Skip header and navigation

10 records – page 1 of 1.

Biological method to pre-dry lumber with wetwood

https://library.fpinnovations.ca/en/permalink/fpipub39015
Author
Yang, D.-Q.
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Yang, D.-Q.
Date
March 2007
Material Type
Research report
Physical Description
62 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Yeasts
Wetwoods
Seasoning
Bacteria
Series Number
General Revenue Project No. 4030
4030
Location
Québec, Québec
Language
English
Abstract
Wetwood, or water pocket, has higher moisture content (MC) and lower permeability than normal wood, which cause problems for lumber drying. The high moisture content of wetwood usually requires relatively long periods for adequate drying; consequently, it causes a high risk for developing checks, splits, crook, bow and twist of lumber in kiln drying. These problems have not been solved by any physical, chemical or mechanical methods yet. Using biological method to pre-dry lumber containing wetwood is a new concept introduced in this project. Wetwood is formed by bacteria growth inside normal wood. Some fungi are able to kill bacteria and to utilize foetid liquid produced by these micro-organisms. Consequently, the permeability of wetwood can be increased and the lumber drying rate can be improved. The present project intends a research on biological method to pre-dry lumber containing wetwood, and to evaluate efficacy and economic benefit of such a biological treatment. Wetwood of balsam fir, sub-alpine fir and aspen was cultured on nutrient media, and several species of bacteria and yeasts were isolated. The bacteria and yeasts were re-inoculated on normal wood of balsam fir. All inoculated micro organisms caused wetwood formation in 2 weeks. The MC of the inoculated wood blocks increased from 41% to 220-240%, whereas the control samples without inoculation reached only 110%. When control samples were dried to a MC of 13%, the inoculated wood samples still had MCs between 80% and 105%. The selection of biological control agents was conducted on both agar plates and on balsam fir wetwood blocks, and 2 fungal candidates demonstrated promising results. The field test showed that pre-treating balsam fir wetwood lumber with the selected best biocontrol candidates, wood stain was reduced by 94%, warping reduced up to 13%, and checking reduced up to 30% compared with untreated controls. Drying time was reduced by 33% (24 hours) compared with drying fresh lumber. CT scanner was able to detect wetwood locations inside a piece of lumber, and the wetwood was identified in heartwood, sapwood or both wood tissues. After the bio-treatment, the wetwood contents of boards were significantly reduced. Economical analysis showed that the biological treatment would cost $4-7/Mfbm depending on treating method used. Reduction of 33% of drying time by the treatment in this study could save energy cost by $6-13/Mfbm depending on kiln drying energy used. The treatment could reduce lumber degrading loss by $8.5-37.4/Mfbm base on this study. The benefit of the treatment is significant, but will be affected by pre-drying operation, kiln type, energy use and drying schedule. The biological treated lumber is resistant to fungal infection during pre-drying period, and the lumber products are clean and free of moulds and stain infection. Acknowledgements We specifically would like to thank Pierre Lemieux, Scierie Leduc, for providing testing wetwood materials. We also appreciate the support and guidance provided by the project’s industry liaison officers: François Saillant, Natural Resources Canada; Léandre Bélanger, Domtar. Their participation was the key to the success of this project.
Wetwood
Seasoning - Predrying
Yeasts
Bacteria
Biological Control
Fungi
Documents
Less detail

Biological method to pre-dry lumber with wetwood

https://library.fpinnovations.ca/en/permalink/fpipub38957
Author
Yang, D.-Q.
Date
March 2006
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Yang, D.-Q.
Date
March 2006
Material Type
Research report
Physical Description
67 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Yeasts
Wetwoods
Seasoning
Bacteria
Series Number
General Revenue Project No. 4030
4030
Location
Québec, Québec
Language
English
Abstract
Wetwood, or water pocket, has higher moisture content and lower permeability than normal wood, which cause problems for lumber drying. The high moisture content of wetwood usually requires relatively long periods for adequate drying; consequently, it causes a high risk for developing checks, splits, crook, bow and twist of lumber in kiln drying. These problems have not been solved by any physical, chemical or mechanical methods yet. Using biological method to pre-dry lumber containing wetwood is a new concept introduced in this project. Wetwood is formed by bacteria growth inside normal wood. Some fungi are able to kill bacteria and to utilize foetid liquid produced by these micro-organisms. Consequently, the permeability of wetwood can be increased and the lumber drying rate can be improved. The present project intends a research on biological method to pre-dry lumber containing wetwood, and to evaluate efficacy and economic benefit of such a biological treatment. Trees of balsam fir, sub-alpine fir and aspen were felled and cut into lumber. Isolation of causal agents was conducted from wet pockets of these wood species by using peptone agar and malt extract agar media. A total of 319 cultures were obtained from the wetwood of these three wood species. Three bacteria and two yeasts were isolated from balsam fir wetwood, 2 bacteria and 1 yeast were more frequently isolated from aspen wetwood, and 2 bacteria and 5 yeasts were obtained from sub-alpine fir. Two bacteria were isolated from the wetwood of all 3 wood species: Shigella sonnei and Pseudomonas fluorescens. Other bacteria and yeasts isolated were identified as Aerococcus viridans, Chryseomonas luteol, Candida boidinli, C. zeylanoides, Cryptococcus albidus, C. laurentii, C. terreus, and Rhodotorula mucileginosa. In addition to these identified bacteria and yeasts, two other yeasts isolated from balsam fir and sub-alpine fir wetwood were unabile to be identified. Six bacteria and yeast isolates were re-inoculated on normal wood of balsam fir; they were A-a (a bacterium isolated from aspen and identified as Shigella sonnei), A-c (a yeast isolated from aspen and identified as Cryptococcus laurentii), B-a (a bacterium isolated from balsam fir and identified as Shigella sonnei), B-c (a mixture of 2 bacteria isolated from balsam fir and identified as Shigella sonnei and Aerococcus viridans), Y-2 (an unidentified yeast isolated from balsam fir), and SaB-2 (a bacterium isolated from sub-alpine fir and identified as Shigella sonnei). The result showed that all of these micro-organisms caused wetwood formation on inoculated normal wood samples in 2 weeks. This result indicates that wetwood formation in trees is not caused by only 1 micro-organism but is more likely caused by several species (either bacteria or yeasts) that can colonise well in the wood of trees. The moisture contents (MC) of the inoculated wood blocks increased from 41.2% to 220-240 %, whereas the MCs of the control samples submerged in a liquid culture medium without inoculation reached only 110%. When control samples were dried to a MC of 13%, the inoculated wood samples still had MCs between 80% and 105%. This result indicates that drying lumber containing wetwood will take double the time required to dry normal lumber without wetwood. An antagonist test using fungal candidates was conducted on agar plates. In this test, 6 potential fungal antagonists and 6 wetwood causal agents (WCA) were used. The six fungal antagonists were Gliocladium roseum (a bioprotectant developed by Forintek), a white isolate of Ophiostoma piliferum (a fungus used in a commercial bioprotectant, Cartapip), a white isolate of Ceratocystis resinifera (an anti-sapstain biological agent used by Chantal Morin at Laval University), Geotrichum sp.A (a white fungus in Deuteromycetes isolated from Jack pine logs, DP3/5B-3a, 1998), Geotrichum sp. B (a white fungus in Deuteromycetes isolated from balsam fir logs, DF3/1B-1b, 1998), and Phaeotheca dimorphospora (a biological control agent of tree disease from Laval University). The six wetwood causal agents were A-a (a bacterium isolated from wetwood of aspen), A-c (a yeast isolated from wetwood of aspen), B-a (a bacterium isolated from wetwood of balsam fir), Y-2 (a yeast isolated from wetwood of balsam fir), SaB-2 (a bacterium isolated from wetwood of sub-alpine fir), and SaY-4 (a mixture of a yeast and a bacterium isolated from wetwood of sub-alpine fir). The results showed that Geotrichum sp.A and Geotrichum sp.B were the most effective against all 6 WCA inoculated; they reduced growth of the WCA in 7 days and completely absorbed colonies of WCA in 11 days. G. roseum, O. piliferum, and C. resinifera were moderately effective against 5 WCAs, but not effective on bacterium A-a that was isolated from aspen wetwood. P. dimorphospora was the least effective against any of these WCA. The three promising fungal antagonists, Geotrichum sp., G. roseum and the white isolate of O. piliferum, selected from agar plate test were used for an antagonist test on balsam fir wetwood blocks in the laboratory conditions. This test was conducted on small wetwood samples (2 x 4 x 1 inch) in incubators at 25°C and two relative humidity ranges (100% and 75% RH). The results showed that all these three fungi were able to establish on wood surfaces and able to reduce wetwood contents. At 25°C and 75% RH, Geotrichum sp. was the most effective to reduce wetwood content in samples, followed by G. roseum, and then by O. piliferum. G. roseum and Geotrichum sp. not only reduce wetwood content, but also inhibit mold growth and wood stain, compared with untreated control samples. At 25°C and 100% RH, the moisture contents of treated and untreated samples were not changed in any week of the testing period. This result indicates that biological pre-dry wetwood samples should not be conducted at this high relative humidity condition. A test was conducted to investigate the inhibitory ability of Geotrichum sp., the wetwood control candidate, against sapstaining fungi on wood. The results showed that if balsam fir wood wafers were inoculated with Geotrichum sp. 3 days before the staining fungi, no staining fungi grew on these samples. If wood wafers were inoculated with Geotrichum sp. and staining fungi at the same time, samples were covered by both Geotrichum sp. and the staining fungus Ophiostoma piceae in a ratio of 1:1. If wood wafers were inoculated with the staining fungi 3 days before Geotrichum sp., samples were absolutely covered by the staining fungus and fully stained. A study on environmental effects on the growth of Geotrichum sp., the wetwood control agent, showed that this fungus started growth at 5°C, had optimal growth between 20-25°C, stopped growth at 30°C, and died at 40°C. Geotrichum sp. had a wide range of pH requirement and grew well in agar medium at pHs between 3 and 10. Geotrichum sp. started to grow at 29% MC, and the speed of the growth increased along with the increase of MC in wood. The best fungal growth of Geotrichum sp. was observed on wood blocks containing 56% MC. Geotrichum sp. was able to grow on wood of jack pine, black spruce, balsam fir, sub-alpine fir and aspen, but it grew better on wood of jack pine, balsam fir and black spruce than on sub-alpine fir and aspen. Geotrichum sp. was able to grow together with an anti-sapstain fungus, Gliocladium roseum, without any antibiotic or incompatible growth reaction. In the laboratory conditions, the biological treated boards reduced wood MC by 22-37% more than untreated boards. Untreated boards were fully covered by molds and stain after 8 weeks in storage, and 0% of boards was acceptable for use. The biological treated boards were less affected, with 35-75% of pieces acceptable. The time required for drying biological treated boards was estimated reducing by 10.5 hours compared with untreated controls. After drying, the biological treated boards reduced the rate of crook, bow and twist by 5-20%, but increased the rate of split and check by 5-12%, compared with untreated controls. The total deformation rate was reduced up to 5% by the best biological treatment. In the field conditions, untreated boards were 100% affected by molds and stain after 8 weeks in storage, whereas the best biological treated boards were only affected by 6%. Drying biological treated and untreated boards took similar times, but it was estimated reducing drying time by 48 hours compared with fresh boards. Compared with untreated controls, the biological treated boards reduced the rate of crook, bow and twist by 2-13%, and reduced the rate of split and check by 3-30%. The total deformation rate was reduced by 5-22%, depending on the treatments. CT scanner was able to detect wetwood locations inside a piece of lumber, and the wetwood present in either heartwood, sapwood or both wood tissues. After the bio-treatment, the wetwood contents of boards were significantly reduced.
Wetwood
Seasoning - Predrying
Yeasts
Bacteria
Biological Control
Fungi
Documents
Less detail

Identify viable non-commodity softwood lumber product diversification opportunities available to Alberta producers

https://library.fpinnovations.ca/en/permalink/fpipub37808
Author
Wahl, A.
Date
April 2006
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wahl, A.
Contributor
Alberta Sustainable Resource Development
Date
April 2006
Material Type
Research report
Physical Description
44 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Alberta
British Columbia
Utilization
Softwoods
Markets
Series Number
W-2341
Location
Vancouver, British Columbia
Language
English
Abstract
In view of the long-standing nature of the Canada-U.S. softwood lumber dispute, this literature review examines opportunities for softwood products that are currently not affected by the dispute. This includes non-commodity softwood products for the U.S. market and softwood lumber opportunities in the domestic Canadian market, Asia and Europe.
Alberta Alliance Project No. 5130-05 pertaining to softwoods - Utilization; softwoods - Markets
Documents
Less detail

Biological method to pre-dry lumber with wetwood

https://library.fpinnovations.ca/en/permalink/fpipub42290
Author
Yang, D.-Q.
Date
March 2005
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Yang, D.-Q.
Date
March 2005
Material Type
Research report
Physical Description
44 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Yeasts
Wetwoods
Seasoning
Bacteria
Series Number
General Revenue 4030
Location
Sainte-Foy, Québec
Language
English
Abstract
Wetwood, or water pocket, has higher moisture content and lower permeability than normal wood, which cause serious problems for lumber drying. The high moisture content of wetwood usually requires relatively long periods for adequate drying; consequently, it causes a high risk for developing checks, splits, crook, bow and twist of lumber in kiln drying. These problems have not been solved by any physical, chemical or mechanical methods yet. Using biological method to pre-dry lumber containing wetwood is a new concept introduced in this project. Wetwood is formed by bacteria growth inside normal wood. Some fungi are able to kill bacteria and to utilize foetid liquid produced by these micro-organisms. Consequently, the permeability of wetwood can be increased and the lumber drying rate can be improved. The present project intends a research on biological method to pre-dry lumber containing wetwood, and to evaluate efficacy and economic benefit of such a biological treatment. Trees of balsam fir, sub-alpine fir and aspen were felled and cut into lumber. Isolation of causal agents was conducted from wet pockets of these wood species by using peptone agar and malt extract agar media. A total of 319 cultures were obtained from the wetwood of these three wood species. Three bacteria and two yeasts were isolated from balsam fir wetwood, 2 bacteria and 1 yeast were more frequently isolated from aspen wetwood, and 2 bacteria and 5 yeasts were obtained from sub-alpine fir. Two bacteria were isolated from the wetwood of all 3 wood species: Shigella sonnei and Pseudomonas fluorescens. Other bacteria and yeasts isolated were identified as Aerococcus viridans, Chryseomonas luteol, Candida boidinli, C. zeylanoides, Cryptococcus albidus, C. laurentii, C. terreus, and Rhodotorula mucileginosa. In addition to these identified bacteria and yeasts, two other yeasts isolated from balsam fir and sub-alpine fir wetwood were unabile to be identified. Six bacteria and yeast isolates were re-inoculated on normal wood of balsam fir; they were A-a (a bacterium isolated from aspen and identified as Shigella sonnei), A-c (a yeast isolated from aspen and identified as Cryptococcus laurentii), B-a (a bacterium isolated from balsam fir and identified as Shigella sonnei), B-c (a mixture of 2 bacteria isolated from balsam fir and identified as Shigella sonnei and Aerococcus viridans), Y-2 (an unidentified yeast isolated from balsam fir), and SaB-2 (a bacterium isolated from sub-alpine fir and identified as Shigella sonnei). The result showed that all of these micro-organisms caused wetwood formation on inoculated normal wood samples in 2 weeks. This result indicates that wetwood formation in trees is not caused by only 1 micro-organism but is more likely caused by several species (either bacteria or yeasts) that can colonise well in the wood of trees. The moisture contents (MC) of the inoculated wood blocks increased from 41.2% to 220-240 %, whereas the MCs of the control samples submerged in a liquid culture medium without inoculation reached only 110%. When control samples were dried to a MC of 13%, the inoculated wood samples still had MCs between 80% and 105%. This result indicates that drying lumber containing wetwood will take double the time required to dry normal lumber without wetwood. An antagonist test using fungal candidates was conducted on agar plates. In this test, 6 potential fungal antagonists and 6 wetwood causal agents (WCA) were used. The six fungal antagonists were Gliocladium roseum (Forintek bioprotectant), a white isolate of Ophiostoma piliferum (Cartapip), a white isolate of Ceratocystis resinifera (an anti-sapstain biological agent produced by Chantal Morin at Laval University), Oidium sp.A (a white fungus in Deuteromycetes isolated from Jack pine logs, DP3/5B-3a, 1998), Oidium sp. B (a white fungus in Deuteromycetes isolated from balsam fir logs, DF3/1B-1b, 1998), and Phaeotheca dimorphospora (a biological control agent of tree disease from Laval University). The six wetwood causal agents were A-a (a bacterium isolated from wetwood of aspen), A-c (a yeast isolated from wetwood of aspen), B-a (a bacterium isolated from wetwood of balsam fir), Y-2 (a yeast isolated from wetwood of balsam fir), SaB-2 (a bacterium isolated from wetwood of sub-alpine fir), and SaY-4 (a mixture of a yeast and a bacterium isolated from wetwood of sub-alpine fir). The results showed that Oidium sp.A and Oidium sp.B were the most effective against all 6 WCA inoculated; they reduced growth of the WCA in 7 days and completely absorbed colonies of WCA in 11 days. G. roseum, O. piliferum, and C. resinifera were moderately effective against 5 WCAs, but not effective on bacterium A-a that was isolated from aspen wetwood. P. dimorphospora was the least effective against any of these WCA. The three promising fungal antagonists, Oidium sp., G. roseum and the white isolate of O. piliferum, selected from agar plate test were used for a following antagonist test on balsam fir wetwood blocks in the laboratory conditions. This test was conducted on small wetwood samples (2 x 4 x 1 inch) in incubators at 25°C and two relative humidity ranges (100% and 75% RH). The results showed that all these three fungi were able to establish on wood surfaces and able to reduce wetwood contents. At 25°C and 75% RH, Oidium sp. was the most effective to reduce wetwood content in samples, followed by G. roseum, and then by O. piliferum. G. roseum and Oidium sp. not only reduce wetwood content, but also inhibit mold growth and wood stain, compared with untreated control samples. At 25°C and 100% RH, the moisture contents of treated and untreated samples were not changed in any week of the testing period. This result indicates that biological pre-dry wetwood samples should not be conducted at this high relative humidity condition. A test was conducted to investigate the ability of Oidium sp., the wetwood control candidate, against sapstaining fungi on wood. The results showed that if balsam fir wood wafers were inoculated with Oidium sp. 3 days before the staining fungi, no staining fungi grew on these samples. If wood wafers were inoculated with Oidium sp. and staining fungi at the same time, samples were covered by both Oidium sp. and the staining fungus Ophiostoma piceae in a ratio of 50 to 50%. If wood wafers were inoculated with the staining fungi 3 days before Oidium sp., samples were absolutely covered by the staining fungus and fully stained.
Wetwood
Seasoning - Predrying
Yeasts
Bacteria
Biological Control
Fungi
Documents
Less detail

Strategic program area on design and processes - Improve the value chain : project 2 - Log sorting strategies for Aspen

https://library.fpinnovations.ca/en/permalink/fpipub37774
Author
Goudie, D.
Date
March 2005
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Goudie, D.
Contributor
Alberta Science and Research Authority
Date
March 2005
Material Type
Research report
Physical Description
18 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Value added
Utilization
Populus utilization
Populus
Logs
Grading
Aspen
Alberta
Series Number
W-2237
Location
Vancouver, British Columbia
Language
English
Abstract
Although significant volumes of Alberta's trembling aspen resource are being used for pulp and for oriented strand board production, the species can be accurately referred to as "under-utilized" with respect to the production of solid wood products. It is well documented that the aspen's external indicators of quality correlate poorly with internal characteristics, making it particularly difficult to identify suitable sawlogs. This means that the greatest challenge around cutting aspen into solid wood products continues to be the identification of logs that are of suitable quality. This report details the development of an experimental log grade rule for use when evaluating aspen logs. The rule was developed to more accurately segregate those aspen logs that can be profitably cut to high-valued solid wood products from those more suitable for conversion to oriented strand board or pulp. In the first phase of the study, three samples each consisting of thirty logs that met the revised criteria were sawn, and lumber grade yields were calculated. Although the results were encouraging, it was recognized that larger samples needed to be evaluated. To this end, in the second phase, additional, larger samples were sawn, and grade yields again determined. Test results from the second samples largely replicate the first samples and show that logs that meet the revised criteria will more consistently yield high grades of lumber. The question of available volumes of the experimental log grade is also an important one. This report describes evaluations of aspen logs in inventory at three large manufacturing facilities in Alberta. It is inferred that between 1.5% and 3.5% of the log volume in sampled inventories meet the criteria for new log grade. Recommendations for follow up work include: detailed case studies that consider all of the economics of building and operating an aspen grade mill; a more comprehensive analysis of harvested volumes of aspen in order to more accurately estimate the available volumes of sawlogs meeting the standards for the new log grade rule; an analysis of the costs and benefits of using x-ray scanning technology to sort out aspen sawlogs from those more suitable for pulp or oriented strand board production; and an analyis of remanufacturing opportunities based on estimated yields of cuttings from the experimental log grade.
AFRI - AFRI-711G-05 pertaining to Populus - Utilization; Value added - Alberta; Grading - Logs
Documents
Less detail

Strategic program area on design and processes - Improve the value chain : project 2 - Log sorting strategies for Aspen

https://library.fpinnovations.ca/en/permalink/fpipub37793
Author
Goudie, D.
Date
March 2004
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Goudie, D.
Contributor
Alberta Science and Research Authority
Date
March 2004
Material Type
Research report
Physical Description
10 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Value added
Utilization
Populus utilization
Populus
Logs
Grading
Aspen
Alberta
Series Number
W-2288
Location
Vancouver, British Columbia
Language
English
Abstract
One of the major constraints to the growth and development of a value-added sector for trembling aspen in the solid wood industry concerns the inherent variability in quality of the resource. Much of the resource is simply not suitable for the extraction of lumber grades required to service markets for higher valued wood products, and those logs that are suitable for grade extraction are often difficult to identify. Recent market research details an interest in higher valued grades of aspen, particularly in Asia. On the basis of that market research it is worth investigating the predictive value of an alternative system of identifying aspen logs well suited for the production of high-grade lumber. This report details the conception and application of an experimental log grade rule for use when evaluating samples of aspen logs. The rule is intended specifically to separate high valued aspen sawlogs from those more suitable for conversion to oriented strand board or pulp. The log grading system presently used to evaluate most hardwood logs that are graded, one developed by the United States Forest Service, has been shown to do a poor job in estimating the value of aspen logs. The new log grade rule was based on the existing system, which was modified slightly to reflect some inherent characteristics of aspen. Three samples each consisting of thirty logs that met the revised criteria were evaluated. Test results reported here show that logs that meet the revised criteria will more consistently meet higher grades of lumber; however, more work must be done to confirm the predictive value of the new rule. In addition the issue of available volumes of logs meeting the revised criteria must be addressed.
AFRI - AFRI-700VA-03 pertaining to Populus - Utilization; Value added - Alberta; Grading - Logs
Documents
Less detail

Developing kiln drying schedules for the Alberta wood industry

https://library.fpinnovations.ca/en/permalink/fpipub37757
Author
Garrahan, Peter A.
Date
March 1999
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Garrahan, Peter A.
Contributor
Alberta Department of Economic Development and Tourism
Date
March 1999
Material Type
Research report
Physical Description
20 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Drying
Kilns
Alberta
Series Number
W-2192
Location
Vancouver, British Columbia
Language
English
Abstract
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.
Kiln drying
Documents
Less detail

Accelerated aging and outdoor weathering of aspen waferboard

https://library.fpinnovations.ca/en/permalink/fpipub4743
Author
Alexopoulos, J.
Date
March 1991
Edition
41549
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Alexopoulos, J.
Date
March 1991
Edition
41549
Material Type
Research report
Physical Description
39 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Alberta
Manitoba
Saskatchewan
Waferboards
Utilization
Aspen
Aging
Series Number
Forestry Canada No. 1
E-1235
Location
Ottawa, Ontario
Language
English
Abstract
Waferboard
Aspen - Utilization
Waferboard - Aging
Documents
Less detail

Evaluation of lumber kilns and drying practices in a number of B.C. and Alberta sawmills

https://library.fpinnovations.ca/en/permalink/fpipub37116
Author
Mackay, J.F.Graham
Date
June 1985
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Mackay, J.F.Graham
Date
June 1985
Material Type
Research report
Physical Description
22 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Seasoning kiln drying
Seasoning
Drying
Kilns
British Columbia
Alberta
Series Number
W-344
Location
Vancouver, British Columbia
Language
English
Abstract
Seasoning - Kiln drying - Alberta
Seasoning - Kiln drying - British Columbia
Documents
Less detail

Chip production at four size categories of Alberta sawmills : an assessment of production volumes and cost

https://library.fpinnovations.ca/en/permalink/fpipub745
Author
Mayer, D.A.
Date
August 1984
Edition
37058
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Mayer, D.A.
Date
August 1984
Edition
37058
Material Type
Research report
Physical Description
8 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Waste utilization
Utilization
Studs
Saw mills
Recovery
Costs
Alberta
Series Number
W-268
Location
Vancouver, British Columbia
Language
English
Abstract
Chips - Recovery - Alberta
Chipping - Cost - Alberta
Waste - Utilization for pulp - Alberta
Sawmilling studies - Alberta
Documents
Less detail

10 records – page 1 of 1.