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Konstrukční návrh extruderu pro 3D tisk kompozitních součástí / Design of the extruder for 3D printing the composite partsŠmalec, Petr January 2017 (has links)
The diploma thesis is focused on 3D printing of composites parts. Thesis deals with methods of additive manufacturing and describes principle of selected 3D printing technologies. In addition to additive technologies, the theoretical part presents an overview of composite materials and methods of composite production. Then there are four concepts that lead to 3D printing of continuous fiber reinforced composites components. The final concept is selected according to multi-criteria analysis and then designed. Designed extruder allows 3D printing of composite materials. The principle of the function consists of fiber impregnation by matrix inside the heat chamber and then deposition of composite on printing platform. The extruder also consist of fiber cutting mechanism. The extruder's ability is verified by the experiment.
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Simulation par CFD et mesure en ligne de la distribution des temps de séjour et la qualité de mélange dans une extrudeuse bi-vis / CFD simulation and online measurement of the residence time distribution and mixing quality ina twin- screw extrudersZhang, Xian-Ming 10 November 2008 (has links)
Aujourd’hui le développement de nouveaux matériaux polymères ayant de bonnes propriétés repose de plus en plus sur des procédés de mélange ou de compoundage de polymères au lieu de recourir à la synthèse de nouvelles molécules. L’action du mélange peut fortement influer sur la morphologie des matériaux polymères multi-constituants. Les extrudeuses bi-vis (TSE) sont souvent utilisées comme mélangeurs/réacteurs pour des procédés de mélange, de compoundage et d’extrusion réactive. Cependant, l’étude sur la qualité du mélange dans les TSE demeure un grand défi en raison de la complexité géométrique et du caractère transitoire de l’écoulement. Cette thèse a pour objet de développer un nouvel instrument en line pour mesurer en temps réel la distribution des temps de séjour (DTS) qui caractérise la performance du mélange axial et la capacité de convoyage de différents types d’éléments de vis basées sur l’analyse de l’écoulement transitoire et l’évaluation systématique de la théorie de mélange dans les TSE. Le mélange distributif des polymères fondus est caractérisé par la génération de l’aire des interfaces, un paramètre difficile à mesurer expérimentalement. Alors on fait appel à des simulations numériques de type CFD / The development of new materials with improved properties seems to rely nowadays more on blending and compounding than on the synthesis of chemically new polymers. Mixing may have a great effect on the morphology and structure of multi-component polymer materials. Twin-screw extruders (TSE) are widely used as mixers/reactors for blending, compounding, and reactive processing. This work aimed at developing a new instrument to measure in real time the residence time distribution (RTD) which characterizes the axial mixing and transport abilities of different screw elements based on the analysis of the transient flow pattern and systematic evaluation of mixing theory in TSE. Distributive mixing of polymer melts is characterized by the generation of interfacial area, which is experimentally much more difficult to measure. This 3D numerical simulation based on CFD is adopted
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Etudes théoriques et expérimentales de la processabilité du polyéthylène à ultra-haute masse molaire / Theoretical and experimental studies of the processability of ultra-high molecular weight polyethyleneGai, Jing-Gang 16 July 2009 (has links)
Aujourd’hui le développement de nouveaux matériaux polymères ayant de bonnes propriétés repose de plus en plus sur des procédés de mélange ou de compoundage de polymères au lieu de recourir à la synthèse de nouvelles molécules. L’action du mélange peut fortement influer sur la morphologie des matériaux polymères multi-constituants. Les extrudeuses bi-vis (TSE) sont souvent utilisées comme mélangeurs/réacteurs pour des procédés de mélange, de compoundage et d’extrusion réactive. Cependant, l’étude sur la qualité du mélange dans les TSE demeure un grand défi en raison de la complexité géométrique et du caractère transitoire de l’écoulement. Cette thèse a pour objet de développer un nouvel instrument en line pour mesurer en temps réel la distribution des temps de séjour (DTS) qui caractérise la performance du mélange axial et la capacité de convoyage de différents types d’éléments de vis basées sur l’analyse de l’écoulement transitoire et l’évaluation systématique de la théorie de mélange dans les TSE. Le mélange distributif des polymères fondus est caractérisé par la génération de l’aire des interfaces, un paramètre difficile à mesurer expérimentalement. Alors on fait appel à des simulations numériques de type CFD / The development of new materials with improved properties seems to rely nowadays more on blending and compounding than on the synthesis of chemically new polymers. Mixing may have a great effect on the morphology and structure of multi-component polymer materials. Twin-screw extruders (TSE) are widely used as mixers/reactors for blending, compounding, and reactive processing. This work aimed at developing a new instrument to measure in real time the residence time distribution (RTD) which characterizes the axial mixing and transport abilities of different screw elements based on the analysis of the transient flow pattern and systematic evaluation of mixing theory in TSE. Distributive mixing of polymer melts is characterized by the generation of interfacial area, which is experimentally much more difficult to measure. This 3D numerical simulation based on CFD is adopted
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Uticaj ekstrudiranja na promene odabranih fizičko-hemijskih svojstava sojeKukić Predrag 02 February 2018 (has links)
<p>Cilj istraživanja je da se utvrde promene hemijskog sastava proizvoda na izlazu iz ekstrudera i prese (sojine pogače i ulja), tj. njihovog kvaliteta sa aspekta njihove dalje primene u proizvodnji stočne hrane, primene u prehrambenoj industriji ili daljoj primeni sojinog ulja u proizvodnji biodizela, a sve u funkcionalnoj zavisnosti od promenljivih karakteristika ulazne sirovine i parametara rada ekstrudera. Ekstrudiranje sojinog zrna vršilo se na ekstruderu tip E751, proizvođača „SREM PRODUKT“ DOO iz Laćarka, a presovanje na presi tip PM-5S proizvođača „BRONTO“ iz Ukrajine. Istraživanja koja su sprovedena u ovoj doktorskoj disertaciji rađena su kao doprinos proširenju znanja vezanih za proces proizvodnje sojine pogače i sojinog ulja, a pored toga kako bi dobili praktične smernice za optimalnu kontrolu i modelovanje procesa estruzije i ceđenja soje kao i projektovanja ekstrudera. U cilju dobijanja i analiziranja podataka koji bi mogli da utvrde promene hemijskog sastava proizvoda na izlazu iz ekstrudera i prese (sojine pogače i ulja), tj. njihovog kvaliteta sa aspekta njihove dalje primene u proizvodnji stočne hrane, primene u prehrambenoj industriji ili daljoj primeni sojinog ulja u proizvodnji biodizela, a sve u funkcionalnoj zavisnosti od promenljivih karakteristika ulazne sirovine i parametara rada ekstrudera, sprovedena su eksperimentalna i laboratorijska ispitivanja. Eksperimentalna istraživanja su namenjena praktičnoj primeni kojom bi se proces proizvodnje sojine pogače i sojinog ulja mogao usavršiti i optimatizovati. Rezultati koji su dobijeni ovim istraživanjima mogu biti korisni svima koji se bave proizvodnjom sojine pogače i sojinog ulja. Eksperimentalna istraživanja obavljana su na ekstruderu tip E-751 i presi tip PM-5S, ali su rezultati primenjivi i na drugim ekstruderima i presama drugih proizvođača koji koriste soju kao sirovinu i proizvode sojinu pogaču i sojino ulje. Na osnovu izvršenih istraživanja, obrađenih i prodis<br />___________________Doktorska disertacija, autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________IV od 34<br />kutovanih rezultata došlo se do funkcionalnih zavisnosti između pojedinih parametara ekstruzije i od promenljivih karakteristika ulazne sirovine sa jedne strane i karakteristika ekstrudata i sojinog ulja sa druge strane i na osnovu toga došlo se do određenih zaključaka. Na osnovu eksperimentralnih ispitivanja ocenjen je uticaj promene odabranih fizičkohemijskih svojstava soje pri ekstrudiranju zrna soje. U disertaciji se krenulo od analize polazne sirovine tj. soje i njenog sadržaja proteina, ulja, slobodnih masnih kiselina i vlage, a zatim variranjem režima rada ekstrudera tj. doziranja ulaznog materijala praćeno preko opterćenja pogonskog elektromotora ekstrudera izraženog preko jačine struje [A], površine otvora mlaznice i vlažnosti soje, praćen je sadržaj slobodnih masnih kiselina, fosfora i vlage u sojinom ulju posle presovanja ekstrudata, kao i sadržaj proteina, vlage, ulja, aktivnost ureaze i PDI u sojinoj pogači. Na osnovu sprovedenih istraživanja došlo se do funkcionalnih zavisnosti između zadatih režima rada ekstrudera, ulazne sirovine i odabranih fizičko-hemijskih svojstava soje pri ekstrudiranju zrna soje. Tako da se sa porastom površine otvora mlaznice i doziranja mase povećava se produkcija sojine pogače. Produkcija sojine pogače se povećava i kada se vlažnost ulazne sirovine povećava. Sa povećanjem vlažnosti ulazne sirovine i interakcije doziranja mase i površine otvora mlaznice sadržaj vlage u sojinoj pogači se povećava. Na osnovu izvedenih istraživanja može se tđ. zaključiti da sa povećanjem površine otvora mlaznice ekstrudera raste sadržaj ulja u sojinoj pogači za svaku od tri vlažnosti soje kao ulazne sirovine, dok sa povećanjem doziranja ulazne sirovine smanjuje se sadržaj ulja u sojinoj pogači za svaku od tri mlaznice. Povećanjem površine otvora mlaznice ekstrudera, dolazi do smanjenja sadržaja proteina u sojinoj pogači, dok je obrnuto kod povećanja doziranja ulazne sirovine, tj. sa povećanjem doziranja sirovine u ekstruder povećava se sadržaj proteina u sojinoj pogači. Pozitivan efekat aktivnosti ureaze (∆pH) u<br />___________________Doktorska disertacija, autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________V od 34<br />sojinoj pogači je za veće vrednosti kako površine otvora mlaznice, tako i interakcije promenljivih W (vlažnosti soje) i D (doziranje mase soje određeno preko opterećenja elektromotora). U sojinoj pogači PDI se povećava sa povećanjem vlažnosti ulazne sirovine, površine otvora mlaznice ekstrudera i doziranja zrna soje kao ulazne sirovine. Razmatrajući dobijene podatke za sojino ulje dobijeno ceđenjem produkta ekstruzije dobijenog ekstruzijom soje sa predviđenim vlažnostima ulazne sirovine došlo se do zaključka da se produkcija ulja smanjuje sa povećanjem površine otvora mlaznice ekstrudera, a da pri povećanju doziranja ulazne sirovine povećava se produkcija sojinog ulja. Sadržaj vlage u sojinom ulju smanjuje se sa povećanjem površine mlaznice ekstrudera, kao i sa povećanjem doziranja ulazne sirovine. Na osnovu ocenjenog modela najveće vrednosti sadržaja SMK se postižu pri najmanjim razmatranim vrednostima vlažnosti ulazne sirovine, pri čemu sadržaj SMK se povećava sa povećanjem doziranja mase. Sadržaj fosfora u ulju se smanjuje sa povećanjem doziranja ulazne sirovine u ekstruder. Veća temperatura eksturzije [oC] postiže se pri manjim vrednostima vlage i površine otvora mlaznice. Sa povećanjem doziranja mase i pri fiksnim vrednostima vlage i površine otvora mlaznice očekivana vrednost temperature eksturzije opada. Sa povećanjem doziranja sirovine u ekstruder maksimalna očekivana vrednost potrošene energija po kilogramu produkcije (sojina pogača + sojino ulje) se smanjuje. Sa povećanjem doziranja sirovine u ekstruder maksimalna očekivana vrednost potrošene energije po kilogramu produkcije sojine pogače se smanjuje. Sa povećanjem doziranja sirovine u ekstruder minimalna očekivana vrednost potrošene energije po kilogramu produkcije sojinog ulja se povećava</p> / <p>AB <br /><br />The aim of this research is to determine the changes in chemical composition of the products at the outlet of the extruder and press (soya meal and oil), i.e. their quality in terms of their further use in animal feed production, food industry or the further use of soybean oil in bio-diesel production, with the functional correlation between the variable characteristics of feedstock and operating parameters of the extruder. Extrusion of soybeans was carried out on the extruder, type E-751, manufactured by "SREM PRODUKT" DOO from Lacarak, and pressing of oil on the press, type PM-5S, manufactured by "BRONTO" from Ukraine. Studies that were conducted in this PhD Thesis were done as a contribution to the expansion of knowledge related to the production process of soya cake and soya oil, and to provide practical guidelines for the optimal control and modeling of the extrusion process and squeezing soybeans, as well as for the designing of the extruder. Some experimental and laboratory tests were conducted in order to obtain and to analyze data that could determine changes in chemical composition of the products at the outlet of the extruder and press (soya cake and oil), i.e. their quality in terms of their further use in animal feed production, food industry or the further use of soybean oil in bio-diesel production, all with the functional correlation between variable characteristics of feedstock and operating parameters of the extruder. Experimental researches are intended for practical application, by which the production process of soya cake and soybean oil could be enhanced and optimized. The results obtained in these researches can be useful to everyone involved in the production of soya cake and soya oil. Experimental studies were carried out on the extruder, type E-751 and the press, type PM5S, but the results are also applicable to other extruders and presses from other manufacturers, that use soybean as a raw material and produce soybean cake and soybean oil. The conducted researches, processed and discussed results have led to the functional correlations between different extrusion parameters and variable characteristics of the incoming raw<br />___________________Doktorska disertacija, autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________IX od 34<br />materials on the one hand, and the characteristics of the extrudate and soybean oil on the other hand, and further on to the certain conclusions. Based on the experimental researches, the impact of changes in selected physical and chemical properties of soybeans was evaluated in the extrusion of soybeans. The PhD Thesis started with the analysis of raw material i.e. soybean and its composition: protein, oil, free fatty acids (FFA) and moisture, and then, the content of free fatty acids, phosphorus and moisture in soybean oil after pressing the extrudate were monitored, as well as protein, moisture, oil, urease activity and PDI (Protein Dispersibility Index) in soya cake by varying the operating mode of the extruder, i.e. feeding of raw material, monitored via load of the main drive motor of the extruder expressed through amperage [A], the die openings surface and moisture of soybeans. The conducted researches have led to the functional correlations between the preset operating modes of the extruder, incoming raw material and selected physical and chemical properties of soybeans in the extrusion process. Thus, with increasing the die openings surface and feeding mass, the production of soya cake is being increased as well. Production of soya cake is also increased with the increase of moisture in the incoming raw material. Moisture content in soya cake is being increased with the increase of moisture content in a feedstock and interactions of feeding mass and the die openings surface. Based on the conducted researches, it can be concluded that the oil content in soybean cake is being increased with the increase of the extruder die openings surface for each of the three moisture content in soybean as a feedstock, while the oil content in soybean cake is being decreased with increased dosage of feedstock for each of the three extruder dies. By increasing the surface area of the extruder die openings, there is a decrease of the protein content in soya expeller cake, while vice versa, with an increase in the dosing of input raw material, i.e. with increasing dosage of raw material to the extruder, the protein content in soya expeller cake is increased. The positive effect of urease activity (ΔpH) in soya cake is for larger values of the surface of extruder die<br />___________________Doktorska disertacija, autor:Kukić Predrag_____________________<br /><br /><br />_______________________________________________________________X od 34<br />openings as well as for the interaction of variables W (moisture in soybean) and D (soybean mass dosage determined via the load of the main electric motor). PDI in soybean cake increases with the increase in moisture content of raw material, the surface of the extruder die openings and the dosing of soybeans as a feedstock. Considering the data obtained for soybean oil, manufactured by squeezing the extruded soy product with the predicted moisture content in the feedstock, it has been concluded that the oil production decreases with increasing the surface of the extruder die openings, while by increasing the dosage of incoming raw material, the production of soybean oil is increased. Moisture content in soybean oil is reduced with the increase of the surface of the extruder die openings, as well as with an increase in dosage of feedstock. Based on the evaluated model, the largest values of FFA content were achieved with the smallest considered values for the moisture content in the incoming feedstock, wherein the content of FFA increases with increasing the feeding mass. The phosphorus content in the oil decreases with increasing the feeding of raw material into extruder. Higher extrusion temperatures [oC] are achieved at the lower values of moisture and surface of extruder die openings. With increasing the feeding mass and fixed values of moisture content and die openings surface, the expected value of the extrusion temperature decreases. With increasing the dosage of raw materials into the extruder, the largest expected value for the energy, spent per kilogram of production (soybean cake + soybean oil), decreases. By increasing the dosage of raw materials in the extruder, the largest expected value for the energy, spent per kilogram of soya cake production, is reduced. With increasing the dosage of raw materials in the extruder, the lowest expected value of energy, spent per kilogram of soybean oil production, increases</p>
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Modélisation du mélange de polymères chargés et de la casse de fibres rigides en extrusion bivis / Modelling filled polymers mixing and rigid fibres break-up in twin-screw extrudersDurin, Audrey 04 April 2012 (has links)
Dans cette thèse, nous avons voulu exploiter et étendre les outils de simulation à notre disposition pour proposer des méthodes de caractérisation et de prédiction du mélange à différentes échelles. À l'échelle locale d'écoulements macroscopiques, nous avons voulu exploiter les possibilités offertes par le logiciel de simulation 3D éléments finis XimeX® et y apporter des améliorations dans le but d'obtenir un outil d'étude du mélange distributif de particules dans un polymère par extrusion bivis. Nous avons ainsi enrichi la méthode éléments finis existante à l'aide de la bibliothèque éléments finis CimLib© du Cemef pour atteindre une plus grande précision de calcul, puis nous avons testé plusieurs méthodes de lâchers de particules afin de simuler le déplacement de charges dans la matrice polymère au cours du mélange. Nous avons ensuite appliqué quelques méthodes de caractérisations du mélange, dont une inédite, à ces lâchers de particules, et ce dans le cas de plusieurs géométries de vis. À l'échelle de la particule, on s'est intéressé aux mécanismes conduisant à la casse de fibres rigides, telles que les fibres de verre, lors du mélange avec un polymère en extrusion bivis. Nous avons choisi de faire des hypothèses assez importantes afin de simplifier ce problème extrêmement complexe et nous avons proposé une méthode de simulation de l'évolution de la distribution des longueurs de fibres le long de l'écoulement basée sur la conservation de la masse des fibres. Nous avons utilisé comme paramètres de cette simulation les résultats de calcul 1D obtenus par le logiciel Ludovic® qui repose sur des approches de type ALH. Nous avons ensuite comparé quelques résultats de calcul à des distributions de longueurs mesurées sur des échantillons prélevés le long d'une extrudeuse bivis. / In this thesis, we have attempted to use and to extend previously developed simulation tools to propose characterisation and mixing prediction methods at different scales. At a local macroscopic flow scale, we attempted to use the possibilities given by the 3D finite element software XimeX® and to improve it in order to obtain a tool for mixing simulation of filled polymers in twin-screw extruders. Thus we have enriched the existing finite element method using the Cemef finite element library CimLib© in order to achieve a greater computation accuracy. Then we have tested several particle tracking methods to predict the fillers displacement into the matrix during mixing. Furthermore, we have applied several characterisation methods to these particles tracking results for different screw geometries. At the particle scale, we have focused on the mechanisms leading to rigid fibres (such as glass fibres) breakage during mixing with polymer in twin-screw extruders. We have some assumptions in order to simplify this extremely complex problem. We then have proposed a simulation method of the evolution of the fibres length distribution along the flow. This method is based on the fibres mass conservation. We have used the results of the Ludovic® software 1D computations based on lubrication theory as impute parameters for this simulation. Then we have compared some computational results to length distributions measured on experimental samples taken along a twin-screw extruder.
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Desenvolvimento de novos compostos de borracha natural a partir da desvulcanização em extrusora com rosca dupla / Development of new natural rubber compounds from devulcanization in a twin-screw extruderBarbosa, Rafael 08 March 2017 (has links)
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Previous issue date: 2017-03-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The present study investigated the utilization efficiency of an intermeshing
co-rotating twin-screw extruder (ICTSE) in the devulcanization of natural rubber
compounds (NR), evaluating the physical, chemical and mechanical characteristics
of these materials in each project step. Three accelerated compounds with different
sulfur concentrations were submitted to torque rheometry and vulcanized according
these results aiming the achievement of elastomers with different crosslinks
densities. The influences on the characteristics of the devulcanized material caused
by the variation of the extruder barrel temperature, screw rotation, thermoplastics
addition and material stiffness were evaluated. Thermogravimetric analysis (TGA),
differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), soluble
fraction extraction and crosslink density were performed, evaluating the
devulcanized compound. Horikx's theory was also used as an indicator of selective
crosslink cleavage, defining the compounds to be revulcanized for comparison with
the virgin pure material. The revulcanization was carried out with the mixture of the
devulcanized compound with the pure, in the proportions of 30/70 w/w, respectively,
and in the devulcanized compound singularly, with addition of complementary
vulcanization system in both cases. The mechanical, dynamic-mechanical and
crosslink density properties of the revulcanized compounds were characterized and
evaluated in relation to the properties of the pure compounds. The increase in the
concentration of uncrosslinked BN chains and the concentration of sulfur
compounds in the extruded samples was observed by thermal tests and
spectrocopy, together with the verification of a high level of devulcanization
percentage, according to Flory-Rehner, evidencing the regeneration of the natural
rubber existent. Also, satisfactory mechanical properties were found in the
revulcanized compounds, especially when using auxiliary thermoplastics, revealing
the great potential of ERDCI processing for the reuse of discarded BN compounds. / O presente estudo avaliou a eficiência de utilização de uma extrusora com
rosca dupla co-rotacional e interpenetrante (ERDCI) na desvulcanização de
compostos de borracha natural (BN), avaliando as características físicas, químicas
e mecânicas destes materiais em cada fase do projeto. Três compostos acelerados
com diferentes concentrações de enxofre foram submetidos a reometria de torque,
e vulcanizados de acordo com a curva reométrica, para obtenção de elastômeros
com diferentes densidades de ligações cruzadas. Foram avaliadas as influências
nas características do material desvulcanizado, causadas pela variação da
temperatura do barril da extrusora, velocidade de rotação das roscas, adição de
termoplásticos e módulo elástico do material. Análises de termogravimetria (TGA),
calorimetria exploratória diferencial (DSC), espectroscopia no infravermelho (FTIR),
fração solúvel (FS) e densidade de ligações cruzadas foram realizadas, avaliandose
o composto desvulcanizado. A teoria de Horikx também foi utilizada como
indicativa da seletividade de ruptura de ligações cruzadas, definindo os compostos
a serem revulcanizados para comparação com o material virgem. A revulcanização
foi realizada com a mistura de 30 %(m/m) do composto desvulcanizado e 70
%(m/m) do puro, e também com 100 % do composto desvulcanizado, e adição de
sistema de vulcanização complementar. Caracterizou-se os compostos
revulcanizados quanto às suas propriedades mecânicas, dinâmico-mecânicas e
densidade de ligações cruzadas. Através dos ensaios TGA, DSC, FTIR e a
verificação de alto nível de percentual de desvulcanização pela teoria de Flory-
Rehner, foi observado o aumento da concentração de cadeias de BN não
reticuladas e da concentração de compostos de enxofre nas amostras extrudadas,
evidenciando a regeneração da BN presente nos compostos. Também foram
encontradas propriedades mecânicas satisfatórias nos compostos revulcanizados,
principalmente quando utilizados termoplásticos auxiliares, revelando o grande
potencial do processamento por ERDCI para a reutilização de compostos de BN
descartados.
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Chocolat3D : En choklad 3D-skrivare med dubbla skrivhuvuden och hantering av två typer av chokladCarina, Bui, Eric, Oscarsson January 2017 (has links)
Hur långt spänner sig utvecklingen av 3D-skrivare? Projektet Chocolat3D syftar till att expandera det hastigt växande användningsområdet för 3D-skrivartekniken. Genom att utveckla ett nytt 3D-skrivarsystem där användaren enbart behöver tillsätta choklad till systemet, börjar skrivaren automatiskt smälta och temperera choklad för att sedan påbörja en utskrift. Systemet kan göra en utskrift med två typer av choklad, och ett koncept för hur rengöring av skrivaren är framtagen. Projektet består av två projektgrupper, där projektgrupperna har indelade fokusområden mot mekatronik, respektive data och elektronik. Rapporten avhandlar arbetet som utförs av två högskoleingenjörsteknologer med inriktning inom mekatronik, på Högskolan i Halmstad. Målet med arbetet är att identifiera och konstruera de delsystem som behövs för att modifiera en 3D-skrivare framtagen för utskrift med plast, till en 3D-skrivare för utskrift med choklad. Metoderna som gruppen undersöker, utvärderar och tillämpar är befintliga lösningar inom chokladindustrin, samt dagens 3D-skrivarteknologi. Tester för metoder presenteras för att göra kritska val för de ingående delsystemen. Arbetet resulterade i utveckling av fyra delsystem. Skrivaren och designen, som bas för projektet, ett extruderingssystem för utskriften av choklad. Ett tempereringssystem, för automatisk temperering av choklad, samt ett koncept för invändig rengöring av skrivaren. Det är en kombination av befintliga metoder som bidrar till en innovativ choklad 3D-skrivarprototyp för marknaden inom additiv tillverkning. / How far is it possible to take the 3D-printing technology? The project Chocolat3D aims to expand the already rapid growing area of use within the 3D-printing technology. By developing a new 3D-printing system where the user only needs to add chocolate to the process, the printer will automatically to melt and temper chocolate and then start the printing process. The system is able to print in two different types of chocolate, and a concept of internal cleaning is developed. The project consists of two project groups, where the project groups have divided areas of focus between mechatronics, respective software and electronics. This thesis cover the work of two engineering-graduates within mechatronics, at Halmstad University. The aim of the work is to identify and design the subsystems needed to modify a 3D printer built for printing with plastic, into a 3D printer for printing chocolate. The methods the group investigates, evaluates and applies are existing solutions in the chocolate industry, as well as today's 3D printing technology. Tests for methods are presented to make critical choices for the new subsystems. The work resulted in the development of four subsystems. The printer and the design, acting as a base for the project. An extrusionsystem, for the printing of chocolate. A temperingsystem, for automatic tempering of chocolate, and aswell a concept for internal cleaning of the printer. It is a combination of existing methods that contribute to an innovative chocolate 3D printer prototype within the additive manufacturing market. / Chocolat3D
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Nouveau procédé de fractionnement de la graine de Neem (Azadirachta Indica A. Jussi) sénégalais : production d'un bio-pesticide d'huile et de tourteau / New fractionation process of Neem (Azadirachta Andica A. Jussi) seed : production of bio-pesticide, oil and cakeFaye, Mamadou 29 November 2010 (has links)
Originaire de l'Inde, le neem (Azadirachta indica Juss.) est un arbre présent dans les zones tropicales sèches et subtropicales d'Asie, d'Amérique et d'Afrique. Au Sénégal, il produit en moyenne 50 kg par an d'un fruit sous forme de drupe ellipsoïdale, qui contient en général une graine, d'un poids moyen de 270 ± 30 à 91 % de matière sèche. La variabilité des caractéristiques des graines (45 à 48 % de coques fibreuses : cellulose 52 à 54 %, hémicelluloses 24 à 28 %, lignine 7 à 9 % ; 52 à 55 % d'amandes : lipides 45 à 58 %, protéines 20 à 23 %j) et des huiles extraites (acides palmitiques : 17 à 19 %, stéarique : 14,5 à 17,5 %, oléique : 42 à 48,5 %, linoléique : 16,5 à 20 % ; stérols totaux : 3 à 5 g/kg) est analysée pour 5 régions du Sénégal. L'extraction de l'azadirachtine, principal principe actif phytosanitaire de la graine, par différents solvants (méthanol, éthanol, eau) révèle une teneur de 2 g par kg de graine, localisée essentiellement dans l'amande (3,9 g/kg). Les conditions d'expression de l'huile de graine de neem sont étudiées en presse mono-vis OMEGA 20 et en extrudeur bi-vis CLEXTRAL BC 21. Dans les meilleures conditions, 65 et 68 % de l'huile sont exprimées, 7 à 10 % de l'azadirachtine sont entraînées avec l'huile, et le tourteau contient 14 % de lipides, 14 % de protéines et près de 2 g/kg d'azadirachtine. Le fractionnement acqueux, sous cisaillement intense des graines, conduit à l'extraction de 55 % des lipides, 50 % des protéines et 80 % de l'azadirachtine, séparés sous forme d'une émulsion stable, de composition : eau 70 %, huile 25 %, protéines 4 %, azadirachtine 6 g/kg, et d'une phase aqueuse. L'étude de la mise en œuvre du procédé d'extraction et de séparation, en extrudeur bi-vis CLEXTRAL BC 21 puis BC 45, permet de produire en continu 0,3 kg d'émulsion stable par kg de graine traitée (20 kg/h) avec un ratio eau/graine de 2 et une température de 60°C. Le tourteau ne contient plus que 0,6 g/kg d'azadirachtine, et l'émulsion stable qui en contient 5 g/kg peut être directement mise en œuvre dans les formulations d'insecticide totalement biosourcés. / Originally from India, neem (Azadirachta indica Juss.) is a tree found in the dry tropics and subtropics of Asia, America and Africa. In Senegal, it produces an average of 50 kg per year of a fruit as a drupe ellipsoid, which generally contains a seed, with an average weight of 270 ± 30 to 91% dry matter. The variability of seeds (45 to 48% of capsular cellulose 52-54%, 24-28% hemicellulose, lignin 7-9% 52-55% almonds: 45 to 58% lipids, proteins 20 to 23% j) and extracted oils (palmitic acid: 17 to 19%, stearic: 14.5 to 17.5%, oleic acid: 42 to 48.5%, linoleic: 16.5 to 20% total sterols: 3 5 g / kg) was analyzed for five regions of Senegal. Extraction of azadirachtin, the main active ingredient of the plant seed by different solvents (methanol, ethanol, water) shows a content of 2 g per kg of seed, mainly localized in the kernel (3.9 g / kg ). The expression conditions of neem seed oil were studied in single-screw press OMEGA 20 and twin-screw CLEXTRAL BC 21. Under optimum conditions, 65 and 68% of the oil is expressed, from 7 to 10% of azadirachtin are entrained with the oil and meal contains 14% fat, 14% protein and about 2 g / kg azadirachtin. Watery splitting under intense shear seeds, led to the extraction of 55% lipids, 50% protein and 80% of azadirachtin, separated as a stable emulsion, composition: water 70% oil 25%, 4% protein, 6 g azadirachtin / kg, and an aqueous phase. The study of the implementation of the method of extraction and separation, twin-screw extruder and then CLEXTRAL BC 21 BC 45, produces continuous stable emulsion 0.3 kg per kg of treated seed (20 kg / h) with a ratio water / seed of 2 and a temperature of 60 ° C. The cake contains only 0.6 g / kg of azadirachtin, and stable emulsion which contains 5 g / kg can be directly implemented in the formulations of insecticide biosourced completely.
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3D tisk kmenových buněk a analýza mikroskopických obrazů / 3D bioprinting of stem cells and analysis of microscopic imagesKandra, Mário January 2017 (has links)
In this diploma thesis we are discussing about using 3D bioprinting in tissue engineering. We are discribing using biomaterials for construction scaffolder and aplication stem cells in 3D bioprinting. Last section of theoretical part deals with very often used techniques of 3D bioprinting and we are focused on extrusion technique. In the practical part we propose a method for print vasculars structures. We realized prototype of print head, her design and 3D printing of individual parts. To mechanical part we create a control system for printing control. At the end we visualize the organization of the cells using program modules.
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Extensional Mixing Elements for Improved Dispersive Mixing in Extrusion OperationsPandey, Vivek 07 September 2020 (has links)
No description available.
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