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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Evaluation of Corn Distiller’s Dried Grains with Solubles as a Functional Material to Replace Synthetic Resin in Wood Particleboards

Liaw, Joshua Dong Xiong January 2019 (has links)
Corn distiller’s dried grains with solubles (DDGS) is mostly marketed as a livestock feed due to its high protein content of 30%. Recently, the proteins in DDGS have shown potential to act as binding agents along with melamine-urea-formaldehyde resin. However, it is unknown if DDGS can be chemically functionalized as a natural binder to replace synthetic resin in particleboard. In this study, several formulations were tested using various concentrations of acetic acid and sodium hydroxide treatments with combinations of temperature, DDGS concentrations, particle sizes, and wax. FTIR results indicated that DDGS proteins were decoupled through acid or alkali treatments, and acid treated DDGS in particleboards displayed higher improvements in internal bond strength as well as the moisture resistance of the particleboards. These results suggest that acid or alkali treated DDGS has potential to act as a natural binder for manufacturing medium-density particleboard.
12

Analysis of Calcutta bamboo for structural composite materials

Ahmad, Mansur 23 August 2000 (has links)
Land use issues have dramatically changed the timber supply outlook for our nation's forest products industry. Since demand for wood products shows no sign of abating, alternative products must be developed. Bamboo is a very promising alternative raw material for the manufacture of structural composite products. It is fast growing, economical, renewable and abundant throughout the world. Bamboo has physical and mechanical properties that are comparable to many commercial timber species, and thus, may easily be processed using existing technology from the wood-based composites industry. Bamboo can be cultivated in the U.S., and thus has the potential to relieve some of the harvesting pressure from our nation's forestlands. However, the use of specific bamboo species for structural composite products will require a thorough investigation of the material as well as its interaction with other components. Thus, the primary objective of this dissertation is to determine the properties of Calcutta bamboo and its interaction with adhesives. The properties investigated were relative density, dimensional stability, equilibrium moisture content, bending strength and stiffness, tensile strength, pH, buffer capacity, wettability and the adhesive penetration. In addition to this, a prototype bamboo parallel strip lumber (BPSL) was manufactured and tested for its physical and mechanical properties. The relationships among the properties of Calcutta bamboo and the prototype bamboo composite were also investigated. As the result of these investigations, it is concluded that Calcutta bamboo is technically a suitable raw material for structural composite products. This result may also be applicable for the utilization of other bamboo species, thus aiding companies in decisions regarding investment in bamboo plantations and manufacturing facilities in the U.S, Malaysia and other parts of the world. The primary benefits from this research may be the development of new products to serve growing markets, and thereby relieving some of the pressure to harvest forestlands. / Ph. D.
13

Improvement of Oil Palm Wood Properties Using Bioresin / Verbesserung der Eigenschaften des Ölpalmenholzes durch Einsatz von Naturharz

Erwinsyah, Erwinsyah 27 May 2008 (has links) (PDF)
Die ausWestafrika stammende Ölpalme (Elaeis guineensis Jacq) ist zur populärsten Kulturpflanze in Südostasien geworden. Als Haupterzeugnisse dieser Pflanze gelten die Öle der Früchte und der Fruchtkerne. Die weltweite Nachfrage nach diesen beiden Haupterzeugnissen nimmt sehr rasch zu. Ursache hierfür ist die breite Anwendungspalette dieser Pflanzenöle, wie z.B. Bratöl, ölbasierte Chemikalien und ölbasierte Nahrungsmittel, Kosmetika, Waschmittel, Biobrennstoff usw. Indonesien und Malaysia sind die Hauptproduzenten und Hauptlieferanten solcher Produkte und decken über 85% des weltweiten Bedarfs. Mit Extensivierung der Ölpalmplantagen sehen sich die Erzeugerländer zunehmend mit ernstzunehmenden Umweltprobleme konfrontiert, da nach Erreichen der wirtschaftlichen Lebenspanne (Umtriebszeit) von 25 Jahren große Mengen an festen, biologischen Abfallstoffe bei der Neubegründung der Bestände anfallen. So sollen z.B. im Jahre 2010 laut Vorhersagen mehr als 20 Mill. Kubikmeter Ölpalmen- Holz jährlich anfallen... / Oil palm (Elaeis guineensis Jacq) becomes the most popular crop, especially in Southeast Asia, than its origin,West Africa. World demand of two main products from this crop (e.g. crude palm oil and palm kernel oil) increases very rapidly, due to very wide ranges use of these vegetable oils for industrial purposes, such as fried oil, oleo-chemical and -food, cosmetics, detergent, biofuel and etc. Indonesia and Malaysia are the main producers and supplying more than 85% of world consumption. On the other hand, due to the economic life span of this popular crop (25 years), the producer countries have been facing a serious environmental problems concerning to the solid biowaste handling of oil palm industry, particularly the oil palm trunk after replanting activity. Starting 2010, it is predicted that more than 20 millions cubic meter biomass from oil palm trunk available annually...
14

Desenvolvimento de compósitos utilizando lodo da indústria têxtil na produção de concreto não estrutural.

ALTIDIS, Marina Elizabeth Dias. 02 February 2018 (has links)
Submitted by Gustavo Nascimento (gustavo.diniz@ufcg.edu.br) on 2018-02-02T13:11:21Z No. of bitstreams: 1 MARINA ELIZABETH DIAS ALTIDIS - TESE PPGCEMAT 2014.pdf: 3254058 bytes, checksum: a79dcea655b13895244c80449cb4813d (MD5) / Made available in DSpace on 2018-02-02T13:11:21Z (GMT). No. of bitstreams: 1 MARINA ELIZABETH DIAS ALTIDIS - TESE PPGCEMAT 2014.pdf: 3254058 bytes, checksum: a79dcea655b13895244c80449cb4813d (MD5) Previous issue date: 2014-08-29 / O interesse pela utilização de resíduos industriais, tais como lodo tem crescido como alternativa tanto na redução do volume desse passivo ambiental quanto na obtenção de um produto a ser utilizado na construção civil. Este trabalho tem como objetivo desenvolver e avaliar as propriedades físico-mecânicas de concretos formados a partir do uso de lodo da indústria têxtil, visando sua aplicação na construção civil. O lodo têxtil foi seco em estufa a 110ºC por vinte e quatro horas e triturado em moinho para adquirir granulometria adequada e em seguida submetido às seguintes análises: termogravimetria, análise térmica diferencial, espectroscopia vibracional de absorção no infravermelho, difração de raios-X, análise química, lixiviação, solubilização e microscopia óptica. Foram confeccionados corpos de prova de concreto utilizando os traços 1:3 e 1:4 com teores de substituição de 0 %, 3 %, 5 % e 7 % de lodo no agregado miúdo, com 7, 28 e 60 dias de cura e realizaram-se os seguintes ensaios: abatimento do tronco do cone, de resistência à compressão axial, resistência à compressão diametral, absorção, índice de vazios, massa especifica, microscopia óptica, microscopia eletrônica de varredura, lixiviação e solubilização. Os resultados das caracterizações do lodo têxtil apresentaram a compatibilidade química e estabilidade térmica suficiente para sua incorporação no concreto, entretanto verificou um alto teor de matéria orgânica. Já o ensaio de lixiviação classificou o lodo têxtil como resíduo perigoso, devido o extrato lixiviado ultrapassar o limite para os metais ferro e manganês. Já nos corpos de provas os ensaios de lixiviação e solubilização mostraram que os metais encontram-se encapsulados no concreto com teores de até 7 % de lodo têxtil. Nas microscopias realizadas nos corpos de provas de concretos, verificou-se a pouca interação do lodo com os constituintes do concreto. Já a absorção de água apresentou uma tendência de aumento, quando cresceu a quantidade de lodo têxtil, mas os valores ficaram abaixo de 10 %, podendo ser considerado de boa qualidade. No que se refere aos resultados de resistência à compressão ocorreu uma diminuição desta com o teor de lodo têxtil. No traço 1:3 com teores de até 7 % de lodo e no traço 1:4 com até 5 % de lodo o concreto foi considerado moderado, e para o traço 1:4 com 7 % de lodo foi classificado como concreto não estrutural. / Interesting in the use of industrial waste, such as sludge has grown both as an alternative in reducing the volume of this environmental liability as in getting a product to be used in civil building. This work aims to develop and evaluate physical and mechanical properties of concrete formed from the use of textile industry sludge, for its application in civil building. The textile sludge was dried at 110°C for twenty-four hours and milled in a grinder to get proper particle size and then subjected to the following tests: thermogravimetry, differential thermal analysis, vibrational infrared absorption spectroscopy, X-ray diffraction,chemical analysis, leaching, solubilization and optical microscopy. Concrete specimens were fabricated using the ratios 1:3 and 1:4 under levels of sludge substitution of 0 %, 3 %, 5 % and 7 % in the small aggregate, with7, 28 and 60 days of curing and performed the following tests: cone trunk reduction, compressive strength, tensile splitting strength, absorption, void ratio, specific gravity, optical microscopy, scanning electron microscopy, and leaching. The results of the textile sludgecharacterizations showed the chemical compatibility and thermal stability sufficient for its incorporation in concrete, however it was found a high content of organic matter. Again, leaching test rated the textile sludge dangerousand, because the extract leaching exceed the limit for the metals iron and manganese. The sample tests regarding solubilizatio and leaching tests showed that metals are encapsulated in concrete with levels of up to 7 % of textile sludge. In microscopy performed on test samples of concrete, there was a little interaction with the sludge constituents of the concrete. The water absorption presented increase trend when increased the amount of textile sludge, but the values were below 10 % and can be considered good quality. Regarding theresults of compressive strength occurred decrease relatedto the textile sludge content. On the ratio 1:3, with sludge levels up to 7 %, and the ratio 1: 4 up to 5 % of suldge level, the the concrete was considered moderate, and the ratio 1:4 up to 7 % of sludge, the concrete was classified as non structural.
15

Utilização de resíduos da espécie Dipteryx polyphylla (Cumarurana), Dipteryx odorata (Cumaru) e Brosimum parinarioides (Amapá) na produção de painéis de madeira aglomerada com resina poliuretana à base de óleo da mamona

Lima, Mirian Dayse Furtado 06 July 2012 (has links)
Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-09-30T15:30:42Z No. of bitstreams: 1 Dissertação - Mirian Dayse Furtado Lima.pdf: 14927258 bytes, checksum: c5d6ad1eae22a73a98998965f51d8c8b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-30T19:27:42Z (GMT) No. of bitstreams: 1 Dissertação - Mirian Dayse Furtado Lima.pdf: 14927258 bytes, checksum: c5d6ad1eae22a73a98998965f51d8c8b (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-09-30T19:36:38Z (GMT) No. of bitstreams: 1 Dissertação - Mirian Dayse Furtado Lima.pdf: 14927258 bytes, checksum: c5d6ad1eae22a73a98998965f51d8c8b (MD5) / Made available in DSpace on 2015-09-30T19:36:38Z (GMT). No. of bitstreams: 1 Dissertação - Mirian Dayse Furtado Lima.pdf: 14927258 bytes, checksum: c5d6ad1eae22a73a98998965f51d8c8b (MD5) Previous issue date: 2012-07-06 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The wood processing industries use generates a timber of about 40% of the total volume of the processed timber, and the remainder in other words 60% are used in boilers and brickworks for a power generation, especially in some areas of North. However, the burning of waste wood there generating other residue, ash, whose destination is a landfill. This paper presents a study on the potential use of three types of tropical wood waste, Cumarurana (Dipteryx polyphylla), Cumaru (Dipteryx odorata) and Amapá (Brosimum parinariensis), the production of particleboard, using polyurethane resin based on castor oil as a binder. There was a chemical and physical characterization of the waste based on TAPPI standard. In the first stage waste Cumarurana panels (1000 and 1300 g) were produced by keeping the resin content 15%. The mechanical results of these panels were below the requirements of the NBR ABNT 14810-2 (2006). In the second stage panels Cumaru and Amapá were produced according to a factorial design, in different conditions of amount of residue (1000 to 1500g) and content of resin (10-15%) and these were characterized by tests based on the physical and mechanical standard NBR ABNT 14810-3 (2006). For panels Cumaru, the factorial design showed that the waste is a significant factor (95% confidence) at its maximum level (1500g) to increase the compaction ratio. Mechanical analysis (MOR, MOE and Face Screw) showed that both the residue and the resin are significant factors in the levels studied indicating that higher values are obtained at higher levels (1500 g, 15%). For all these tests the values obtained in 1500 g of panels are in accordance with normative standards. For the panels with waste Amapá by the experimental design, it was observed that the residue and the resin are significant factors, when the response variable and MOE and MOR, indicating that the best results are obtained using mechanical greater amount of waste. However, only the results of MOR for panels 1300 and 1500 g a 15% were above of the normative requirements. The internal adhesion tests were within the normative standards for both panels Cumaru and Amapá. / O processamento da madeira em indústrias madeireiras gera um aproveitamento de cerca de 40% do volume total das toras processadas, sendo que o restante, ou seja, 60% são utilizados em caldeiras e olarias para a geração de energia elétrica, principalmente em alguns locais da região Norte. No entanto, com a queima desses resíduos de madeira há a geração de outro resíduo, as cinzas, cuja destinação é o aterro. Este trabalho apresenta um estudo sobre o potencial uso de três tipos de resíduos de madeiras tropicais, Cumarurana (dipteryx polyphylla), Cumaru (Dipteryx odorata) e Amapá (Brosimum parinariensis), na produção de painéis aglomerados, utilizando resina poliuretana à base de óleo de mamona, como aglomerante. Fez-se a caracterização química e física dos resíduos baseadas na norma TAPPI. Na primeira etapa, painéis com resíduos de Cumarurana (1000 e 1300 g) foram produzidos mantendo o teor de resina em 15 %. Os resultados mecânicos desses painéis foram abaixo dos requisitos exigidos pela Norma NBR ABNT 14810-2 (2006). Na segunda etapa os painéis de Cumaru e Amapá foram produzidos seguindo planejamento fatorial, em diferentes condições de quantidade de resíduo (1000 a 1500g) e teor de resina (10 a 15%) e estes foram caracterizados através de ensaios físicos e mecânicos baseados na norma NBR ABNT 14810- 3 (2006). Para os painéis de Cumaru, o planejamento fatorial mostrou que o resíduo é um fator significante (95% confiança) no seu nível máximo (1500g) para aumentar a razão de compactação. Análises mecânicas (MOR, MOE e Arrancamento de Parafuso na Face) mostraram que tanto o resíduo quanto a resina são fatores significativos nos níveis estudados, indicando que maiores valores são obtidos em níveis mais altos (1500 g e 15%). Para todos esses ensaios os valores obtidos em painéis de 1500 g estão de acordo com os padrões normativos. Para os painéis com resíduo de Amapá, através do planejamento experimental, observou-se que o resíduo e resina são fatores significativos, quando a variável resposta é MOR e MOE, indicando que melhores resultados mecânicos são obtidos utilizando maior quantidade de resíduo. Porém, apenas os resultados de MOR, para painéis a 1300 g e 1500 g a 15% apresentaram-se acima dos requisitos normativos. Os testes de adesão interna apresentaram-se dentro dos padrões normativos, tanto para painéis de Cumaru quanto para Amapá.
16

Contribution des fibres de polypropylène et métalliques à l'amélioration du comportement du béton soumis à une température élevée / Contribution of polypropylene and steel fibres in improving the behaviour of concrete subjected to high temperature

Pliya, Bidossessi amen prosper 29 November 2010 (has links)
Le but de ce travail de recherche est d'étudier l'effet de fibres de polypropylène et de fibres métalliques sur le comportement du béton soumis à une température élevée. D'une part, les fibres de polypropylène ont été ajoutées au béton pour améliorer sa stabilité thermique, et d'autre part les fibres métalliques ont été ajoutées au béton pour améliorer ses propriétés mécaniques résiduelles. De nouvelles formulations de béton ont ensuite été définies, en utilisant un cocktail de fibres de polypropylène et métalliques, afin d'améliorer à la fois la stabilité thermique et les propriétés mécaniques résiduelles du béton. Quatre familles de bétons ont été étudiées : - bétons témoins sans fibres, - bétons contenant des fibres de polypropylène, - bétons contenant des fibres métalliques, et – bétons contenant un cocktail de fibres de polypropylène et métalliques. Trois rapports eau/ciment sont utilisés : 0.30, 0.45 et 0.61. Les éprouvettes de béton, issues de ces compositions, ont été soumises à des cycles de chauffage – refroidissement de la température ambiante à une température de consigne de 150°C, 300°C, 450°C et 600 °C. La vitesse de chauffage a été fixée à 1 °C.min-1. Les teneurs en fibres étaient de 0.11, 0.17 ou 0.22 % en proportion volumique pour les fibres de polypropylène et de 0.25, 0.38 ou 0.51 % pour les fibres métalliques. Les proportions volumiques de cocktail de fibres étaient de 0.49, 0.60, 0.62 et 0.73%. La stabilité thermique, les propriétés mécaniques (résistance en compression, résistance en traction, module d'élasticité), la porosité initiale et résiduelle des bétons formulés ont été analysées. La perte de masse des éprouvettes lors des différents chauffages a été aussi mesurée.Cette étude expérimentale aboutit à la formulation de bétons dont à la fois la stabilité à haute température et le comportement mécanique après refroidissement sont améliorés. / The aim of this study was to investigate the effect of polypropylene and steel fibres on the behaviour of concrete subjected to high temperature. Polypropylene fibres were added to the studied concrete mixes in order to improve the concrete thermal stability. Steel fibres were added to the studied concrete mixes in order to improve the concrete residual mechanical properties. News concretes mixes were then designed by adding a cocktail of polypropylene fibres and steel fibres in order to improve both the thermal stability and the residual mechanical properties of the studied concrete. Four groups of concrete mixes were studied: - concretes without fibres, - concretes with polypropylene fibres, - concretes with steel fibres, and - concretes with a cocktail of polypropylene and steel fibres. Three water/cement ratios were used: 0.30, 0.45 and 0.61. The concrete specimens were subjected to various heating – cooling cycles from the room temperature to 150°C, 300°C, 450°C and 600 °C. The heating rate was fixed at 1 °C.min-1. The amounts of fibres in the concrete were 0.11%, 0.17% or 0.22% in volume for polypropylene fibres and 0.25%, 0.38% or 0.51% in volume for steel fibres. The amounts of fibres in concrete with a cocktail of polypropylene and steel fibres were 0.49, 0.60, 0.62 and 0.73%, in volume. The thermal stability, the initial and residual mechanical properties (compressive strength, tensile strength, modulus of elasticity), the porosity and the mass loss of the studied concrete mixes were investigated.This experimental study shows a way to design a concrete mix in order to improve both the thermal stability and the residual mechanical properties.
17

Painéis de alta densidade para aplicação em pisos: produção e avaliação de desempenho / High density panels for application in floors: production and performance evaluation

Varanda, Luciano Donizeti 12 September 2016 (has links)
Temas relacionados ao desenvolvimento de novos materiais têm sido cada vez mais abordados e discutidos, num contexto em que questões como meio ambiente, sociedade, economia de energia e aproveitamento de resíduos, vêm se tornando relevantes. Neste cenário, faz-se necessário estudar aplicações de insumos alternativos na produção de pisos de madeira, tanto para reduzir o consumo de essências tropicais quanto para suprir o aumento da demanda de madeira nas indústrias deste segmento. O objetivo deste estudo foi produzir painéis de partículas homogêneos de alta densidade, com resíduos de madeira de Pinus elliottii e casca de aveia (Avena sativa), aderidos sob pressão com dois tipos de adesivo, poliuretano à base de óleo de mamona e melamina formaldeído, nos percentuais de 11 e 13%, e avaliar o desempenho físico-mecânico de tais painéis para aplicação em pisos. O desempenho físico-mecânico dos painéis (Planejamento I - 20 tratamentos) foi avaliado com base nas normas ABNT NBR 14810 (2006 e 2013). Realizou-se análise de variância (ANOVA) para testar a influência dos fatores individuais (percentual de casca de aveia, percentual de adesivo e tipo de adesivo), além das interações entre tais fatores (dois a dois e três a três) nas propriedades físico-mecânicas dos painéis. Também foi avaliado o desempenho para pisos, tanto dos painéis (Planejamento II - 12 tratamentos) quanto de três espécies de madeira tropical (Angelim Vermelho, Dinizia excelsa; Cumaru, Dipteryx odorata e Jatobá, Hymenaea sp.), segundo diversas normas relacionadas a pisos de madeira. Os resultados apontaram propriedades físico-mecânicas dos painéis, em alguns tratamentos superiores aos requisitos estipulados por normas nacionais e internacionais. Quanto ao desempenho para pisos, os painéis apresentaram desempenho semelhante as três espécies de madeira, na maioria das propriedades avaliadas. A análise de porosimetria por intrusão de mercúrio confirmou a similaridade entre os painéis (do Planejamento II) e as três espécies de madeira avaliadas, evidenciando a potencialidade dos painéis produzidos para aplicação na indústria de pisos engenheirados. / Matters related to the development of new materials have been increasingly addressed and discussed in a context where issues such as the environment, society, energy and waste recovery economy, is becoming relevant. In this scenario, it is necessary to study alternative inputs for applications in the production of wood floors, both to reduce the consumption of tropical essences as to meet the increasing demand for wood in industries in this segment. The aim this study was to produce high density homogeneous particleboard with waste wood of Pinus elliottii and oat hulls (Avena sativa), adhered under pressure with two types of adhesive, castor oil-based polyurethane and melamine formaldehyde, the percentage of 11 and 13%, and evaluate the physical and mechanical performance of such panels for use in floors. The physical-mechanical performance of the panels (Planning I - 20 treatments) was evaluated based on the NBR 14810 (2006 and 2013) standards. We conducted an analysis of variance (ANOVA) to evaluate the influence of individual factors (oat hulls percentage, adhesive percentage and type of adhesive), and the interactions between these factors (two by two and three by three) on the physical properties-mechanical panels. It was also evaluated the performance for floors, both panels (Planning II - 12 treatments) as three species of tropical wood (Angelim Vermelho, Dinizia excelsa; Cumaru, Dipteryx odorata e Jatobá, Hymenaea sp.), according to various standards related to wood floors. The results indicated physical and mechanical properties of the panels, in some treatments superior to the requirements stipulated by national and international standards. As for performance flooring, panels statistically equivalent to the three species of wood, most of the evaluated properties. Porosimetry analysis by mercury intrusion confirmed the similarity between the panels (from Planning II) and the three wood species evaluated, demonstrating the potential of the panels produced for use in the flooring industry engineered.
18

Fabricação e qualificação de placas compostas de serragem e plástico reciclável / Manufacture and qualification of sawdust and recyclable plastic based panel

Quinhones, Rogério 05 June 2007 (has links)
A utilização de polímeros ligno-celulósicos combinados com polímeros artificiais na forma de materiais compostos é fruto do desenvolvimento de uma linha de pesquisa que tinha como objetivo inicial a utilização dos primeiros como enchimento de uma matriz termofixa ou termoplástica aglutinante. Com o advento da necessidade do reaproveitamento de resíduos de processos industriais, as pesquisas e a utilização de resíduos fibrosos e partículas de madeira cresceram em importância e passaram a contribuir ainda mais decisivamente no desenvolvimento de novas técnicas, processos, equipamentos e insumos que possibilitam ampla gama de aplicações dos produtos obtidos. O presente trabalho objetivou a fabricação de placas compostas de serragem de duas espécies amplamente utilizadas em serrarias combinada com polietileno de baixa densidade reciclável (PEBD). Serragem e farinha de madeira de Pinus elliottii e Eucalyptus grandis , provenientes de lenho e de casca, foram separadas, beneficiadas e misturadas com partículas de PEBD também classificadas por tamanho, na proporção de 40% de madeira e 60% de plástico. A mistura foi prensada a 150 ° C por 30 minutos à pressão de 3 MPa. Foram fabricadas 44 placas de 6 mm de espessura nominal e 40 x 50 cm de lados, em 4 repetições de 11 tratamentos. Foram produzidos corpos-de-prova de todas as placas para os ensaios físicomecânicos segundo a norma ASTM D-1037, determinando-se a massa específica, o teor de umidade, a variação da massa e da espessura ocorridas em 2 e 24 horas de imersão em água, o módulo de elasticidade e o módulo de ruptura na flexão estática, a resistência à compressão e a força máxima de arrancamento de prego e de parafuso de fenda. O lenho de Pinus de granulometria fina combinado com PEBD fino apresentou as melhores propriedades físicomecânicas. Os tratamentos com lenho de Eucalyptus obtiveram o melhor desempenho geral e naqueles em que se utilizou a casca de Pinus os resultados não foram satisfatórios. Dentre os tratamentos que utilizaram cascas, a de Eucalyptus de granulometria grossa foi superior. O lenho de Pinus , principalmente em granulometrias mais finas e homogêneas revelaram-se promissores na utilização externa e as placas obtidas de casca de Pinus revelaram um grande potencial de utilização em usos internos não estruturais, como material alternativo. / Using ligno-celullose polymers combined with artificial polymers in form of composite material is result of a developing research line which had as initial objective the use of the firsts as just filling material in an agglutinant thermoplastic matrix. Due to the necessity of reusing industrial processing residues, the research and utilization of fiber and woody particles had grown in importance and started to contribute on the development of new techniques, processes, equipment and materials that make possible creating a huge variety of products and applications. The present work had the objective of manufacturing composite boards using sawdust from two different species widely used in sawmill combined with recyclable low density polyethylene. Pinus elliotii and Eucalyptus grandis sawdust and wood flour, produced from lumber and bark had been separated, treated and mixed with PEBD particles also classified by size, in the proportion of 40% wood and 60% plastic. The mixture was pressed at 150 °C during 30 minutes under 3 MPa pressure. It were manufactured 44 boards 6 mm nominal thickness and 40 x 50 cm sides in 4 replications of 11 treatments. Samples were obtained from all boards for physicmechanical tests according to ASTM D – 1037 standard, determining specific gravity, moisture content, mass and thickness variation occurred in 2 and 24 hours in water, modulus of elasticity and modulus of rupture in the static bending, compression strength and the withdrawal load of nail and screw. The Pinus wood of thin granulosity combined with thin LDPE had presented better physic-mechanical properties. The treatments in which was used Eucalyptus wood had shown better general performance and those in which was utilized Pinus bark had not presented satisfactory performance. Amongst the treatments in which bark was used, the Eucalyptus of thick granulosity had showed better performance. Boards made of Pinus wood specially in thinner and homogeneous granulosities seems to be excellent for exterior application and those in which was used Pinus bark had shown great potential as an alternative material for non structural purposes for interior applications.
19

Contribution à l'étude de la saturation des tissus simples et multicouches : tissus 2D et 3D / Contribution to the study of the woven fabrics "2D and 3D" saturation

Dalal, Mohamed 16 November 2012 (has links)
Le tissu est réalisé par un entrecroisement, appelé armure [1], de 2 réseaux de fils, un longitudinal et un transversal 2D et de plus de 2 réseaux 3D. Les propriétés de ces tissus seront fonction de la quantité de fil insérable dans l'armure, quantité dont la limite doit être déterminée de façon précise. Hors, à ce jour, cette limite est très mal connue [2]. Donc, l'utilité principale du calcul des limites de tissabilité est de savoir si un tissu 2D ou 3D est réalisable ou non sur une machine à tisser. Les coefficients de difficulté permettent d'éviter des productions endommageant le matériel et aussi d'apprécier a priori les problèmes de rendement de production des articles proches des limites de tissabilité tel que les tissus techniques. Il est d'autre part possible de déduire certaines caractéristiques techniques de l'article réalisé. Ces calculs peuvent en effet quantifier le serrage des fils entre eux et permettre de déduire les caractéristiques mécaniques et physiques. Les raisons motivant ces recherches sont d'une part d'éviter un surcoût de production en essayant de tisser un article, 2D ou 3D, impossible à tisser et d'autre part de diminuer les casses des fils et l'usure des éléments de la machine à tisser à cause d'une surcharge sur le métier à tisser pendant l'opération de tissage. Après la mise en place d'un plan d'expérience de tissage, l'étude des propriétés mécaniques et physiques d'un nombre représentatifs de tissus 2D et 3D et la modélisation des structures tissées a permis de proposer de nouvelles équations de saturations et de limite de tissabilité en particulier pour le 3D [3]. Par ailleurs, à partir de ces équations, il est possible de prévoir, pour une contexture et une armure donnée en 2D ou 3D, la masse maximale de fil insérable dans le tissu ainsi que la difficulté qui sera rencontrée lors du tissage. Les relations théoriques nouvelles proposées, indices de saturation numérique et indice de saturation massique ont été confirmées par les résultats expérimentaux et Il a été conclu que les équations et abaques qui en découlent sont des outils utiles pour l'industrie de tissage traditionnel et technique. / The woven fabrics 2D and 3D are made by interlacing warp and weft, called pattern [1]. The properties of these woven fabrics will depend on the number of yarns into the woven fabrics, quantity whose limit must be determined accurately. Out, to date, this limit isn't very well known [2]. So, the main purpose of calculating the limit of weavability is whether a 2D or 3D woven fabric is feasible or not on a loom. The degree of difficulty can avoid damaging production equipment and also to assess a priori the efficiency problems of producing near the limits of weavability as technical fabrics. It is further possible to infer some specifications of the article made. These calculations can quantify the tightess and allow them to deduct the mechanical and physical properties. The reasons for this research are first to avoid additional costs of production in trying to weave 2D or 3D fabrics, impossible to weave and second to reduce breakage and wear parts of weaving machine due to an overload on the loom during the weaving operation. After the establishment of an experimental weaving and studies of mechanical and physical properties of a representative number of 2D and 3D woven fabrics, the modeling of woven structures allowed to propose new saturation and limit of weavability equations particularly for 3D [3]. Moreover, from these equations, it is possible to provide for a given texture and pattern in 2D or 3D, the maximum yarn inserted into the woven fabrics and the difficulty will be encountered during weaving. The new proposed theoretical relationships, numerical saturation index and weight saturation index were confirmed by experimental results and it was concluded that the equations and abacus are useful tools for the traditional and technique weaving industry.
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Fabricação e qualificação de placas compostas de serragem e plástico reciclável / Manufacture and qualification of sawdust and recyclable plastic based panel

Rogério Quinhones 05 June 2007 (has links)
A utilização de polímeros ligno-celulósicos combinados com polímeros artificiais na forma de materiais compostos é fruto do desenvolvimento de uma linha de pesquisa que tinha como objetivo inicial a utilização dos primeiros como enchimento de uma matriz termofixa ou termoplástica aglutinante. Com o advento da necessidade do reaproveitamento de resíduos de processos industriais, as pesquisas e a utilização de resíduos fibrosos e partículas de madeira cresceram em importância e passaram a contribuir ainda mais decisivamente no desenvolvimento de novas técnicas, processos, equipamentos e insumos que possibilitam ampla gama de aplicações dos produtos obtidos. O presente trabalho objetivou a fabricação de placas compostas de serragem de duas espécies amplamente utilizadas em serrarias combinada com polietileno de baixa densidade reciclável (PEBD). Serragem e farinha de madeira de Pinus elliottii e Eucalyptus grandis , provenientes de lenho e de casca, foram separadas, beneficiadas e misturadas com partículas de PEBD também classificadas por tamanho, na proporção de 40% de madeira e 60% de plástico. A mistura foi prensada a 150 ° C por 30 minutos à pressão de 3 MPa. Foram fabricadas 44 placas de 6 mm de espessura nominal e 40 x 50 cm de lados, em 4 repetições de 11 tratamentos. Foram produzidos corpos-de-prova de todas as placas para os ensaios físicomecânicos segundo a norma ASTM D-1037, determinando-se a massa específica, o teor de umidade, a variação da massa e da espessura ocorridas em 2 e 24 horas de imersão em água, o módulo de elasticidade e o módulo de ruptura na flexão estática, a resistência à compressão e a força máxima de arrancamento de prego e de parafuso de fenda. O lenho de Pinus de granulometria fina combinado com PEBD fino apresentou as melhores propriedades físicomecânicas. Os tratamentos com lenho de Eucalyptus obtiveram o melhor desempenho geral e naqueles em que se utilizou a casca de Pinus os resultados não foram satisfatórios. Dentre os tratamentos que utilizaram cascas, a de Eucalyptus de granulometria grossa foi superior. O lenho de Pinus , principalmente em granulometrias mais finas e homogêneas revelaram-se promissores na utilização externa e as placas obtidas de casca de Pinus revelaram um grande potencial de utilização em usos internos não estruturais, como material alternativo. / Using ligno-celullose polymers combined with artificial polymers in form of composite material is result of a developing research line which had as initial objective the use of the firsts as just filling material in an agglutinant thermoplastic matrix. Due to the necessity of reusing industrial processing residues, the research and utilization of fiber and woody particles had grown in importance and started to contribute on the development of new techniques, processes, equipment and materials that make possible creating a huge variety of products and applications. The present work had the objective of manufacturing composite boards using sawdust from two different species widely used in sawmill combined with recyclable low density polyethylene. Pinus elliotii and Eucalyptus grandis sawdust and wood flour, produced from lumber and bark had been separated, treated and mixed with PEBD particles also classified by size, in the proportion of 40% wood and 60% plastic. The mixture was pressed at 150 °C during 30 minutes under 3 MPa pressure. It were manufactured 44 boards 6 mm nominal thickness and 40 x 50 cm sides in 4 replications of 11 treatments. Samples were obtained from all boards for physicmechanical tests according to ASTM D – 1037 standard, determining specific gravity, moisture content, mass and thickness variation occurred in 2 and 24 hours in water, modulus of elasticity and modulus of rupture in the static bending, compression strength and the withdrawal load of nail and screw. The Pinus wood of thin granulosity combined with thin LDPE had presented better physic-mechanical properties. The treatments in which was used Eucalyptus wood had shown better general performance and those in which was utilized Pinus bark had not presented satisfactory performance. Amongst the treatments in which bark was used, the Eucalyptus of thick granulosity had showed better performance. Boards made of Pinus wood specially in thinner and homogeneous granulosities seems to be excellent for exterior application and those in which was used Pinus bark had shown great potential as an alternative material for non structural purposes for interior applications.

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