Browsing by Author "Vicente, José"
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- Liquefied wood as a partial substitute of melamine-urea-formaldehyde and urea-formaldehyde resinsPublication . Esteves, Bruno; Martins, João; Martins, Jorge; Cruz-Lopes, Luísa; Vicente, José; Domingos, IdalinaMaritime pine (Pinus pinaster) sawdust was used to produce liquefied wood by the polyhydric method with acid catalysis. The process was optimized to produce the highest amount of liquefied wood. Wood liquefied at 160ºC for 90 min was used in the adhesion tests. The bond strength of veneer glued with urea-formaldehyde and melamine-urea-formaldehyde resins and several mixtures of liquefied wood with urea- formaldehyde and melamine-urea-formaldehyde wasevaluated by automated bonding evaluation system. With the increase in liquefied wood content the bond strength decreased. Nevertheless for 20% liquefied wood the reduction of internal bond strength is relatively small and still within the minimum standards required. When 70% of liquefied wood is employed there is a significant decrease in bond strength. In conclusion it is possible to use a small amount of maritime pine sawdust liquefied wood as a partial substitute of urea-formaldehyde and melamine-urea-formaldehyde resins in the particleboard production, thus decreasing the formaldehyde content.
- State of the art of industrial wood protection in PortugalPublication . Nunes, Lina; Carmo, Júlia; Vicente, José; Esteves, BrunoThis work intended to give a perspective of industrial wood protection in Portugal. A survey was made of the companies treating wood mainly for use classes 3 and 4 such as autoclave treatments with biocides and wood modification procedures. Currently there are 23 companies with 33 production plants with an autoclave installed for wood preservation by impregnation. There are also two companies producing modified wood by thermal treatment. Most of the plants are located in the central and northern regions of Portugal. The leading preservation chemicals used in Portugal are Tanalith E and Celcure brands. The main wood species used in all companies is Pinus pinaster from local producers. The products commercialized by the treating companies are diverse: pre-fabricated houses, garden furniture and playgrounds, decks, poles, stakes, and sawn wood. Modified wood producers sell mostly decks and cladding. Considerable changes are expected in the next few years due to the requirements of European Directives and the typical constraints of the Portuguese market.