The objective of this research was to determine whether the pinewood nematode can colonize all coastal wood species and to develop heat and/or chemical treatments to eliminate it from infected lumber. Much of the effort in this project was expended in developing the proposal for the cooperative research program entitled "The use of heat treatment in the eradication of PWN and its vectors from softwood lumber". Two major pieces of work required in preparation for this proposal were as follows: the development of the experiment design and statistical analysis necessary to demonstrate the reliability of the pasteurization process; and, the selection and testing of a model for analyzing the results of the heating studies on different wood species and different thicknesses of lumber.
In this paper, the finite element method is used to examine the affect of the standard bandsaw operating parameters - such as blade width, blade thickness, span length, tooth size, bandmill strain and roll-tensioning stresses - on lateral tooth stiffness. The results are presented graphically. Specific examples of how changes to the operating parameters can affect tooth stiffness are presented and indicate that, for some conditions, increases in bandmill strain of over 40% are required to regain tooth stiffness lost through reducing blade thickness by one gauge. The relationship between the fundamental torsional frequency and lateral tooth stiffness, for a range of roll-tensioning positions, is examined and shows that an increase in frequency is always accompanied by increase in tooth stiffness. The converse, however, is not always true.
Unseasoned spruce heart veneer was incised and steam-press dried using platen pressures of 25, 100 and 200 psi. Three-ply plywood panels were then prepared from these densified veneers. Results showed that the stiffness values for laminated veneer lumber (LVL) made with low stiffness SPF veneer or combinations of SPF and Douglas-fir veneer can be greatly increased and meet the 2,000,000 psi MOE marketing requirement using two methods. One involves impregnating unseasoned SPF veneer with phenolic resin and the second method involves using a special lay-up of the SPF and Douglas-fir veneers. These results will greatly help in marketing LVL using western veneer species. New technology of incising, moisture tolerant adhesives and self-generated steam developed at Forintek substantially reduced pressing time by about 40% which will make the manufacture of LVL more economical.
Forintek Canada Corp., as a scientific organization, was commissioned by the Task Force on Pasteurization of Softwood Lumber to lead a research initiative to examine heat treatment (pasteurization) as an alternative to kiln drying for the eradication of pinewood nematode (PWN) and a sawyer beetle (Monochamus) from green, unseasoned softwood lumber. The project had a laboratory component (Phase I) where statistical analysis for confidence and reliability could be used to determine a mortality curve for PWN on wood samples. Concurrent studies (Phase II) using laboratory dry kilns were done to measure heating times for a wide range of wood species and selected wood species of different thicknesses. From the first two Phases of the project a demonstration (Phase III) of the successful application of pasteurization to green lumber was then arranged at three sawmill sites across Canada, with verification by scientists of the European Economic Community (EC) team. Finally, Phase IV in the project evaluated some alternate technologies to pasteurization.
The objective of this project was to develop a new feed speed control system for band saws. This system regulates the feed speed based on the cutting depth measured ahead of the saw. In comparison to other feed speed control systems presently used in sawmill operations, the new system allows maximum feed speeds without overfeeding the saw and also avoids underfeeding. The equipment developed basically involves two laser light generators which place laser lines along the saw cut on the saw entry and saw exit side, two cameras which locate the position of the laser or saw lines, and a microprocessor which processes the information from the cameras, determines the feed speed based on the known relationship between sawing variables and gives the signal to the carriage drive. Considerable experimenting was required to accurately measure the distance between the laser lines on the saw log due to colour variations of the long surface and more so due to the irregular geometry of many saw logs. Also a high working speed of the system had to be achieved to correspond to the high feed speeds used in sawmill operations. The new feed speed control system was tested with Forintek's 5-ft band mill. It was found that the actual feed speed set by the feed speed control, and the calculated feed speed were in close agreement showing that the system is able to effectively control the feed speed based on the cutting depth. Additional work is needed and will be carried out to further refine the system before commercialization can be undertaken.
The present invention consists of a method of protecting wood or wood products against unwanted sapstain by treating said wood with one or more biological control microorganisms selected from the genus Gliocladium, (fungi: Hyphomycetes), that either prevents the growth of undesirable sapstaining organisms, or prevents the formation of discolouration by these organisms.
The purpose of this study was to determine flatwise and edgewise bending strength ("MOR") and stiffness ("MOE") of spruce and pine 1.5-inch by 3.5-inch by 48-inch laminated veneer lumber ("LVL") specimens parallel to grain. The experimental spruce and pine data was pooled together to give a combined spruce-pine data set.
Appendix 1 to Forestry Canada No. 35, Contract no. 1812L007 on
lumber and laminated veneer strength.
The purpose of this small study was to examine the effect of various test methods upon the bending moduli of elasticity and to determine the bending strength of selected Douglas-fir and spruce laminated veneer lumber specimens.
Forintek Canada Corp., as a scientific organization, was commissioned by the Task Force on Pasteurization of Softwood Lumber to lead a research initiative to examine heat treatment (pasteurization) as an alternative to kiln drying for the eradication of pinewood nematode (PWN) and a sawyer beetle (Monochamus) from green, unseasoned softwood lumber. The project had a laboratory component (Phase I) where statistical analysis for confidence and reliability could be used to determine a mortality curve for PWN on wood samples. Concurrent studies (Phase II) using laboratory dry kilns were done to measure heating times for a wide range of wood species and selected wood species of different thicknesses. From the first two Phases of the project a demonstration (Phase III) of the successful application of pasteurization to green lumber was then arranged at three sawmill sites across Canada, with verification by scientists of the European Economic Community (EC) team. Finally, Phase IV in the project evaluated some alternate technologies to pasteurization.
A series of dispersion-resin plywood formulations were prepared in the laboratory and their bond performance assessed on incised spruce veneer at 10% m.c. Excellent bond quality results were achieved in these laboratory experiments as indicated by high average % wood failure values of over 90%. To further develop the plywood dispersion resin, a pilot plant trial at a gluing company was conducted and again excellent bond quality results were achieved. A large quantity of the plywood dispersion resin was prepared and a successful mill trial at Cantree Plywood was carried out. This trial demonstrated that more dimensionally stable panels can be prepared from high m.c. veneer. The waferboard dispersion technology developed in this study helped facilitate a mill trial using high moisture content face wafers.
The recent introduction of optimizing technology for cross-cutting boards (chop saw operation) has raised questions about the merits of this technology versus conventional manual systems in the British Columbia remanufacturing sector. A review of the existing technology available to chop lumber (both manual and computerized) was undertaken. A total of 30 remanufacturing plants were visited. Background material was obtained from journal articles and literature from suppliers. The relative merits of the systems in use are discussed.
Western hemlock is a species that is highly susceptible to compression wood (CW) formation, an abnormal wood tissue that forms on the under side of leaning tree stems and branches. When lumber cut from logs containing CW is dried, the CW shrinks approximately 10 times normal in the parallel to grain direction, resulting in degrade, at times severe, due to warp in the form of crook and bow. In this project a technique using an ultrasonic materials evaluation system (UME) was tested for its ability to detect CW. Since stress wave velocity, in addition to being dependent on elastic properties and material density, is also a function of growth ring orientation, a slope of grain indicator was evaluated for its ability to measure growth ring orientation, to be used in conjuction with the UME.
Application de la vision artificielle dans les scieries europeennes : un rapport de voyage prepare pour le Conseil national de recherches du Canada (Mai 1988)
