A field test of six millwork preservatives has been ongoing for twenty years, using a simulated window corner, or "Y-joint", as the test unit. Three preservatives provided excellent protection to white pine and white spruce: 5% pentachlorophenol in varsol, phenyl mercury oleate in varsol, and 0.75% oxine copper in varsol.
The objective of this initiative is to re-evaluate Forintek's research strategy and the Canadian Wood Council's technology transfer strategy in durability of wood products and systems in the light of changing industrial, regulatory, environmental, and social factors. Forintek and the CWC chose to undertake this process jointly, in order to develop well-matched parallel activities that are mutually supportive and grounded in common underlying objectives. In this way, both organizations can most effectively and efficiently address our members' needs in an area of growing challenges for the wood industry.
The first step in the strategic planning process was the creation of a joint CWC/Forintek Durability Guidance Group. This group was canvassed for input on high priority issues related to wood durability. Forintek and CWC then developed ideas for deliverables or tasks in research and technology transfer, respectively. At this stage we are looking for input on the degree to which this draft strategy addresses industry needs.
During the last decades, Engineered Wood Flooring and Laminated Flooring experienced dramatic increase in demand from consumers in Europe and Asia, and those two products have taken large market share to the traditional hardwood strip flooring and to other floor covering material like textile, vinyl, etc. In North America, these new multi-layer parquets are just taking off, in 1997, Engineered Wood Flooring share of hardwood flooring was 34% and growing fast. This compares with a market share of 67% in Europe. There appears to be much room for growth in North America. The rapid increase of hardwood flooring products in the world in recent years associated with the decrease of available hardwood raw material made the multi-layer and laminated flooring products interesting alternatives for the hardwood flooring industry. Canada is an important supplier of the hardwood raw material for the European production of both hardwood and EW Floorings. Since some volumes of EWF production from Europe are exported to North America, we do not see any reason why they should not be manufactured in Canada with a competitive advantage. The window of opportunity is there to be exploited.
High Pressure Laminate flooring, a composite product made of High Density Fiberboard (HDF) overlaid by coated paper and presenting a very high-resistance surface finish, is also growing very fast in the U.S. The focus was less on this product in this report since contrarily to EWF, HPL flooring is already being produced in Canada. Also a high capacity for manufacturing this product is currently being built in S-E Asia and in China and we know these countries are low-cost producers, very hard to compete with.
Standards and methods for testing such products were reviewed. It was observed that the European market is very much standard driven, German standards leading the way in that respect. North American are more driven by "lifetime limited warranties”, although some voluntary standards have been defined by the industry. In any case, all testing methods that were observed in these standards can be performed in Forintek materials testing laboratories.
The main problems associated with such products are certainly their negative reaction to variation of moisture content. In this report, methods for predicting those reactions were elaborated in terms of quality of construction and performance. More specifically, testing methods were defined, tried and found to be effective to test surface planeity, gap formation associated with shrinkage and cupping. A process quality control method was also proposed to help eventual producers to control their gluing process. Certainly more research needs to be done to find the best parameters in terms of products and methods of production to develop high quality products that consumers will like to use in their home. Additional research is also required in order to find which backing and core materials could provide the future Canadian EWF industry a sustainable competitive advantage.
§ Wood chemistry and structure affecting durability
§ Natural durability of Canadian species
§ Organisms attacking wood
§ Types of decay fungi
§ Factors necessary for biodeterioration
§ Time required for decay to occur
§ Decay characteristics of Canadian softwoods
§ Other influences on decay initiation
The project Decision Aids for Durable Wood Construction underwent a major review with the hiring of a new project leader (O'Connor) in September 1998. In consultation with the project liaisons, the work on this project since its start-up in 1993 was examined, the primary task of developing a computer-based tool for the building industry was reconsidered, the context of worldwide research into building envelope moisture failures was reviewed, and a revised project plan was proposed.
Decision Aids was a self-contained project for its first three years, with efforts concentrated on knowledge acquisition, expert system experimentation and other foundation work for development of a computer tool. With a rise of interest in building envelope moisture failures across North America and elsewhere, Decision Aids activity shifted into a mode that was reactive to projects and events external to Forintek. This was necessary due to the level of effort external agencies, media and research labs were devoting to the topic. In particular, where the actions of outsiders began to have an influence on wood in construction, we found it critical to participate in order to ensure the fair and correct treatment of wood.
The new project leader was asked to review the project and either get the project back on its original track or suggest a redirection. The project goal, to assist end users in best application of wood, was determined to be sound. In addition, the project leader recommended that resources continue to be allocated to participation in outside research efforts and other related activities. However, it was recommended that the project objective to develop computer-based decision tools be reassessed. Instead, the project leader recommended a course of action focused on tasks both shorter in term and smaller in scope, which will enable Forintek to deliver results better tailored to the immediate needs of industry in a time of building envelope moisture failure "crisis."
The new project plan is split into two areas: 1) address building envelope moisture failures that are due to existing information not arriving in the right hands (i.e., a technology transfer problem); and 2) address building envelope moisture failures that are due to a lack of information (i.e., a research problem). The technology transfer area will create a formal plan for communication to the building industry, will enable Forintek to experiment with developing pathways to that new target audience, and will provide the means for the wood industry to provide helpful durability information to the public through a relatively neutral third party (Forintek). The research area will explore opportunities for limited scope experiments or collaborative field studies of wood system durability performance, with the intent of verifying or modifying codes, standards and best practice guides.
This project was initiated to provide technical assistance to the Alberta wood drying industry. The specific objective was to identify opportunities to improve product quality through modification of the drying schedules. Seven mills representing almost 50% of the solid, softwood lumber production in the province were selected for the project. All mills provided a great deal of cooperation and commitment to the project was excellent. In general, lumber drying operations in Alberta are in good physical condition and operating personnel have a sound knowledge of basic drying concepts.
In general, drying schedules were found to be quite harsh. the specific concerns at most mills related to too rapid a heat-up rate and extremely low relative humidity at the end of the drying cycle. Most of the schedule modification called for more gradual and controlled heat-up rates with higher wet-bulb temperatures. The objective of this modification is to avoid setting up conditions othat promote variability in moisture content from board to board. Higher relative humidity is required at the end of the drying cycle to avoid over-drying faster drying boards. Achieving a reduction in final moisture content variability and a higher overall average moisture content should be the objective of drying schedule modifications.
Mill visits were used not only to review drying schedules but also to conduct a brief inspection of drying practices and equipment. It would be unproductive to identify schedule modifications if there were obvious shortcomings in other areas of the operation that would make it difficult to implement or over-shadow the effect. The primary concern with drying equipment is the leakiness of the structures. A common recommendation to mills was to tighten up kiln doors and walls in order to retain more moisture in the kiln environment. Another area of concern was related to lumber handling operations. Most problems in this area could be addressed through educating and training staff working at stackers, handling material in the yard, or preparing loads for the kiln.
Logging and log storage practices at all of the mills visited has a serious and detrimental impact on the drying operations. At most times of the year, operators are having to deal with a wood supply that has a mix of initial moisture content conditions. Most mills seem to manage the small percentage of balsam fir in their mix effectively. Some future gains may be achieved through refined presorting techniques that take into account initial MC variability as well as differing drying characteristics between species.
Given the remarkable growth of engineered wood products (EWP) in recent years, and considering industry’s desire to maximise product recovery and value, Forintek undertook a literature search and mill visits to investigate drying practices in Eastern Canada regarding major engineered products (MSR lumber, finger-jointed studs, wood I-joists, glued-laminated beams), and how such practices affect manufacturing processes.
The study revealed that most plants were equipped with on-line moisture detectors to reject undesirable pieces, but, with a few exceptions, little effort was made to adapt drying specifications to EWP requirements. The lumber used was generally dried to the same standards as commodity lumber (19 per cent maximum) even though high moisture contents caused pieces to be downgraded by MSR machines, and moisture content differentials between adjoining pieces was thought to be responsible for some poor finger-joints in structural studs. Based on the experience of some mills, questions were raised as to the effect of high-temperature drying on mechanical properties.
However, attitudes were observed to be changing to a client focus as operations became better established, especially in integrated plants. Recommendations made to support improved returns through drying quality include investigation of 1) the effect of moisture content differentials on finger-joints, 2) optimum moisture contents and drying schedules for MSR production, and 3) the effect of high-temperature drying on I-beam flange material performance.