Your search resulted in 550 documents. Displaying 25 entries per page.
Experiences with an industrial system for controlled thermal wood modification in pressurized unsaturated steam
2014 - IRG/WP 14-40678
Thermal wood modification in pressurized reactors has a long history, but these processes are to date industrially scarcely used, because of the relatively complicated process equipment, compared to the more common high-temperature processes in kilns at atmospheric pressure. However, based on our practical experience with the FirmoLin® process, supported by recent scientific findings, it is foun...
W Willems
Effects of various preservative treatments on the mechanical and physical properties of plywood
1993 - IRG/WP 93-40007
The technical properties of plywood are related to both the intrinsic characteristics of its composing wood species and the quality and performance of the glue bond which acts as an interface between veneer sheets. Consequently mechanical and physical testing and glue bond strength analysis offer an appropriate means for studying the effect of preservative treatments on the overall quality of plyw...
J Van Acker, M Stevens
Long-term performance of a "wax" type additive for use with water-borne pressure preservative treatments
2000 - IRG/WP 00-40159
Field performance results are updated for matched CCA treated decking boards with and without an emulsion water repellent additive incorporated with the initial pressure treatment. Decks have been exposured for over 9 years in Harrisburg, NC. Boards were evaluated for in-service and laboratory performance for water repellent efficacy, as well as additive loadings in the boards after this exposure....
A R Zahora
Combined effects of the treatment of wood with formaldehyde
1978 - IRG/WP 3117
Treatment of fibrous materials with reagents in a vapor phase is neither new nor unique. Numerous examples exist in literature of vapor phase experiments on cellulose fibers and fabrics, and on wood. For many years the textile research and industry have used vapor phase processes for the treatment of textiles. The chemical modification of cellulose is based on different types of reactions e.g. est...
M Stevens, J Schalck
Practical testing of wood preservatives to prevent weathering damage and infection by micro-organisms on spruce and pine
1989 - IRG/WP 3530
Brush application, is generally used to prevent wooden window frames from decay caused by influence of weathering and fungi. Accordingly 10 boards of pine (Pinus sylvestris) and spruce (Picea abies) were treated with 10 commercially used wood preservatives. The efficiency of fungicides by using chiptest and blue stain test (EN 152), the effectiveness against weathering as well as the course of col...
R Gründlinger, O Janotta, H Melzer, K Messner
Effect of double-vacuum and vacuum-pressure impregnation with water-borne preservatives on the dimensional characteristics of spruce
1990 - IRG/WP 3613
Air-dried planed spruce (Picea abies) samples were treated with a water-borne preservative (micro-emulsion) and one oil-borne type both containing azaconazole and deltamethrin. Each set of samples contained equal number of specimens with different growth ring orientation, heartwood content and density. In addition to the preservative retention and the penetration of a.i., the swelling of the sampl...
J Van Acker, M Stevens, G Rustenburg
Washboard effect: A surface deformation of spruce resulting from vacuum-pressure impregnation with water-borne preservatives
1987 - IRG/WP 3450
The washboard effect has been observed in sawn spruce after both commercial and laboratory based preservative treatments and is of increasing economic importance. The effect is defined as a specific phenomenon at the wood surface. It is distinct from internal collapse in the wood, but it may occur in association with internal collapse damage. Experimental investigations on the causes of washboardi...
H Willeitner, R J Murphy
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
Dynamics of pressure changes in wood during impregnation
1990 - IRG/WP 3615
Conventional methods of impregnation have to be improved for achieving better penetration of refractory wood species. Basic requirements for an adjustment of treatment schedules are, amoung others, a profound knowledge of the course of pressure changes in the wood during treatment. A new method of pressure measurement was developed which supplies exact and reproducible data. The results show that ...
R D Peek, S Goetsch
Treatability of waterstored poles of Norway spruce by sap-displacement and pressure treatment with Boliden K33 and creosote
1973 - IRG/WP 328
Poles of windthrown Norway spruce were stored in bark under water sprinklers for 11-20 months or fully submerged in a lake for 3 years (tab. 1 and 2). Water content after storage is shown in fig. 1 and 8. Treatment with Boliden K33 by sap-displacement (open tank suction) gave a poor result. The Danish requirements of delivery claim a penetration of 20 mm and a net retention of 12 kg/m³ in outer 2...
P Moltesen, E Borsholt, B Bang
A novel solvent penetration assessment technique for wood preservativation treatments using waterborne systems
1990 - IRG/WP 2346
Solvent and hence solute (a.i.) penetration during any wood preservation treatment cycle and the flow pathways taken by the solvent in the wood are crucial elements in determining the adequacy of any treatment. Inadequate solvent penetration into specimens or an inappropriate tissue throughflow pattern during impregnation will markedly affect the distribution pattern achieved by many non-diffusibl...
A J Pendlebury, J Coetzee, E Sorfa, A Botha
The relationship between the electrical resistance and fixation of water-borne CCA salts and pressure-treated wood
1991 - IRG/WP 3657
Two investigations at 22°C and 30°C have been carried out. The electrical resistance in the treated wood and chemical analyses of the remaining amount of unfixed copper, chromium and arsenic were investigated. Samples impregnated with water were used as references. To hold the samples moist during the investigation, each sample was wrapped in a polyethylene plastic foil immediately after impregn...
F G Evans, B Nossen
The effect of chemical treatment on the moisture distribution of Pinus radiata D.Don subjected to wick action
1999 - IRG/WP 99-40135
Radiata pine sapwood stakes were treated with a range of chemicals, including an ammoniacal copper quaternary ammonium compound (ACQ), a copper-chrome and arsenic (CCA) solution and a CCA-oil treatment, potassium linoleate copper linoleate, a paraffin wax and a proprietary alkyd resin. The effect of these treatments on the extent of water absorption and moisture movement through the stakes was inv...
J Hann, P Vinden
Tebuconazole - A new triazole fungicide for wood preservation
1990 - IRG/WP 3629
The main cause of economic damage to timber and millwork worldwide are Basidiomycetes (brown and white rot). After testing a wide range of triazole derivatives for their effectiveness against decay fungi, Tebuconazole, a triazole compound, was selected. The physico-chemical, toxicological and ecotoxicological data of this substance are described. Tebuconazole is unleachable, light-stable, heat-sta...
R Gründlinger, O Exner
Some aspects of testing water repellents
1998 - IRG/WP 98-40113
Several test methods are used to determine the efficiency of water repellent treatments on wood. The most common are: contact angle measurement, swelling rate of samples immersed under water and, the increase in mass of wood samples with time or after a fixed period of time either fully immersed under, or partially immersed in or floating on water.
In this paper, some fundamental aspects of the l...
D Lukowsky, M Farnow, T Rypstra
CCFZ, a new type of water-borne wood preservative for vacuum pressure impregnation
1991 - IRG/WP 3643
By combination of CCF-Salt types with zinchexafluorosilicate a remarkable improvement of efficacy is achieved. In the same time the ecotoxicoligical data become more save. As well as the efficacy against wood-destroying organisms (Basidiomycetes, Soft rot and Long horn beetle) the basic data to evaluate the ecotoxicological behaviour of a CCFZ-Salt are described and compared with the properties of...
W Metzner, D Seepe, H-W Wegen
Performance of water-borne pressure treated fence posts - A practical application of the new Canadian field test data base
1988 - IRG/WP 2305
50 years of test plot data acquisition have been recently set up as a computerized database. The new database which contains information on the service life of a great number of non durable Eastern Canadian wood species treated with various preservatives and many application processes is presented. As an example for its use, a summary of the performance of fence posts treated with waterborne prese...
E E Doyle, R Dubois, J P Hösli
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 par...
D De Sousa Castro Reimão, J M Palacios
Penetration and absorption of water-borne preservatives in conifers from the Western United States: A preliminary report
1988 - IRG/WP 3475
The treatment of most softwoods from the western United States with waterborne chemicals poses a major challenge. Although many of these species are commercially treated with waterbornes, there is considerable debate about their treatability. At present, there is little or no information on the treatability of western wood species with waterborne chemicals. The lack of accurate treatability inform...
S Kumar, J J Morrell
Redistribution of boric acid in radiata pine during drying after preservative treatment
1993 - IRG/WP 93-40010
Samples of 100 x 50 mm² radiata pine were processed with a variety of options to produce dry, boron-treated wood. Concentrations of boric acid in the central one-ninth and in the whole of the wood cross-sections were determined by chemical analysis and compared. Diffusion treated material was dried by air, conventional kiln (70/60°C), or high temperature kiln (120/70°C). Four different predryin...
A J Bergervoet, D R Page, J A Drysdale
The potential of high pressure pulsation processes to treat white spruce lumber with water-borne preservatives
1988 - IRG/WP 3471
Laboratory work using end sealed 4x8x46 cm³ white spruce samples has been done to explore the suitability of three variants of a 2.1 MPa pulsation process for the impregnation of white spruce with CCA. The results showed that the process improved significantly the penetration of the preservatives and reduced significantly cell collapse, when compared with the results of treatment using a 2.1 MPa ...
J P Hösli, J N R Ruddick
Preservative treatment of Golla cane (Daemonorops jenkinsiana) by pressure process
2007 - IRG/WP 07-40379
The feasibility of preservative treatment of golla cane (Daemonorops jenkinsiana (Griff) Mart). by pressure process has been studied using water borne preservatives CCB (copper-chrome-boron). Cane samples of three different lengths 1m, 2m and 3 m. were treated at different pressure and time period to evaluate the extent of penetration and retention of preservative chemicals. It was observed that t...
K Akhter, M Hoque Chowdhury
Moisture adsorption isotherms of wood studies using a dynamic vapour sorption apparatus
2009 - IRG/WP 09-20398
Five types of wood including two Malaysian hardwoods acacia mangium (Acacia mangium) and sesenduk (Endospermum malaccense), two temperate softwoods, Sitka spruce (Picea sitchensis), radiata pine (Pinus radiata) and Accoya (commercially modified wood) were studied to determine their moisture sorption behaviour using a Dynamic Vapour Sorption (DVS) apparatus. The isotherm plot for each species teste...
J Zaihan, C A S Hill, S Curling
Kinetic Water Vapour Sorption of Sitka Spruce at Variable Temperature Using the Parallel Exponential Kinetics Model
2010 - IRG/WP 10-40512
In this study the water vapour sorption of Sitka spruce (Picea sitchensis (Bongard) Carr.) was measured using a Dynamic Vapour Sorption (DVS) apparatus and then analysed using the parallel exponential kinetics (PEK) model. The water vapour sorption rate of wood quickly increased when the relative humidity was changed. With the elapse of time, the sorption rate gradually decreased within any specif...
Yanjun Xie, C Hill
Theoretic discussion on the way and driving forces of moisture migration in wood during vacuum drying
2011 - IRG/WP 10-40538
Most of parameters in conventional drying cannot explain a lot of phenomena appeared in vacuum condition, so it is necessary to further explore the moisture migration way and driving forces in wood under vacuum condition. For the water movement channel in wood is very narrow, the characteristic of heat and mass transfer in wood is similar to that in microscale. This article applies theory of liqui...
Zhengbin He, Xueli Yao, Liqiong Chen, Songlin Yi