Navegando por Assunto "Coconut fiber"

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Acesso aberto (Open Access)
Comportamento mecânico e de flamabilidade de compósito de polipropileno reclicado com fibra de coco e hidróxido de alumínio
(Universidade Federal do Pará, 2006-05-02) SILVA, Vera Lúcia Dias da; DIAS, Carmen Gilda Barroso Tavares; http://lattes.cnpq.br/2113791118142177
The plastic recycling has been an interesting possibility to minimize the destiny problem of the plastic residues. The polypropylene (PP) is enters the types polymers of larger consumption, therefore the utilization of this material has been enabling the studies development of great scientific and social relevance. This polymer presents excellent cost-performance relation, besides can be easily conformed and to exibit mechanical properties that turns it useful in several applications. However, this material when being burnt generates products that act as combustible so that, for some uses, flame resistance good is necessary. This can be gotten by flame retardant addition, that has the intention to increase the resistance of this material to the ignition and, at the same time reducing the propagation speed of the flame. The aluminium hydroxide, or simply alumina hydrate, is the flame retardant agent used most in the market, therefore it also acts as smoke suppressant and it does not liberate toxic gases during the burning. However, for such properties, high alumina hydrate concentrations are necessary. This causes deterioration in the physical properties of the materials for not have reinforcing character. The natural fibres own good reinforcement capacity when combined adequately with polymers. Also presenting advantages as low cost, low density, biodegradability and in the combustion does not emanate toxic gases. In this work, mixtures contend alumina hydrate and coco fibres had been incorporated polypropylene with the objective of if finding an properties rocking adequate for use of this composite with characteristics flame resistance and mechanical performance. The composites were molded by hot compression and characterized by IV, DRX, MEV, mechanical and non-flammability tests. Increase in the elasticity modulus of the composites in general was observed, as well as increase in the tenacity resistance of the PP/coco fiber composite regarding pure PP. The results had indicated the efficiency of alumina hydrate as it flame retardant, in all the composites, except PP/F, classifying the materials as V-0 according to international norm UL 94V.
Acesso aberto (Open Access)
Desenvolvimento de painéis confeccionados a partir de fibras de coco para controle acústico de recintos
(Universidade Federal do Pará, 2008-10-31) VIEIRA, Rodrigo José de Andrade; SOEIRO, Newton Sure; http://lattes.cnpq.br/7303174583088137
A reasonable alternative for noise control in enclosures is based on the use of sound absorption materials (porous and fibrous), which convert acoustic energy into heat, due to air viscosity. The material acoustic absorption characteristic is determined by its sound absorption coefficient, which depends mainly on frequency, sound incidence angle, density, thickness and internal structure of the material. From the Amazon, due to its enormous biodiversity, thousands of natural products and sub products are retrieved, some of which are not completely used. Thus, many residues reach other industrial sectors, such is the case of the coconut fiber, which can be used in many ways. Therefore, the present work defines and describes an acoustic panel manufacturing process, based on coconut fiber, including the experimental determination of important parameters for noise control in enclosures. Also, a numerical model is implemented to investigate cost and quality control parameters, in order to assist the development and manufacturing of new panels. First, the necessary information is collected to start the development process of coconut fiber panels, following an “informational project” methodology. Next, all the steps related to the panel manufacturing process are described, looking forward to obtaining its acoustical, mechanical and physical-chemical main properties. From the numerical simulations, one tries to analyze and predict the coconut fiber panel behavior (apart from a commercially available acoustical panel), and investigate its influence over the acoustical parameters of an auditorium (reverberation time, sound pressure decay, and intelligibility). With the development of the coconut fiber panels, one expects to contribute for the creation of new sectors on the local economy, mainly considering the elevated costs of the actual acoustical panels available in the market. Finally, another outstanding advantage of the coconut fiber panels proposed here is the possibility of its usage in the context of regional architecture, where emphasis is given on local materials.