Solvent-free extrusion emulsification (SFEE) is a recently developed process for producing submicron particles with high viscosity polymers inside a twin-screw extruder without the use of hazardous solvents. Its dependency on a catastrophic phase inversion makes the process knowingly sensitive to a variety of formulation and operational variables, causing a narrow window of production. The purpose of this thesis was to investigate and improve process stability as well as widening operational window. Transient effects of the start-up procedure was investigated by considering the process stability and particle size distribution. The transient sensitivity corresponded to the residency of material in the dispersion zone. When a sub-optimal water/surfactant fraction was allowed to produce an undesired polymer-water (thick lamella) morphology, this morphology continued to persist until the critical first half of the dispersion zone was purged of existing mass. Lot to lot variability of polyester resin was used to investigate the sensitivities of the SFEE process more deeply to better understand the mechanism involved. In this case, acid number was shown to have a significant effect on the initial amount of water needed in the dispersion zone for phase inversion, resulting in an emulsification boundary dependent on the resin acid number. In fact, a significant correlation was found between the acidic end groups of the resin and the maximum amount of water content that could be used in the dispersion zone. The effect of feed rate, screw speed, dispersion length, and surfactant concentration were studied for their individual influence on widening the emulsification boundary. The most significant improvement was observed by applying a longer dispersion length or lower feed rate because both significantly increase the residence time. The effect of residence time on the emulsification boundary was attributed to the total strain imposed on the polymer/water mixture which was related to interfacial growth in the dispersion zone. / Dissertation / Doctor of Philosophy (PhD)

No description available.

No / Experimental observations of melt temperature profiles and melting performance of extruder screws are reported. A novel temperature sensor consisting of a grid of thermocouple junctions was used to take multiple temperature readings in real time across melt flow in a single screw extruder. Melt pressure in the die and power consumption were also monitored. Three extruder screws at a range of screw speeds were examined for a commercial grade of low density polyethylene. Results showed melt temperature fields at low throughputs to be relatively independent of screw geometry with a flat-shaped temperature profile dominated by conduction. At high throughputs, melting performance and measured temperature fields were highly dependent upon screw geometry. A barrier-flighted screw with Maddock mixer achieved significantly better melting than single flighted screws. Low temperature "shoulder" regions were observed in the temperature profiles of single-flighted screws at high throughput, due to late melting of the solid bed. Stability of the melt flow was also dependent upon screw geometry and the barrier-flighted screw achieving flow with lower variation in melt pressure and temperature. Dimensionless numbers were used to analyze the relative importance of conduction, convection, and viscous shear to the state of the melt at a range of extrusion conditions.

Es wird untersucht, ob in Schneckenextrudern verwendete Förderelemente aus Stahl durch das Oberflächenfeinwalzen der schraubförmigen Mantelfläche gleichzeitig geglättet und verfestigt werden können. Steigungsprofile, zu denen auch die Förderelemente zählen, werden bislang oft nach der Hauptformgebung wärmebehandelt und im harten Werkstoffzustand spanend feinbearbeitet. Formgebung, Wärmebehandlung und Feinbearbeitung sind voneinander getrennte Prozessschritte. In dieser Arbeit besteht das Ziel, die Verfahrenseingangsgrößen für die Kombination aus Formgebung und definierter lokaler Werkstoffverfestigung beim Walzen zu erarbeiten. Zu diesem Zweck werden sowohl am Steigungsprofil selbst als auch an einem davon abgeleiteten Rotationsprofil simulative, experimentelle sowie analytische Untersuchungen durchgeführt. Es werden geometrische, kinematische und werkstofftechnische Gesichtspunkte beleuchtet. Aufbauend auf dem Vergleich zwischen Simulationsergebnissen mit der Finite-Elemente-Methode und im Versuch ermittelten Daten werden Haupteinflussfaktoren auf die geometrischen Abweichungen sowie die Härtesteigerung in der Bauteilrandschicht ermittelt. Mit Hilfe eines neu entwickelten sensorischen Werkstückträgers wird die Drehbewegung des Werkstücks erfasst. Aus den analytischen Betrachtungen wird schließlich ein Modell zur qualitativen Beschreibung des Walzkraftverlaufs abgeleitet, das zur Vorauswahl von Verfahrenseingangsgrößen genutzt werden kann. Im Ergebnis wiederholter Messungen wird deutlich, dass mit der geometrischen Gestaltung einer Walzvorform gezielt Einfluss auf Umformgrad und damit Verfestigung im Bauteil genommen werden kann. An den untersuchten hochfesten korrosionsbeständigen austenitischen Stählen ist eine Verdopplung der Halbzeughärte möglich. Die beim Spanen der Vorformen auftretenden Formabweichungen haben großen Einfluss auf die Beschaffenheit der Zielgeometrie sowie die erzielbare Härtesteigerung. Durch Kenntnis der realen Werkstückdrehbewegung während des Walzens lassen sich Rückschlüsse auf die Werkzeuggestaltung und die Walzparameter ziehen. Aufgrund der Untersuchungsergebnisse wird das Verfahren für die Anwendung an korrosionsbeständigen Bauteilen mit mittleren Verschleißschutzanforderungen empfohlen.:1 Einleitung 2 Stand der Technik 3 Zielstellung der Arbeit 4 Beschaffenheit der Werkstücke und Werkzeuge 5 Modellbildung mit Hilfe der FEM 6 Versuchsvorbereitung und Eingangsgrößen 7 Vergleich der Verfahrenskenngrößen in Simulation und Experiment 8 Analytisches Modell zur qualitativen Vorhersage der Walzkraft 9 Bauteileigenschaften nach dem Walzen 10 Zusammenfassung und Ausblick / A combined surface burnishing and mechanical hardening process for steel conveying elements in screw extruders is examined. Helical profiles, that also comprise conveying elements, are often heat treated after shaping followed by fine processing. Shaping, heat treatment and fine processing are sequential process steps. This work deals with the investigation of rolling process parameters that enable both low geometrical deviations and high work hardening of the screw material. For this purpose, helical and axisymmetric profiles are analyzed with simulative, experimental and analytical methods. The investigations highlight geometrical, kinematical and material-related aspects. The main factors with influence on screw geometry and hardness increase in the component subsurface are investigated by means of the comparison between simulative and experimental results. An intelligent workpiece carrier is applied to analyze the part rotation. Based upon analytical observations, a calculation model for the prediction of the rolling force curve over workpiece rotation is developed. This model supports predefining the process input variables. Repeated measurements indicate that the geometrical design of the machined preforms allows for individual strain and hence hardness distributions in the part subsurface. Hardness can be doubled in the investigated corrosion resistant austenitic high strength steels. Form deviations of the part and hardness increase are strongly dependent on geometrical deviations of the preform. Knowledge of part rotation during rolling enables to draw conclusions for tool design and rolling parameters. Based on the results it is suggested to apply the rolling procedure to parts in environments which require high corrosion resistance and moderate wear resistance.:1 Einleitung 2 Stand der Technik 3 Zielstellung der Arbeit 4 Beschaffenheit der Werkstücke und Werkzeuge 5 Modellbildung mit Hilfe der FEM 6 Versuchsvorbereitung und Eingangsgrößen 7 Vergleich der Verfahrenskenngrößen in Simulation und Experiment 8 Analytisches Modell zur qualitativen Vorhersage der Walzkraft 9 Bauteileigenschaften nach dem Walzen 10 Zusammenfassung und Ausblick

The aim of this thesis is the investigation of modeling and optimization particularities of tubular polymerization reactors. The original work is divided in two sections, the first treating a modeling and optimization study of tubular reactors for methyl methacrylate polymerization in solution, and the second, an experimental and theoretical study of L-lactide reactive extrusion. In the first section, reactor simulations in similar operating conditions were performed in order to select a representative kinetic model among the published kinetic models for MMA solution polymerization. Two widely used numerical algorithms, one based on Pontryagin's Minimum Principle and the other a Genetic Algorithm, were compared for an average-complexity optimization problem. The results showed a superior robustness of the Genetic Algorithm for this category of problems. The second part of the thesis deals with the modeling and optimization of L-lactide reactive extrusion. A kinetic model is proposed and its parameters estimated using nonlinear estimation numerical procedures based on experimentally measured data. Reactive extrusion experiments were performed in representative operating conditions. The Llactide/ polylactide flow in the extruder was characterized by simulation using the commercial software LUDOVIC®. The simulated residence time distributions characteristics are used to model the reactive extrusion process of two approaches, an axial dispersion model and a compartment model, based on compartments whose characteristics are deduced from the simulations using LUDOVIC®. The modeling results are in good agreement with the measured data in the same operating conditions.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-05-25T19:49:56Z No. of bitstreams: 1 DissBDQ.pdf: 27222907 bytes, checksum: eb17b232bd0096bfa1e0fb1dd7f4bf74 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-30T13:44:57Z (GMT) No. of bitstreams: 1 DissBDQ.pdf: 27222907 bytes, checksum: eb17b232bd0096bfa1e0fb1dd7f4bf74 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-05-30T13:45:05Z (GMT) No. of bitstreams: 1 DissBDQ.pdf: 27222907 bytes, checksum: eb17b232bd0096bfa1e0fb1dd7f4bf74 (MD5) / Made available in DSpace on 2017-05-30T13:50:33Z (GMT). No. of bitstreams: 1 DissBDQ.pdf: 27222907 bytes, checksum: eb17b232bd0096bfa1e0fb1dd7f4bf74 (MD5) Previous issue date: 2015-10-06 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / In this study nanocomposites of polyamide-6 (PA-6) reinforced with silica nanoparticles (SiO2) were prepared in order to promote improved mechanical properties for engineering applications. The nanoparticles’ surfaces were chemically modified with the silane agent 3-aminopropyltrimethoxysilane (3- APTMS) to improve the chemical and physical interactions between them and the PA-6 matrix. Nuclear magnetic resonance analysis (NMR) and Fourier transform infrared absorption spectroscopy (FT-IR) showed that 3-APTMS grafting on nanoparticles surface was accomplished. The nanocomposites mixing process was studied in two forms: by torque rheometry, using a torque rheometer internal mixer; and in a co-rotating and intermeshing twin-screw extruder. A preliminary study of the influence of processing variables at the torque rheometer on the degradation of polyamide-6 matrix was performed. The results showed that the greater the filling volume of the mixture in the chamber and the rotational speed of the rheometer’s rotors, the lower the degradation of the polyamide-6. Based on this preliminary study, compositions with 1, 2, and 4 % weight of SiO2 nanoparticles, both unmodified and chemically modified with 3-APTMS were prepared in the torque rheometer. The nanocomposites were compression molded and it was observed that nanocomposites reinforced with 1 wt.% SiO2, both unmodified and surface-modified, presented the best tensile properties. For the nanocomposite samples processed in the twin-screw extruder, the influence of relevant variables – nanoparticle content, chemical surface modification, physical form of the fed PA-6 (granule and powder), rotational speed of screws and extruder feed rate – on mechanical, thermal, and dynamic-mechanical properties were studied. The samples were afterwards injection molded and it was observed that the samples produced using 1 wt.% surface-modified and 100% finely ground PA-6 showed the higher tensile modulus and yield strength values. / Neste estudo foram preparados nanocompósitos de poliamida 6 (PA6) reforçados com nanopartículas de sílica (SiO2), com o objetivo de promover melhoria de propriedades mecânicas para aplicações de engenharia. A superfície das nanopartículas foi modificada quimicamente com o agente silano 3-aminopropiltrimetoxisilano (3-APTMS) para melhorar as interações químicas e físicas entre elas e a matriz de PA6. Análises de ressonância magnética nuclear (RMN) e espectroscopia de absorção no infravermelho por transformada de Fourier (FT-IR) mostraram que houve sucesso na funcionalização das nanopartículas com o agente silano. O processo de mistura dos nanocompósitos foi estudado de duas formas: por meio de reometria de torque em um misturador interno; e em extrusora com rosca dupla co-rotacional e interpenetrante. Um estudo preliminar da influência das variáveis de processamento no reômetro de torque sobre a degradação da poliamida 6, mostrou que quanto maior o volume de preenchimento da câmara de mistura e a velocidade de rotação dos rotores do reômetro, menor foi a degradação da poliamida 6. Com base neste estudo preliminar, foram preparadas no reômetro de torque composições com 1, 2 e 4% em massa de nanopartículas de SiO2 não modificadas e modificadas quimicamente com 3- APTMS. Os nanocompósitos obtidos foram moldados por compressão, tendo sido observado que os nanocompósitos reforçados com 1 %m. de SiO2 não modificada apresentaram as melhores propriedades mecânicas de resistência à tração e deformação na ruptura em ensaio de tração, enquanto os nanocompósitos com 1 %m. de nanosílica modificada apresentaram as melhores propriedades mecânicas de módulo elástico também no ensaio de tração. Para as amostras de nanocompósitos processadas na extrusora de rosca dupla, foram estudadas as influências do teor de nanopartículas, da modificação química superficial, da forma física da PA6 alimentada (grânulo e pó), da velocidade de rotação das roscas e da taxa de alimentação da extrusora sobre as propriedades mecânicas, térmicas e dinâmico-mecânicas. Posteriormente, os corpos de prova foram moldados por injeção e observou-se que a amostra cuja composição polimérica foi de 100% de PA6 fina e reforçada com 1 %m. de nanosílica modificada superficialmente pelo agente silano 3- APTMS apresentou os maiores valores de módulo de elasticidade e de tensão no escoamento no ensaio mecânico sob tração.

Submitted by HUMBERTO FABRIZZI DE FIGUEIREDO PUPO null (betopupo@gmail.com) on 2017-08-31T20:25:11Z No. of bitstreams: 1 Tese_Humberto_Pupo.pdf: 4727522 bytes, checksum: bc9418ef91885cfe96ab6372394b80b6 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-09-01T14:51:09Z (GMT) No. of bitstreams: 1 pupo_hff_dr_bot.pdf: 4727522 bytes, checksum: bc9418ef91885cfe96ab6372394b80b6 (MD5) / Made available in DSpace on 2017-09-01T14:51:09Z (GMT). No. of bitstreams: 1 pupo_hff_dr_bot.pdf: 4727522 bytes, checksum: bc9418ef91885cfe96ab6372394b80b6 (MD5) Previous issue date: 2017-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A utilização dos resíduos sólidos como matéria-prima pode diminuir consideravelmente a extração de recursos naturais, diminuindo assim o impacto sobre o meio ambiente. Dentre os resíduos, os plásticos estão entre os que mais apresentam problemas, pois, mesmo quando descartados corretamente nos aterros sanitários, causam danos ao formarem uma camada impermeável que dificulta a compactação do lixo, afetando as trocas de líquidos e gases gerados e reduzindo a eficiência do processo de biodegradação da matéria orgânica. Diante dos problemas, este trabalho teve por objetivos avaliar a viabilidade técnica de utilização de dois tipos de processos: a extrusora dupla rosca e o misturador termocinético (Drais), na produção de compósitos de BOPP (Polipropileno Biorientado metalizado), reforçados com resíduos de cascas, de eucalipto (CE) e de arroz (CA). Das misturas entre esses resíduos, foram confeccionados 10 tratamentos, de onde se extraíram os corpos de provas, moldados por injeção. Foram avaliadas as propriedades mecânicas (flexão – módulo de ruptura-MOR e módulo de elasticidade-MOE, resistência à tração, resistência ao impacto e dureza Shore D), térmicas (avaliação da condutividade térmica e isolamento térmico), termomecânica (temperatura de deflexão sob aquecimento-HDT) e morfológica, com microscópio estéreo e aumento de 50 vezes para analisar a estrutura interna do corpo de prova, depois de fraturado pelo ensaio de impacto. Para análise das propriedades mecânicas dos corpos de provas, foram utilizadas como referência as normas ASTM D638-14, ASTM D790-10, ASTM D256-10 e a ASTM D-2240-15, para os ensaios de tração, flexão, impacto e dureza Shore D, respectivamente. Para as análises térmicas foi utilizada a norma ASTM E1530-11. Para o HDT, foi utilizada a norma ASTM D648-16. Os resultados mostraram influência de todos os parâmetros analisados nas propriedades dos compósitos. O uso de reforço (CE e CA) nos dois tipos de processos melhorou as propriedades de flexão e de resistência à tração em relação à matriz sem reforço e piorou as propriedades de resistência ao impacto e de dureza Shore D. Com relação à matriz sem reforço, a extrusora mostrou influência no ensaio de resistência à tração. Para adição de casca de eucalipto, o misturador termocinético (Drais) mostrou influência no ensaio de MOE. Já para adição de casca de arroz, a drais mostrou influência nos ensaios de flexão – MOR e MOE e na resistência à tração. Houve melhor adesão entre fibra e matriz nos compósitos confeccionados por extrusão em relação aos confeccionados na drais. As CE apresentaram melhor adesão com a matriz, em relação às CA. Os vazios – bolhas de ar foram observados em todos os tratamentos, com exceção dos tratamentos com ausência de reforço (BOPP 100). Esses vazios foram observados em maior proporção nos compósitos com CE em relação aos compósitos com CA, e também nos compósitos processados na extrusora em relação à drais. Os melhores resultados foram obtidos utilizando o misturador termocinético (Drais) e para as maiores proporções de cascas usadas ou na ausência delas. Porém, pelo fato de o processo utilizado na Drais ser por batelada, a extrusora se torna mais eficiente, levando em consideração o rendimento da produção. Os melhores resultados foram com a utilização de casca de eucalipto. Para os ensaios de flexão MOR, MOE e de resistência à tração, apresentaram interação entre os processos e os resíduos testados. Confirmou-se a viabilidade técnica de utilização de resíduos sólidos industriais (BOPP e CE) e agroindustrial (CA) na produção de compósitos fibra-polímero, sendo que o controle dos processos utilizados é fundamental para a qualidade do produto final. / The use of solid waste as raw material can considerably reduce the extraction of natural resources, thus reducing the impact on the environment. Among residues, plastics are among the most problematic ones because, even when they are properly disposed in landfills, they cause damage by forming a barrier layer which makes it difficult to compact the garbage, affecting the exchange of generated liquids and gases, reducing the efficiency of the biodegradation process of the organic matter. Before such problems, the objective of this work was to evaluate the technical feasibility of two types of processes, the double screw extruder and the thermokinetic mixer - dryser, in the production of BOPP (Bioriented metallized Polypropylene) composites, strengthened by residues of barks eucalyptus (CE) and rice (CA). From the mixtures among these residues 10 treatments have been prepared, from where the test bodies were extracted, molded by injection. Mechanical properties (flexurerupture modulus-MOR and elasticity modulus-MOE, tensile strength and impact strength towards Shore D hardness), as well as thermal (thermal conductivity and thermal insulation evaluation), thermo-mechanical (heat deflexion temperature-HDT) and morphological characteristics have been evaluated by using a stereo microscope and 50x magnification to analyze the internal structure of the test body, after being fractured by the impact test. For analyzing the mechanical properties of the proof bodies the standards ASTM D638-14, ASTM D790-10, ASTM D256-10 and ASTM D-2240-15 have been used as a reference for tensile, bending, impact and Shore D hardness tests, respectively. For the thermal analyzes, the ASTM E1530-11. For the HDT the ASTM D648-16 standard was used. The results showed the influence from all the analyzed parameters on the composites properties. The use of reinforcement (CE and CA) in both types of processes have improved the flexure and tensile strength properties in relation to the non-reinforced matrix and has worsened the impact strength properties as well as the Shore D hardness. Concerning the non-reinforced matrix, the extruder showed influence on the tensile strength test. For the addition of CE, the thermokinetic mixer - dryser has showed influence in the flexure modulus test. As for rice husk addition, dryser has showed influence in flexure (stress tests on maximum strengthMOR and elasticity modulus-MOE and tensile strength). There was a better adhesion between fiber and matrix, in the composites made by extrusion, compared to those made in the dryser. The CE has shown better adhesion with the matrix, compared to CA. The voids - air bubbles have been observed in all treatments with no reinforcement (BOPP 100). These voids have been more often observed in composites with CE, compared to the composites with CA and also in composites processed in the extruder, in relation to the dryser. The best results were obtained by using the thermokinetic mixer - dryser and for the largest proportions of the barks or in their absence. However, because the process used in Drais is by batch, the extruder becomes more efficient, taking into account the yield of the production. The best results have been from the use of CE. For flexure - MOR and MOE and tensile strength, there was an interaction among the processes and the tested residues. The technical feasibility of the use of industrial solid wastes (BOPP and CE) and agroindustrial (CA) in the production of fiberpolymer composites has been confirmed, and the control of the processes used is fundamental for the quality of the final product.

This Master's Thesis is focused on the design and control of a small-series production line, for the production of segmetal arches and plastic reductions. It is about the conversion from a semi-automatic line to a fully automatic line. The production line consists of an extruder, a cutting unit, a exhaust unit, three pressing machines and a manipulator. Every single machine has a custom control for which was selected a baseplate with microcontroler ATmega 128 and designed powerful part of inputs and outputs. There is a simple communication between the machines. Appropriate elements were used for conversion of every individual part of the production line. The whole system is programmed with software called AVR Studio4.

Das Ziel dieser Arbeit bestand in der Erarbeitung von Verfahrenskonzepten zur stofflichen Nutzung von Fichtenrinde und im Nachweis deren technischer Realisierbarkeit. Dabei wurden drei Verfahrensvarianten zur Herstellung eines festen Rindenwerkstoffes mit guter Dämmwirkung, einem schüttfähigen Dämmstoff in Form von Pellets und Granulaten und einem Werkstoff mit hoher Festigkeit und Oberflächengüte erarbeitet. Zu Beginn der Arbeit wurden Qualitätsziele der Produktkennwerte formuliert, die für Rindenprodukte bisher nicht erreichbar waren. Diese sollten trotz der Maßgabe, auf synthetische Bindemittel zu verzichten, erreicht werden. Die konsequente Anwendung verfahrenstechnischer Grundoperationen mit bewährten Apparaten, erweitert durch ein neues System aus Heizung und Kühlung während der Pressverdichtung, ermöglichten das Erreichen und zum Teil Übertreffen der geforderten Qualitätsziele. Die technische, aber auch wirtschaftliche Umsetzung ist möglich.

L’enrobage à sec par action mécanique permet de formuler des particules composites dont les fonctionnalités et les propriétés physiques, comme l’écoulement, sont améliorées et cela sans l’ajout de solvant ou de liant. Actuellement la plupart des procédés d’enrobage à sec sont conduits en mode discontinu. L’objectif de ce travail est donc de développer et d’étudier une opération d’enrobage à sec par un procédé continu innovant, une extrudeuse bi-vis corotative sans filière, constituant une rupture technologique dans son domaine. Dans le cadre de ce travail, des sphères de cellulose microcristalline, appelées particules hôtes sont enrobées avec soit des talcs de différentes granulométries soit du stéarate de magnésium, nommées particules invitées. Dans un premier temps, le comportement des particules hôtes est étudié dans le procédé. Les particules sorties du procédé sont analysées par microscopie électronique à balayage, par granulométrie laser et par voluménométrie. Pour la configuration de vis présentant que des éléments de transport, la vitesse de rotation des vis (25 à 200 rpm) et le débit d’alimentation (0,5 à 2 kg/h) choisis influencent le taux de remplissage dans le fourreau, et pour un taux supérieur à environ 14 % : la quantité de particules endommagées est négligeable. Un taux de remplissage faible favorise les frictions particules-particules ou particules-métal au niveau de l’entrefer. L’ajout de zones de mélanges dans la configuration des vis accentue ce phénomène de brisure par l’augmentation des contraintes de cisaillement. Par ailleurs, des masses retenues de la poudre dans le fourreau évoluent linéairement en fonction de la masse de poudre transportée en un tour de vis pour différentes configurations de vis. Ces relations laissent penser à l’existence d’un volume mort. Les mesures de distribution de temps de séjour mettent en évidence par l’application d’un modèle d’association de réacteurs idéaux, la présence d’écoulement piston et d’un volume mort. Dans un second temps, la faisabilité d’une opération d’enrobage à sec par le procédé étudié est analysée. Une couche d’enrobage continu de talc modifiant le comportement hydrophile des particules hôtes, est obtenue pour une vitesse de rotation de vis de 50 rpm et une configuration de vis cisaillante. Le type de particules invitées influence la morphologie de la couche d’enrobage : de type film avec le stéarate de magnésium et de type discret avec le talc micronisé. Néanmoins les propriétés de taille, d’écoulement, de compressibilité des particules composites sont semblables à celle des particules hôtes, seule la propriété de mouillabilité est modifiée. La présence de stéarate de magnésium diminue le temps de séjour des particules dans le procédé grâce à son caractère lubrifiant. / Dry particle coating with mechanical action allows the production of composite particles whose functionalities and physical properties, such as flowability, are improved thanks to the absence of solvent or binder. Currently, most of dry particle coating processes are carried out in a discontinous mode. The objective of this work is thus to develop and study a dry particle coating operation with a continuous innovative process, twin screw co-rotating extruder without die, constituting a technological rupture in this application field. For this, spherical particles of microcristalline cellulose, as host particles, are coated with either talc particles of two sizes or magnesium stearate particles (MgSt), as guest particles. Firstly, the host particles behaviour is studied in the process. The exiting particles are analyzed by scanning electronic microscopy, laser granulometry and tapping test. Regarding the transport configuration, the chosen screw speed (between 25 an 200 rpm) and the feed rate (between 0.5 and 2 kg/h) have an important influence on the filling level in the barrel. For a filling level superior to approximatly 14 %, the quantity of broken particles is not significant. A low filling level facilitates the particle-particle or particle-metal friction in the barrel gap. When more mixing zones are added to the screw configuration, the shear stresses increase and, therefore, the breakage particle phenomenon becomes more prominent. Futhermore, the retained powder mass increases linearly when the transported mass in one screw turn increases for all the screw configurations. These evolutions suggest the existence of a dead volume. The residence time distribution mesurements highlight, thanks to the application of flowing model, the presence of plug-flow and a dead volume. Secondly, the feasibility of using the process for dry particle coating is analyzed. A continuous coating layer of talc modifiying the hydrophilic behaviour of the host particles is obtained for a low screw rotation speed (50 rpm) and a screw configuration with one mixing zone. The type of guest particles influence the morphology of the coating layer: film layer with the MgSt particles and discontinous layer with the micronized talc. However, size, flow and compressibility of the coated particles are similar to the ones of the initial host particles, only the wettability properties are modified. The presence of MgSt decreases the particle mean residence time in the process thanks to its lubricant action.