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Alternatives to slack wax

https://library.fpinnovations.ca/en/permalink/fpipub2802
Author
Wan, Hui
Date
March 2012
Edition
39428
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wan, Hui
Date
March 2012
Edition
39428
Material Type
Research report
Physical Description
27 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Waxes
Strands
OSB
Oriented strandboard
Orientation
Series Number
General Revenue Report Project No. 201004857
E-4780
Location
Québec, Québec
Language
English
Abstract
In this project, a comprehensive experiment studied the impact of wax type, wax content, wax heating temperature and wax molecular weight on OSB panel performance. It shows that to allow tall oil, hydrogenated soybean wax, linseed oil, and low density polyethylene (LDPE) to be used for OSB, further work is needed. We need to add wax in the OSB process; otherwise panel dimensional stability will be ruined. There is an optimal wax content of around 1% in OSB production. The wax content in OSB panel did not need to be higher than 1%. With the waxes tested, wax heating temperature should be higher than 90°C. At a fixed wax heating temperature, optimal wax molecular weight is 520 Daltons for OSB application. Applying high molecular weight wax (600 Daltons) on panel surface may help to improve panel bending strength. The experiment shows that partial substitution of slack wax with LDPE at the OSB panel surface layer may be feasible. Experimental results also show that using contact angle and surface tension tests may help us to screen waxes for OSB panel application. Based on the experimental data, one should handle different waxes in different ways. By engineering wax application parameters one can develop a cost effective way to produce composite panels to meet dimensional stability requirement. Further testing on the feasibility of using contact angle and surface tension to differentiate wax should be conducted. Emulsifying low density polyethylene should be further investigated. Further research is also needed to verify how wax operational parameters affect panel strength.
WAX
Oriented Strand Board (OSB)
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Biotechnology to improve mould, stain and decay resistance of OSB

https://library.fpinnovations.ca/en/permalink/fpipub42285
Author
Yang, D.-Q.
Wang, Xiang-Ming
Wan, Hui
Date
March 2005
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Yang, D.-Q.
Wang, Xiang-Ming
Wan, Hui
Contributor
Canada. Canadian Forest Service
Date
March 2005
Material Type
Research report
Physical Description
75 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Materials
Series Number
Canadian Forest Service No. 31
Location
Sainte-Foy, Québec
Language
English
Abstract
This project aimed to develop technologies for protecting OSB raw materials from biodegradation and to explore biological pre- or post-treatments to increase the durability of panels so they would better resist mould, stain and decay. The project was conducted in five parts. Part one involved developing a biological technology to protect OSB raw materials from biodegradation. The results of this part of the work showed that all untreated logs, with or without bark, were seriously degraded by moulds, stain and decay fungi after a summer storage period of five months. The logs with bark were more degraded than the debarked logs, and the log ends were more degraded than the middle sections. After summer storage, 55% to 83% of the wood was degraded in untreated logs. The biological treatment was effective, only 4% to 16% of the wood in treated logs was infected by various fungi after a five-month storage period. Furthermore, the biological treatment was more effective on logs without bark than logs with bark, and more effective on yellow birch and aspen than on red maple. After one year in storage, the total infection rates of untreated logs ranged from 68% to 91%, whereas the rate for biologically treated logs ranged from 27% to 49%. Strands cut from untreated logs contained 50% to 75% of grey or blue stained strands, whereas those cut from biologically treated logs contained 10% to 25% of such strands. Panels made using biologically treated logs had the lowest thickness swelling (TS) and water absorption (WA) values compared with panels made using fresh-cut logs and untreated stored logs. The other physical and mechanical properties of the various panels made for this test were comparable. For the mould resistance, all panels made from fungal treated logs had better mould resistance than those made from freshly cut and untreated logs. Panels made of strands cut from fungal treated debarked logs had better mould resistance than the panels made from fungal treated bark-on logs. The second part of the research consisted of investigating antifungal properties of barks from various wood species. In this part, antifungal properties of barks from 6 wood species: aspen, red maple, yellow birch, balsam fir, white spruce and white cedar were screened in a laboratory test against moulds, staining fungi, white-rot and brown-rot fungi. Based on the colony growth rate of moulds, stain and decay fungi on bark-extract-agar media, white spruce bark was the best at inhibiting growth of these fungi, followed by red maple bark. White cedar and balsam fir bark somewhat inhibited certain fungi tested. Aspen and yellow birch bark did little or nothing at all to inhibit fungal growth. The third part involved developing a biological treatment technology by using naturally resistant wood species to increase the durability of panels so they would better resist mould, stain and decay. In this part, a series of tests were conducted using various wood species. These tests included a) using white cedar to improve panel durability; b) optimizing manufacturing conditions for producing durable panels with white cedar; and c) using other wood species to produce mould-resistant panels. The results showed that three-layer panels made using white cedar strands in the face layers and aspen strands in the core layer at different ratios were mould and decay resistant. White spruce heartwood-faced panels were highly mould resistant and moderately decay resistant. In addition to being mould resistant, white spruce heartwood-faced aspen panels also had better internal bond (IB), modulus of rupture (MOR) and modulus of elasticity (MOE) properties, compared with aspen panels. The panels with black spruce in surface layer had mechanical and mould-resistance properties that were similar to those with white spruce in surface. The panels with surface layer of Eastern larch heartwood were non-resistant to moulds and slightly resistant to decay, but they had better IB, TS and WA properties compared with the other types of panels. The fourth part of the research consisted of developing a biological treatment technology by using fungal antagonists to increase the durability of panels against mould, stain and decay. In this part, two major tests were conducted using various fungal species. They were: a) treating wood strands with three antagonistic fungi, Gliocladium roseum, Phaeotheca dimorphospora and Ceratocystis resinifera, to increase OSB panel durability; and b) treating wood strands with a lignin-degrading fungus, Coriolus hirsutus, to reduce OSB resin usage. The results of this part of the work showed that all of the 4 fungal species used grew well on aspen strands in four weeks, and strands in all treatments had normal wood color after incubation. For IB property, panels made of fungal treated strands were better or similar to the control panels. Panels made of fungal treated strands had higher TS and WA values than untreated control panels. For mechanical properties, panels made of fungal treated strands had a slight lower dry MOR and higher wet MOR than control panels. For mould resistance, panels made of fungal treated strands were infected by moulds one week later than the untreated control panels, and reduction of mould infection rates was detected on fungal treated panels within 6 weeks. After 6 weeks, all panels, treated or untreated, were seriously infected by moulds. Reducing resin usage in fungal treated panels did not affect panel density. Compared with untreated control panels, the IB property of panels made of fungal treated strands was slightly increased by using normal dosage of resin or a reduced dosage by 15%, but slightly decreased with a resin reduction by 30%. There was a negative linear correlation of the panel TS and WA properties with resin reduction by using fungal treated strands. For the mechanical properties, panels made of fungal treated strands had lower dry MOR and MOE values, but higher wet MOR values (except for a resin reduction of 30%) than panels made of untreated strands. The fifth part involved protecting OSB against mould and decay by post-treatment of panels with natural extracts from durable wood species and from fungal antagonists. In this part, three tests were conducted using extracts of white cedar heartwood and extracts of a fungal antagonist. These tests were: a) screening antifungal properties of natural extracts against mould and decay fungi; b) post-treating OSB panels with white cedar heartwood extracts and finishing coats; and c) post-treating OSB panels with fungal metabolites. The results of this part of the work showed that the mycelial growth of all fungi tested (moulds, staining fungi, white-rot and brown-rot fungi) was inhibited by the extracts of white cedar heartwood and extracts of the fungal antagonist, P. dimorphospora, on agar plates. Panel samples dipped with the cedar extracts got slight mould growth on the 2 faces and moderate mould growth on the 4 sides, whereas the panel samples dip-treated with the fungal extracts got the minimal mould infection among the panels tested. The results of the mould test on the post-treated panels with extracts of white cedar heartwood and three coating products showed that slight or no mould growth was detected on any sample dip-treated with the extracts and then brushed with finishing coats. The decay test showed that most post-treated samples had less weight losses than untreated control samples.
Composite materials - Durability
Biotechnology
Documents
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Biotechnology to improve mould, stain and decay resistance of OSB

https://library.fpinnovations.ca/en/permalink/fpipub42231
Author
Yang, D.-Q.
Wang, Xiang-Ming
Wan, Hui
Date
March 2004
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Yang, D.-Q.
Wang, Xiang-Ming
Wan, Hui
Contributor
Canada. Canadian Forest Service
Date
March 2004
Material Type
Research report
Physical Description
46 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Materials
Series Number
Canadian Forest Service No. 31
Location
Sainte-Foy, Québec
Language
English
Abstract
Oriented strand board (OSB) is widely used in house construction in North America. In Canada, OSB panels are commonly made of aspen strands and are susceptible to mould and decay when they get wet. Building envelope failures due to mould, decay or poor construction practices can negatively impact the image of wood. This can lead to product substitution that in turn can affect the wood industry’s overall competitiveness. To ensure durability of OSB panels, the most important consideration is the use of mould- and decay-resistant panels to prevent fungal attack. Using low environmental impact technology to improve the durability of OSB products could have market-related advantages over using chemical protection products. This project aimed to develop technologies for protecting OSB raw materials from biodegradation and to explore biological pre- or post-treatments to increase the durability of panels so they would better resist mould, stain and decay. The project was divided into three parts. Part one involved developing a biological technology to protect OSB raw materials from biodegradation. In this part, aspen, red maple and yellow birch trees, which are commonly used to make OSB in Canada, were felled in May and cut into 4-foot logs. These logs were then equally divided into two groups (16 logs each) with one group keeping its bark and the other having it removed. These debarked and “bark-on” logs were further divided into two groups, each containing 8 logs. One group of logs was treated with a bioprotectant and another group served as a control. The treated and untreated logs were stored separately in Forintek’s yard. Two inspections were conducted, one at the end of the growth season (in October after a 5-month storage period) and the other after one year. During each inspection, four logs from each test group were examined for fungal degradation (mould, stain and decay), and then cut into strands to be used for manufacturing panels. The panels’ physical and mechanical properties and mould resistance were evaluated. The second part involved developing a biological pre- or post-treatment technology by using naturally resistant wood species to increase the durability of panels so they would better resist mould, stain and decay. In this part, a series of tests were conducted using various wood species. These tests included a) determining the antifungal properties of bark from various wood species; b) using white cedar to improve panel durability; c) optimizing manufacturing conditions for producing durable panels with white cedar; d) using other wood species to produce mould-resistant panels; and e) post-treating panels with extracts of durable wood species. The third part consists of developing a biological pre- or post-treatment technology by using fungal antagonists to increase the durability of panels against mould, stain and decay. This part will be conducted in the 2004-2005 fiscal year, and results will be included in next year’s report. The results of the first part on the protection of raw materials showed that all untreated logs, with or without bark, were seriously degraded by moulds, stain and decay fungi after a summer storage period of five months. The logs with bark were more degraded than the debarked logs, and the log ends were more degraded than the middle sections. After summer storage, 55% to 83% of the wood was degraded in untreated logs. The biological treatment was effective, only 4% to 16% of the wood in treated logs was affected by various fungi after a five-month storage period. Furthermore, the biological treatment was more effective on logs without bark than logs with bark, and more effective on yellow birch and aspen than on red maple. After one year in storage, the total infection rates of untreated logs ranged from 68% to 91%, whereas the rate for biologically treated logs ranged from 27% to 49%. Among these treated logs, the logs ends were degraded from 31% to 62%, whereas the middle sections were degraded from 7% to 26%. Strands cut from untreated logs contained 50% to 75% of grey or blue stained strands, whereas those cut from biologically treated logs contained 10% to 25% of such strands. Panels made using biologically treated logs had the lowest TS and WA values compared with panels made using fresh-cut logs and untreated stored logs. The other physical and mechanical properties of the various panels made for this test were comparable. The antifungal properties of bark from six wood species (aspen, red maple, yellow birch, balsam fir, white spruce and white cedar) were investigated in the second part of this research project. Based on the colony growth rate of moulds, stain and decay fungi on bark-extract-agar media, white spruce bark was the best at inhibiting growth of these fungi, followed by red maple bark. White cedar and balsam fir bark somewhat inhibited certain fungi tested. Aspen and yellow birch bark did little or nothing at all to inhibit fungal growth. The research also showed that the white cedar heartwood-extract-agar medium not only inhibited decay fungi growth, but also inhibited the growth of moulds and staining fungi. The bark-extract-agar medium of this wood species was less effective in inhibiting fungal growth than the heartwood was. Three-layer panels made using white cedar heartwood strands in the face layers and aspen strands in the core layer at a ratio of 25:0:25 were mould and decay resistant, but the panels “blew” easily during manufacturing and their mechanical properties were not satisfying. The overall mould infection rate on white cedar heartwood-faced panels was 0.8, which indicated that the panel was mould resistant. White spruce heartwood-faced panels were highly mould resistant and moderately decay resistant. The overall mould infection rate on white spruce heartwood-faced panels was only 0.2 after 8 weeks of exposure to high humidity environmental conditions. In addition to being mould resistant, white spruce heartwood-faced aspen panels also had better IB, MOR and MOE properties, compared with aspen panels. The panels with black spruce in surface layer had mechanical and mould-resistance properties that were similar to those with white spruce in surface. The panels with surface layer of Eastern larch heartwood were non-resistant to moulds and slightly resistant to decay, but they had better IB, TS and WA properties compared with the other types of panels. The overall mould infection rate on the panel with surface layer of Eastern larch heartwood was 3.7, which was similar to the rate for aspen control panels. Aspen panels (serving as control panels) were seriously affected by moulds with overall mould infection rates ranging from 3.8 to 4.9. Aspen panels with surface layer from whole-wood strands (using both sapwood and heartwood) from white cedar, in a ratio of 25:50:25 and pressed at 220°C for 150 seconds, were well bonded and had IB, TS, WA and MOE values that were similar to those of aspen control panel, but with a higher MOR. All the panels’ properties met the requirements of the standard. This type of panel also was the least infected by moulds, especially in the face layers which rated a 0.2. The panel sides were moderately infected, rating a 2.6, this occurring mostly in the middle layer of aspen strands. The overall rate of this type of panel was 1.0, which indicated that the panels were resistant to mould infection. This type of panel was also highly resistant to brown rot and moderately resistant to white rot. Panels made of steam-treated white cedar whole-wood strands and aspen strands at a ratio of 3:7 based on oven-dry weight also had low infection rates: the average face infection rate was 1.2; the side infection was 2.4 and the overall rate was 1.6. Compared with aspen panels, this type of panel also had high MOR and MOE values and low TS and WA values. In the case of white cedar whole-wood strands faced aspen panels, when the pressing time was increased from 160 seconds to 180 seconds at 200°C, the panels’ IB strength and MOE increased whereas the panels’ TS, WA and MOR decreased. By increasing the pressing temperature from 200°C to 240°C and pressing for 160 seconds, the panels’ IB strength, MOR and MOE increased and the panels’ TS and WA decreased sharply. At a pressing temperature of 240°C and a pressing time of 180 seconds, the panels’ IB strength, MOR and MOE increased significantly and the panels’ TS and WA decreased significantly. These data showed that aspen panels with surface layer from white cedar whole strands at a ratio of 25:50:25 and pressed at 240°C for 180 seconds had the best mechanical and physical properties. All panel samples were slightly infected by moulds on the faces. A fair amount of mould occurred on the sides of panels pressed at 200°C for 160 seconds and 180 seconds and those pressed at 240°C for 180 seconds. The panels pressed at 240°C for 160 seconds were the least infected by mould (with an infection rate of 0.3). Panels pressed at 200°C had a white-yellowish colour, whereas those pressed at 240°C were yellow-brownish and darker than those pressed at 200°C. Panels pressed at 200°C for 160 or 180 seconds and those pressed at 240°C for 160 seconds were highly decay resistant, especially to brown rot. The decay resistance of panels pressed at 240°C for 180 seconds was lower compared with the other panels. Compared with aspen panels, panels with surface layer from steam-treated white cedar strands and aspen strands at a ratio of 7:3 based on oven-dry weight had higher TS, WA, MOR and MOE values and a similar IB value. Panels with surface layer from steam-treated white cedar strands and aspen strands at a ratio of 4:6 based on oven-dry weight had the highest IB value. A reduction in mould and decay resistance corresponded to a reduction in the proportion of white cedar strands in the face layers. The overall mould growth rate was 1.27 on panels with surface layer from steam-treated white cedar strands and aspen strands at a ratio of 4:6, 0.6 on panels with surface layer from steam-treated white cedar strands and aspen strands at a ratio of 7:3, and 0.4 on panels faced with 100% white cedar whole strands, respectively. Panels made from 100% white cedar whole-wood strands or a mixture of whole-wood strands of white cedar and aspen (50:50) in the core layer were “blown” after pressing. Panels made from a mixture of white cedar and aspen strands at a ratio of 25:75 in the core layer and aspen strands in the face layers had superior IB, MOR and MOE values than other panels. However, their TS and WA values were also higher than those of white cedar-faced panels. Panels made from a mixture of white cedar and aspen strands at a ratio of 25:75 in the core layer and white cedar strands in the face layers had the worst physical and mechanical properties among all the panels made for this test. The tests results for mould showed that panels made with a mixture of white cedar and aspen strands at a ratio of 25:75 in the core layer and aspen strands in the face layers ware seriously attacked by moulds and had an overall mould growth rate of 4.2. No mould infection was found on panels made from 100% white cedar strands. Panels made from a strand mixture of white cedar (50%) and aspen (50%) in the core layer and white cedar strands in the face layers had little mould infection. The overall mould growth rate on this type of panel was 0.2. Compared with the control aspen panels, aspen panels with surface layer from white cedar whole-wood strands at a ratio of 15:70:15 had similar IB and TS values, a lower WA value and higher MOR and MOE values. When the white cedar strand proportion in the face layer was increased from 15% to 25%, the panels’ IB strength and WA decreased, but their MOR and MOE values increased. Panels with surface layer from white cedar strands at a ratio of 15:70:15 had little infection from moulds on the face and bottom layers, but had an increased infection rate on all four sides. The average overall infection rate of this type of panel was 0.5. When the white cedar in the panels’ face layer was increased from 15% to 25%, the average infection rate on the panels’ faces was still 0.1, but the infection rate of the panels’ sides dropped from 1.2 to 1.0. The overall rate was 0.4. In terms of decay resistance, panels with surface layer from 25% white cedar strands performed better than those with surface layer from 15% white cedar.
Composite materials - Durability
Biotechnology
Documents
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Developing structural wood composite products from MPB wood

https://library.fpinnovations.ca/en/permalink/fpipub39273
Author
Hsu, W.H.E.
Wan, Hui
Xu, H.
Dai, Chunping
Date
March 2010
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Hsu, W.H.E.
Wan, Hui
Xu, H.
Dai, Chunping
Contributor
Forestry Innovation Investment.
Date
March 2010
Material Type
Research report
Physical Description
18 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Wood
Utilization
Insect killed
Series Number
W-2755
Location
Vancouver, British Columbia
Language
English
Abstract
Within the limits of this study, the results indicate that it is quite possible to develop new Engineered Structural Lumber products from MPB wood and to maximize its value for uses in traditional and next generation wood buildings. New product and processing technologies have to be developed first to convert severely dried and checked MPB wood into competitive structural lumber products. Further research and development, particularly in stranding technology for dry logs is recommended.
Dendroctonus monticolae
Insect-killed wood - Utilization
Documents
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Development of value-added products from BC low-quality wood resource using nano-based technology literature review

https://library.fpinnovations.ca/en/permalink/fpipub5727
Author
Cai, X.
Akhtar, A.
Feng, Martin
Wan, Hui
Zhang, S.Y. (Tony)
Date
March 1909
Edition
39278
Material Type
Research report
Field
Sustainable Construction
Author
Cai, X.
Akhtar, A.
Feng, Martin
Wan, Hui
Zhang, S.Y. (Tony)
Contributor
Forestry Innovation Investment.
Date
March 1909
Edition
39278
Material Type
Research report
Physical Description
22 p.
Sector
Wood Products
Field
Sustainable Construction
Research Area
Advanced Wood Materials
Subject
British Columbia
Research
Glue
Series Number
W-2770
Location
Vancouver, British Columbia
Language
English
Abstract
A literature review was conducted to identify potentially effective nano-based technology for improving wood attributes in order to develop competitive specialty wood products. The review covered both conventional chemical treatment methods and nano-based methods. Traditional chemical treatments have shown to be effective in improving wood hardness, dimensional stability, stiffness, fire resistance, UV resistance, biological resistance and aesthetic appeal. However, nanotechnology offers new opportunities for further improving wood product attributes due to some very unique and desirable properties of chemical materials in the form of particles in nano scale. The advantages of nanotechnology appear to be particularly obvious when applied to create polymer nanocomposites such as wood coatings. Polymer nanocomposites consist of a continuous polymer matrix which contains inorganic particles of a size below approximately 100 nm at least in one dimension. Due to the material nature of solid wood products, creating a continuous polymer matrix with effective inorganic nanoparticles inside wood cells and lumens would be very difficult. The most promising areas of applying nanotechnology to create improvement opportunities would be wood coatings and wood adhesives. It is recommended that research be carried out to explore the potential of nanotechnology in wood coatings and adhesives and their applications in B.C. wood species and wood products.
Finishing
Glue - Research
Nanotechnology
Documents
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Effect of liquid PF resin viscosity, powder PF resin particle size, and liquid PF/powder PF combination ratio on OSB performance

https://library.fpinnovations.ca/en/permalink/fpipub38978
Author
Wang, Xiang-Ming
Wan, Hui
Date
October 2006
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Xiang-Ming
Wan, Hui
Date
October 2006
Material Type
Research report
Physical Description
36 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Mechanical properties
Strandboards
Resin
Oriented strandboard
Orientation
Series Number
General Revenue Project No. 2689
2689
Location
Québec, Québec
Language
English
Abstract
Response Surface Design (Design-Expert 6.0.5) was used in the experimental design for investigating the influence of liquid PF (LPF) resin viscosity (90, 180, 270 cps), powder PF (PPF) resin particle size in terms of grinding time (0, 15, 30 min), and LPF/PPF combination ratio (25/75, 50/50, 75/25) on strand board performance. Response Surface Analysis suggests a significant quadric model for predicting wet modulus of rupture (MOR) and water absorption (WA) properties. A barely significant linear model was established to predict IB strength. No significant models could be established for dry MOR, dry modulus of elasticity (MOE), MOR retention, and thickness swelling (TS) properties. Response Surface Optimization suggests that the optimal IB, wet MOR, and WA would be 0.59 MPa, 16.9 MPa, and 33.0%, respectively, with 270 cps, 30 minutes, and 25/75 for the optimal resin viscosity, powder grinding time, and LPF/PPF ratio. Resin viscosity, powder grinding time, and LPF/PPF ratio do not significantly influence dry MOR, dry MOE, MOR retention, and TS properties. This study also implies that reducing powder particle size can improve resin efficiency in terms of increased resin coverage and uniform distribution.
Oriented strandboard - Strength
Resin
Documents
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Effect of MDI and powder PF combination binder system on OSB performance

https://library.fpinnovations.ca/en/permalink/fpipub42151
Author
Wang, Xiang-Ming
Wan, Hui
Date
October 2002
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Xiang-Ming
Wan, Hui
Date
October 2002
Material Type
Research report
Physical Description
33 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Strandboards
Resin
Oriented strandboard
Orientation
Series Number
General Revenue 2689
Location
Sainte-Foy, Québec
Language
English
Abstract
In North America, resin binder systems used for OSB production are normally either in powder form such as powder phenol-formaldehyde (PPF) or in liquid form such as liquid phenol-formaldehyde (LPF) resin and diphenylmethane diisocyanate (MDI). To improve resin efficiency and bond quality, recent OSB production has shown a trend toward the utilisation of liquid and powder resin combination system such as LPF/PPF and MDI/PPF. This study was conducted to investigate effects of MDI/PPF combination binder system on strand board performance. The main variables included (1) MDI/PPF combination ratio (100/0, 75/25, 50/50, 25/75, 0/100), (2) mat moisture variation (uniform 7% MC, average 7% MC obtained by mixing 2%MC and 12%MC strands at a ratio of 50/50), (3) storage time of resinated strands prior to pressing (<0.5 h, 1.0 h, 2 h), and (4) resin content/type based on a similar basis of resin cost (2.4% MDI, 3.5% LPF, 3.5% PPF, 0.875%LPF/2.625%PPF). There was an optimal MDI/PPF combination ratio for improving resin efficiency regarding resin bond quality and cost savings. Homogeneous strand boards bonded with 75/25 and/or 50/50 MDI/PPF combination were statistically comparable to MDI bonded panel regarding internal bond (IB), thickness swelling (TS), water absorption (WA), dry/wet modulus of rupture (MOR) and modulus of elasticity (MOE) properties. A further decrease in the amount of MDI in the combination significantly reduced the board performance. MDI was susceptible to react with water in the strands after blending, which in turn resulted in a detrimental effect on the panel properties. An increase in storage time significantly increased TS and WA, and decreased wet MOR properties of boards. Increasing storage time also reduced IB and wet MOE properties. However, the reduction was not significant at the 95 percent confidence level. MDI and MDI/PPF (50/50) binder systems were more tolerant to furnish MC variation compared to PPF resin. A change in mat MC condition from uniform 7% to average 7% significantly increased TS value and reduced dry MOR and wet MOE properties of PPF bonded panels. However, this change in the moisture condition did not affect MDI/PPF panel, but significantly enhanced MDI panel performance in terms of IB, TS, and WA properties. Spraying water to the top of mat prior to pressing did not influence panel performance regarding all panel properties. The study on different resin systems for strand boards on a similar basis of resin cost showed that MDI produced lower TS and WA panels compared to PPF, LPF and LPF/PPF (25/75) combination. However, no significant difference between these four resin bonded panels was observed in consideration of other panel properties such as IB, dry/wet MOR, and dry/wet MOE.
Oriented strandboard - Manufacture
Resin
Documents
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Effect of powder and liquid PF resin combination binder system on OSB performance

https://library.fpinnovations.ca/en/permalink/fpipub42138
Author
Wang, Xiang-Ming
Wan, Hui
Date
August 2002
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Xiang-Ming
Wan, Hui
Date
August 2002
Material Type
Research report
Physical Description
50 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Strandboards
Resin
Phenols
Oriented strandboard
Orientation
Glue
Series Number
General Revenue 2689
Location
Sainte-Foy, Québec
Language
English
Abstract
The current OSB production has shown a trend toward the utilisation of liquid and powder phenol-formaldehyde (PF) resin combination binder system in order to improve resin efficiency. A new resin application system equipped with two nozzles for liquid resin and one blower for powder resin application has been installed at Forintek. To understand how the resin application system affects resin efficiency as measured by improved resin coverage and physical and mechanical properties, an experiment was conducted to manufacture a series of OSB panels with various powder/liquid resin combination ratios (0/100, 25/75, 50/50, 75/25, 100/0), resin contents (2.0%, 3.5%, 5.0%), and dwell times (1, 2, 3 min) during blending. Two statistical methods, Duncan’s Multiple Range Test and Response Surface Analysis, were used for the analysis of variance (ANOVA) of resin coverage on the surfaces of strands and mechanical and physical properties of OSB panels made from these strands. The former method was employed to determine the means of panel properties significantly different at the 95 percent confidence level, and the latter to determine the significant model terms at the 95 percent confidence level in Response Surface Quadratic Model and to predict the overall trends of panel properties and/or resin coverage influenced by these model terms. This study indicated that among the variables investigated resin content was the only attributing factor that significantly affected resin coverage and all panel properties, including internal bond strength (IB), thickness swelling (TS), water absorption (WA), modulus of rupture (MOR) and modulus of elasticity (MOE) at the 95 percent confidence level. An increase in resin content broadened the resin coverage and meanwhile improved panel performance for both blowing and tumbling methods used for powder application. In addition, an overall increase in resin coverage improved IB, TS, WA and MOR, but not MOE. Powder/liquid combination (between 25/75 and 75/25) improved resin efficiency regarding IB and TS properties of panel compared to powder or liquid resin alone. When blowing method was used for powder application in powder PF/liquid PF combo system, a shorter dwell time (1 min) was optimal for resin efficiency compared with a longer dwell time (2 or 3 min). The reverse trend was observed when tumbling method was utilised for powder application in the powder binder system. An overall comparison between the two blending methods for the powder also indicated that the blowing method had an advantage over the tumbling method regarding resin efficiency and bond quality at a short dwell time.
Resin
Oriented strandboard
Glue, Phenolic
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Effect of resin application sequence, content, and powder/liquid combination ratio on OSB performance

https://library.fpinnovations.ca/en/permalink/fpipub42314
Author
Wang, Xiang-Ming
Wan, Hui
Date
July 2005
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Xiang-Ming
Wan, Hui
Date
July 2005
Material Type
Research report
Physical Description
43 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Resin
Oriented strandboard
Application
Series Number
General Revenue Project No. 2689
Location
Sainte-Foy, Québec
Language
English
Abstract
Powder and liquid phenol-formaldehyde (PF) combination binder system has been commonly used in North America for oriented strand board (OSB) manufacturing. This binder system has shown its suitability for improving resin efficiency and bond quality as compared with either powder PF (PPF) or liquid PF (LPF) resin. This study was conducted to investigate the effect of resin application sequence (LPF-PPF-LPF, LPF-PPF, PPF-LPF), resin content (3.0%, 5.5%, 8.0%), and PPF/LPF combination ratio (50:50, 65:35, 80:20) on strand board performance. Board properties evaluated include internal bond (IB), thickness swelling (TS), water absorption (WA), dry and wet modulus of rupture (MOR), dry modulus of elasticity (MOE), edgewise shear, and compression shear strength. In addition, a non-destructive test method (TROBEND) developed at Forintek was also used to measure the modulus of elasticity (MOE) and shear modulus of elasticity (G). Response Surface Methodology (RSM) was used in the experiment design. Significant response surface models were established for individual panel properties, including the linear model for IB, dry MOR, dry MOE, and compression shear, as well as the quadric model for TS, WA, and wet MOR, and 2FI (two factor interaction) for edgewise shear. ANOVA for response surface model indicated that the resin content was a significant model term for IB, TS, dry MOR and MOE, wet MOR, and compression shear properties. An increase in resin content improved these board properties. Powder/liquid ratio was a significant model term for TS, WA, and wet MOR. Resin application sequence was not a significant model term for any panel property, but its interaction with resin content was a significant model term for edgewise shear property. In most cases, the interactions between experimental variables were not significant model terms for predicting panel properties, but they still revealed some trends. Regarding Sequence 3 (PPF-LPF), 50:50 PPF/LPF ratio (lower level) resulted in higher IB, dry MOR, and compression shear, while 80:20 PPF/LPF (higher level) yielded lower WA and higher dry MOE. For Sequence 2 (LPF-PPF), 65:35 PPF/LPF ratio (middle level) favoured TS, while 50:50 PPF/LPF ratio (lower level) favoured wet MOR. Sequence 1 (LPF-PPF-LPF) combined with 50:50 PPF/LPF ratio (lower level) also gave lower WA values. In general, an increase in resin content improved the board properties with the above combinations. In addition, Sequence 3 (PPF-LPF), with 3.0% resin (lower level), yielded higher edgewise shear strength regardless of resin application sequence. An attempt was made to correlate the panel mechanical properties measured using both destructive and non-destructive test methods. The strongest correlation was observed between IB and compression shear (R2=0.70), followed by TORBEND G with modulus of elasticity (TORBEND MOE) (R2=0.40), and TORBEND G with compression shear (R2=0.28) and with IB (R2=0.26). However, no correlation seemed to exist between MOE (static bending) and TROBEND MOE. An image analysis indicated that an increase in resin content significantly increased resin coverage on strand surface. At each resin content (3.0%, 5.5%, and 8.0%), a decrease in PPF/LPF ratio in Sequence 1 (LPF-PPF-LPF) or an increase PPF/LPF ratio in sequence 3 (PPF-LPF) seemed to result in higher resin coverage. Resin coverage seemed to correlate to TS (R2=0.45), IB (R2=0.42), compression shear (R2=0.39), TORBEND G (R2=0.39), dry MOR (R2=0.25), wet MOR (R2=0.25), and dry MOE (R2=0.18). However, resin coverage did not seem to correlate to WA, TORBEND MOE, or edgewise shear properties.
Resin application
OSB
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Effect of resin type and strand surface characteristics on OSB performance

https://library.fpinnovations.ca/en/permalink/fpipub38942
Author
Wang, Xiang-Ming
Wan, Hui
Date
March 2006
Material Type
Research report
Field
Wood Manufacturing & Digitalization
Author
Wang, Xiang-Ming
Wan, Hui
Date
March 2006
Material Type
Research report
Physical Description
37 p.
Sector
Wood Products
Field
Wood Manufacturing & Digitalization
Research Area
Advanced Wood Manufacturing
Subject
Mechanical properties
Strandboards
Resin
Oriented strandboard
Orientation
Series Number
General Revenue Project No. 2689
2689
Location
Québec, Québec
Language
English
Abstract
This study aimed to investigate how resin type (powder, liquid, powder/liquid combination) in conjunction with knife (sharpening) angle (22o, 32o) in strand preparation, and strand-drying temperatures (114oC, 160oC, 195oC) influenced the performance of aspen/white birch strand boards. Strands were characterized for curvature, surface roughness, and resin coverage. Board performance was evaluated by internal bond (IB), dry modulus of rupture (MOR), dry modulus of elasticity (MOE), wet MOR, thickness swelling (TS), and water absorption (WA). Strand characteristics showed that white birch strands curled more than aspen strands for all experimental conditions. An increase in strand-drying temperature generally increased the extent of strand curvature. The 32o knife resulted in less curled strands than the 22o knife for aspen at 114oC, 160oC, 195oC, while the opposite result was found for birch at 114oC and 195oC. White birch strands showed a higher degree of surface roughness than aspen strands for all strand flaking and drying conditions. For aspen/white birch mixed strands, the 22o knife seemed to yield higher resin coverage than the 32o knife at 160oC and 195oC, while the opposite result was observed at 114oC for powder resin (PPF) and powder/liquid combination (PPF/LPF). In terms of wood species, birch strands normally showed higher resin coverage than aspen strands. Higher resin coverage was found on the loose side rather than the tight side of strands for both aspen and white birch. Among 15 board manufacturing conditions (in terms of knife angle, strand-drying temperature, and resin type), overall stronger boards were produced with 32o knife-cut strands compared with 22o knife-cut strands. These results imply that the 32o knife seems to produce strands more suitable for making strand boards with PPF or PPF/LPF resin. With 32o knife-cut strands, the PPF/LPF combo yielded overall better quality boards than did PPF; however, both PPF/LPF and PPF resins produced much stronger boards than LPF resin. The poor performance by LPF resin can probably be attributed to a relatively higher resin viscosity and the resulting poor resin distribution. Preheating resin at 35oC may not be enough to atomize the resin through the nozzle spraying system. These results imply that the use of a liquid and powder combination binder system seems to improve bond quality even though the liquid resin has a higher level of viscosity than is normally required for OSB manufacturing. Resin types (PPF, PPF/LPF) had less influence on board performance for strands flaked at 22o. This study showed that strand preparation conditions (knife angle, strand-drying temperature, and resin type) influenced strand characteristics (strand curvature, surface roughness, and resin coverage). However, the influence was not considered significant enough to be able to draw a clear conclusion on the impact of strand characteristics on board performance. It is believed that an increase in strand width (1.25-in wide aspen and birch strands were used in this study) would have a greater impact, especially concerning strand curling and folding problems and variation in resin distribution within and among strands. Acknowledgements Many thanks to all of the participating member mills for their technical support. A special thanks is extended to Dr. When-Huan (Bill) Man, visiting scientist from Beijing Forestry University, Beijing, China, for his assistance in the measurements and analyses of strand curling, strand surface roughness, and resin coverage on strand surfaces. The help of Ms. Johanne Emard, secretary in the Composite Wood Products Department at Forintek, for progress report formatting is also appreciated.
Oriented strandboard - Strength
Resin
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