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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
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
Comparison of cubic and plug samples for preparation and data assembly in permeability study
2000 - IRG/WP 00-20197
In order to determine if plug experimental samples (PES: 30 x 15 mm2 diameter) could be used for inspection of wood permeability characteristics, radial and longitudinal flow directions were prepared according to either PES or cubic experimental samples (CES: 100 x 20 x 20 mm3) from the sapwood zone of Sitka spruce and treated by tanalith-C according to full-cell process. Results from the two preparation techniques agreed in the test to determine the mean percentage of void volume filled by liquid both radially and longitudinally, while the preparation process (i.e. machining, sealing, etc.) of the experimental samples and the period of the data collection was quite longer in CES than that for PES in either flow direction.
An effective preservative treatment of borak bamboo (Bambusa balcoona Roxb.)
1996 - IRG/WP 96-40070
Adequate penetration and retention of CCA and CCB has been obtained in predried Borak Bamboo (Bambusa balcooa Roxb.), aboundantly grown in Bangladesh, with Full Cell Pressure Process. The treated bamboo can be used as building materials, the sufficient treatability ensured its long term best utilization at ground contact and indoors. Which will keep the environmental & socio economical conditions of Bangladesh more viable and normal.
A K Lahiry, S Begum, G N M Ilias, M A Matin Sheikh, M A B Fakir, M I Hossain
Analysing the characteristic role of moisture content for drying and fluid flow in Sitka spruce. - Part 1: The drying process of sapwood and heartwood of two different thickness of Sitka spruce using a kiln. - Part 2: Effects of moisture content on longitudinal permeability of Sitka spruce in vertical variation of the tree
2000 - IRG/WP 00-40173
The characteristic role of the moisture content in Sitka spruce (Picea sitchensis (Bong.) Carr.) that grown in the United Kingdom was examined by this study on the basis of (1) the reduction of moisture content in two different thickness of sapwood and heartwood by kiln drying process, and (2) the effects of moisture content to the longitudinal void volume filled of tanalith-C by the full-cell process from base (1 m) to apex (3 m) of the tree in sapwood zone. Accordingly, conclusions on indication of the drying process of sapwood and heartwood, and vertical variation of longitudinal flow with effects of moisture were listed separately: (1) Comparison of Drying Characteristic of Sapwood and Heartwood: The two different thickness (300x30x30 mm3 and 300x20x20 mm3) of sapwood and heartwood of Sitka spruce was dried using the suggested drying schedule in kiln. The reduction of moisture was schematically diagrammed according to sapwood and heartwood stakes. The reduction of moisture followed the same downward trend that sapwood (S) loses more moisture than heartwood (H) although the small stakes of S and H lost moisture rapidly compared with the large ones. (2) Vertical Variation of Moisture Content and Longitudinal Permeability: The 90 kiln dried defect free sapwood stakes (150x25x25 mm3) of Sitka spruce was taken from base to apex of the trees at 1, 2 and 3 m above ground level. After having the determination of moisture content in each experimental stake, the treatment was carried out by the full-cell process with CCA preservative (Tanalith-C) using a model pressure treatment plant. Significant differences observed among the tree heights from 1 to 3 m showing that slightly increases of moisture content from base to apex and conversely decreases of longitudinal void volume filled by preservative fluid.
A behaviour of CCA penetration of fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications
2006 - IRG/WP 06-40346
A behaviour of CCA penetration of Bornmulleriana fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications was illustrated for the main flow directions by the experimental pictures.
I Usta, R Despot, M Hasan
The effects of density on vertical variation of permeability of Sitka spruce within tree
2000 - IRG/WP 00-40156
Tree improvement of Sitka spruce is a combination of silviculture and tree breeding aimed at producing higher quality products including increased growth rate and timber yield, and wood density. It is useful to know annual ring structure and density distribution when studying the quality of wood, grading it, or determining how the wood structure affects residual flow in softwoods. Since density is a factor under genetic control, the study in this article details the effects of density on longitudinal and radial permeability of Sitka spruce from base to apex. Comparison of overall means of both longitudinal and radial void volume filled (%) suggest that longitudinal permeabilities were almost the mirror image of those for the radial permeability along the tree trunk.
Leaching of copper, chromium and arsenic from CCA-treated slash pine heartwood
1994 - IRG/WP 94-50020
Drying green slash pine with any of three high temperature drying schedules produced a product in which both the sapwood and the heartwood could be penetrated with CCA using a modified Bethell treatment schedule. Required H3 retentions were achieved in both sapwood and heartwood, from 200 litres per m³ charge uptake. Post-treatment fixation/drying was accomplished by three different regimes, including an accelerated fixation. Although acceptable preservative penetration and retention was achieved in the heartwood, arsenic fixation (as determined by both AWPA procedure E11-87 and U.S. EPA TCLP procedure) was inferior to that attained in the sapwood. TCLP leachates from 1 cm³ heartwood blocks contained up to 4.5 mg/l arsenic, very close to the maximum value (5.0 mg/l) currently permitted in Australia for arsenic waste disposal. Though there are clear advantages in achieving heartwood penetration, caution must be exercised to ensure that this step does not compromise the accepability of the product. No process modification could be accepted if it introduced possibilities of exceeding safe disposal limits for sawdust and offcuts, or building site contamination.
M J Kennedy, G Palmer
Preservation of two Indonesian timber species for marine environment purposes
1994 - IRG/WP 94-10079
This paper deal with the experiment of CCA full cell processed two non-durable Indonesian species for placed in the marine environment. 80 samples of 5 x 5 x 60 cm³ dried durian (Durio zibethinus) and mahogany (Swietenia mahagony) timber were CCA-full cell processed using 4 combination treatment of: without steaming; one hour steaming; 3% and 5% CCA solution concentration. 40 samples of them were field tested in the sea water in Rambut island beach near by Jakarta. The results shows that mahogany very difficult to treat and not recommended to be placed in marine environment, while CCA retention in durian timber could reach 29.91 kg/m³ and meet the requirement of retention for timber to be placed in marine environment. After two month field test in sea water full cell processed drian with 5% CCA solutin concentration could prevent marine borers attack.
P Permadi, I M Padlinurjaji, F Rasmita
A study on the pressure impregnation of Eucalyptus globulus fence posts with CCA preservatives. Part 1
1988 - IRG/WP 3470
This paper describes the impregnation with CCA preservatives by full-cell process of Eucalyptus globulus fence-posts. Several treatments were made for different times of initial vacuum and treating pressure, with fence-posts from two coppice plantations (1st and 2nd rotations), assembled into three diameter classes: small, medium, large. The results concerning the absorption and lateral penetration of the product reveal that impregnation of Eucalyptus globulus though difficult is often possible. The highest average values were recorded in the small diameters, yet the standard deviation in all three classes is quite remarkable. Moreover fence-posts from the 1st rotation stand show a better behaviour with the treatment. There seems to be no significant correlation between absorption and initial vacuum or treating pressure times.
D De Sousa Castro Reimão, L Nunes
Investigation of temperature effect on fixation of Celcure preservative (ACC) in beech (Fagus orientalis)
2001 - IRG/WP 01-40200
In this research, the fixation speed of Celcure 2% (ACC) preservative salt, under temperature of 17°C, 27°C and 50°C, on intact and stained wood specimens of beech was investigated. For this purpose, blocks of wood with 5x5x7 cm dimensions were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. For measuring the percentage of fixation through time, the specimens were extracted by using hydraulic pressure equipment, under 69 Mpa pressure. The pH of extraction was measured with the method of diphenyl Carbazid and by using spectrophotometer. This measurement was done continuously and the amount of 6- valence chromium concentration present in the extract was compared with the amount of chromium concentration in the primary solution and then the percentage of fixation was calculated. The results showed that the decrease in 6-valence chromium is accompanied with increase of pH, this is due to absorption of positive hydrogen ion by 6-valence chromium for reduction to 3-valence chromium and also ion-exchange of active components with wood during the primary phase of fixation. Also, the time necessary for reaching complete fixation in intact and stained wood in the fixation temperature conditions of 17, 27 and 50°C were 1075, 501, 109 hours, respectively. In general, the results showed that temperature has effective role in accelerating of fixation process and in this respect, intact and stained wood did not show significant statistical difference.
A Karimi, M Ghorbani
A study on the pressure impregnation of Eucalyptus globulus fence-posts with CCA preservatives. Part 2
1989 - IRG/WP 3514
This paper describes the second part of a study on pressure impregnation of Eucalyptus globulus fence-posts with CCA preservatives presented at the IRG 19th Meeting. Fence-posts of three diameter classes, were treated, considering only one treatment schedule. The results show possibility of vacuum-pressure impregnation of blue gum fence-posts, with diameter less than 9 cm, though mainly by longitudinal penetration, which is usually conditioned by the length of the fence-post.
L Nunes, D De Sousa Castro Reimão
A novel guide for the determination of the physical properties of wood including kiln drying and full-cell preservative treatment
2004 - IRG/WP 04-20298
An ideal flow chart for the sequential experimental determination of a range of physical properties relevant to wood drying and subsequent preservation was designed as a novel guide to assist wood scientists. In this manner, data assembly and experimental processing are shown. This was designed according to experience and published literature. Aspects emphasised in this review were the physical properties which effect the manner of processing particularly in respect to preservative treatment of wood. For this purpose a total of 93 references covering 8 topics (descriptive wood anatomy, physical properties of wood, shrinkage and swelling, wood density, moisture content, fibre saturation point, wood drying (by oven and kiln) and liquid permeability) were reviewed.
I Usta, M D C Hale
Trial to determine a suitable schedule for radial and longitudinal treatment of plug samples by comparison of changes in the fluid retention and the treated area
2001 - IRG/WP 01-40211
A full-cell process was carried out using different treatment schedules for radial and longitudinal samples because of the anisotrophy of flow. When timbers are impregnated with preservatives much better penetrations are obtained via the end grain than laterally (across the grain). Therefore, suitable schedules for radial and longitudinal flow directions were determined in an trial experiment using locally grown Sitka spruce, Queen Charlotte Islands (QCI) provenance, from Beddgelert Forest in North Wales. The full cell experimental schedules used were: initial vacuum 15 minutes at -0.84 bar and various pressure periods that was 5 bar pressure in radial flow direction for 15, 45, and 60 minutes, 3 bar pressure in longitudinal flow direction for 3, 6, and 9 minutes. No final vacuum was applied. After the treatment, the fluid uptake was calculated, and the fluid retention was determined on a whole-block basis. After fixation, plugs were dried and cut longitudinally through the centre and copper penetration was determined by spraying a 1% solution of Chrome Azurol-S on the cut surface and observing the blue colour indicative of copper. The preservative penetration was then measured by image analyser as depth (mm) and as total treated area (%). From the experimental data, it was concluded that the suitable schedules are 5 bar pressure for 45 minutes for the radial flow direction, and 3 bar pressure for 7 minutes for the longitudinal flow direction. Therefore these schedules are suggested to be used to examine the permeability of the different seed origins in both radial and longitudinal flow directions.
A note on te seasoning, preservative treatment and suitability of debdaru (Polyalthia longifolia Benth & Hooker.) for poles
1995 - IRG/WP 95-40056
The main work is to determining the suitability of Debdaru (Polyalthia longifolia Benth.) as poles from Government and Village forests are investigated. The poles of Debdaru are easily treatable with CCA preservative by full-cell pressure method, but difficult to dry (air & kiln). Proper quality control must be maintain from procurement to treatment, specially during physical selection & drying (air & kiln) otherwise it may be discard as pole. Debdaru poles have been found suitable for power and Telecomunication lines with very keen care.
G N M Ilias, M D Rokib-ul-Hafiz
Chemical treatment of ten Amazonian timber species of low natural durability
1991 - IRG/WP 3640
The objective of this work was to evaluate the performance of 10 amazonian wood species of low natural durability, to treatment with CCA preservative (2% concentration): it was concluded that all species studied are easily treated with this preservative. The sapwood showed high absorption and total penetration. The heartwood is relatively easy to preserve, exception to Parkia nitidae (Fava), Qualea paraensis (Mandioqueiras), Erisma unicatum (Quarubarana), and Virola sp (Ucuúba), which presented some restrictions. Nevertheless, it does not mean that their treatment is impossible.
C S Neta, B F Vianez
Notes on a wood preservation industry in Medan, North Sumatera, Indonesia
1987 - IRG/WP 3405
This paper deals with a descriptive account on the development of a wood preservation industry in Medan, North Sumatera (Indonesia). The industry was established in 1974 when the State Owned Electicity Corporation decided to use wooden power poles for their distribution network in North Sumatera province. However, the use of wooden power poles was discontinued in 1981, so as the preservation industry was severely affected. Some notes on the results of the full cell process, particularly on the percentage of over- and under-charged treatment, is also described in this paper.
N Supriana, A Murad
The effect of rate of pressure application on preservative uptake along and across the grain of fir (Abies bornmulleriana Mattf.) at different ramp and constant pressure times
2004 - IRG/WP 04-20292
This study was particularly design to determine the preservative uptake at different ramp (rate of increase in pressure) and constant pressure times on longitudinal, tangential and radial penetrations of fir (Abies bornmulleriana Mattf.) which grown indigeneously in Turkey. The samples of 2 cm cubes of kiln-dried wood (nominated to 12% moisture content) were treated at different ramp times varied from very fast to very slow rates of pressure (bar) per time (seconds) at 5, 15, 30, 60, and 90 sec. and the maximum pressure of 4 bars -in the treating vessel to refusal- was applied at the constant pressure time for 5 min. The preservative uptake was determined as the percentage of void volume filled (VVF%) for either flow directions at each ramp time. The results showed that the VVF% was, as expected, markedly greater in the longitudinal flow direction than both in the tangential and radial flow directions. In comparison to the VVF% laterally, it was greater in tangential direction than in radial direction in either treatment schedules. In this issue, although the trend seemed to be the similar between the flow directions, quite different patterns were observed within each direction for penetration and ramp times. Accordingly, conclusions were listed separately for each flow direction.
Protection of rubberwood timber. Part 1: Impregnation with boron preservatives
1989 - IRG/WP 3551
Rubberwood (Hevea brasiliensis) were treated with a 3% proprietary mixture of borax/boric acid using three different treatment schedules i.e. full-cell, full-cell to refusal and full-cell with 12 cycles of vacuum/pressure. Freshly cut samples had mean preservative retentions of 187 kg/m³, 214 kg/m³ and 178 kg/m³ respectively. Pre-air dried samples for one week had retentions of 252 kg/m³, 308 kg/m³ and 282 kg/m³ respectively. An increase of pressure time from 45 minutes to 90 minutes allowed for slightly higher retention values. Preservative retentions of the core (20 mm² around the centre) from freshly sawn samples were 0.08-0.13% m/m BAE (boric acid equivalent), 0.04-0.19% m/m BAE and 0.04-0.21% m/m BAE for the full-cell, full-cell to refusal and full-cell with 12 cycles vacuum/pressure treatment respectively. Retention values of similar samples from the surface up to a depth of 10 mm were 0.36-1.51% m/m BAE for the 3 different treatments.
L T Hong, C C K Liew
Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalculated to the total dry mass of the preservative. Simultaneously, there was performed biological test according to EN 113 for the investigated mixture and different concentrations: 0,1; 0,16; 0,25; 0,4; 0,63; 1,0; 1,6; 2,5. The obtained fungicidal value let to determine the depth of biological resistance of impregnated wood within the impregnated zone.
K Lutomski, B Mazela
Industrial fixation of chromium based wood preservatives
1990 - IRG/WP 3630
Fixation is an abstract and non-defined process. Nevertheless it is a specified requirement in most impregnation standards. The impregnation industry is facing increased pressure to deliver fixed products and to increase the safety of the handling of impregnated products. Industrial fixation of impregnated wood can be obtained by using different methods. The purpose of the process is to transform hexavalent chromium to the trivalent stage, where also arsenic and copper compounds are fixed. Through laboratory and practical tests A/S The Danish Wood Treating Co.Ltd (DWT) has developed an accelerated industrial fixation system. The system has been developped for accelerated fixation of chromium based wood preservatives in Pinus sylvestris. To satisfy the requirement of avoiding dripping outside the impregnation plant and hence the possibility of soil contamination, the process has been accomodated to provide a surface dry and non-dripping product at the end of the cycle. To support the process and to set the results in perspective a simple method of establishing the degree of fixation has been developped.
Tilting and vacuum treatment - two methods to obtain a non-dripping freshly treated timber
1989 - IRG/WP 3535
Modern impregnation plants are designed to prevent spread of impregnation solutions from the plant through leakage, etc. It is also important that freshly treated timber does not spread solutions through dripping on the storage area. To prevent this, the impregnation procedure is terminated with a vacuum period. In many plants in Sweden this period is minimized or even excluded to gain time. Instead the freshly treated timber is tilted for some time before it is transported to the storage area. To evaluate the effect of these two methods to get a non-dripping freshly treated timber a small study was carried out by the Swedish National Testing Institute (SP) together with the Swedish Wood Preservation Institute (SWPI).
I Johansson, M-L Edlund
Variation in biological performance of CCA caised by preservative application method
1996 - IRG/WP 96-40072
A series of laboratory studies to investigate the influence of treatment application method on CCA performance in Cosican pine has been completed. Biological decay tests, such as serial exposures, were used to induce decay in wood at preservative retentions of up to 10 kg/m³ CCA salts. Significant differences in performance of the preservative against either brown, white or soft rot decay fungi were found depending upon the preservative application method used. The full-cell process gave the greatest level of CCA performance against Coniophora puteana whereas the Lowry empty-cell process gave the best performance against Coriolus versicolor and soft rot fungi. Pre-treatment steaming caused a general reduction in preservative efficacy. Analysis of the treated wood using FT-IR spectroscopy and electron microscopy with EDS for preservative micro-distribution indicated modification of the wood cell wall by steaming and differential distribution of copper depending on preservative application method. A hypothesis is proposed to account for the observed differences in preservative performance with treatment method.
P R Newman, R J Murphy
Microdistribution of water-borne preservatives in blue gum treated by full-cell process
1990 - IRG/WP 3617
The present work deals with the study of the microdistribution of copper, chrome and arsenic elements in Eucalyptus globulus Labill. sapwood, treated with a CCA water-borne preservative by full-cell process, with the help of scanning electron microscopy together with energy dispersion X-ray analysis technique. The work shows that the retention of CCA elements is high in vessels and vasicentric parenchyma as well as in the wood rays, whereas it is quite low in fibres. There are also some differences between retention obtained in the two levels of depth of radial penetration considered, increasing or constant rate of variation with depth having been found. Conclusion reached point to the need of obtaining high enough salt retention in sapwood in order to avoid this irregularity of microdistribution of CCA preservatives in Eucalyptus globulus round wood and ensure adequate durability.
D De Sousa Castro Reimão, J M Palacios
The susceptibility to sludging of sulfate and oxide CCA
1990 - IRG/WP 3599
Radiata pine sapwood was treated separately with a sulphate CCA-C and an oxide CCA in a pilot scale pressure plant using a full cell process. CCA solutions were recovered from the final vacuum phase, placed in plastic tubes, and their susceptibility to sludging determined by examining changes in solution pH, time required for sludge to form and weight and chemical composition of sludge formed. Sulphate CCA-C solutions showed a pH rise of 0.33 above the initial solution pH of 2.01 and a sludge, largely composed of arsenic and chrome, formed after 6-8 weeks. Oxide CCA solutions in contrast showed smaller pH changes and did not form sludge. Addition of glucose or ethanol to freshly prepared sulphate CCA-C and oxide CCA solutions at 25°C resulted in sludge formation with both formulations but sludge formed earlier and in greater quantities with the sulphate CCA-C. The results indicate that the oxide CCA is more resistant to sludging than the conventional sulphate CCA and suggest that the use of the former in treatment plants could reduce sludge formation. Further methods to minimize sludge formation in treatment plants are also discussed.
B T Mutandadzi, P D Evans