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Sankt Veit an der Glan, Austria

Gonzalez-Garcia S.,University of Santiago de Compostela | Feijoo G.,University of Santiago de Compostela | Heathcote C.,Carinthian Competence Center | Kandelbauer A.,Carinthian Competence Center | Moreira M.T.,University of Santiago de Compostela
Journal of Cleaner Production

European consumption of wood-based panels reached record levels in recent years driven mostly by demand from end-use sectors: residential construction, furniture, cabinets, flooring and mouldings. The main panel types are composite boards such as particleboard, high density fiberboard (HDF), medium-density fiberboard (MDF) and other adhesively bonded composites such as plywood and wet-process fiberboard (hardboard). The synthetic resins used in their manufacture come from non-renewable resources, such as oil and gas. Several consequences are associated to this type of adhesives: variation in the availability and cost of these wood adhesives depends on raw materials, the formaldehyde emissions as well as the limited recyclability of the final product. Hence, in the search for alternatives to petroleum-based wood adhesives, efforts are being devoted to develop adhesives by using phenolic substitutes based on lignin, tannin or starch. In this context, the forest industry is increasingly approaching to enzyme technology in the search of solutions. The main goal of this study was to assess the environmental impacts during the life cycle of a new process for the manufacture of hardboards manufacture, considering the use of a two-component bio-adhesive formulated with a wood-based phenolic material and a phenol-oxidizing enzyme. This new product was compared to the one manufactured with the conventional phenol-formaldehyde resin. The study covers the life cycle of green hardboards production from a cradle-to-gate perspective, analysing in detail the hardboard plant and dividing the process chain in three subsystems: Fibers Preparation, Board Forming and Board Finishing. Auxiliary activities such as chemicals, bio-adhesive, wood chips, thermal energy and electricity production and transport were included within the system boundaries. Global warming (GW), photochemical oxidant formation (PO), acidification (AC) and eutrophication (EP) were the impact categories analysed in this study. Additionally, the cumulative energy demand was evaluated as another impact category. According to the results, four stages significantly influenced the environmental burdens of the production system: laccase production, on-site thermal energy and electricity production as well as wood chipping stage. Due to the environmental impact associated to the production of green bonding agents, a sensitivity analysis with special focus on the eutrophying emissions was carried out by evaluating the amount of laccase and lignin based phenolic material used. The combined reduction in both bonding agents may slightly reduce the contributions to this impact category. In addition, a hypothetical scenario with no laccase and with a higher concentration of the lignin based material (25% more) could improve the environmental profile in all impact categories with a reduction of 1.5% in EP. Further research should focus mainly on laccase production, in order to reduce its energy demand as well as on the amount of green adhesive required to obtain mechanical and swelling properties similar to those of conventional hardboard. © 2010 Elsevier B.V. All rights reserved. Source

Badila M.,Carinthian Competence Center | Jocham C.,Carinthian Competence Center | Zhang W.,Zhejiang Agriculture And forestry University | Schmidt T.,TIGER Coatings GmbH and Co. KG | And 4 more authors.
Progress in Organic Coatings

The powder coating of veneered particle boards by the sequence electrostatic powder application - powder curing via hot pressing is studied in order to create high gloss surfaces. To obtain an appealing aspect, veneer sheets were glued by heat and pressure on top of particle boards and the resulting surfaces were used as carrier substrates for powder coat finishing. Prior to the powder coating, the veneered particle board surfaces were pre-treated by sanding to obtain good uniformity and the boards were stored in a climate chamber at controlled temperature and humidity conditions to adjust an appropriate electrical surface resistance. Characterization of surface texture was done by 3D microscopy. The surface electrical resistance was measured for the six veneers before and after their application on the particle board surface. A transparent powder top-coat was applied electrostatically onto the veneered particle board surface. Curing of the powder was done using a heated press at 130 °C for 8 min and a smooth, glossy coating was obtained on the veneered surfaces. By applying different amounts of powder the coating thickness could be varied and the optimum amount of powder was determined for each veneer type. © 2014 Elsevier B.V. Source

Badila M.,Carinthian Competence Center | Dolezel-Horwath E.,Carinthian Competence Center | Zikulnig-Rusch E.M.,Carinthian Competence Center | Schmidt T.,Tiger Coatings GmbH | And 2 more authors.
European Journal of Wood and Wood Products

Surface coated wood-based panels play a major role in the forest products industry as materials for construction and furniture elements in numerous interior and exterior applications. Their most important feature besides appropriate mechanical performance and chemical durability is an appealing visual appearance. In this contribution, recent research on the compatibility between two UV-curable inks and different melamine formaldehyde based surface films is presented. The surface texture properties of the printing substrates were investigated by roughness measurements. Substrate surface free energy was measured by contact angle measurements using three different testing liquids covering a wide range of polarities (glycerol, ethylene glycol and diiodomethane). The physical shape of the inkjet ink drops which were placed on the LPM printing substrates was monitored and recorded over time and used as an indicator for the wetting behavior of the tested inks and hence the printability. By combining contact angle and pendant drop measurements the surface tension of the inks was determined. The theoretical findings were confirmed by technological printing tests. To this end, as a hands-on method to establish inksubstrate wetting and compatibility flow coating tests were run and the most suitable ink was selected for printing. The printing results were closely related to the surface properties of the printing substrates. © Springer-Verlag 2012. Source

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