Hardwood flour was biologically converted with 3 fungal species, and ammonium lignosulfonate was biologically modified with 3 enzyme cocktails.
Ten types of panels were made of bio-modified or unmodified wood flour and ammonium lignosulfonate. All panels were manufactured at target density (850 kg/m3), temperature (220°C), pressure (300 psi) and pressing time (220 sec) without any resin and additives.
Among all formulations, the biomaterials, consisted of bio-modified hardwood flour by the fungal specie 332A, or bio-modified ammonium lignosulfonate by enzymes extracted from 76A and 329A, were most effective and showed significantly higher internal bonding (IB) strengths.
Further investigation of the bio-modification of the kraft lignin for bio-composites is conducted in 2013-2014 financial year (ongoing) and will be reported in 2013-2014.
In December, 2012, Kevin Groves from FPInnovations visited a Canadian OSB mill to demonstrate an FPInnovations prototype vision scanning system for simultaneously monitoring fines, strand width and alignment on the forming line.
Prior to the mill trial, the width and fines measurements were calibrated based on known quantities of fines and strand width sizes. During laboratory calibration, there was a linear relationship between scanner versus actual width values with an R² correlation of 0.98. The measurement prediction accuracy was estimated with a root mean square error (RMSE) of 0.1 inches. With fines, there was a linear relationship between scanner measurement versus actual values with an R² of 0.99. The measurement prediction accuracy was estimated with a RMSE of 2 % (fines percentage).
The alignment angle of each strand was measured from -90° to 90° with 0° set as the principal forming line direction. The scanner’s measurement of alignment is described by percent alignment (PA) as proposed by Geimer (1976). PA gives an alignment of 100% for perfectly aligned strands and 0% alignment for random strand distribution.
At the mill the camera was set up 36 inches above the top face mat on the forming line. Strand width, alignment and fines measurements were collected continuously from approximately 5:00 pm December 19 to 9:25 am December 20. On December 19 the mill ran overnight with 7/16” panel production at a former height of 5 inches. During this time scanner measurements showed that average alignment remained relatively constant at approximately 70% while average strand width gradually decreased from approximately 0.75 to 0.7 inches, and fines increased from approximately 8% to 18%.
The next morning (December 20) beginning at 7:50 am, the former height was changed in stages from 5 to 8 inches with corresponding scanner measurements showing a decrease in alignment from 70% to 45%. The scanner was effective in tracking these height changes with results showing an inverse linear relationship between former height and alignment. Saved images were later analyzed to determine actual alignment for comparison to the onsite scanner measurements. Results showed a good correlation with an R² of 0.98 between measured versus actual alignment. The accuracy of strand alignment measurement was estimated with a RMSE of 3 PA.
Although this was a short trial, the scanner effectively demonstrated simultaneous, real time measurements of fines, strand width and alignment.
In the Plywood/LVL manufacturing process adhesive application is one of the main variable costs, accounting for more than 30% of the total operating costs. Glue spray and roll spreader applicators are used by the majority of mills. While the current manual method for measuring spread rates is adequate for spot checks, there is nothing currently available that monitors spread rate continuously to effectively monitor and control spread variability. Mills believe that a real time glue measurement scanner would be a valuable tool for optimizing their applicator to reduce variability, thereby allowing the mill to use lower spread rates and save on glue costs. An automatic system will reduce downtime and improve production rate.
In 2012, a prototype glue scanning system was developed at the FPInnovations Vancouver laboratory and was successfully demonstrated at the West Fraser, Alberta Plywood Division mill, in Edmonton. The scanner was installed on one of the glue spray lines to automatically measure and record PF glue spray spot size and glue coverage distribution in real time.
The scanner demonstrated that it can be used as part of the mill’s quality monitoring to ensure that glue application is within target application levels.
A prototype scanning system successfully demonstrated the capability of real-time, log pocket monitoring that can be used to alert operators of improper pocket filling practice.
Several previous FPInnovations studies have shown that the log pocket filling is often poorly controlled resulting in poor log alignment and/or incomplete filling that adversely affects both flake quality and strander productivity. Until now there have been no systems available to automatically measure the alignment of logs being fed into the strander or measurement of the actual filling of the strander pockets. An automated monitoring system is needed to signal operators when the log pocket is improperly loaded. This feedback can allow operators to maintain proper log filling procedure to maximize flaking quality.
In March 2013 a machine vision scanning system comprised of a camera, 2 line lasers and computer with image analysis software, was tested for two days at the Peace Valley OSB mill (PVOSB) in Fort Saint John, BC. The scanner’s camera and lasers were mounted 13 feet above the center of the log pocket base. Images of pocket filling were acquired and analyzed for pass/fail conditions. Two image groups were selected for analysis, one of full pocket, aligned logs (pass) and the other containing misaligned logs and/or insufficient pocket fill (fail). For all pocket scans, scanner measurements were compared to manual visual classification.
Approximately 50 different pockets were scanned with results and images saved for analysis. For fill height and vertical log alignment measurement, the scanner correctly identified >95% of all the pockets examined. However, log alignment measurement in the horizontal x-y plane did not function as intended due to poor image contrast that could not be resolved during the mill trial. This technique has been shown to work well in previous pilot plant tests (Groves, 2012) which confirms that the underlying measurement fundamentals are sound. It is recommended that only minor lighting adjustments are required for the scanning system to work well in a mill setting.
Implementing this technology in OSB mills should help to reduce the occurrence of poor pocket filling that can adversely affect strand quality. It should be noted that even small improvements to strand quality and productivity can yield significant cost benefits. It is estimated that reducing fines by a modest 1% and improving productivity by 1% can return in excess of $1 million/year based on an average size Canadian OSB mill.
In plywood mills finished panels are manually graded and sorted based on specific defects. The panel edges are especially difficult to grade by human visual inspection due to the small nature of different defects, especially at higher line speeds. This can result in misread errors that can be costly.
In this project a prototype scanner, based on 3D laser profilometry, was developed by FPInnovations and demonstrated in two Canadian plywood mills for automatic edge grading. At both mills, panels were scanned on the production line in real time, collecting full length, 3-dimensional edge profiles in the x, y and z coordinate fields that were then analyzed by computer software sub-routines to identify defects for each panel. The data was processed to categorize groups of data points, depending on the edge profile depth (z-axis) variation, length (x-axis) and height (y-axis) into the specific defect categories of core, top and bottom edge void, core gap and core overlap, based on the values of predetermined edge profile thresholds.
Results from the two mill tests showed that the scanner was effective with a correct identification rate greater than 80%. The lack of panel hold-downs at each mill resulted in extreme height variation of the panel edges and this limited the defect detection accuracy. Based on the tests, the technology for automated edge grading is feasible. Longer term mill evaluations are recommended with adequate panel hold-downs in place before confirming that this technology is ready for commercialization.
Four major forces are driving interest in wood fibre based insulation products in Canada and other parts of the world: Changing energy codes for buildings; Densification in urban areas; A need to develop alternate uses for pulp chips and low quality wood fibre; and demand for renewable and green products.
LignoForce lignin, a product obtained in a specific stage of kraft lignin production from black liquor of the pulping process, possesses unique characteristics and is cheaper than ordinary kraft lignin. This project studied this particular lignin as a substitute for corncob/Superbond fillers in PF glue mixes for plywood production. The lignin was evaluated in lab tests and in plywood mill production trial. PF glue mixes with 50% corncob/Superbond substituted by the lignin were produced and evaluated for plywood production. The test glue mixes were found to be comparable to the control in viscosity, stability and bond performance. This project demonstrated that LignoForce lignin is a viable substitute for corncob/Superbond fillers in the plywood industry. It should be noted that the procedure to incorporate LignoForce lignin into the glue mix is simple but different from the traditional mixing procedure during the glue mix preparation. The test glue mix with LignoForce lignin has the potential to be applied by different methods, such as glue spreader, curtain coater, and glue spray line.
Chitosan is an amino polysaccharide deacetylated from chitin, which is naturally occurring in large amount in shells of marine crustaceans. Chitosan is soluble in weakly acidic aqueous solutions and possesses an adhesive property. Chitosan has received much attention for medical and industrial applications; however, only limited studies have been conducted on the application of chitosan as a wood adhesive because of its bonding properties on wood are poor. To improve the adhesive quality of chitosan resin, an innovative study on chitosan adhesives has been conducted to use selected fungal species to modify chitosan and improve its bonding property, to synthesize non-formaldehyde resin with the fungus-modified chitosan and to prepare UF and PF resins enhanced with the fungal modified chitosan. Bonding properties of wood composites made with these chitosan-based green wood adhesives in terms of lap-shear strength were significantly improved in this study. Unmodified chitosan solution was not compatible with ammonium lignosulfonate liquid, liquid PF resin, soybean resin, PF powder, or soybean flour, but was compatible with UF resin (liquid), PVA resin, or phenol. With addition of chitosan in UF and PVA resins, both dry and wet shear strengths of plywood panels were improved comparing with the use of the control UF and PVA resins without chitosan. A number of chitosan and chitosan-reinforced UF resins as binder for particleboard manufacturing have been prepared. Six (6) types of particleboards with different levels of resin loadings and press conditions were manufactured and evaluated for the bond quality of chitosan and chitosan-reinforced UF resins. The results showed that all formulations of chitosan-UF adhesives were able to produce particleboards with nice appearance, even those made of only with 1% of chitosan resin alone. All chitosan resins, alone or added to UF resins, had a better IB strength than UF control resin. The panels made of 1% of chitosan resin plus 66% of UF resin in a 1:1 ratio had the highest IB strength.
Le mandat du projet consiste en la réalisation d’essais avec un équipement d’acquisition générique NIR (Near Infrared) dans le but de développer des modèles mathématiques pouvant être utilisés pour déterminer le taux d’humidité des planches de bois franc pour quatre essences : le chêne rouge, l’érable à sucre, le merisier et l’érable argenté.
Une fois les modèles développés les objectifs plus spécifiques sont d’évaluer le niveau de précision de mesure de la teneur en humidité sur du bois parfaitement équilibré ainsi que déterminer les impacts sur les lectures provenant des facteurs suivants : l’essence, la densité, la qualité de surface, la température du bois, le gradient de teneur en humidité ainsi que la vitesse de passage des planches. Finalement, des essais doivent être réalisés sur du bois provenant directement de l’industrie et n’ayant subi aucun traitement d’équilibrage en laboratoire pour connaître le niveau de précision de lecture dans ces conditions.
Hardwood initiative - Part 5: Development of new processes and technologies in the hardwood industry : Best practices to avoid hardwood checking. Part II. Prevention of checking by proper storage methods
Wood checking in many wood species causes considerable economic loss in hardwood industry. They can occur on logs, green timber, kiln- or air-dried lumber and final furniture or flooring components during manufacturing, drying processing, storage and end-use. Wood checking is difficult to be completely eliminated, but can be controlled to an acceptable level by a proper protective measure. This report provides scientific data on the effectiveness of the most common and up-to-date protective products and methods to prevent checking in logs, green lumber and components of sugar maple and yellow birch during storage in Quebec.
In the experiment, five commercial protective products were tested on logs and green lumber and three methods were evaluated on furniture components after storage for 8 weeks. The results showed that these protective measures were necessary and effective, more or less, to prevent checking in these stored wood products. For protecting stored logs and green lumber from end checking, the most effective treatment was those logs or lumber end-painted with a white coating product. For protecting stored components from checking, the most effective measure was either end sealed with a paper or pile wrapped with a plastic sheet. No checking was detected on any component of sugar maple and yellow birch protected with either of these two methods after exposure to the extreme environmental conditions for 8 weeks.
Élément 5 : Initiative de recherche sur les bois feuillus - Développement de nouveaux procédés et de nouvelles technologies pour le secteur des bois feuillus ; Meilleures pratiques pour éviter la formation de gerces et de fentes sur les produits de bois feuillus. Deuxième partie : Prévention des gerces et des fentes par des méthodes de stockage appropriées
La formation de gerces et de fentes dans le bois d’un grand nombre d’essences entraîne des pertes économiques considérables pour le secteur des produits de bois feuillus. En effet, les gerces et fentes peuvent se former sur les billes, les sciages à l’état vert et les sciages séchés au séchoir et à l’air et sur les composants de meubles ou les revêtements de sol et ce, en cours de fabrication de séchage, de transformation, de stockage et d'utilisation finale. Bien qu'il soit difficile d'empêcher complètement la formation de gerces et de fentes sur les produits du bois, il est toutefois possible d'en limiter le nombre à un niveau acceptable par l'application de mesures appropriées. Le présent rapport fait état de connaissances scientifiques sur l’efficacité des méthodes et des produits de protection les plus couramment utilisés pour limiter la formation des gerces sur les billes, les sciages à l’état vert et les composants issus du bois d’érable à sucre et de bouleau jaune en stockage au Québec.
Dans le cadre de la présente étude, cinq (5) produits protecteurs ont été appliqués sur des billes et des sciages à l’état vert. Par ailleurs, l’efficacité de trois (3) méthodes a été établie au bout d’une période de stockage de huit (8) semaines. Les résultats ont révélé que ces mesures de protection s’imposaient et qu’elles permettaient dans une certaine mesure, de prévenir la formation de gerces et de fentes sur les produits du bois en question. L’application d’un enduit blanc aux extrémités des billes et des sciages verts stockés s’est révélée le traitement le plus efficace contre la formation de gerces et de fentes. L’encollage d’un papier aux extrémités des composants stockés ou leur enveloppement avec une membrane en plastique s’est révélée la méthode la plus efficace pour les protéger contre la formation de gerces et de fentes.
Au terme d’une période de stockage de huit (8) semaines dans des conditions environnementales extrêmes, aucune gerce ou fente n’a été détectée sur les composants en bois d’érable à sucre et de bouleau jaune protégés au moyen de l’une ou l’autre de ces deux méthodes.
