Your search resulted in 19 documents.
The use of pressure cycling to improve heartwood penetration in Pinus radiata (D. Don)
1995 - IRG/WP 95-40050
This study investigates the effect of cycling pressure on the treatability of radiata pine heartwood. The results indicate that liquid penetration into the heartwood is affected by the preconditioning method used and pressure treatment time. There is no significant improvement in the penetration of Pinus radiata (D. Don) heartwood when a cycling or pulsation process is used.
P R S Cobham, P Vinden
The effect of treatment method on CCA efficacy in Corsican pine
1992 - IRG/WP 92-3723
As part of a study into the influence of application method on preservative efficacy Corsican pine (Pinus nigra) samples (50 x 50 x 400 mm³) were treated with a CCA formulation using Bethel, Steam/Bethel or Lowry processes. Full penetration of the preservative at a gross level was confirmed using a copper disclosing reagent. The preservative was allowed to fix and then samples were converted into mini-blocks (30 x 10 x 5 mm³) to produce decay test samples from various locations within the larger samples. After leaching, sets of replicate mini-blocks were exposed to the decay fungi Coniophora puteana FPRL 11E, Coriolus versicolor FPRL 28A, and Chaetomium globosum FPRL S70K. Equivalent sets of leached blocks, were analysed using atomic absorption spectrophotometry to determine preservative concentration and balance. The results of this study have been used to assess the effect of preservative application method on CCA efficacy. They also indicate how treatment method affects the distribution of the active elements of the preservative throughout the treated wood.
P R Newman, R J Murphy
Steam conditioning of partially dried radiata and Corsican pine roundwood
1988 - IRG/WP 3499
The effect of partial air drying prior to steam conditioning and its effect on subsequent preservative treatment by the Bethell treatment process was investigated. A high standard of preservative treatment was obtained in both radiata and Corsican pine, irrespective of whether a period of partial drying was imposed before or after steam conditioning.
P Vinden, D R Page, K Nasheri
Resin bleed after light organic solvent preservative treatment - the effect of drying method and process type
1986 - IRG/WP 3378
The effects of drying method and treatment process type on resin bleed were investigated. High-temperature drying of resinous radiata pine (Pinus radiata D. Don) heartwood resulted in improved wood permeability, higher preservative uptake, and greater resin bleed when treated by the Rueping process. Resin bleed was reduced substantially when timber was treated by the Lowry process, and totally eliminated when Bethell-treated. The incorporation of 2% wax into the preservative formulation may control resin bleed after Rueping treatment.
The effect of creosote and Basilit on the boards of 4 wood species against destructive fungi in Northern Iran
1989 - IRG/WP 3555
The results of the experiments conducted on the boards of maple, hornbeam, alder and beech, show that under the humid and moderate climate condition of Northern Iran, after 30 months, the witness samples were about 10% destructed by fungi, especially by Schyzophyllum commune and Coriolus versicolor. The impregnated samples by Creosote Basilite using Rueping and Bethell methods, were quite intact. There was no difference between these two chemicals. Among destructed boards, maple and hornbeam containing the most sugar and starch materials are more senitive than beech and alder. Until 50% destruction of witness samples, the experiments will follow up.
Preservative treatment of Pinus elliottii
1987 - IRG/WP 3435
The treatment of Pinus elliottii with copper-chrome-arsenic preservative by four alternative seasoning and treatment methods is investigated. Steam conditioning followed by either alternating pressure method (APM) or 'Q' treatment resulted in inadequate preservative penetration. Air drying or high temperature drying followed by the Bethell process resulted in a high standard of treatment.
P Vinden, L Carter
Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed.
H M Barnes, T L Amburgey, R W Landers
Effect of treatment process on performance of copper-chrome-arsenate. Part 2: Field stake tests
1995 - IRG/WP 95-40046
Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation stakes were installed in a randomised plot in the Whaka graveyard located on the FRI campus. Stakes were inspected at yearly intervals using AWPA M-10 standard procedure. After 5 years' exposure performance was strongly correlated with preservative retention expressed either as copper retention or total element (Cu+Cr+As) retention. Treatment process had very little effect on performance and confirmed results obtained from similar material exposed in fungus cellar tests. Implications of these results for commercial treatment operations are discussed.
M E Hedley, J Anderson, J B Foster, B E Patterson
Microwave conditioning of Pinus radiata D. Don for preservative treatment
2000 - IRG/WP 00-40182
This paper reviews the effect of pressure steam conditioning on the permeability and treatability of green radiata pine heartwood and the potential for substituting microwave conditioning for steaming. The penetration of liquids into radiata pine occurs mainly in the radial tissue. The permeability of green radiata pine improves following steam conditioning by blowing out the soft radial tissue. The moisture content of the wood is also reduced following steam conditioning thus increasing the air void volume available for liquid penetration. Intensive microwave irradiation is found to improve the permeability of radiata pine and reduce wood moisture content concurrently thus facilitating immediate impregnation with wood preservatives.
P Vinden, G Torgovnikov, J Romero
Wood protection processes in the Asean countries
1994 - IRG/WP 94-40034
This paper presents the wood processing practices in the Asean countries composing Indonesia, Malaysia, Philippines, Singapore, and Thailand except Brunei. The development of wood preservation industry in these countries started as early as 1922 to 1960. As in other industrial countries, treatment pressure with creosote of utility poles, railway sleepers, and marine pilings are the prime commodities that require long term protection. The introduction of water-borne preservatives covered the treatment of sawn timber and other lignocellulosic materials. It covers the historical background and development of the industry in each country, treatment processes both pressure and non-pressure of commodities e.g. power poles, railway sleepers, marine pilings, housing components, furniture, and other lignocellulosic materials requiring protection against biological deterioration. Technical problems are common and varied due to different treatment standard specifications and preservatives specially water-borne types. The pollution aspect of preservating plants and the prohibition and control of some wood preservatives is a growing concern of the environmentalists. Wood preservation in the Asean countries will stay on and geared towards the treatment of industrial tree plantations, rubberwood, palms and bamboos.
F R Siriban
Service life of pressure treated deckings of spruce in direct contact with the ground
1988 - IRG/WP 3463
For decking outdoors in Sweden, pressure treated Scots pine (Pinus sylvestris L.) is used, on account of its treatability. The feasibility of using instead the refractory Norway spruce (Picea abies Karst.) is tested in a field trial. The spruce decks were treated together with pine decks with an ordinary Bethell process. As yet, after more than four years of exposure, neither in the battens nor in the slats of the treated spruce decks any visible sign of decay has been observed. The status of the deckings is followed up with observations of the moisture content and with Pilodyn measurements of the depth of penetration of the striker pin. The pressure treated spruce material has a consistently lower moisture content and mostly also a lower penetration depth of the Pilodyn striker pin than other untreated material.
J B Boutelje, T Sebring
Internal pressure monitoring during the treatment of Pinus radiata (D. Don)
1995 - IRG/WP 95-40049
The use of micro-transducers to monitor the internal pressure of wood during treatment is investigated. The rates of pressure transfer in radiata pine sapwood and heartwood are compared during Bethell treatment with copper chrome and arsenic preservative. The effect of pre-conditioning treatments are also evaluated using micro-transducer monitoring. It is anticipated that knowledge of the changes in internal pressure in wood during treatment will lead to improvements in treatment schedules and processes particularly for treatment of impermeable timbers.
P R S Cobham, P Vinden
Effect of treating process on efficacy of CCA in a laboratory decay test
1990 - IRG/WP 3628
Test samples of Pinus radiata sapwood measuring 40x40x500 mm³ were treated with a range of concentrations of the copper-chrome-arsenate (CCA) formulation "Tanalith C" using Rueping (empty cell), Lowry (empty cell) and Bethell (full cell) treatment processes. Samples were then reduced to 40x40x7 mm³ test blocks and exposed to the decay fungus Coniophora puteana using an agar/block technique. Replicate blocks were analysed for preservative components. Regression analyses of percentage weight losses of test blocks against total Cu+Cr+As retentions (TAE) showed differences in efficacy of the preservative when applied by the three different processes, the order of effectiveness being Bethell > Lowry > Rueping. Two hypotheses are proposed to explain the results: (1) Disproportionation within the wood of preservative salts when applied by empty cell processes, (2) Differences in distribution of preservative elements following treatment by the three processes.
M E Hedley, K Nasheri, J G Van der Waals
Treatment application method and CCA efficacy in Corsican pine - Assessment by serial exposure and soil burial tests
1993 - IRG/WP 93-40006
A previous report on this research (Newman and Murphy, 1992) identified possible variation in the efficacy of a CCA preservative applied to Corsican pine (Pinus nigra var. maritima) dependant upon the treatment application method (Bethel, Lowry or Steam/Bethel). This paper presents further data from biological testing of CCA treated Corsican pine using serial exposure and unsterile soil techniques. After 3 serial exposures to Coniophora puteana FPRL 11E and Coriolus versicolor FPRL 28A the treated wood performed in the order Bethel > Steam/Bethel > Lowry and Lowry > Bethel > Steam/Bethel respectively. Weight losses in the order of 40% and 30% were generated by Coniophora puteana and Coriolus versicolor at retentions of 3.9 kg/m³ and 1.0 kg/m³ CCA respectively. After 12 and 26 weeks unsterile soil burial the order was Lowry > Bethel > Steam/Bethel with weight losses of up to 30% at 1.0 kg/m³ CCA. The data are considered in relation to the decay mechanisms of the various biological agents used.
P R Newman, R J Murphy
Effect of treatment process on performance of copper-chrome-arsenate. Part 1: Fungus cellar tests
1995 - IRG/WP 95-40045
Pinus radiata sapwood stakes 20 x 20 x 400 mm³ were treated with CCA Type C using a range of concentrations and three treatment processes; Bethell, Lowry and Rueping. Preservative retention was determined by chemical analysis of treated material. Following fixation, fungus cellar stakelets, 5 x 10 x 180 mm³ were cut from treated material and after leaching were exposed in unsterile soil beds in the FRI Fungus Cellar. Results after 65 months' exposure indicate that performance was related only to preservative retention. Differences in treatment process had little effect on decay resistance. This is in contrast to results from pure culture decay tests, reported earlier, which indicated that disproportionation of preservative elements using empty cell processes and low preservative concentrations had significant effect on durability.
M E Hedley, J Anderson, J B Foster, B E Patterson
A new vacuum/pressure plant system
1988 - IRG/WP 3479
In the subtropical regions, the problem of wood supplying becomes more and more difficult to be solved. In that context, the Centre Technique Forestier Tropical had paid a particular attention to the valorization of products issued from plantations in dry zones of Africa. In these plantations, the products of clearings can be used as fencing, stakes or for traditional construction. However in these trunks of small diameter, the sapwood which represents a large proportion of the ligneous matter utilized, possesses a poor natural resistance as much as in regard to decay as in regard to wood-destroying insects and particularly termites. For that reason a rational use of the round woods cannot be considered without the help of wood preservation. The single dipping or brushing being insufficient mainly for the timber in ground contact and the traditional vacuum-pressure treatment being considered too expensive by local authorities, the Centre Technique Forestier Tropical tried to imagine a new system of treatment.
C Dalois, R Schwartz, G R Y Déon
Application of paint primers after light organic solvent preservative treatment
1986 - IRG/WP 3381
The application of three alternative paint primers is investigated, including a slow-drying oil-based primer, a fast-drying oil-based primer, and a fast-drying water-based primer. The treatment schedules employed, in particular the evacuation period after treatment, have a marked effect on subsequent paintability. Priming can potentially be carried out immediately after treatment with approved Timber Preservation Authority schedules, providing that (1) a fast-drying primer is employed (either water-based or oil-based), (2) solvent recovery by evacuation is continued for an extended period (45 min, c. -85 kPa) immediately after treatment, and (3) either the Lowry or the Bethell process is employed.
Rehabilitación del Portón del templo parroquial de San Juan Vicario de Comanja, Michoacán, México
2008 - IRG/WP 08-40431
The pine gate of the San Juan Vicario parochial temple in the city of Comanja, Michoacan, Mexico was rehabilitated. The gate was damaged by termites, worms, fungi and weathering. Gate metallic bearings were rusted. The lower parts of the gate were the most deteriorated. For rehabilitation, galvanized steel bearings were designed and manufactured and then implemented into the building. Replacement wood pieces were made from pine treated with chromate-copper-arsenate (CCA salts). The pieces were treated using the full cell method, called the Bethell process, to 100% penetration. Se rehabilitó el portón de madera de pino del templo parroquial de San Juan Vicario de la ciudad de Comanja, Michoacán , México. El portón estaba deteriorado por termitas, carcoma, hongos y condiciones climáticas. Presentaba cojinetes metálicos en dónde esta soportado el portón. Las partes bajas del portón eran las más deterioradas. Para rehabilitarlo se diseñaron y manufacturaron nuevos cojinetes metálicos en acero galvanizado. Las nuevas piezas fueron de madera de pino tratadas con sales de Arsenato Cromatado de Cobre (sales CCA) impregnadas al 100 % por el método de presión y vacío denominado de célula llena o proceso Bethell.
J Reséndiz Sánchez, J Cruz de León
Decay Resistance of Maple (Acer Insigne) Wood Against White Rot
2010 - IRG/WP 10-10740
In this study, the decay resistance of maple (Acer insigne) in natural state and treated with ACC (Acid copper chromate) was investigated against the white rot fungus (Coriolus versicolor). ACC is a kind of water borne preservatives that was used in this study for treating specimens under vacuum and pressure (Bethell procedure) with 3 percent concentration. In conducting mentioned evaluation, kolleschale’s method according to DIN 52176 and B.S. 838: 1961 were used in completely randomized block design. Specimens were contaminated with cultured fungus for fourteen weeks in condition (22, 75% relative humidity). After this period, weight reduction, compressive strength (parallel to grain) and hardness of specimens were tested. Under test conditions weight reduction of control sample were much higher than treated ones. Compressive strength (parallel to grain) and hardness of treated samples were higher than control ones.
V Tazakor Rezaei