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Temperature and pressure inside wood during creosote impregnation
1991 - IRG/WP 3649
Creosote gives the best protection against decay for sleepers and poles. However, it has a major drawback - bleeding. Modified impregnation processes to reduce bleeding have been tried. For developing such processes it is important to know the actual temperature and pressure inside the wood. This paper describes measurement of temperature and pressure inside wood during creosote impregnation. The experiments have been performed at a research plant using poles of Scots pine (Pinus sylvestris L.). Boiling under vacuum before impregnation increased the temperature inside the sapwood to 80-90°C within 1½ hours. The pre-pressure of the Rueping process applied in the vessel raised the pressure inside the sapwood immediately to the same level as in the vessel. When the oil-pressure was applied the pressure inside the wood rose more slowly and generally did not reach the level in the vessel. During the final vacuum there was still pressure above atmospheric inside the wood in most of the experiment charges.
Ö Bergman


Survey of conditioning treatment practices in the Philippines
1975 - IRG/WP 349
The wood preservation industry in the Philippines is at present beset by many problems. An association of the industry similar to those existing in other countries has only been initiated last year by FORPRIDECOM. It is hoped that the formal organisation of this association will bring into focus the importance of this particular industry in the economic and industrial development of the country. Likewise, for the past years, treatment specifications suitable for Philippine conditions, wood species, and wood products are non-existent. Treatment specifications are usually patterned after those of other countries but in most cases, specifications of the American Wood Preservers' Association (AWPA) are generally followed regardless of whether they may or may not apply to our existing climatic conditions and to local wood species. It was only last year, however, that a series of discussions and formulations of acceptable treatment specifications had been started for which substantial progress is being made in co-operation with the private sectors.
R F Casin


Survey of North American practice in conditioning forest products before preservative treatment
1972 - IRG/WP 308
Seasoning requirements for the wide range of forest products which are treated with preservatives and fire retardants must be capable of dealing with a very complex set of conditions which are summarized under a number of variables including type and hazard of end use, the most effective distribution of preservative, a wide range of cross sectional dimensions, the possibility of seasoning by a range of special methods which are in part dependent upon available treating facilities and a wide range of physical properties of the wood including, for example, its permeability to fluids. In addition, the wide range of species utilized in end uses requiring preservation means that large inventories are associated with certain seasoning processes such as air drying to the cost of the treater and consumer. There have been trends to use rapid seasoning methods wherever possible, such as boultonizing, and there are now trends to extend the use of other drying methods to some of the products of a larger cross section which are given preservative treatment. These products include railway cross ties and utility poles, and the methods include, for example, vapour drying and special techniques of kiln drying.
J Rak, T S McKnight


Survey of practical methods for conditioning of forest products before preservative treatment
1971 - IRG/WP 39
The seasoning of forest products is undertaken for a wide range of end uses and is becoming increasingly required for applications and building construction and secondary manufacturing industries. A wide range of applications of new technology and specifically required seasoning schedules is being actively developed for such requirements, but less attention has been given to the means by which wood can be prepared for successful preservation treatments by seasoning or more general conditioning treatments. Much of the knowledge of the practical means of achieving good treatments through prior seasoning and conditioning resides in the skill and experience of larger treating companies. Although many of the pertinent means of achieving proper pretreatment seasoning are mentioned in important sets of standards, such as those of the American Wood Preservers Association (AWPA) and the Canadian Standards Association (CSA), it is often necessary for the consumer of treated forest products to develop the appropriate means of seasoning for his special case through reliance on the knowledge of the treater. In the case of a large consumer, such as the major utilities, there is often his own body of experience gained through the activities of a research and development group.
J Rak, T S McKnight


Interaction of Boultonizing and through-boring of Douglas fir sapwood
2018 - IRG/WP 18-40833
The interaction of combining through-boring and Boultonizing treatment effects on strength properties was investigated. Small, clear Douglas fir beams were through-bored and/or Boultonized in full factorial design and evaluated for toughness, MOE and MOR. The simulated through-boring treatment lowered the mechanical properties but the Boultonizing process did not. There was also no evidence for a negative synergistic interaction of the through-boring and Boultonizing treatments. These data suggest that there is no need for concern about combining through-boring and Boultonizing treatments for Douglas fir utility poles, and actually may help industry further as the results also suggest that commonly applied mechanical property reductions for Boultonizing treatments may not be necessary.
F Gasteiger, J Lloyd, A Taylor