Your search resulted in 195 documents. Displaying 25 entries per page.
The use of propionic acid to prevent Pinus patula biodeterioration during outside chip storage in Zululand
1989 - IRG/WP 3531
Pinus patula SCHIEDE ET DEPPE IN SCHLD. ET CHAM. is susceptible to biodeterioration during outside chip storage (OCS), reducing pulp quality and tear and burst indices of resulting paper. Accelerated laboratory trials showed that chips treated with 2% (w/v) propionic acid and stored for 17 weeks, produced pulp of quality indistinguishable from fresh untreated chips. Pulp tests during field trials ...
S Ismail, E J Smith, A A W Baecker
Resistance of wood inorganic material composites against decay fungi and subterranean termites
1996 - IRG/WP 96-40062
Double diffusion process was applied to the treatment of small sound sapwood specimens [20(T) x 20(R) x 10(L) mm³] of Cryptomeria japonica D. Don. The specimens were consecutively dipped in the two kinds of acqueous solutions to form water insoluble deposits within the wood after an expected reaction between the solutes. Following the comparison of deposits formed and treating conditions (tempera...
K Tsunoda, T Yoshimura, M Takahashi, S Hirao, H Usui
Long term experiments for assessing the diffusion of boric acid and diluorides from local preservative pills in spruce and pine
1996 - IRG/WP 96-40065
For the experimental assessment of the diffusion of boric acid and difluorides over a three year period 2 tests were set up. In a test with large spruce blocks (150 x 150 x 300 mm³) 3 different pill types were exposed to 3 different climates: climate room (20°C, 65% r.h.), wet room (20°C, 95% r.h.), and to outside exposure. In a test with open L-joints without paint, with an alkyd paint and wit...
W J Homan, H Militz
Preservative treatment of Golpata (Nypa fruticans) using CCA (Chromated Copper Boric Acid)
1999 - IRG/WP 99-40131
Golpata (Nypa fruticans) leaves provide a cheap but practical source of roof thatches. This study was carried out to determine whether the life span of Golpata could be extended by using CCB (Chromated Copper Boric Acid) treatment. Both leaves and midribs of Golpata , with different moisture contents ranging 16.63% to 70.67%, at the start of the experiment were treated with four different concentr...
G N M Ilias, F Abdullah, M O Hannan, S M Feroz
Tests with ammoniacal copper and alkyl ammonium compounds as wood preservatives
1984 - IRG/WP 3299
Formulations based on copper and alkyl ammonium compounds in ammonia solution have been tested in a fungus cellar on Pinus radiata and Fagus sylvatica. This type of products gives promising results as wood preservatives, especially on hardwood and are safe to destroy by e.g. combustion. The best results were achieved with a dialkyl ammonium compound, Cu/octyldecyl dimethyl ammonium chloride (NH3)....
C-E Sundman
Hemicellulosic induction of oxalic acid in Postia placenta
1994 - IRG/WP 94-10060
Most studies suggest that enzymes produced by brown-rot fungi are too large to penetrate sound wood structures, even after decay begins. Thus, nonenzymatic agents have been proposed to initiate brown-rot decay. We have reported that the brown-rot fungus Postia placenta MAD-698 initiates a 2-fold decrease in wood pH within 7 days of colonization which is mediated by production of oxalic acid. Strai...
F Green III, M Larsen, T L Highley
Comparison of methods for monitoring CCA fixation
1994 - IRG/WP 94-40023
The CCA fixation status in the outer 12.5 mm of pole sections of southern pine (Pinus sp.), red pine (Pinus resinosa) and lodgepole pine (Pinus contorta var. latifolia) were followed during fixation at 21°C under non-drying conditions by the following procedures: - Qualitative CrVI indication by the chromotropic acid spot test. - Quantitative CrVI in the expressate by the diphenylcarbazide method...
P A Cooper, Y T Ung, G Zanjani
Effect of humic acid on leaching of CCA from treated wood
2000 - IRG/WP 00-50151
Laboratory studies indicate that relatively high concentrations (1.000 - 10.000 ppm) of humic acids can increase the leaching of chromium and copper from CCA-C treated wood, and that copper is most affected. They also show that leaching with natural water samples can result in higher leaching of all components than leaching with distilled water. Evaluation of CCA component retentions and mass bala...
P A Cooper, D Jeremic, J L Taylor, Y T Ung
The long road to understanding brown-rot decay. A view from the ditch
1995 - IRG/WP 95-10101
Interest in understanding how brown-rot fungi decay wood has received increasing interest in recent years because of a need to identify novel targets that can be inhibited for the next generation of antifungal wood preservatives. Brown-rot fungi are unique in that they can degrade holocellulose (cellulose and hemicellulose) in wood without first removing the lignin. Furthermore, they degrade holoc...
F Green III, T L Highley
Acceleration of boric acid uptake into the subterranean termite, Coptotermes formosanus Shiraki using steamed larch wood
2000 - IRG/WP 00-10353
Laboratory tests were done to measure the efficacy of addition of steamed larch (Larix leptolepis (Sieb. et Zucc.) Gord.) heartwood extracts for the uptake of boric acid against the termite, Coptotermes formosanus Shiraki. Paper discs were treated with the water-soluble fraction obtained from hot-water extracts of steamed larch wood (S-Water) with or without 0.01-2.0% boric acid, followed by expos...
W Ohmura, S Doi, S Ohara
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
Targeted inhibition of wood decay (Using everything but the kitchen sink)
1997 - IRG/WP 97-10203
Low molecular weight oxidative decay agents have been implicated in the degradation of wood by brown-rot decay as evidenced by chemical analysis of brown-rotted wood and detection of oxalic acid and hydroxy radicals. Fenton chemistry (H2O2 / Fe++) is often proposed as the mechanism for generating hydroxy radicals. Previous authors have shown iron to enhance the brown-rot hydrolysis of wood, while ...
F Green III, T A Kuster, T L Highley
Wood surface pretreatments with metal tannates
1989 - IRG/WP 3552
The sequential application of aqueous solutions of tannins derived from radiata pine bark and water-soluble metal salts was examined as a means of improving the water repellency of wood surfaces. Nine metal salts were screened in combination with tannin solutions and, based on water repellency of pretreated filter paper, four were selected for further study. The two-step application of tannin solu...
D V Plackett, D R Cronshaw
Status of wood preservation industry in India
2005 - IRG/WP 05-30388
The paper traces the history of wood preservation industry in India, listing various mile stones for creation of treating capacity. The preservation industry developed with the development of rail road system on the line of most other developed countries. The most popular wood preservatives are CCA, CCB, ACC, Creosote and recently LOSP have also appeared in the market. The major users of CCA is th...
S Kumar
Removal of copper, chromium and arsenic from CCA treated wood using boron compounds
2005 - IRG/WP 05-50230
This study evaluates the copper (Cu), chromium (Cr) and arsenic (As) removal from CCA treated wood using boron compounds such as boric acid, borax (sodium tetraborate), and Timbor (DOT, disodium octaborate tetrahydrate) at varying (3 and 5%) concentrations. Remediation processes were taken at 1, 5 and 10 day intervals. Metals in remediated chips or sawdust were then analyzed using ICP and XRF. Res...
B Tarakanadha, T Hata, S N Kartal, W J Hwang, Y Imamura
Influence of carboxylic acids on LEACHING of copper amine based preservatives
2005 - IRG/WP 05-30365
The importance of chromium free preservatives is increasing. Leaching of copper from wood preserved with such solutions is still higher compared to leaching from wood impregnated with copper chromium ones. In order to decrease leaching, different carboxylic acids (octanoic, 2-etilheksanoic, decanoic) were added to copper/amine/boron aqueous solutions. Experiment of leaching of copper from Norway s...
M Humar, P Kalan, F Pohleven
Leachabilty and efficacy of fatty acid derived boron esters as wood preservatives - leachability and efficacy of fatty acid derived boron esters as wood preservatives
2004 - IRG/WP 04-30351
Borates have many advantages as wood preservatives. However, boron is susceptible to depletion under humid conditions and this restricts its outdoor use. In order to reduce boron leachability in treated wood, one of the anticipative approaches is to use organic fixed boron-based preservatives. This study investigated the leachability of six boron ester compounds as potential preservatives. Scots p...
A Mohareb, J Van Acker, M Stevens
Relationship between degradation of wood, cellulose or lignin-related compounds and production of hydroxyl radical or accumulation of oxalic acid in cultures of brown-rot fungi
1994 - IRG/WP 94-10062
The degradation activities of brown rot fungi against wood, cellulose, and lignin-related compounds were measured in cultures containing glucose or wood as a carbon source. Also the activities of one-electron oxidation and hydroxyl radical production and the amount of oxalic acid present in the cultures were measured. The degradation activities of the fungi against wood, crystalline cellulose and ...
S Itakura, T Hirano, H Tanaka, A Enoki
Influence of acidification on decay processes of CCB treated wood
2004 - IRG/WP 04-10514
The phenomenon of copper tolerance by brown rot fungal strains has been known for a long period but the complete mechanism of copper tolerance by these fungi is not understood yet. Copper tolerance has previously been linked to oxalic acid excreted by copper tolerant brown rot fungal strains. This acid reacts with copper in the wood to form an insoluble and therefore less toxic copper oxalate. The...
M Humar, S A Amartey, M Šentjurc, F Pohleven
Soil treatment tests with the three products of boric acid for the prevention of the hyphal growth of Serpula lacrymans
1992 - IRG/WP 92-3693
Laboratory soil treatment tests were conducted for the evaluation of fungicidal or fungistatic effect of boric acid products against Serpula lacrymans. Boric acid products tested were the following three: a thickened boric acid solution in triethanolamine, boric acid-silica gel complex granules, and a nonwoven fabric laminated with a polypropylene film and coated with boric acid granules on one si...
S Doi, A Yamada, Y Mineki, M Mori
Old and new facts on the dry rot fungus Serpula lacrymans
1991 - IRG/WP 1470
The article collates some of the recent literature on the biology of the dry rot fungus Serpula lacrymans. The fungus can grow at 28°C, and maximum wood moisture is above 55%. Serpula Iacrymans degrades crystalline cellulose. The intensive production of extracellular oxalic acid is neutralized by calcium and iron. There is considerable variation among the strains with regard to factors such as gr...
O Schmidt, U Moreth-Kebernik
Reduction of preservatives leaching from wood by the application of animal proteins
2005 - IRG/WP 05-30387
The investigations consisted in the estimation of the effectiveness of protein borates and protein propionates in wood preservation against Coniophora puteana. The estimation was made on the basis of mass losses caused by the test fungus action against treated wood which was subjected to leaching with water. The investigations were performed for Scots pine wood (Pinus sylvestris L.) treated with p...
B Mazela, I Ratajczak, M Bartkowiak
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Remedial treatment of creosoted railway sleepers of redwood by selective application of boric acid
1980 - IRG/WP 3134
An ideal preservative for remedial treatment must primarily be characterized by two requirements. First, it must have an ability to diffuse and distribut evenly into the wood and secondly, it must be fixed properly so that it does not leach out too fast. However, these two characteristics conflict with each other, and the choice of preservative must of necessity be a compromise. Wood preservatives...
C Bechgaard, L Borup, B Henningsson, J Jermer
Preservative treatment of rubber wood (Hevea brasiliensis) to increase its service life
2005 - IRG/WP 05-40320
Rubber wood (Hevea brasiliensis) possess excellent properties for interior designing, wood working and furniture making. But it is very much susceptible to sap stain and mould fungi which decreases the service life. For profitable uses , it is necessary to increase the service life of rubber wood. To protect the rubber wood from wood degrading agents, the sawn timber were treated with Borax – b...
K Akhter