Your search resulted in 209 documents. Displaying 25 entries per page.
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
The effect of pretreatments on the impregnation of air-dried sawn Belgian spruce
1988 - IRG/WP 3490
In general the impregnation of airdried spruce results in a variable treatment and limited penetration. This is the result of pit aspiration that occurs during drying of the spruce sapwood and heartwood. Spruce timber is becoming of greater importance in Belgium and hence research for better treatment of this vulnerable wood species is needed. Squared airdried timber of different dimensions were e...
J Van Acker, M Stevens
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 thes...
C Dalois, R Schwartz, G R Y Déon
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
Danish wood preservatives approval system with special focus on assessment of the environmental risks associated with industrial wood preservatives
2001 - IRG/WP 01-50166-01
The following is a description of the procedure used by the Danish Environmental Protection Agency to assess the environmental risks associated with preservatives used in the pressure impregnation of wood. The risk assessment covers issues considered to be of significance for the environment and which are adequately documented so as to allow an assessment. Such issues are persistence and mobility ...
Status of the research and development of a new preservative system (EFPL) for pressure treatment of spruce in Canada
1975 - IRG/WP 348
Our work has been to develop a system which would have the stability of the ACA system and the formulation flexibility of the CCA system enabling properties such as fixation of arsenic, water repellency, appearance and cost to be controlled. Our permeability studies of spruce using a method previously developed indicated that an ammoniacal solution of copper arsenate is an excellent candidate for ...
J Rak, M R Clarke
Manual of a mini treating plant for waterborne preservative treatment of timber and bamboo
1999 - IRG/WP 99-40130
This contributional article includes machinaries and equipments necessary for a small wood treating plant for the pressure treatment of tim bers with waterborne preservatives along with the cost and design. The preservative treatment limitations, treatment schedules and specifications for different products have been described. The cost of a mini treating plant will be 6,00,000 Tk. (13,000 US$), s...
A K Lahiry
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
Health aspects concerning the use of bifluorides in wood
1981 - IRG/WP 3173
An attempt has been made to find a correlation between the quantities F¯ and HF present among other ions in an 'Improsol' solution consisting of NH4F.HF and KF.HF, the quantity absorbed by the wood from this after immersion and the toxicological effects of this treated wood when it is used in rooms destined for the residence of people or animals or for the storage of foodstuffs....
H F M Nijman
Non-pressure treatability of plywood by CCA, CCB and boron
2005 - IRG/WP 05-40295
Study on diffusibility and absorbability of CCA, CCB and boric acid in 3 mm thick 3-ply hardwood plywood at water saturated and air-dry conditions and dipped at same concentration (5%) and same duration of time (12 hours) revealed complete diffusion of all the preservatives at water saturated condition. Only the CCA-C was found absorbed by the plywood at air-dry condition. The rate of absorption a...
A K Lahiry
Improved equipment and technique for high pressure sap displacement impregnation of natural round wood
1972 - IRG/WP 309
Hitherto the main problem in the practical application of high pressure sap displacement impregnation (HPSD) has been in devising a satisfactory cap. Such a cap must be easily fitted to different size log ends to give a leak proof seal. The present contribution describes a new type of cap and sealing system designed to meet these requirements....
C G W Mason, F B Shorland
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper-chrome-arsenic preservative
1981 - IRG/WP 3150
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. We have evaluated the influence of steaming on treatability with a waterborne CCA preservative....
C R Coggins
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
Borate thermal treatments
1992 - IRG/WP 92-3715
Green, partially seasoned (air-dried, steam conditioned), or kiln-dried southern pine timbers were treated thermally using 15% disodiumoctaborate tetrahydrate solution. After treatment, sections were stored under non-drying conditions to allow for diffusion. Results showed that effective treatment meeting the AWPA minimum retention (0.17 B203 pcf [2.72 kg/m³] in the outer inch) and penetration (2...
H M Barnes, R W Landers, L H Williams
Radical changes in the requirements for more safe pressure impregnation in the Nordic countries in 1988
1990 - IRG/WP 3581
After introduction of quality control schemes and standards in the Nordic countries during the seventies, the first radical change of the standards and practice of work took place after pressure from the labor unions and authorities in 1988 and 1989 in Denmark and in Sweden. A new class of preservation with less retention for out of ground contact use was introduced, fixation times were prolonged ...
Recycling of pressure impregnated timber and preservatives - incineration techniques
2001 - IRG/WP 01-50166-19
The object of the recycling research projects is to determine the technical and economical requirements of the recycling of CCA-impregnated wood. In the first recycling of impregnated timber project the amount and location of recyclable treated wood in Finland was determined and the costs of recycling were calculated. An incineration test was also made (1998). The conclusion of the first project i...
T Syrjänen, E Kangas
Light organic solvent preservative treatment schedules for New Zealand-grown radiata pine
1986 - IRG/WP 3379
The influence of pressure differential and treatment time on preservative uptake and distribution in radiata pine heartwood and sapwood is investigated. Treatment schedules are defined which minimise solvent usage but ensure complete sapwood penetration and optimise heartwood penetration....
Creosoted radiata pine by non-pressure methods
1988 - IRG/WP 3486
Posts of Pinus radiata have been impregnated with creosote by immersion for 1, 3, and 7 days, and by hot-and-cold open tank with hot bath temperatures at 40°C and 60°C. On the basis of the retention rates obtained, suitable procedures are described for wood elements that are going to be in ground contact, and an analysis is made of the way in which the variables tested affect the results....
M V Baonza Merino, C De Arana Moncada
Report on the treated piles and fenders in the wharves in Port Moresby harbour, and the Huon Gulf, Lae
1977 - IRG/WP 433
To investigate the resistance of Papua New Guinea timber, vacuum pressure impregnated with Copper-Chrome-Arsenic salts, to marine borer attack in the waters of Papua New Guinea....
S M Rayner, C R Levy
Imprégnation de bois ronds par déplacement de sève à Madagascar
1975 - IRG/WP 352
M Fougerousse, P Guéneau
Survey of conditioning treatment practices in India
1978 - IRG/WP 3127
India has 75.3 million hectares (ie about 24% of total land area) under forests out of which the area of productive forests, from which industrial wood is available, is about 60 million ha. The Task Force on Forest Resources Survey has tentatively estimated that the total growing stock in Indian Forests is 24,000 million cubic metres (m³). The total recorded production of wood in the country is r...
M C Tewari
Exposure monitoring of creosote vapors
1989 - IRG/WP 3511
Creosote oils contain hundreds of compounds. During impregnation and handling of treated wood the main component in the vapors released in air is naphthalene. Other main components are alkyl naphthalenes, indene, phenol and its methyl derivatives, benzothiophene, diphenyl, acenaphthalene and fluorene. In the measurement of creosote vapors, naphthalene can be used as an indicator agent. One of the ...
P Heikkilä, M Loutamo, V Riihimäki, M Romo
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
Patent on the use of tannic acid and ferric chloride against marine borers, etc
1982 - IRG/WP 495
R Mitchell, T D Sleeter
Diffusion treatment plants (Latin America - Africa)
1974 - IRG/WP 333
B N Prasad