Radiation curable coatings are presently the standard in the wood flooring industry. Their great properties paired with their fast curing explain why they are now the most used coatings for prefinished wood flooring. Although important improvements can still be brought to these coatings. During the last years, nanoparticles have gained increasing interest in the paint and coatings industries. It could lead to similar results for the thermoset materials.
In this project, metal oxides (alumina, silica and zirconia) and clay nanoparticles were added in a typical UV acrylate formulation for wood flooring. This formulation was chosen mostly for its wear resistance, low yellowing and fast curing.
Nanoparticles were added in the acrylate formulation by different techniques (high speed mixing, ball milling, bead milling and three roll milling). Then, article size characterization was performed. Different techniques were employed according to the nanoparticles studied (metal oxides or clay). Microscopic experiments were also performed with an aim of supporting these results.
Then, nanoparticles and coupling agents addition effects on curing (speed and percentage of curing) were studied by photo-calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-FTIR).
Mechanical properties (hardness, adhesion, scratch resistance, wear resistance, direct and reverse impact resistance) were evaluated. Optical properties (color, gloss, haze and optical clarity) and thermal properties were also assessed.
For clay-based coatings, an analysis of variance (ANOVA) was performed in order to determine if clay loading and clay dispersion affect the mechanical and optical properties.
In wood products, such as parquetry, cabinetry and furniture, some of the performance criterions are related to moisture transfer between their different construction layers. Non homogenous moisture transfer usually results in the product’s deformation . Engineered Wood Parquet Flooring (EWPF) is an important case, which presents non homogenous moisture transfer due to its utilisation in service. Many types of varnish are available on the market. Physical properties of those varnishes such as hardness and abrasion resistance are readily available from the manufacturers. No data on water vapour diffusion is available, so this study is focused on this specific topic. Water vapour coefficient was determined for 6 commercial and industrial varnishes. These values will be used in further modelling work on EWPF.
In summer 2001 we ran one field experiment to test the feasibility of Sylvanex (formerly Cartapip 97) as a biocontrol agent to protect logs from being stained by wild-type bluestain fungi. Freshly felled lodgepole pine logs were spray-treated with Sylvanex, dispersed in water, or with water alone (referred to as non-treated). Sampling of the piles of logs took place after 6 weeks and again after 13 weeks. The bluestained area on discs taken from the logs was measured in the laboratory. The data clearly indicate that Sylvanex can control bluestain in freshly felled lodgepole pine logs if applied immediately after felling to the total log exterior. After six weeks of summer storage, when logs are most vulnerable, Sylvanex-treated logs remained almost spotless compared to heavily stained non-treated logs. After 13 weeks of storage there was moderate stain development in Sylvanex-treated logs but the amount was significantly less than in non-treated logs. The product, and the concept of using albino isolates to control stain, therefore has potential for industrial use. Before Sylvanex is used industrially on a large scale it is recommended that additional studies should investigate whether adjuvants, such as spreaders and stickers, or using higher concentrations of biocontrol agent improve its performance and consistency. In addition the efficacy of the product should be tested on other wood species.
Development of bluestain in logs prevents the Canadian forest industry from producing maximum-value products from a considerable portion of the resource every year. The major purpose of this project was to determine the practical and economic feasibility of using an albino stain of a common bluestain fungus Ophiostoma piliferum (Cartapip 97, recently renamed Sylvanex) or equivalent albino fungi to control sapstain in lodgepole pine logs. We also tested the Forintek's eastern laboratory integrated control technology (fungus Gliocladium roseum with alkali). Different activities were planned but as results developed some had to be modified or dropped and others added to the planned work. The various aspects of this work are described in the set of reports that are included in the appendices.
Stains - Fungal - Control - Tests
Pinus contorta Dougl. var. latifolia - Stains - Fungal
The project initially focussed on harvester transmission of staining fungi and insect transmission to logs in the forest and sawmill yard. Both harvesters and insects were confirmed to be major sources of bluestain infection. This work emphasized the importance of insect control measures in mill yards and a new project on mitigating harvester-related bluestain was recommended. Other related projects targeted potential control measures, such as sour-felling (crown drying) to reduce nutrients and moisture, biological control using albino fungi, and inventory control. Biocontrol work continued to be done under this project in 2005. We have assisted with the registration of a biocontrol agent and also examined the feasibility of developing a prototype harvester applicator system in collaboration with UBC mechanical engineering students. This spawned a separate project that looks into development of a spray applicator system on a commercial scale. In February 2004 and August 2005 we examined sources of bluestain in sawmills, such as air, sawdust and machinery. This work showed machinery as a possible mechanism for spreading bluestain from one piece of lumber to another during the milling. As each piece of work was completed, further data gaps were identified.
A concept for an outdoor test facility in Vancouver for building enclosure materials and components has been under study by Forintek and others since Fall 2000. Phase One - a preliminary feasibility study - was previously completed. This report describes accomplishments to date of Phase Two, a transition phase involving identification of a project custodian, further concept development, development of a business plan, preparation for fundraising and identification of potential sites.
Thermal treatments to improve the dimensional stability and durability of wood for exterior applications impart a pleasant dark brown colour but this rapidly fades to gray when exposed to weathering. A coating may solve this problem but adhesion to oil-thermal-treated wood may be an issue. The general objective of this research is to investigate the feasibility of coating oil-thermal-treated post-Mountain Pine Beetle (MPB) lodgepole pine for above-ground residential products such as siding. This is a continuation of previous research in 2006/07 on treating post-MPB lodgepole pine sapwood with oil-thermal treatment, also funded by FII. The current project focuses on surface modification and coating systems evaluation for this treated pine by laboratory tests, and initiating field tests for monitoring long-term coatings performance.
The project was carried out in collaboration with Dr. Paul Cooper of the University of Toronto, Dr. Phil Evans of the University of British Columbia, and Dr. Sam Williams of the Forest Products Laboratory of USDA. Based on the study carried out by FPInnovations–Forintek Division, Sikkens Cetol 123 and SuperNatural showed good adhesion on oil-thermal-treated pine, but the appearance of SuperNatural was preferable for the targeted applications. Hence, SuperNatural was selected for a long-term field test in Vancouver.
Based on the study undertaken by FPL, an aluminum isopropoxide sol-gel precursor was able to improve surface adhesion of the oil-thermal-treated wood for a water-borne finish, but did not improve the adhesion for solvent-borne finishes. The oil-thermal treatment did not appear to appreciably change the hardness or Young’s modulus of the wood based on the nano-indentation measurements. It was also found that the oil-thermal-treated wood could be easily treated with hydroxymethylated resorcinol (HMR), a coupling agent for coating. Its efficacy on coatings performance is being evaluated using an outdoor exposure test.
Based on the University of Toronto’s study, the oil-thermal treatment reduced the wettability of the wood to a number of solvents and had an adverse effect on coating curing and adhesion. Light sanding improved the wetting and resulted in improved adhesion. Among all the finishes evaluated, SuperNatural clear finish formed a hard coat with good adhesion.
The study by the University of British Columbia found that plasma treatment is able to remove oil from the surface of oil-thermal-treated pine, and increased its wettability as well as adhesion to coatings. Scanning electron microscopy, confocal profileometry, and Fourier transform infra-red spectroscopy also indicated that high-energy plasma treatment impacted wood structures, particularly around pits. The consequence of the plasma treatment on coatings performance is being studied with a weathering test.
Overall, the study showed that oil-thermal-treated blue-stained pine can be coated to improve weathering performance for exterior above-ground applications. It confirmed that sanding can improve the coatings performance. The effects of a coupling agent and plasma treatment on coatings performance are to be reported. Thermal modifications may provide a promising way to improve dimensional stability and also mask blue stain for post-MPB lodgepole pine. However, the potential bleeding of oil from wood with initially intense blue stain poses a major challenge for coating application and for developing residential appearance products from the post-MPB lodgepole pine using such an oil-thermal treatment. In that case, alternative thermal treatment processes, particularly using steam as the heating medium, could be considered.
This report summarises those issues embodied in building codes and product standards with implications for marketing solid wood siding in Canada and selected other countries. The intention is that technical knowledge gaps can be identified and possibly filled before marketing white spruce siding. Literature searches were done and personal contacts with experts in these countries were made in order to place siding in the context of international codes and standards. However database searches identified only a few documents related to the performance requirements of solid wood cladding products. These issues are discussed under three main headings: material and construction, fire resistance and durability, and weather protection. Apart from fire there is very little reference to solid wood siding in either North American or international building codes. It appears that the long use of the product has effectively been grandfathered in traditional siding application and use. This is, however, not the case for non-solid wood siding where a number of material-specific standards exist which ensure that the products have comparable performance to traditional products or to address performance deficiencies that are specific to that material. Wood siding use in new markets will not be grandfathered in, and there will probably be a need to develop standards and data similar to those for non-wood products.