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Authors
Abstract(s)
Os derivados de madeiras, em particular os aglomerados de fibras e de partículas, têm sofrido vários desenvolvimentos ao longo das últimas décadas, quer pela modificação da sua matéria-prima de base (utilização de diferentes espécies de madeira, inclusão de reciclados, etc.), quer pela modificação dos sistemas adesivos utilizadas (novas resinas e novos processos de síntese, novos catalisadores, incorporação de captadores de formaldeído), e mesmo pela alteração das suas propriedades físico-mecânicas (densidades, perfil de densidades, resistência interna, rigidez, etc.).
Os derivados de madeiras são utilizados, como matéria-prima, essencialmente em duas indústrias: construção e mobiliário. Se na primeira as propriedades físico-mecânicas, e principalmente a sua estabilidade dimensional, são o principal critério de avaliação de qualidade, na segunda os aspetos estéticos e de custo de maquinação são os mais importantes. A redução da atividade registada na indústria da construção obrigou os fabricantes de aglomerados de madeira a investir na indústria do mobiliário. Historicamente a indústria do mobiliário não tem explorado as potencialidades dos novos derivados de madeira (derivados de madeira com novas funcionalidades.
Os aspetos estéticos e o custo de maquinação, principais critérios pelos quais a indústria de mobiliário avalia os diferentes derivados de madeira, estão intimamente ligados com as condições de maquinação sejam elas o tipo de operação unitária, a geometria e dimensão dos elementos cortantes, a velocidade de processamento, etc.
O principal objetivo deste trabalho é estabelecer as bases que permitam a construção de um ábaco que permita aos utilizadores finais selecionar as condições de operação, em particular de corte, para um conjunto alargado de tipos de derivados de madeira em função da qualidade da aresta ou do custo da operação.
ABSTRACT: Wood-based panels, in particular fibreboards and particleboards have been suffered several developments in the last decades: modification of the raw-material (use of different wood species and recycled wood, etc.), modification of adhesive systems (new resins and new synthesis procedures of formaldehyde resins, incorporation of new catalysts and formaldehyde scavengers), as well as the modification of physico-mechanical properties (density, density profile, internal bond, stiffness, etc.). Wood-based panels are used as raw-materials, mostly in two industrial sectors: construction and furniture. In the first, the physico-mechanical properties and dimensional stability are the major requirements for quality evaluation, in the second one, the aesthetic appearance and the machining costs are the most important. The crisis on the construction sector drove the wood-based panels manufacture to invest in the furniture sector. Historically, the furniture sector has not been explored the capabilities of the new wood-based panels (wood-based panels with new functionalities). The aesthetic appearance machining costs of wood-based panels, the majors requirements of the furniture industry are closely linked to machining conditions, such as the type of processing operation, geometry and size of the cutting elements, processing rate, etc. The main objective of this work is to establish the bases for the build-up a machining conditions abacus, especially focused on sawing, that will permit the end users to select the best machining conditions to get either a given edge quality or a production cost for a large set of wood-based products.
ABSTRACT: Wood-based panels, in particular fibreboards and particleboards have been suffered several developments in the last decades: modification of the raw-material (use of different wood species and recycled wood, etc.), modification of adhesive systems (new resins and new synthesis procedures of formaldehyde resins, incorporation of new catalysts and formaldehyde scavengers), as well as the modification of physico-mechanical properties (density, density profile, internal bond, stiffness, etc.). Wood-based panels are used as raw-materials, mostly in two industrial sectors: construction and furniture. In the first, the physico-mechanical properties and dimensional stability are the major requirements for quality evaluation, in the second one, the aesthetic appearance and the machining costs are the most important. The crisis on the construction sector drove the wood-based panels manufacture to invest in the furniture sector. Historically, the furniture sector has not been explored the capabilities of the new wood-based panels (wood-based panels with new functionalities). The aesthetic appearance machining costs of wood-based panels, the majors requirements of the furniture industry are closely linked to machining conditions, such as the type of processing operation, geometry and size of the cutting elements, processing rate, etc. The main objective of this work is to establish the bases for the build-up a machining conditions abacus, especially focused on sawing, that will permit the end users to select the best machining conditions to get either a given edge quality or a production cost for a large set of wood-based products.
Description
Mestrado em Engenharia de Madeiras.
Keywords
MDF Aglomerado de partículas SuperpPan Maquinação Caracterização da aresta Total waviness Sensores piezoelétricos Parâmetros de maquinação Exigências de corte Molduradora de quatro faces
Citation
Publisher
Instituto Politécnico de Viseu. Escola Superior de Tecnologia e Gestão de Viseu