatment performance based on more laborious standard mechanical tests, and demonstrate the potential for use of the Pilodyn as a tool to evaluate wood composites in test exposures with minimal destruction....
E L Schmidt, M G Dietz
Effect of soft-rot decay on the static bending strength of wood
1991 - IRG/WP 2361
In this study, a modified static bending test has been developed as a method for measuring soft-rot decay in soil bed studies. A good correlation was found between the strength loss of the southern pine test specimens and extent of decay. This data suggests that it may be possible to develop a dynamic test based on stress relaxation that is more sensitive than static bending....
D D Nicholas, J A Wilson, R C Vasishth
Acetylation of lignocellulosic materials
1989 - IRG/WP 3516
A simplified procedure for the acetylation of lignocellulosic materials has been developed. The acetylation is done with a limited amount of liquid acetic anhydride without the addition of a catalyst or an organic co-solvent. Dimensional stability and biological resistance are both much improved by the acetylation. Equilibrium moisture content in acetylated material is considerably lower than in u...
P Larsson, A-M Tillman
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
The shower test method. A leaching test for assessing preservative losses from treated timber under simulated open storage conditions
1993 - IRG/WP 93-50001-04
In the late 1980's against the background of increasing environmental concern a laboratory based accelerated leaching test method for assessing preservative losses-from stored, treated timber was developed by the Dutch organisation for applied Scientific Research (TNO). This test method quantifies the amount of specific preservative components which leach from treated timber under simulat...
J B G A Havermans, W J Homan, M J Boonstra
A simple non-destructive means of testing poles in situ
1982 - IRG/WP 2167
Anonymous
A Preliminary Report on the Properties of Engineered Wood Composite Panels Treated with Copper Naphthenate
2005 - IRG/WP 05-40294
This paper reports on our preliminary investigation of the properties of randomly oriented strandboard which had waterborne or powdered copper naphthenate (CuN) incorporated into the board during manufacture. When compared to zinc borate-treated controls (ZnB), the mechanical properties of strandboard (MOR, MOE, work-to-maximum load, internal bond strength) were not adversely affected by treatmen...
J W Kirkpatrick, H M Barnes
Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing:
tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%);
treated beech-wood samples were naturally aged without their contact with grou...
L Reinprecht
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
Accelerated laboratory soil contact decay test using soil amended with composted wood
2004 - IRG/WP 04-20284
The effect of amending soil with wood compost on the decay rate of wood wafers in contact with the unsterile soil, as measured by radial compression strength loss, was explored. It was found that the addition of composted wood to the soil significantly increased the wood decay rate. The reason for this acceleration in wood decay is not entirely clear, but appears to be at least partially associate...
D D Nicholas, H Borazjani, T Schultz
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
The rate of losses of creosote from power transmission poles during storage
1998 - IRG/WP 98-50101-24
The purpose of this work was to study the rate of losses of creosote from power transmission poles and its consequences on the expected life of the poles stored for a long period in horizontal position. Apart from this main target of the study, the results could allow a rough estimate of the load of creosote substances on the soil especially when the poles are stored and this load accumulates over...
Z Vassou, A Satanakis, C Koutsikopoulus, J Petinarakis
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
Field stake test assessment with the Pilodyn
1980 - IRG/WP 2136
The Pilodyn, which was originally developed to estimate the degree of soft rot in wooden poles, was thought to have potential for giving a quantitative measure of the extent or depth of decay in field test stakes. In the present work a 2-joule Pilodyn with 2.0-mm diameter pin was used in an attempt to limit depth of pin penetration (to 10-15 mm) without reducing scale sensitivity. The results show...
M E Hedley, R W Naish
Volatile losses of wood preservatives
1973 - IRG/WP 236
The purpose of the work we have undertaken so far has been to try to quantify the volatile losses which occur in treated timber, and to examine some of the factors which influence these losses. The preservative compound chosen for the initial part of the programme was the contact insecticide g-BHC. This was attractive for several reasons, not the least of which was that specific and sensitive anal...
J W W Morgan, D F Purslow
Paper for discussion - Incising of spruce to improve preservative penetration
1973 - IRG/WP 318
Large quantities of whitewood or Norway spruce (Picea abies) are regularly imported into the United Kingdom from continental Europe. In addition, increasing amounts of Sitka spruce (Picea sitchensis) are likely to become available over the next decade from the Forestry Commission. In many ways spruce is a good structural timber, eg it is relatively cheap and easily available, it has adequate stren...
W B Banks
Acetylated solid wood. Laboratory durability test (part 2) and field trials
1995 - IRG/WP 95-40048
Degradation of acetylated beech, pine and poplar by soft rot fungi was related to strength loss in a laboratory test. No strength loss was noticed for poplar acetylated to a weight percent gain (WPG) of more than 11.2% and beech with a WPG of 12.8%. Several field trials were set up to determine the durability of acetylated products in practice. They included a field test to determine the durabilit...
E P J Beckers, H Militz, M Stevens
The degradation of wood surfaces by water
1984 - IRG/WP 3289
Thin radial/longitudinal sections (~100 µ) of Scots Pine (Pinus sylvestris) and lime (Tilia vulgaris), were exposed to deionised water over the temperature range 25-65°C. Losses in wet tensile strength and toughness occurred rapidly at temperatures from about 50°C upwards. After about 2 months' exposure pine lost some 10-30% of its tensile strength and 20-60% of its toughness. For lime...
W B Banks, P D Evans
Effect of Scytalidium lignicola on decay resistance and strength of wood
1994 - IRG/WP 94-10061
We reported previously that in laboratory tests, pretreatment of Douglas-fir and Southern Pine blocks with Scytalidium lignicola prevented decay. In the present work, we determined 1) the ability of Scytalidium lignicola to colonize and survive in wood exposed in the field, 2) the decay resistance of blocks removed from previously treated Scytalidium lignicola wood and 3) the effect of Scytalidium...
T L Highley