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Online measurement of plywood glue quality

https://library.fpinnovations.ca/en/permalink/fpipub37833
Author
Groves, C. Kevin
Date
April 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Groves, C. Kevin
Date
April 2007
Material Type
Research report
Physical Description
12 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Veneer gluing
Veneer
Quality control
Qualitative analysis
Process control
Plywood
Gluing
Series Number
4576
W-2428
Location
Vancouver, British Columbia
Language
English
Abstract
The main objective of this project was to determine practical methods for enabling veneer mills to continuously monitor glue spread over the entire veneer surface during production and to alert mill personnel to problems as they occur. Several mills were visited to determine the main factors affecting glue coverage and uniformity for roll spreaders, curtain coaters, foam extruders and spray applicators. For each of these applicator types, the feasibility for online spread measurement was assessed based on observations and discussions with mill personnel. It was observed that with all applicator types, problems are a common occurrence due to a wide range of factors ranging from viscosity fluctuations and flow blockages to veneer surface roughness. It is apparent that mills could greatly benefit from having an automated system for real time monitoring of glue application quality for detecting glue deficiency and providing valuable feedback for the mill to minimize problems such as poor bonding, delamination, etc. From the experimental phase of the project, it was demonstrated that near IR (infra-red) light could be used to probe through phenolic glue coatings on veneer with results linking the degree of IR light absorption to the coating thickness (R² > 0.95). Tests also showed the feasibility of using this method for urea formaldehyde (UF) glue mixes. Based on the findings a computerized, optical scanning system was developed using tungsten halogen work lights as an IR source and an IR sensitive camera as the detector. For the setup, lights were angled downward at 45 degrees to illuminate the full width of the veneer surface with the camera mounted directly above the illuminated area to measure the IR reflectance. A computer with imaging software developed by Forintek was used to record the readings and calculate the glue spread. To simulate mill conditions, the entire system was mounted on a laboratory veneer conveyor and then used for scanning full-size veneer sheets at production line speeds. Pilot plant tests and a subsequent mill trial demonstrated that the scanning system was effective for continuous, online measurement of phenolic glue spread over the entire surface area of 4x8-foot veneers. Following this project, Forintek has planned to facilitate the transfer of this technology to industry through involvement with a project to install an advanced prototype scanning system at a Forintek member mill.
Veneers - Gluing
Plywood - Gluing - Tests
Gluing - Processes - Quality control
Computerized process control
Documents
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Development of panelboard statistical process control methods : plywood case studies

https://library.fpinnovations.ca/en/permalink/fpipub37838
Author
Wang, Brad J.
Dai, Chunping
Date
May 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Brad J.
Dai, Chunping
Date
May 2007
Material Type
Research report
Physical Description
31 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Statistical methods
Statistical analysis
Simulation
Quality control
Qualitative analysis
Materials
Series Number
4575
W-2438
Language
English
Abstract
Statistical process control (SPC) involves using statistical techniques to analyze and monitor the variation in manufacturing processes and maintain processes to fixed targets. The use of SPC will greatly enhance the in-mill quality control program. To demonstrate the benefits of applying SPC in general panelboard products, the current member mill application of SPC was first reviewed in this study. Mill visits and a survey were conducted to identify and prioritize the areas for improvement in plywood manufacturing. Key process variables were determined in terms of product performance, productivity and material recovery. Subsequently, different SPC statistics/control charts were reviewed and effective tools for process control were selected. A two-step sampling and statistical analysis method was established for panelboard quality control with a given confidence level. Coupled with this panelboard quality control module, an integrated computer software program, PanelSPC®, was developed for mill data acquisition, data analysis and decision-assistance. The software helps establish histograms and X-bar and Range (R) (or standard deviation, s) control charts for a given process variable and can perform process capability analysis. To address the No. 1 issue, i.e., panel delamination in plywood manufacturing, a practical SPC approach was established. A cause-and-effect diagram was first constructed to identify the checkpoints and key variables involved in the manufacturing process. A histogram chart (Pareto) was then established to: 1) find the root causes of panel delamination due to a low percent wood failure; and 2) identify potential process variables overlooked in the current practice. Mill and laboratory studies were conducted to investigate the effect of key variables on panel gluebond performance using an experimental design approach. The results revealed that panel pressing time and compression ratio (CR) had a tremendous effect on panel gluebond quality. This led to a new direction to reducing panel delamination. As a case study, a production data set of dry Douglas-fir heart veneer width was collected and imported into the PanelSPC® software for statistical analysis. With this off-line SPC tool, the distribution, X-bar and R control charts of the dry veneer width were established. The trial control limits were computed and then revised for continuous production monitoring. The assignable causes were subsequently identified to maintain the dry veneer width under statistical control with less variability. However, in this case, the dry veneer width was still centered incorrectly with many sheets being out of the specification limit. This problem was ultimately tracked to the wider clipping width resulting from inaccurate green veneer sorting. It was demonstrated that with a proper application of SPC, the assignable causes and upstream (in this case) or downstream problems can be detected. By adjusting veneer drying control and green veneer moisture sorting, dry veneer width can be tightly controlled, resulting in approximately 1.9% recovery improvement or about $300,000~$450,000 annual savings for an average plywood mill. With the off-line PanelSPC® tool, sources of process variability can be detected and the manufacturing process can be modified and better controlled to attain greater material recovery, increased product quality and productivity.
Composite materials - Evaluation
Composite materials - Manufacture - Computer simulation
Composite materials - Production - Computer simulation
Composite materials - Statistical methods
Composite products - Manufacture - Computer simulation
Composite products - Manufacture - Quality control
Documents
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Specialty plywood products : a way to increase value recovery from mountain pine beetle (MPB) - attacked lodgepole pine

https://library.fpinnovations.ca/en/permalink/fpipub37839
Author
Wang, Brad J.
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Brad J.
Contributor
Forestry Innovation Investment
Date
March 2007
Material Type
Research report
Physical Description
20 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Wood
Recovery
Insect killed
Series Number
Recipient Agreement No.:FII-MDP-07-0028
Contract No.: 2007 - 5422
W-2439
Location
Vancouver, British Columbia
Language
English
Abstract
Lodgepole pine (Pinus contorta Dougl.) has the best engineering wood properties in the interior BC spruce-pine-alpine fir (SPF) species mix. This report examines the potential to produce more veneer based engineered wood products (EWP) in BC using veneer from the mountain pine beetle (MPB) impacted resource.
Insect-killed wood - Lumber - Recovery
Documents
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Improving productivity, recovery and quality of veneer products with a new pressing method

https://library.fpinnovations.ca/en/permalink/fpipub37840
Author
Wang, Brad J.
Dai, Chunping
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Brad J.
Dai, Chunping
Contributor
Forestry Innovation Investment
Date
March 2007
Material Type
Research report
Physical Description
33 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Veneer
Laminate product
Hot press
Gluing
Series Number
Recipient Agreement No.: FII-MDP-07-0015
Contract No.:2007-5423
W-2440
Location
Vancouver, British Columbia
Language
English
Abstract
Hot pressing is a critical stage in plywood and laminated veneer lumber (LVL) manufacturing. In this study, a new hot pressing method was developed for plywood and LVL products, which integrated both pressure control and position control in one pressing cycle. The optimum pressing parameters and resulting benefits of this method were determined for panels made from stress graded Douglas-fir, white spruce and mountain pine beetle (MPB) veneer through laboratory tests and for white spruce-lodgepole pine-subalpine fir (SPF) veneer through full-size panel tests. The method was further successfully applied in a mill trial using an industrial multi-opening plywood press.
Lumber, Laminated veneer - Manufacture
Gluing - Processes - Hot press
Documents
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Online detection and characterization of MPB wood furnish to optimize OSB mill processing efficiency

https://library.fpinnovations.ca/en/permalink/fpipub37842
Author
Groves, C. Kevin
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Groves, C. Kevin
Contributor
Forestry Innovation Investment
Date
March 2007
Material Type
Research report
Physical Description
16 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Wood
Strandboards
Recovery
Oriented strandboard
Orientation
Insect killed
Series Number
Recipient Agreement No.:FII-MDP-07-0033
Contract No.:2007-5431
W-2442
Location
Vancouver, British Columbia
Language
English
Abstract
In the OSB manufacturing process, logs are processed to produce thin wood strands of a specific size range to maximize the final panel product properties. Today however, the wood supply is changing and there's increasing pressure for mill to use alternative species, especially in BC where large supplies of MPB [Mountain Pine Beetle] pine exist. With MPB pine, mills are faced with the enormous challenges of processing significantly drier wood. This is especially evident at the strander where it is difficult to produce evenly sized strands that are needed for efficient processing and to meet final panel strength properties. The drier wood causes the strander to generate very high levels (from 5-50% of the total volume) of very small wood particles, termed "fines", which significantly reduces the mill's wood recovery. To date, there have been no online, fines measurement technologies available for industry use. To help avoid excessive fines generation, technology for online measurement of fines level and strand size classification needed to be developed to allow mill operators to detect and rectify costly problems when they occur, and provide mill operators with the important feedback needed for controlling the process variables that reduce fines generation. These include controlling: wood conditioning for optimized moisture content, wood flaking temperature, sharpness of cutting and scoring knives and log alignment in the strander.
Oriented strandboard - Manufacture
Insect-killed wood - Lumber - Recovery
Documents
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Minimizing glue dry-out and delamination in plywood. Part 1: softwood plywood

https://library.fpinnovations.ca/en/permalink/fpipub37853
Author
Xu, H.
Dai, Chunping
Chow, Gordon
Andersen, Axel W.
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Xu, H.
Dai, Chunping
Chow, Gordon
Andersen, Axel W.
Date
October 2007
Material Type
Research report
Physical Description
46 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Veneer gluing
Veneer
Plywood manufacture
Plywood
Laminate product
Gluing
Series Number
4574
W-2461
Location
Vancouver, British Columbia
Language
English
Abstract
This work provides scientific support for, and confirms, what most mills already use as rough and dirty rules of thumb as best practices for manufacturing plywood: i.e. dry veneer should be pressed when its temperature is 100°F or less; average veneer moisture can be 4 %; assembly times should not exceed 20 minutes; and glue spreads should be approximately 32 lbs. per M ft2 SGL. In addition, this report used the data generated to formulate multivariate statistical models that could be used to develop or enhance existing in-mill process control software, and/or quality procedures at member operations. This report documents the results of an extensive investigation of plywood dryout and delamination. The study included laboratory and mill tests of key manufacturing variables used in the production of phenol formaldehyde (PF) bonded plywood. Relationships between key variables and plywood quality were used to develop a statistical equation to quantify the effect of veneer moisture content, temperature, assembly time and glue spread rate on wood failure percentage. Testing methods using vacuum/pressure boil-dry-boil, and 6-cycle soak were used and a new multi-step pressing schedule was examined. The following are the main findings:
Veneer with a low moisture content (MC) level is more likely to create glueline dryout than high MC sheets when PF resin is used. Although veneer with a high MC level could minimize the occurrence of dryout, PF gluing systems accept a maximum allowable veneer MC (peak moisture) range of 6 to 8%.
Sheets having temperatures over 100°F are strongly correlated with dryout problems.
An excessively long assembly time approaching 20+ minutes could significantly affect bonding, especially when veneer or ambient temperatures are high.
Increasing glue spread rate can be used to minimize dryout caused by high veneer temperature and low veneer MC; however, a higher glue cost per M ft2 is incurred.
Flexure tests cannot be relied upon to detect bond quality as bending strength is heavily influenced by surface panel properties. During the mill study, it was learned that variations within each of the above mentioned controllable factors could not be avoided in a mill situation. Good manufacturing process control can ensure that all variables stay within ideal ranges and occurrences of dryout are minimized. The statistical models developed during this project could, possibly, be used to develop or enhance process control software. A multiple-step hot-pressing schedule, capable of improving plywood bonding properties with or without sacrificing volume recovery, was developed to minimize bond problems caused by dryout. Existing mill presses may be able to implement this approach seamlessly or after a few minor adjustments have been made. Some mills may have to peel thicker veneer to compensate for increased veneer compression associated with multi pressing and in doing so sacrifice log recovery. Pressing schedules illustrated in this study indicate that press production is not sacrificed as single or multi-step pressing time is identical for most thicknesses. Laboratory tests showed that wood failure percentage figures from a glueline shear test, a standard method for evaluating bond quality, are useful glue dry-out indicators for softwood plywood. An attempt to develop a tack strength test that could assist in evaluating dryout was unsuccessful as excessive variation was present within recorded data.
Veneers - Gluing
Lumber, Laminated veneer - Gluing
Plywood - Manufacture
Documents
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Minimizing glue dry-out and delamination in plywood. Part 2: hardwood plywood

https://library.fpinnovations.ca/en/permalink/fpipub37854
Author
Xu, H.
Dai, Chunping
Chow, Gordon
Andersen, Axel W.
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Xu, H.
Dai, Chunping
Chow, Gordon
Andersen, Axel W.
Date
October 2007
Material Type
Research report
Physical Description
16 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Veneer gluing
Veneer
Plywood manufacture
Plywood
Laminate product
Gluing
Series Number
4574
W-2462
Location
Vancouver, British Columbia
Language
English
Abstract
An extensive investigation of plywood dryout and delamination was conducted in this study. It included laboratory tests of key variables for urea formaldehyde (UF) bonded plywood. A statistical equation was developed to quantify the effect of veneer moisture content, temperature, assembly time, glue spread rate, and amount of catalyst on wood failure percentage. The following are the main findings:
Veneer with a low moisture content (MC) level is more likely to create glueline dryout than high MC sheets when UF resin is utilized. Although veneer with a high MC level could minimize the occurrence of dryout, maximum allowable veneer MC (peak MC) is limited by other factors. UF gluing systems can employ a maximum MC range of 10 to 12%, which is much higher than the one that applies to PF resin (6 to 8%).
Sheets having temperatures over 100°F are strongly correlated with dryout problems.
An excessively long assembly time could significantly affect bonding, especially when veneer or ambient temperatures are high.
Increasing glue spread rate can be used to minimize dryout caused by high veneer temperature and low veneer MC.
In UF gluing systems, catalyst level heavily influences bonding and the extent to which dryout occurs.
Veneers - Gluing
Lumber, Laminated veneer - Gluing
Plywood - Manufacture
Documents
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Through treating post-MPB [Mountain Pine Beetle] lumber : demonstration of treatability

https://library.fpinnovations.ca/en/permalink/fpipub41378
Author
McFarling, S.M.
Morris, Paul I.
Date
February 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
McFarling, S.M.
Morris, Paul I.
Contributor
Canadian Wood Council.
Forestry Innovation Investment.
Date
February 2007
Material Type
Research report
Physical Description
14 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Wood preservation
Wood
Preservation
Insect killed
Series Number
FII-MDP-07-0012
Project No.: 2007-5274
W-2443
Location
Vancouver, British Columbia
Language
English
Abstract
Preservative treatment with borates to achieve termite and decay resistance has the potential to develop new products and markets for post-Mountain Pine Beetle (MPB) affected lodgepole pine lumber. Currently there are upwards of 65 treating plants in the USA treating sillplates with borates and a blue dye. Southern pine is normally used for outdoor treated wood applications; hem-fir and Douglas fir are treated for sillplates in the Western USA. Most US treaters are reluctant to treat SPF because of the very low permeability of the spruce (heartwood and sapwood) component and the low permeability of pine and fir heartwood. If they were offered a more treatable product they might be willing to shift to this material instead of treating southern pine or US hem-fir.
Lumber - Preservation
Insect-killed wood - Preservation
Documents
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2006-07 Lumber properties program

https://library.fpinnovations.ca/en/permalink/fpipub1335
Author
Lum, Conroy
Date
March 2007
Edition
37816
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Lum, Conroy
Contributor
Canadian Forest Service
National Lumber Grades Authority
Date
March 2007
Edition
37816
Material Type
Research report
Physical Description
68 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Mechanical properties
Specifications
Grading
Specification
Series Number
5439
W-2383
Location
Vancouver, British Columbia
Language
English
Abstract
The Canadian lumber industry has identified, as a high priority, the establishment of a multi-year Lumber Properties Program that pulls together a number of urgent initiatives currently underway to establish and/or maintain Canadian lumber design values. The desire is to have an overall program that emphasizes the proper development of a longer-term strategic plan and process to deal with current and future initiatives. Combining the current industry resources with Federal Government contributions through Natural Resources Canada (NRCan), the first step in the Program has been completed: to gather the various initiatives now underway and to begin the formal development of pan-Canadian policies to guide the development, implementation and on-going maintenance of such initiatives. The key activities in 2006-07 were:
Launching of the pilot phase of the on-going monitoring program, and development of a simulation model to assist in determining what sort of trends can be reliably detected and which cannot;
Completion of the in-grade testing program on Canadian Norway spruce;
Analysis of the No.2 2x4 Hem-Fir (N) monitoring study and confirmation of the appropriateness of assigned design values;
Identification of an alternative species grouping procedure for further study;
Starting of a process under the ASTM Committee on Wood to address gaps in the Grade Quality Index provisions in ASTM Practice D1990, and
Establishing a forum for engaging the US in discussions on lumber properties issues. Lumber properties issues crucial to maintaining the competitiveness of Canadian lumber continue to be the same as in previous years: tests and means to adjust for sample representativeness using the Grade Quality Index (GQI), species grouping and re-grouping procedures, and on-going lumber monitoring. As a result, discussion on a pan-Canadian strategy and supporting policies necessary to support Canadian lumber initiatives tend to focus on these three issues. The challenge is to ensure that these issues are dealt with in a way that balances both short and longer-term needs and provides a net overall benefit to the Canadian industry.
Grading - Lumber - Specifications
Lumber Strength
Documents
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Bucking optimization : photocells vs 3D scanning

https://library.fpinnovations.ca/en/permalink/fpipub1346
Author
Orbay, L.
Date
March 2007
Edition
37830
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Orbay, L.
Date
March 2007
Edition
37830
Material Type
Research report
Physical Description
14 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Digitalization
Subject
Simulation
Recovery
Optitek
Optimization
Series Number
4525
W-2419
Location
Vancouver, British Columbia
Language
English
Abstract
This project presents the results of a computer simulation of the recovery obtained from six bucking optimization systems equipped with different scanner and conveyor combinations. Forty sample stems were scanned and stem models developed to provide input for Forintek’s sawing simulation program, OPTITEK®. Input files of both sawmill machinery and their products were developed based upon the operation of a typical sawmill in the Interior of B.C. Optimized bucking solutions were generated, and sample stems were sawn accordingly. Lumber value and volume recovery data were obtained and enabled a performance evaluation of the six bucking optimization systems. In this project the affect of both the log conveying system and the type of scanner was considered. Both lineal and transverse conveyor systems were studied and the effects of true shape, partial true shape and XY scanners were modelled. Various combinations of parameters were studied and the annual dollar production for such combinations were computed. Recommendations are made relating to the different systems studied and how the results may be of benefit to mill optimization.
Bucking - Optimization
Optitek
Optics - Computer simulation
Recovery
Documents
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Accuracy of check modeling and its effect on lumber value recovery

https://library.fpinnovations.ca/en/permalink/fpipub1357
Author
Orbay, L.
Date
March 2007
Edition
37841
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Orbay, L.
Contributor
Forestry Innovation Investment
Date
March 2007
Edition
37841
Material Type
Research report
Physical Description
42 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Seasoning degrade
Seasoning
Recovery
Process control
Prevention
Series Number
Recipient Agreement No.: FII-MDP-07-0016
Contract No.: 2007-5155
W-2441
Location
Vancouver, British Columbia
Language
English
Abstract
Recovery - Process control
Seasoning - Degrade - Prevention
Documents
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Effect of tool wear, tool sharpening, species and temperature on lumber surface and chip quality in chipper-canters using disposable knives - Phase IV

https://library.fpinnovations.ca/en/permalink/fpipub39121
Author
Laganière, B.
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Laganière, B.
Date
March 2007
Material Type
Research report
Physical Description
35 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Quality control
Qualitative analysis
Chippers
Series Number
General Revenue Report Project No. 2663
2663
Location
Québec, Québec
Language
English
Abstract
The purpose of this study was to determine the effects of tool wear, tool sharpening and temperature on lumber surface and chip quality in the conversion of black spruce [Picea mariana (Mill.) B.S.P.] and balsam fir logs [Abies Balsamea (L.) Mill.] with chipper-canters equipped with disposable knives. Lumber quality is determined by losses due to trimming necessitated by large knife marks and wood tear-out, which cause boards to bedowngraded. Chip quality is determined by the proportion of fine particles in chip classification tests. Tests were conducted with black spruce logs in summer (unfrozen conditions) (ave. temp. 9.2°C) and with black spruce and balsam fir logs in winter (frozen conditions) (ave. temp. -14.7°C). As the test progressed, knife wear, chip quality and log surface quality were measured. During the unfrozen tests, the knives operated during 153 hours and they were sharpened after 51 and 102 hours of operation. The fines content increased by 0.6% (1.8 to 2.4%) over the 153-hour operation, which represents a chip revenue loss of 0.3%. Total value losses (based on current lumber prices) were 5.1% with new knives, and reached 9.3% at the end of the 153 hours of operation. During the frozen tests, the knives operated during 48 hours and they were sharpened after 16 and 32 hours of operation. The fines content increased by 1.8% (3.2 to 4.8%) for balsam fir for a 32-hour period; the mean fines content proportion was 4%, which represents a 1.3% increase in fines content. The fines content decreased slightly, by 0.2 % (3.4 to 3.2%) for black spruce over a 48-hour period; the mean fines content proportion was 3.3%, which represents a 0.2% loss in chip revenue. Total losses for black spruce were 5.3% with new knives, and reached 8% at the end of the 48-hour operation period. For balsam fir, total losses were 8.7% with new knives, and reached 9.5% at the end of the 48 hours. The proportion of boards qualifying as Premium grade decreased after each knife sharpening operation under summer and winter conditions. For example, the proportion of boards qualifying for Premium grade with less than 1/32” wood tear-out was 6.8% for new knives, 4.2% for knives sharpened once, and 3.4% for knives sharpened twice (24.5%, 11.9% and 8.4% respectively under winter conditions). Under winter conditions, the proportion of boards qualifying for Premium was lower for balsam fir than for black Spruce. In addition, the proportion of boards qualifying for Premium grade was lower in summer than in winter: those results are difficult to explain, given that knife wear in summer and winter, as were log moisture conditions. The counter-knives were changed between the summer and the winter study. Better fibre separation at the counter-knife can reduce wood tear-out. Other general observations made during this study: 1- Mean chip length decreased with knife wear. 2- Mean chip length decreased after each knife sharpening operation. 3- Balsam fir mean chip length was lower than black spruce logs under frozen conditions. 4- Mean chip length was higher for unfrozen logs than for frozen logs. 5- Fines content proportions increased with knife wear. 6- Fines content increased after each knife sharpening operation. 7- Fines content was lower in unfrozen logs than in frozen logs. 8- Fines content was higher in balsam fir logs than in black spruce logs under frozen conditions. 9- Tear-out volume per surface unit decreased with knife wear. 10- Tear-out volume per surface unit decreased after each knife sharpening operation. 11- Tear-out volume per surface unit was lower for balsam fir than for black spruce under frozen conditions. 12- Tear-out volume per surface unit was higher under frozen conditions than under unfrozen conditions. 13- Tear-out volume per surface unit was proportional to the affected surface area. 14- With black spruce monetary losses incurred under frozen conditions were comparable to those observed after only a third of the operating time under unfrozen conditions. 15- Under frozen conditions, monetary losses were higher for balsam fir than for black spruce. 16- Monetary losses increased after each knife sharpening operation. 17- Mean tear-out depth was higher in balsam fir than in black spruce. 18- Mean tear-out depth increased after each knife sharpening operation. 19- Knife wear reduction (for long and finishing knife) was about 0.020” in summer and in winter. 20- Total tip recession during 16-hour shifts under frozen conditions was slightly lower than or similar to the wear over 51 hours of operation under unfrozen conditions. In general, we can state that, for new knives, tool wear occurs about 3 times faster under frozen conditions than under unfrozen conditions. For sharpened knives, tool wear occurred slightly faster in frozen wood than in unfrozen wood. 21- Long knife edges wore faster than finishing knife edges under both frozen and unfrozen conditions 22- Knife wear rates tended to decrease slightly after each knife sharpening operation. 23- The difference between chip and fines prices was an invariable loss indicator for the fines proportion. For example if the price difference was $110, then 1% fines content corresponded to an invariable value loss of $17,864 (based on a 100,000 m3 log consumption). If the fines content was 3%, then the total fines loss was $53,592 (3 x 17,864). Note: The calculations of the monetary losses were based considering that the totality of the lumber pieces can be classified Premium. In reality, around 30% of the pieces can be Premium; natural wane, rot, knots and other defects cause degrade without being damaged by the debarker or the canter. Losses must then be reduced to 30% of their value if the entire production is considered.
chip quality
Chipper-canters
Documents
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Séchage de bois de construction ÉPS par haute fréquence sous vide

https://library.fpinnovations.ca/en/permalink/fpipub39042
Author
Lavoie, Vincent
Kendall, J.
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Lavoie, Vincent
Kendall, J.
Date
March 2007
Material Type
Research report
Physical Description
21 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Vacuum drying
Vacuum
Softwoods
Seasoning vacuum drying
Seasoning high frequency
Seasoning
Drying
Series Number
E-4251
Location
Québec, Québec
Language
French
Abstract
La technologie de séchage par haute fréquence sous vide est reconnue comme étant la plus performante pour le séchage du bois en ce qui concerne la vitesse de séchage. Elle présente également l‘avantage d’empiler le bois sans baguettes et de presser les empilements en continu entre les électrodes. Peu de données existent quant à sa viabilité économique vu le faible nombre d’installations industrielles. En général, les spécialistes de séchage estiment que les produits à grande valeur (pièces de fortes dimensions, bois d’apparence de couleur pâle, composantes sans défaut) sont des applications ayant les plus grandes probabilités de rentabilité. L’utilisation de la technologie de séchage par haute fréquence sous vide (HFV) pour le bois de construction de l’état vert à sec est économiquement difficile à justifier. Le séchage de l’état vert à sec comporte un coût énergétique important qui réduit considérablement la marge de profit du séchage du bois de construction. Les coûts énergétiques ont été estimés à 26, 37 et 80 $/Mpmp (coût électrique de 0,07$/kWh) pour l’épinette noire, le pin gris et le sapin baumier respectivement. Les temps de séchage pour ces mêmes essences de l’état vert à sec ont été estimés à 10, 14 et 38 heures pour une densité de puissance d’opération de 12 kW/m³. Le reséchage qui nécessite l’évaporation d’une faible proportion de toute l’eau du bois est davantage intéressant car les coûts énergétiques sont réduits de façon considérable. Certains indicateurs laissent croire, qu’il pourrait y avoir un potentiel intéressant pour la technologie de la HFV dans le reséchage de bois résineux du Québec (bois de faible valeur produit à grand volume). Le reséchage consiste à évaporer une faible portion de toute l’eau contenue dans le bois, ce qui entraîne un coût énergétique beaucoup moins important. La reséchage par HFV de bois de construction est pratiqué industriellement dans l’état de Washington aux États-unis. Un séchoir haute fréquence sous vide de 300 kW et de 75 m³ de capacité a été implanté à l’été 2002 pour resécher de la pruche de l’Ouest. La stratégie globale consiste à arrêter le séchage conventionnel prématurément et resécher les pièces demeurées humides. Cette approche favorise une meilleure productivité des séchoirs conventionnels, une meilleure qualité des produits et également une meilleure consommation énergétique. Cette étude qui compare le reséchage haute fréquence sous vide (HFV) versus le procédé conventionnel ACC/MT pour l’épinette noire et le sapin baumier 2x4 a permis de conclure ce qui suit :
Le reséchage de bois de construction d’épinette noire par HFV réalisé à une densité de puissance de 12 kW/m³ a donné des résultats comparables en qualité à celui réalisé à 4 kW/m³ et ce pour une vitesse de reséchage 3 fois plus rapide.
L’utilisation d’une densité de puissance plus élevée diminue l’investissement en capital du séchoir HFV pour une capacité de séchage donnée.
La stratégie de reséchage HFV à 12 kW/m³ réalisable industriellement et qui a donné les meilleurs résultats en qualité a été celle où une pression constante de 30 Torr a été maintenue dans l’enceinte tout au long du cycle.
Le taux de reséchage moyen a été de 2,2 %/heure pour les essais sur l’épinette noire et de 2,8 %/heure pour les essais sur le sapin baumier.
Le reséchage par HFV (12 kW/m³) a été de 4 à 6 fois plus rapide que par procédé conventionnel ACC/MT utilisant des consignes de températures sèche et humide de 200°F et 170°F respectivement. Le reséchage par HFV (12 kW/m³) a donné des meilleurs rapports de vitesse pour le sapin baumier (6 fois) que pour l’épinette noire (4 fois).
Le reséchage par HFV (12 kW/m³) n’a pas favorisé une meilleure qualité de produit que le procédé ACC/MT et ce, même si un lestage 4 fois plus important a été appliqué sur les charges L’information tirée des essais de reséchage comparatifs a permis d’établir des calculs économiques d’aide à la décision préliminaires fort intéressants pour considérer ou non l’utilisation de la technologie HFV pour la pratique de reséchage intentionnel de bois de construction de résineux comme présenté par Elustondo et al., 2005. Dans un contexte où la capacité de séchage actuelle est insuffisante et que l’achat d’un séchoir HFV est considéré pour effectuer le reséchage intentionnel, nous avons estimé une période de retour sur l’investissement de 1,4 ans, ce qui se compare très bien à celle de 1,5 ans provenant de l’étude de Elustondo et al., 2005. Les résultats du présent rapport démontrent que le procédé de séchage conventionnel ACC/MT produit des résultats de reséchage similaires à la technologie HFV en terme de qualité dans des temps de 4 à 6 fois plus longs. Nous estimons alors à environ 3 à 4 mois la période de retour sur l’investissement pour l’achat de séchoir(s) conventionnel (s) considérant que le coût de la technologie de séchage conventionnelle est environ 20 fois inférieure (même capacité) à celui par HFV pour une vitesse de reséchage de 4 fois plus lente (épinette noire). L’approche de reséchage intentionnel demeure extrêmement intéressante pour les gains majeurs qu’elle peut procurer en productivité, qualité et consommation énergétique. La manutention additionnelle des paquets de l’usine de rabotage à la cour à bois ou au séchoir constitue un frein à l’implantation de cette pratique dans l’industrie. L’utilisation d’un système de reséchage en continu à l’usine de rabotage permettrait d’éliminer cette manutention en conservant les gains de l’approche du reséchage intentionnel.
Softwoods - Seasoning
Seasoning - Vacuum drying
Seasoning - High frequency
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Economic impact of sticker spacing on the quality of kiln-dried sofwood construction lumber

https://library.fpinnovations.ca/en/permalink/fpipub39043
Author
Normand, D.
Savard, Marc
Date
February 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Normand, D.
Savard, Marc
Date
February 2007
Material Type
Research report
Physical Description
18 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Seasoning kiln drying
Seasoning
Drying
Kilns
Softwoods
Costs
Series Number
General Revenue Projet No. 4031
4031
Location
Québec, Québec
Language
English
Abstract
Lumber warp is the primary cause for drying degrade. Over the past decade, Canadian producers have been paying increasing attention to the box-store market and that of engineered wood products such as wood I-joists and glued-laminated beams (glulam). One characteristic of these markets is that they require straight and stable lumber. The objective of this study was to determine the effect of sticker spacing on stickering costs and lumber quality. To address this objective, we conducted tests in three stud mills. Stickers were added as required for the assessment of 48-, 32-, 24- and 16-inch spacings, i.e. 3, 4, 5 and 7 stickers respectively with 8-foot lumber. The bundles of test lumber were dried in a single load in all mills. After drying, the lumber was graded by a grading agency inspector. He determined the potential grade before drying and the actual grade after drying for each piece of lumber. The moisture content (MC) of the test lumber was also determined on a sample basis. In Mill 1, we observed that drying degrade for the entire sample was reduced from 2.2 to 1.3% in the bundles spaced at 24 inches, which represented a gain of $3.21/Mbf. As for lumber meeting the requirements for the special grade, degrade was reduced from 71.3 to 49.5%, which is a gain of $10.41/Mbf. In Mill 2, drying degrade decreased from 32.1 to 26.3% when sticker spacing was reduced from 48 to 32 inches, for an approximate gain of $1/Mbf. In this particular mill, a 16-inch spacing failed to improve performance over a 32-inch spacing. As for Mill 3, reducing sticker spacing from 48 to 24 inches decreased drying degrade in the special grade lumber by half, leading to a $5.33/Mbf gain. Drying degrade decreased regularly from 48 to 32 inches and from 32 to 24 inches. Closer spacing benefited lumber quality at both the top and the bottom of the stacks. Optimal spacing in a sawmill should be based on species and stickering costs. As costs vary widely from mill to mill, the report provides information to help users calculate additional stickering costs. We observed significant gains from reduced sticker spacing. Twenty-four-inch spacing should become standard practice in the manufacture of quality lumber. As a rule, closer spacing requires only limited investments, i.e., the acquisition of additional stickers and, occasionally, minor modifications to the stickering equipment.
Softwoods - Seasoning
Seasoning - Kiln drying - Cost
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Sawmill yard management optimization

https://library.fpinnovations.ca/en/permalink/fpipub39047
Author
Goulet, P.
Date
March 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Goulet, P.
Date
March 2007
Material Type
Research report
Physical Description
3 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Saw mills
Optimization
Series Number
General Revenue
Simple Progress Report
5334
Location
Québec, Québec
Language
English
Abstract
Optimization
Sawmills
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Comparaison des différentes entrées d'équarrisseuses : tourne-billes

https://library.fpinnovations.ca/en/permalink/fpipub39051
Author
Bédard, P.
Fournier, Francis
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Bédard, P.
Fournier, Francis
Date
October 2007
Material Type
Research report
Physical Description
13 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Lumber
Manufacturing
Equipment
Series Number
E-4266
Location
Québec, Québec
Language
French
Abstract
Cette étude a été réalisée pour déterminer le niveau de performance optimal des systèmes de tourne-billes automatiques qui équipent la plupart des entrées d’équarrisseuse dans les scieries de bois résineux. L’étude a été réalisée avec un système de tourne-billes à rouleaux quadruple installé devant une entrée d’équarrisseuse de type SLI. Un premier test a permis d’établir la performance initiale du tourne-billes et d’identifier les principales sources d’erreurs de rotation. Une première série de correctifs mécaniques ont été apportés en collaboration avec le manufacturier d’équipement, puis un second test de performance a été réalisé. Une certaine amélioration a été notée, surtout au niveau du maintien des billes, après rotation. Une deuxième série de correctifs ont été apportés pour améliorer la précision de rotation dans le tourne-billes avant d’effectuer un dernier test de performance. Initialement, le système étudié affichait un taux d’erreur de rotation de 36 degrés d’écart-type. Après deux interventions techniques, le tourne-billes a atteint une précision de rotation de 24 degrés d’écart-type. Pour y arriver, certaines composantes mécaniques ont été modifiées et d’autres remplacées dû à l’usure. La programmation des PLC a aussi été revue pour mieux synchroniser les séquences de presses et mieux pré-positionner les rouleaux tourneurs. Une amélioration de rotation simulée de 36 à 24° d’écart-type signifie un gain économique de 2 %, soit 2 $/m³ pour la scierie étudiée. Toutefois le potentiel d’amélioration aurait été deux fois plus important si les erreurs de rotation avaient pu être réduites au niveau de 10 degrés d’écart-type. La précision de rotation aurait probablement pu être améliorée davantage, cependant ce niveau il est assez difficile à atteindre et surtout à maintenir avec la technologie actuelle. Dans le futur, de nouveaux types d’équipements devraient être développés par les manufacturiers pour obtenir de meilleurs résultats, plus spécifiquement pour le débitage des petites billes à haute vitesse. De plus, les tourne-billes pourraient bénéficier de l’ajout de systèmes de suivi et de contrôle en continu pour en assurer un fonctionnement optimal en tout temps. Des systèmes auto-correcteurs en boucle fermée devraient aussi améliorer la performance des tourne-billes à rouleaux.
tourne-billes
équarriseuse
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Optimisation de la vitesse de l'air dans les séchoirs

https://library.fpinnovations.ca/en/permalink/fpipub39052
Author
Lavoie, Vincent
Normand, D.
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Lavoie, Vincent
Normand, D.
Date
October 2007
Material Type
Research report
Physical Description
9 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Drying
Air
Series Number
E-4267
Location
Québec, Québec
Language
French
Abstract
Les principaux travaux réalisés jusqu’à ce jour en usine incluent la cueillette d‘information sur la géométrie des séchoirs et des empilements et la prise des mesures de puissances électriques de ventilation pour une température de l’air de 20°C pour mettre en relation ces mesures avec les vitesses de l’air dans les séchoirs. Les vitesses de l’air et les puissances ont été mesurées dans 6 séchoirs industriels du Québec par une équipe multidisciplinaire formée de personnel technique de FPInnonations - Division Forintek et de l’Institut de recherche d’Hydro-Québec (Laboratoire des Technologies de l’Énergie de Shawinigan). Ces travaux conjoints découlent de l’initiative ÉlectroBois qui dure depuis près de 6 ans maintenant entre les deux instituts. En plus de réaliser ces mesures, l’équipe en place s’est assurée de documenter la géométrie des séchoirs et des empilements pour orienter des travaux de modélisation qui seront effectués ultérieurement dans le projet. Les mesures réalisées dans différents séchoirs industriels ont permis de documenter différentes géométries d’équipements/d’empilements et différents systèmes de ventilation. Les mesures de puissances et de vitesses de l’air ont permis d’établir l’existence de variations importantes d’efficacité de ventilation entre certains séchoirs. Des facteurs potentiels pouvant expliquer ces différences ont été identifiés. L’outil de modélisation et le banc d’essai de ventilateurs permettront de cibler les facteurs ayant le plus d’influence sur l’efficacité de ventilation ce qui permettra à la fin du projet d’établir des recommandations sur l’optimisation de la vitesse de l’air.
séchoir à bois
Documents
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Contrôle en continu du débitage primaire

https://library.fpinnovations.ca/en/permalink/fpipub39073
Author
Fournier, Francis
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Fournier, Francis
Date
October 2007
Material Type
Research report
Physical Description
34 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Digitalization
Subject
Lumber
Optimization
Computer
Series Number
General Revenue Project No. 5337
5337
Location
Québec, Québec
Language
French
Abstract
Les technologies utilisées dans l’industrie du sciage sont de plus en plus complexes et les systèmes optimisés ont remplacé les décisions humaines depuis les 15 dernières années. Les systèmes optimisés requièrent un suivi rigoureux et une paramétrisation adéquate. Le personnel qualifié devient rare, ce qui nécessite des outils de monitorage et de contrôle efficaces. Les systèmes de monitorage sont devenus essentiels pour réduire les périodes où le procédé est hors contrôle. Ce rapport de recherche présente les algorithmes développés pour la surveillance monitorage du débitage primaire. La méthodologie utilisée est basée sur l’utilisation des variables disponibles aux centres de transformation concernés. Cette méthodologie ne nécessite pas l’ajout de nouveaux capteurs, ce qui réduit l’entretien. Par contre, certaines composantes ou parties du procédé ne peuvent être monitorées puisque aucune variable n’est actuellement disponible. C’est en autre le cas pour plusieurs composantes mécaniques qui nécessitent l’ajout de capteurs spécialisés. Les algorithmes développés utilisent des modèles mathématiques simples et facilement applicables à la majorité des scieries résineuses. L’implantation de ces modèles pourra être faite à l’intérieur d’automates programmables, de systèmes d’acquisition de données, de logiciels maison de suivi de production ou de systèmes spécialisés comme le « Smart Mill Assistant ». Le potentiel économique des modèles de monitorage peut être évalué en utilisant les variables disponibles dans les systèmes d’optimisation et en utilisant les modèles de monitorage hors ligne (offline). En traçant graphiquement les résultats des modèles, il sera possible d’évaluer le nombre de fois et le temps total pendant lequel le procédé a été en déviation et de calculer le potentiel économique. Ce potentiel économique des systèmes de monitorage et de contrôle en temps réel dépend de la performance de départ de la scierie, de la capacité du personnel en place pour détecter et identifier rapidement les déviations du procédé et du temps requis pour la correction des problèmes.
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Continuous monitoring of the primary breakdown process

https://library.fpinnovations.ca/en/permalink/fpipub39074
Author
Fournier, Francis
Date
October 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Fournier, Francis
Date
October 2007
Material Type
Research report
Physical Description
34 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Digitalization
Subject
Lumber
Optimization
Computer
Series Number
General Revenue Project No. 5337
5337
Location
Québec, Québec
Language
English
Abstract
Sawmilling technology is becoming increasingly complex and, for the past 15 years, optimized systems have replaced human decision-making on the log and lumber processing line. Optimized systems, however, require close monitoring and adequate parameters. Given the increasing shortage of qualified personnel, the use of effective monitoring and control tools is more critical than ever. Monitoring systems are now required to shorten the periods of time during which the primary breakdown process is not controlled. This research report presents algorithms developed for monitoring the primary breakdown process. The method used to this end is based on available variables for the relevant machine centres. As this method does not require the installation of new sensors, it does not add to the maintenance burden. It should be noted, on the other hand, that certain components of the primary breakdown process cannot be monitored because of a lack of available variables. Such is the case for several mechanical components the monitoring of which requires the installation of specialized sensors. The algorithms generated by this project use simple mathematical models that can easily be adapted to the majority of softwood lumber sawmills. These models can be integrated into programmable controllers, data acquisition systems, in-house production monitoring software or specialized systems, such as the Smart Mill Assistant system. The economic potential of the monitoring models can be determined by using optimization system variables and offline monitoring models. The graphical representation of results generated by the models reveals the number of times the primary breakdown process deviated from process parameters, as well as the duration of such deviations. Their economic impact can be calculated on the basis of this information. The economic benefits of real-time monitoring and control systems depend on initial sawmill performance, the skill of sawmill personnel in quickly detecting and identifying process deviations and the time required to solve related problems.
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Supplementary fibre supplies for the manufacture of MDF and particleboard. Part II. Feasibility study on manufacture of HDF using OSB fines as the raw material

https://library.fpinnovations.ca/en/permalink/fpipub39082
Author
Deng, James
Wang, X.
Wan, Hui
Zhang, S.Y. (Tony)
Date
November 2007
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Deng, James
Wang, X.
Wan, Hui
Zhang, S.Y. (Tony)
Date
November 2007
Material Type
Research report
Physical Description
33 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Strandboards
Oriented strandboard
Orientation
Series Number
General Revenue Report Project No. 5326
5326
Location
Québec, Québec
Language
English
Abstract
An experimental work was carried out to evaluate the feasibility of using OSB fines as supplementary fibre resource to partially replace the commonly used wood fibre resource, such as SPF sawdust or shavings for the manufacture of high density fibreboards (HDF). HDF was made with OSB fines with two different pre-treatments and five different mix ratios. Two pre-treatments of OSB fines were 24-hour water soak and steam preheating. The mix ratios of the OSB fines with SPF fibres included 0% as control, 25%, 50%, 75% and 100%. The panels were also made from green aspen sawdust or aspen chips. A total of 42 panels were made. The fibres were analysed for their fibre geometry, pH value and acid buffer capacity. The panels were evaluated with their internal bond strength (IB), modulus of elasticity (MOE) and modulus of rapture (MOR), thickness swell (TS), edge thickness swell (edge TS) and water absorption (WA) after 24-hour water soak, linear expansion (LE) and face screw holding. The test results suggest that:
Stronger HDF panels could be made from OSB fines up to 75% in the mixture with SPF fibre as compared to those from SPF fibre, and were comparable to SPF panels when 100% OSB fines were used in terms of the mechanical and physical properties.
Comparing panels made from SPF, panels made from OSB fines had better properties in terms of panel dimensional stability. TS, edge TS, and WA reduced significantly with increasing OSB fines content.
Refining steam pressure significantly affected the panel properties. The lowest steam pressure used in the experiment resulted in the best panel properties.
The mechanical properties of the panels were improved with the pre-treatments of OSB fines. Comparing two different pre-treatments, pre-steaming was more effective than water soaking.
There was no significant impact on the panel properties, fibre quality and wood acidity due to the difference in raw material size and moisture content.
In general, under the similar refining process condition, no significant change in fibre length was observed when increasing mix ratio of OSB fines. However, the fines content in fibre was increased when increasing OSB fines content in the furnish. Comparing the fibre refined from 100% SPF to the fibre made with different contents of OSB fines, SPF fibre had the longest fibre length and the lowest fine content.
Fibre acidity was changed when using OSB fines. In general, the refined fibres become more alkaline with increasing OSB fines content.
The study shows that it is very important to identify suitable process conditions for using OSB fines since the optimal process condition for OSB fines would be significantly different from the one normally used for SPF wood.
Fibreboard - Manufacture
Oriented strandboard
medium-density fiberboard
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