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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.
31

Produção e avaliação do desempenho de painéis de partículas orientadas (OSB) de Pinus sp com inclusão de telas metálicas / Production and performance evaluation of Pinus sp oriented strandboard (OSB) with metallic gauze inclusion

Amós Magalhães de Souza 10 July 2012 (has links)
O OSB é um produto derivado da madeira desenvolvido nos Estados Unidos em 1970. É definido como um painel de partículas orientadas, as quais são distribuídas em camadas múltiplas de uma forma predeterminada. À época, o OSB foi criado para substituir o painel de madeira compensada. Todavia, geralmente suas propriedades na flexão estática são inferiores. A proposta principal deste trabalho foi produzir e analisar o desempenho de painéis OSB de Pinus sp e resina poliuretana à base de óleo mamona com inclusão de telas metálicas, objetivando acréscimo nas propriedades de resistência e de rigidez na flexão estática. A produção seguiu o processo laboratorial, consistindo em gerar as partículas, distribuir o adesivo, confeccionar o colchão e prensar à temperatura de 100°C por 10 minutos. O teor de resina adotado foi de 12% tendo como base a massa seca das partículas. Os painéis foram confeccionados com três camadas, as externas tendo direção paralela ao comprimento da chapa e a interna com distribuição randômica. A proporção face/miolo/face foi na faixa de 20:60:20. Com base nas recomendações de documentos normativos brasileiros e europeus foram realizados ensaios de flexão estática, de onde foram determinados os módulos de ruptura (MOR), e módulo de elasticidade (MOE), ensaios de arrancamento de parafusos, adesão interna, teor de umidade, absorção de água, inchamento em espessura e determinação da densidade aparente. Os resultados apontam a eficiência dos painéis OSB produzidos quando comparadas suas propriedades com os valores mínimos exigidos pelas normas e valores encontrados na literatura para painéis desta natureza. A utilização da tela metálica se mostrou não necessária, dada a pouco relevante diferença de MOE e MOR entre os painéis com e sem a tela. / OSB is a wood based product developed in the United States, since 1954. It\'s defined as oriented particles panels, which are distributed in multiple layers of a predetermined shape. At the time, the OSB was created to replace the plywood panel, but usually its bending properties are inferior. The main purpose of this study was to produce and analyze the performance of OSB from Pinus sp and castor oil based polyurethane resin with inclusion of metallic gauzes, aiming to increase strength and stiffness properties in static bending. Panel production followed laboratory process, consisting of particles generation, adhesive distribution, mattress making and a pressing in 100ºC temperature for 10 minutes. The resin content was set at 12% based on particles dry weight. Panels were produced with three layers: the outers with strands in direction parallel to the panel length; internal in randomized distribution. Face/core/face particle proportion was in range of 20:60:20. Based on Brazilian and European codes recommendations, several tests were performed to determine: modulus of rupture (MOR) and modules of elasticity (MOE), in static bending; screw pullout; internal adhesion; moisture content; water absorption; thickness swelling and density. Results showed efficiency of OSB produced comparing their properties with basic codes requirements the standards and literature values for such panels. The use of metallic gauze has been shown not necessary, because of small relevant difference between MOE and MOR for panels with and without gauze inclusion.
32

Wax distribution quantification using digital image analysis techniques

Saunders, Heath G. 10 November 2009 (has links)
A wax distribution quantification procedure using digital image analysis and fluorescence microscopy techniques was developed. The procedure was evaluated by investigating the effect that variable application rates have on wax distribution. The effect of emulsion type and application on |B strength, thickness swell, water absorption, and linear expansion of flakeboard panels were also investigated. Tests revealed that increasing the wax emulsion flow rate and application pressure had a significant affect on wax coverage. A lower amount of flake surface area was covered when the flow rate and air pressure was increased. It was also found that the presence of resin on the flakes affected wax coverage. Resin presence generally increased the wax coverage variability. The application flow rate and pressure also seemed to affect the interaction present between the resin and wax spots. The fractional coverage area of spot size classes was also significantly affected by the emulsion's application parameters. Increasing the flow rate and air pressure was shown to create more variable wax spot distributions. The presence of resin spots on the flakes was also shown to significantly affect the spot size distribution. Changes in the emulsion flow rate and application air pressure also appeared to have a significant affect on wax spot distribution. The type of wax emulsion used, as well as increased application flow rate and pressure, was shown to significantly affect both 2 hour and 24 hour water absorption (by weight). It was found that using a soap based emulsion improved the water absorption characteristics, and that increasing the emulsion's application flow rate and air pressure adversely affected the water absorption. Differences in IB strength and 24 hour thickness swell were also seen between the panels made using increased flow rate and pressure and the panels produced with standard parameters. However, due to possible influence of press malfunctions on the boards performance, conclusions about the effect of increased parameters can not be clearly drawn. No significant difference in linear expansion was seen for any of the samples tested. / Master of Science
33

Uso de pena de galinha na produção de painéis para construção civil / Use of chicken feathers in the production of panels for civil construction

Minutti, Fernanda Aparecida Alonge 24 January 2018 (has links)
Submitted by Fernanda Aparecida Alonge Minutti (fer.alonge@gmail.com) on 2018-05-30T16:01:45Z No. of bitstreams: 1 Fernanda A A Minutti_Dissertação completa_FINAL.pdf: 6994835 bytes, checksum: ab3793efb49bc877a92e10fe9d2d04cd (MD5) / Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-05-30T17:03:36Z (GMT) No. of bitstreams: 1 minutti_faa_me_bauru.pdf: 6888158 bytes, checksum: 03946ea4b9fd3ef6aec72596a601b833 (MD5) / Made available in DSpace on 2018-05-30T17:03:36Z (GMT). No. of bitstreams: 1 minutti_faa_me_bauru.pdf: 6888158 bytes, checksum: 03946ea4b9fd3ef6aec72596a601b833 (MD5) Previous issue date: 2018-01-24 / O presente trabalho apresenta uma alternativa para a minimização do descarte atual, crescente e inadequado do resíduo agronômico pena de galinha (Chicken Feather). Assim, foram estabelecidos parâmetros para gerar um novo produto, painéis de compósitos, com adição de resina ureia-formaldeído, visando verificar as propriedades e possibilidades de aplicação deste produto na construção civil. Ao longo do levantamento bibliográfico, notou-se que a pena de galinha é um tema ainda pouco explorado em pesquisas, traduzindo-se em uma lacuna a ser preenchida. Foi escolhida a resina ureia-formaldeído por ser um componente chave muito utilizado na indústria de chapas particuladas de madeira, o que facilitaria na avaliação comparativa de desempenho do novo compósito. Durante a realização da etapa experimental, constatando-se uma grande dificuldade na trituração das penas, optouse por usá-las inteiras. Ao final desta etapa, a qualidade física das chapas foi insuficiente para a produção dos corpos de prova necessários à realização dos ensaios de caracterização física e mecânica, sendo direcionado aos ensaios de desempenho térmico, para aplicação deste compósito como isolante térmico em edificações. Com a realização destes ensaios, constatou-se o potencial de adequação do material para esta aplicação. Comparados com materiais para isolamento térmico existentes no mercado, os painéis com pena de galinha apresentaram desempenho compatível, bloqueando cerca de 20ºC de temperatura entre uma face e outra. Desta forma, conclui-se que a pena de galinha é um resíduo agronômico com considerável potencial de aproveitamento na produção de painéis, para uso como material isolante térmico em componentes para construção civil. / The present work presents an alternative for the minimization of current, increasing and inadequate disposal of agronomic chicken feather residue. Thus, parameters were established to generate a new product, composite panels, with addition of ureaformaldehyde resin, in order to verify the properties and possibilities of application of this product in civil construction. Throughout the bibliographical survey, it was noticed that the feather of chicken is a subject still little explored in researches, translating into a lacuna to be filled. The urea-formaldehyde resin was chosen as a key component widely used in the wood particleboard industry, which would facilitate the comparative evaluation of the new composite performance. During the realization of the experimental stage, it was verified a great difficulty in the crushing of the feathers, it was chosen to use them whole. At the end of this stage, the physical quality of the panels was insufficient for the production of the test specimens necessary for the physical and mechanical characterization tests, being directed to the thermal performance tests, for the application of this composite as thermal insulation in buildings. With the accomplishment of these tests, it was verified the potential of suitability of the material for this application. Compared with existing insulation materials on the market, the panels with chicken feather showed compatible performance, blocking about 20ºC of temperature between one face and another. Thus, it is concluded that the chicken feather is an agronomic residue with considerable potential for use in the production of panels, for use as thermal insulation material in components for civil construction.
34

A Study On The Utilization Of Waste Cement-bonded Wood Particle Board As A Raw Material And A Secondary Fuel In Cement Manufacturing

Yilmaz, Mustafa 01 September 2012 (has links) (PDF)
A considerable amount of waste is obtained as a result of edge-cutting operations during cement-bonded wood particle board (CBWPB) manufacturing. This waste material which basically contains wood chips and hydrated cement has to be disposed of and does not have any economical value. However, it can be burned in cement rotary kilns and may result in energy savings to a certain extent due to the presence of wood particles as a secondary fuel and since the hydrated cement may be decomposed and then reform clinker compounds during the calcination process. In this experimental study, the possibility of using waste CBWPB in cement manufacturing and its effects on energy consumption and cement characteristics will be investigated. The reference mix, corrective limestone, CBWPB waste and coal, were used as raw materials to prepare six different raw meals whose chemical compositions was similar to reference mix. All six raw mixes (including the reference) were calcined under the same conditions to produce clinkers. The compositions and micro structure of the clinkers obtained were comparatively analyzed by wet analysis, XRF and XRD techniques. Cements were obtained by intergrinding the clinkers with 5% (by mass) gypsum rock and standard tests were carried out on each of the cements. In addition to these, since CBWPB waste contains wood about 30% by weight, its contribution to fuel consumption during clinker production was also analyzed. The test results revealed that CBWPB waste can be used as a cement raw material since CBWPB waste has the similar chemical composition with the reference raw mix. CBWPB, which contains about 30% (by mass) wood, contributes to the heating process during calcination and results in lower amount of primary fuel requirement.
35

Painéis de partículas de bambu e casca de amendoim com adesivo à base de mamona / Particleboard made of bamboo and peanut shell with castor based adhesive

Nasser, Silvia Marana [UNESP] 08 December 2016 (has links)
Submitted by Sílvia Marana Nasser null (silvianasser@gmail.com) on 2016-12-15T16:59:08Z No. of bitstreams: 1 PAINÉIS DE PARTÍCULAS DE BAMBU E CASCA DE AMENDOIM COM ADESIVO À BASE DE MAMONA.pdf: 5198244 bytes, checksum: 3429d1f767cff1870845a126ac510e95 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-12-20T14:01:33Z (GMT) No. of bitstreams: 1 nasser_sm_me_bauru.pdf: 5198244 bytes, checksum: 3429d1f767cff1870845a126ac510e95 (MD5) / Made available in DSpace on 2016-12-20T14:01:33Z (GMT). No. of bitstreams: 1 nasser_sm_me_bauru.pdf: 5198244 bytes, checksum: 3429d1f767cff1870845a126ac510e95 (MD5) Previous issue date: 2016-12-08 / Na atualidade, pesquisas com painéis a base de madeira e outros materiais lignocelulósicos, como o bambu, casca de amendoim, casca de arroz, bagaço de cana de açúcar, entre outros, ganharam espaços buscando aproveitamento para os resíduos agroindustriais. Seguindo essa iniciativa, este trabalho tem como objetivo, determinar as potencialidades dos painéis de partículas aglomeradas homogêneas, construídos com bambu (B), juntamente com partículas de casca de amendoim (A), para aplicação na indústria moveleira e de construção civil, comparando os resultados obtidos nesta pesquisa com outros autores. Para tanto, foram produzidos painéis com partículas aglomeradas em quatro traços onde, através da análise das propriedades físicas e mecânicas conforme a norma brasileira NBR 14810 - 2 (2013), determinou-se os valores de inchamento em espessura 24h, absorção de água 24h, umidade, densidade, resistência a flexão (MOR e MOE), tração perpendicular e arranchamento de parafusos (topo e face). A densidade alvo dos painéis foi de 850 kg/m considerados painéis de alta densidade. O adesivo utilizado foi a poliuretana bi componente a base de óleo de mamona, na proporção de uma parte de poliol para uma parte de pré polímero (12% da massa de partícula = 157,52g). Os resultados analisados, indicam que os traços contendo bambu e amendoim, apresentaram resultados satisfatórios quando comparados à norma, e em alguns casos, com índices bem superiores aos definidos na NBR 14810-2 (2013), e por trabalhos de autores com pesquisas semelhantes. Pelos resultados aqui descritos, o material ensaiado apresenta bom potencial para fabricação de painéis de partículas, com aplicabilidade em condições secas (Tipo P4), conforme a norma, com oportunidade para estudos futuros. / Currently, research on wood-based panels and other lignocellulosic materials, such as bamboo, peanut hulls, rice hulls, sugar cane bagasse, among others, won spaces seeking to use the agroindustrial waste. Following this initiative, this study aims to determine the potential of panels of homogeneous agglomerated particles, built with bamboo (B), along with peanut shell particles (A), for use in the furniture industry and construction, comparing results obtained in this study with other authors. For this purpose, panels were produced with particles agglomerated in four traces which, by analyzing the physical and mechanical properties as the Brazilian NBR 14810-2 (2013), we determined the values of swelling in thickness 24h Water uptake 24h moisture, density, bending strength (MOR and MOE), perpendicular traction and arranchamento screws (top and side). The target density of the panels was 850 kg / m considered high density panels. The adhesive used was a bicomponent polyurethane castor oil base in proportion to one part of polyol to a part of prepolymer (12% particle mass = 157,52g). The analyzed results indicate that the traces containing bamboo and peanuts showed satisfactory results when compared to standard, and in some cases, with much higher rates to those defined in NBR 14810-2 (2013), and works by authors with similar research. The results described herein, the material tested has good potential for the production of particle board, can be applied in dry conditions (Type P4) as the norm, with opportunity for future studies.
36

Využití vedlejších produktů z výroby cementotřískových desek pro podkladní vrstvy / Utilization of by-products from cement-bonded particleboards production in base layers

Dobrovolná, Martina January 2019 (has links)
This thesis deals with the use of by–products from the production of cement–bonded particle boards as an alternative raw material for the stabilization of the subsoil or into a ground solid. The theoretical part briefly describes the current status of waste management. A set of alterantive raw materials used to hydraulically cemented mixtures is listed here as well as the recherche of the foreign research is elaborated from this area. The experimental part of the thesis firstly deals with the choice of raw materials and basic recipes. In the advanced stage the laboratory analyses are carried out on the modified formulas. Based on the results of these analyses the posibility of using by–products from the production of cement–bonded boards for the stabilization of the subsoil is evaluated here.
37

Vývoj cementotřískových desek s matricí modifikovaného složení / Development of cement-bonded particleboards with modified matrix composition

Konečný, Dalibor January 2014 (has links)
In manufacture of cement-bonded particle boards are in present-days used exclusively wooden particles as filler. This thesis deals with a research of possible substitution of this material, especially of waste emerging by production of CBPB itself. At first is completed a survey of possible substitute fillers and czech and foreign literature, dealing with issues of modification of composition of cement-bonded particle boards. In practical part are tested some treatments of waste and its adding to recipe. Further are analysed the influences of substitution of cement by slag and substitution of wooden particles by recycled fibreglass. By laboratory work with CBPB is monitored the influence of amounts of added wather to fresh mixture and also to properties of finished elements.
38

Etude de l’extraction de tanins d’écorce de pin maritime pour l’élaboration de colles tanin-lignosulfonate / Study of maritime pine bark extraction for the preparation of tannin-lignosulfonate adhesives

Chupin, Lucie 07 November 2014 (has links)
Cette étude a deux objectifs principaux : l’extraction de tanins condensés d’écorces de pin maritime et la formulation de colles tanin-lignosulfonate. Deux méthodes d’extraction ont été étudiées. La première est une extraction à l’eau chaude ; c’est une technique simple, peu coûteuse, sans solvant. La deuxième est une extraction assistée par micro-ondes ; c’est une technique innovante, rapide et peu consommatrice en solvant. L’optimisation des conditions d’extraction à l’eau chaude a été réalisée. Les extraits ont été caractérisés par des dosages colorimétriques, leur réactivité au formaldéhyde, par infrarouge à transformée de Fourier (IRTF), par chromatographie en phase liquide à haute pression, par 1H RMN et 2D HSQC RMN. L’impact de la granulométrie sur l’extraction de polyphénols et particulièrement de tanins condensés par extraction assistée par micro-ondes a été étudié pour la première fois. Les deux types d’extraction ont été comparés. L’extraction assistée par micro-ondes a un rendement en extractibles inférieur à l’extraction à l’eau chaude. Mais elle extrait plus de tanins condensés, de flavonoïdes simples et plus de sucres. Quelle que soit la méthode d’extraction, les tanins condensés majoriatires extraits de l’écorce de pin maritime sont de la catéchine, de l’épicatéchine, de l’épicatéchine gallate et de l’épigallocatéchine. Des colles tanin-lignosulfonate ont été produites en utilisant l’héxaméthylènetetramine comme durcisseur. Dans un premier temps, des tanins de mimosa ont été utilisés avec des lignosulfonates de sodium et des lignosulfonates d’ammonium. Les lignosulfonates ont subi deux traitements au glyoxal qui ont été comparés par analyse thermogravimétrique (ATG), par calorimétrie différentielle à balayage (DSC), par les propriétés thermiques et mécaniques de colles et de panneaux de particules avec des lignosulfonates ayant subi les deux traitements ont également été étudiées. L’optimisation du ratio tanin de mimosa-lignosulfonate glyoxalé a été menée et les propriétés thermiques des colles mesurées. L’optimisation des conditions de pressage de panneaux de particules a été réalisée. Des panneaux de particules avec de bonnes performances mécaniques ont été fabriqués. Des colles à base de tanins d’écorce de pin maritime et de lignosulfonates ont été réalisées avec 40% de tanins et 60% de lignosulfonates. Ces colles ont été caractérisées par IRTF, analyse thermomécanique, ATG et DSC. Ces colles sont rentrées dans la fabrication de panneaux de particules. Les émissions de formaldéhyde et la cohésion interne des panneaux ont été mesurées et comparées à des panneaux encollés avec une colle tanin de mimosa-lignosulfonate et une résine urée-formaldéhyde. Grâce à ces résultats, il a été possible de montrer que les panneaux de particules fabriqués à partir de colles bio-sourcées n’émettaient pas de formaldéhyde. / This study has two main objectives: the extraction of condensed tannins from maritime pine bark and the preparation of tannin-lignosulfonate adhesives. Two extraction methods were studied. The first is hot water extraction which is a simple, cheap method without the use of an organic solvent. The second is microwave-assisted extraction which is a fast, innovative method using only a small amount of solvent. Optimum extraction conditions were determined for hot water extraction. The extracts were characterised by their reaction to formaldehyde and by using colorimetric tests, Fourier Transformed Infrared spectroscopy (FTIR), high pressure liquid chromatography, 1H NMR and heteronuclear single quantum correlation 2D NMR.. The two types of extraction were compared. It was found that microwave-assisted extraction produced a lower yield of extractibles than the hot water method but that it produced more condensed tannins, simple flavonoids and sugars. The condensed tannins extracted from maritime pine bark are catechin, epicatechin, epicatechin gallate and epigallocatechin, whatever the extraction method used. Tannin-lignosulfonate adhesives were produced using hexamethylenetetramine as a hardener. First, mimosa tannins were used with sodium lignosulfonates and ammonium lignosulfonates. The lignosulfonates underwent two glyoxal treatments which were compared using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and by determining the thermal and mechanical properties of the adhesives and of the particle boards made using the lignosulfonates resulting from the two treatments. The optimum mimosa tannin-glyoxalated lignosulfonate ratio was determined and the thermal properties of the adhesives were measured. The optimum conditions of pressing the particle boards were determined. Particle boards which recorded a good mechanical performance were produced. Adhesives using maritime pine bark tannins and lignosulfonates were prepared with 40% tannins and 60% lignosulfonates. These adhesives were characterised using FTIR, thermomechanical analysis, TGA and DSC. These adhesives were used to produce particle boards. The emission of formaldehyde and the internal bond of the boards were measured and compared to those of boards made with a mimosa tannin-lignosulfonate adhesive and to those of boards made with a urea-formaldehyde resin. Thanks to these results, we were able to produce particleboards with bio-based adhesives that didn’t emit formaldehyde.
39

Caractérisation mécanique et thermique de biocomposites à matrice polystyrène recyclé renforcée par des coques de cotonnier (Gossypium Hitsutum L.) ou des particules de bois de Kénaf (Hibiscus Cannabinus L.) / Mechanical and thermal characterization of biocomposite materials at matrix recycled polystyrene reinforced by the hulls of cotton (Gossypium Hirsutum L.) or particles of wood of kénaf (HibIscus Cannabinus L. ).

Soulama, Sagnaba 21 November 2014 (has links)
Dans le contexte actuel marqué par une grande émergence des questions environnementales, de l’économie circulaire et du développement durable, la mise au point d’éco-matériaux représente un enjeu majeur qui offre une alternative aux plastiques recyclés en fin de cycles de vie.L’objectif de ce travail est de contribuer au développement de deux éco-matériaux à partir des biomasses végétales cultivables non alimentaires disponibles, associées à des polymères synthétiques recyclés en fin de cycles de vie.Il s’agit d’une part, de développer un matériau biosourcé constitué de polystyrène recyclé, renforcé de coques de cotonnier. Ce matériau devra être susceptible de se substituer au polystyrène dans des domaines d’applications diverses telles que la fabrication de pièces d’isolation thermique, d’habillage intérieur de voitures, des coques de portables cellulaires, d’ordinateurs, de photocopieurs et d’emballages divers.D’autre part, de développer des panneaux de particules en bois de tiges de cotonnier et de tiges de kénaf associés à un liant naturel (la colle d’os) pour une utilisation dans le domaine de l’isolation thermique d’intérieur en remplacement des panneaux de particules élaborés avec la colle urée formaldéhyde.L’influence des paramètres d’élaboration pour chacun des deux matériaux a été analysée. Après optimisation des conditions de mise en œuvre pour chaque matériau, la tenue mécanique, les propriétés thermiques et la microstructure ont été déterminées et optimisées dans chaque cas. / In the current context marked by a large emergence of environmental issues, the circular economy and sustainable development, the development of eco-materials represents a major challenge which offers an alternative to plastics recycled at end of life cycles.The objective of this work is to contribute to the development of two eco-materials from plant biomass non-cultivable food available, associated with synthetic polymers recycled at end of life cycles.It is a part, to develop a biosourced material constitutes of recycled polystyrene, strengthened of hulls of cotton. This material will be likely to be a substitute for polystyrene in areas of various applications such as the manufacture of parts for thermal insulation, interior trim from cars, the hulls of cellular mobile, computers, photocopiers, and various packaging.On the other hand, to develop particle board in wood of cotton stems and stalks of kenaf associated with a binder natural (the glue of bone) for use in the area of the thermal insulation of interior in replacing the panels of particles prepared with glue urea formaldehyde.The influence of the parameters for the development for each of the two materials was analyzed. After optimization of conditions of implementation for each material, the holding mechanical, thermal properties and the microstructure have been determined and optimized in each case.
40

Verwendung von biotechnologisch durch den Rotfäulepilz Heterobasidion annosum in vivo degradiertem Fichtenholz als Rohstoff für die Herstellung von Holzwerkstoffen / Utilisation of biotechnological via the fungus Heterobasidion annosum in vivo degraded spruce wood as raw material for wood based panel production

Bohn, Christian 21 August 2009 (has links)
No description available.

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