Caracterização físico, mecânica e de usinagem para compósitos MDF a base de fibras lignocelulosicas
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Data
2019-02-22
Autores
Bueno, Marcus Antonio Pereira
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Universidade Estadual Paulista (Unesp)
Resumo
O painel de fibras lignocelulósicas, constituído por fibras de madeiras como eucalipto e pinus, hoje em dia já é bastante utilizado na indústria moveleira, substituindo painéis de madeira serrada. Este trabalho foi desenvolvido com o objetivo de avaliar as potêncialidades da fibra de coco aos painéis de MDF (Médium Density Fiberboard) de eucalipto, afim de viabilizar sua utilização na indústria moveleira e construção civil. Para tanto, foram estudadas as propriedades físicas e mecânicas desse novo painel, segundo recomendação da NBR 15.316-2 (2015), e realizados ensaios de caracterização das fibras, ensaio de densitometria por raios-x para avaliar e caracterizar o perfil e densidade dos painéis; ensaio de micro tomografia para avaliar a estrutura e arranjo do painel a fim de verificar a densidade e entrelaçamento entre as duas fibras, espalhamento da resina e possíveis defeitos ocultos nos painéis, ensaio de usinagem para medir a potência consumida na operação de fresamento tangencial e medição da rugosidade média (Ra) e da rugosidade total (Rt). A densidade alvo ficou dentro da margem de 700 kg/m³, o que o define como painel de média densidade. Foram produzidos painéis contendo 5 traços diferentes, sendo o primeiro com 100% fibras de eucalipto (T1), o segundo 80% fibras de eucalipto e 20% fibras de coco (T2), o terceiro 60% fibras de eucalipto e 40% fibras de coco (T3), o quarto 40% fibras de eucalipto e 60% fibras de coco (T4) e o quinto traço (T5) denominado comercial foi adquirido no comercio de Bauru. A quantidade de adesivo utilizado a base de ureia formaldeído foi de 10% da massa total do material seco. Todos os resultados captados foram avaliados e os resultados das aquisições foram tratados estatisticamente para definir quais traços e adesões das fibras de coco e eucalipto se enquadram da padronização e normas vigentes para o MDF. Para os ensaios físicos a adição de fibras de coco piorou a qualidade do painel sendo que no geral o traço T4 foi o que obteve o pior resultado nos ensaios realizados. No ensaio mecânico de tração perpendicular houve uma melhora na qualidade do painel sendo T1 e T2 com 0,29 Mpa e T4 com 0,48Mpa, porem ao mesmo tempo no ensaio de flexão e módulo de elasticidade (MOR e MOE) houve uma piora significativa ao se acrescentar fibras de coco com T1 para MOE obtendo valor de 2958Mpa e T4 com 1290Mpa.
Lignocellulosic fiberboard, made up of wood fibers such as eucalyptus and pine, is now widely used in the furniture industry, replacing lumber panels. This work was developed with the objective of evaluating the potential of coconut fiber to eucalyptus MDF (Medium Density Fiberboard) panels, in order to enable its use in the furniture industry and civil construction. For this purpose, the physical and mechanical properties of this new panel were studied, according to the recommendation of NBR 15.316-2 (2015), and carrie out fiber characterization tests, X-ray densitometry test to evaluate and characterize the profile and density of the panels; micro tomography test to evaluate the structure and arrangement of the panel in order to verify the density and interlacing between the two fibers, resin scattering and possible hidden defects in the panels, machining test to measure the power consumed in the operation of tangential milling and measurement of mean roughness (Ra) and total roughness (Rt). The target density was within the range of 700 kg/m³, which defines it as a medium density panel. Panels were produced with 5 different traits, the first with 100% eucalyptus fibers (T1), the second 80% eucalyptus fibers and 20% coconut fibers (T2), the third 60% eucalyptus fibers and 40% coconut fibers (T3), the fourth 40% eucalyptus fibers and 60% coconut fibers (T4) and the fifth trace (T5) called commercial was acquired in Bauru's trade. The amount of adhesive used based on urea formaldehyde was 10% of the total mass of the dry material. All the results obtained were evaluated and the results of the acquisitions were statistically treated to define which traits and adhesions of the coconut and eucalyptus fibers fall within the standardization and current norms for MDF. For the physical tests, the addition of coconut fibers worsened the quality of the panel, and in general the trace T4 was the one that obtained the worst result in the tests performed. In the mechanical test of perpendicular tension there was an improvement in the quality of the panel being T1 and T2 with 0.29 MPa and T4 with 0.48 MPa, but at the same time in the test of flexion and modulus of elasticity (MOR and MOE) there was a significant worsening when adding coconut fibers with T1 for MOE, obtaining a value of 2958 MPa and T4 with 1290 MPa.
Lignocellulosic fiberboard, made up of wood fibers such as eucalyptus and pine, is now widely used in the furniture industry, replacing lumber panels. This work was developed with the objective of evaluating the potential of coconut fiber to eucalyptus MDF (Medium Density Fiberboard) panels, in order to enable its use in the furniture industry and civil construction. For this purpose, the physical and mechanical properties of this new panel were studied, according to the recommendation of NBR 15.316-2 (2015), and carrie out fiber characterization tests, X-ray densitometry test to evaluate and characterize the profile and density of the panels; micro tomography test to evaluate the structure and arrangement of the panel in order to verify the density and interlacing between the two fibers, resin scattering and possible hidden defects in the panels, machining test to measure the power consumed in the operation of tangential milling and measurement of mean roughness (Ra) and total roughness (Rt). The target density was within the range of 700 kg/m³, which defines it as a medium density panel. Panels were produced with 5 different traits, the first with 100% eucalyptus fibers (T1), the second 80% eucalyptus fibers and 20% coconut fibers (T2), the third 60% eucalyptus fibers and 40% coconut fibers (T3), the fourth 40% eucalyptus fibers and 60% coconut fibers (T4) and the fifth trace (T5) called commercial was acquired in Bauru's trade. The amount of adhesive used based on urea formaldehyde was 10% of the total mass of the dry material. All the results obtained were evaluated and the results of the acquisitions were statistically treated to define which traits and adhesions of the coconut and eucalyptus fibers fall within the standardization and current norms for MDF. For the physical tests, the addition of coconut fibers worsened the quality of the panel, and in general the trace T4 was the one that obtained the worst result in the tests performed. In the mechanical test of perpendicular tension there was an improvement in the quality of the panel being T1 and T2 with 0.29 MPa and T4 with 0.48 MPa, but at the same time in the test of flexion and modulus of elasticity (MOR and MOE) there was a significant worsening when adding coconut fibers with T1 for MOE, obtaining a value of 2958 MPa and T4 with 1290 MPa.
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Palavras-chave
Painéis de fibras, Fibra de coco, Resíduos agroindustriais, Microtomografia, Raio-X