The diploma thesis Rationalization technology of production tools is divided into two parts. The first part is focused on injection molding of plastic materials and analysis current status of production injection tools. The second part contains proposal of rationalization steps in the production process and evaluation of rationalization.

This master’s thesis focuses on a design of injection mold which is used for manufacturing of a plastic holder of roof rack. The first part includes shape analysis of the holder and explains function of the product as well as specify essential requirements which must be met. The choice of the most suitable manufacturing technology is followed by theoretical part which deals with literature review of plastic materials, technology of injection molding and basics of injection mold designing. Practical part includes overall design of the mold for the holder of roof rack based on technological calculations. Practical part is followed by mold flow analysis simulation showing suitability of designed mold along with selection of suitable injection molding machine based on product construction design and technological process of manufacturing. The conclusion of master’s thesis includes an economical evaluation of proposed manufacturing technology.

The aim is to design a single purpose machine for drilling and slotting plastic molding and then pressing the internal mechanics. First is described the current product technology, according to which the defined parameters of the basic units of the machine. Then described two possible design concepts devices whose suitability is then evaluated multi-criteria method.

Due to increasing demands on component integration, functionalization, saving weight or material, the density and weight of thermoplastic parts could be influenced significantly by using the thermoplastic foam injection molding process. The characteristic three-layer structure offers numerous advantages for applications, such as weight reduction, increasing the specific bending stiffness with a simultaneous low tendency to warp and optimizing thermal and acoustic properties. For a subsequent joining process, however, difficulties arise due to the thin solid skin layer. Minimum joining distances during welding can no longer be met geometrically and the mechanical properties of the components are reduced. The present study is intended to analyze the interaction between the microcellular structure of the injection molded parts, the influence on the joining process and the resulting mechanical properties. Therefore, a cooperation of Chemnitz University of Technology and University of Bayreuth was founded to investigate the correlation between injection molding and welding by vibration and infrared for microcellular polypropylene and polyamide materials. In addition to various materials with and without fiber reinforcement, the influence of storage time and different joint types were investigated in this study. The aim was to improve the knowledge of process - material - structure - properties as well as to prepare guidelines for the transfer to industrial applications. The results have shown that the characteristic three-layer structure has a considerable inhomogeneity, depending on the used material, the foaming process and the process parameters. However, the weldability of foamed thermoplastics strongly depends on the internal structure due to the injection molding parameters, the storage time between foam injection molding and welding process, the joint type and the welding process itself.

Manufacturing of Mechanical Supporting Foamed Sheets by processing Free Flowing Phenolic Molding Compounds with the Foam Extrusion and its Characterization

Thermoplastische Kunststoffe werden zur Steigerung der mechanischen Eigenschaften häufig mit Kurzfasern verstärkt, wodurch sich jedoch eine anisotrope Eigenschaftscharakteristik einstellt. Dies führt oftmals zu ungewohntem Werkstoff- und Bauteilverhalten. Die Fertigungsparameter und -randbedingungen im Spritzgießprozess besitzen einen großen Einfluss auf lokale Faserorientierungen, wovon auch die globalen Bauteileigenschaften abhängen. Für eine werkstoffgerechte Auslegung von derartigen Bauteilen sind tiefgreifende Verständnisse über die mechanischen, thermischen und rheologischen Eigenschaften sowie die Kopplung von Spritzgieß- und Bauteilsimulation unerlässlich. Diese sogenannte integrative Simulation wird am Beispiel eines Strukturbauteiles aufgezeigt.

The purpose of this research is to investigate the mechanical, microstructural and corrosion performance of the ferritic stainless steel coarse powders, used in Metal Injection Molding (MIM) process. Three coarser powders made by Höganäs AB, were examined along with a commercially available fine MIM powder and samples from sheet metal. The studied powders were individually mixed with binders and then injection molded in the shape of dog bone shaped tensile bars. These green samples were then debinded and sintered to examine under different characterization methods. The methods used for examining the samples were tensile test, hardness test, metallography, SEM, chemical analysis, and salt spray test. After a comparative study of these different materials, it turns out that the chemical composition and the process parameters have more effect on materials properties compared to only particle size distribution in studied materials. After this study, 434 coarse powder was preferred upon the PolyMIM 430 fine powder, because of its lower price and same performance as that of PolyMIM 430.

En el Perú existen pequeñas empresas envasadoras de aceite que han comenzado a producir sus propios envases, con diseños básicos, equipos manuales y con baja productividad, lo que implica que no logren avanzar y en enfocarse en su Core Business, la producción y venta de aceite, y no ser rentables. Para ello la propuesta es el desarrollo de nuevos diseños de envases o mejorar los existentes, fabricación de moldes de alta performance, mejorar la productividad, y que el cliente pueda tener disponibilidad y flexibilidad de envases que van en acorde con su Plan de Producción, logrando de esta manera que el cliente se enfoque en su Core Business, al tener este proceso tercerizado; de esta manera contará con alto valor agregado a su producto y podrá desarrollar nuevas estrategias de ventas para su crecimiento y desarrollo, minimizando riesgos para su negocio. En este Trabajo de Investigación se demuestra que los procesos de tercerización en el soplado de envases plásticos en pequeña y medianas empresas envasadoras de aceite es muy importante, porque colabora en poder desarrollar nuestras estrategias de mercado como: nuevos formatos, nuevas marcas, diferentes diseños, etc.; lo que hace que al producto final sea más asequible a los consumidores y a diversos segmentos de mercado, al tener un socio estratégico que camina con el cliente con el desarrollos de nuevos proyectos. El modelo de negocio CANVAS, planteado para el desarrollo de este Trabajo de Investigación, logra visualizar de mejor manera la propuesta de valor para estos negocios, lo que no implica que estos modelos sean de exclusividad para envasadoras de aceite, sino también para el envasado de diversos productos como jugos, néctares y otros; el cual podría ser de gran impacto para los productos de agroexportación, y poder darles mayor valor agregado a los productores nacionales. / In Peru, there are many small oil packaging companies that have started to produce their own packages, with basic designs, manual equipment and low productivity, which means they can’t progress nor focus on their Core Business, oil production and sales, and they are not profitable. For that reason, we propose to create new packages designs or improve those that already exist, produce high performance molds, improve productivity and offer clients packages in line with their Production Plan. In that way, clients will focus on their Core Business because that process will be outsourced, their products will have a high added value and they will be able to put into practice new sale strategies in order to grow and develop with minimum risks for their business. This Research Project proves that the outsourcing process in plastic blow molding packages in small and medium-sized oil packaging companies is very important, because it helps develop new market strategies: new formats, new brands, different designs, etc., which makes the final product more affordable to consumers and diverse market segments, given that the company has a strategic partner who supports the new projects of the client. The Business Model CANVAS, used to develop this Research Project, visualizes better the value proposal for this type of business. Although, this model is not exclusive for oil packaging companies, but also for many different packaging companies like juice packaging companies, etc. This can have a huge impact in agro-export products, and it can add value to national producers. / Tesis

3D printing is a revolutionary manufacturing method that allows the productions of engineering parts almost directly from modeling software on a computer. With 3D printing technology, future manufacturing could become vastly efficient. However, it is observed that the procedures used in 3D printing differ substantially among the printers and from those used in conventional manufacturing. In this thesis, the mechanical properties of engineering products fabricated by 3D printing were comprehensively evaluated and then compared with those made by conventional manufacturing. Three open-source 3D printers, i.e., the Flash Forge Dreamer, the Tevo Tornado, and the Prusa, were used to fabricate the identical parts out of the same material (acrylonitrile butadiene styrene). The parts were printed at various positions on the printer platforms and then tested in bending. Results indicate that there exist substantial differences in mechanical responses among the parts by different 3D printers. Specimens from the Prusa printer exhibit the best elastic properties while specimens from the Flash Forge printer exhibit the greatest post-yield responses. There further exist noticeable variations in mechanical properties among the parts that were fabricated by the same printer. Depending on the positions that the parts were placed on a printer platform, the properties of resultant parts can vary greatly. For comparison, identical parts were fabricated using a conventional manufacturing method, i.e., compression molding. Results show that compression molded parts exhibit more robust and more homogeneous properties than those from 3D printing. During 3D printing, the machine code (e.g., the Gcode) would provide the processing instructions (the x, y, and z coordinates and the linear movements) to the printer head to construct the physical parts. Often times the default processing instructions used by commercial 3D printers may not yield the optimal mechanical properties of the parts. In the second part of this thesis, the orientation-dependent properties of 3D printed parts were examined. The multi-layered composite theory was used to design the directions of printing so that the properties of 3D printed objects can be optimized. Such method can potentially be used to design and optimize the 3D printing of complex engineering products. In the last part of this thesis, the printing process of an actual automobile A-pillar structure was designed and optimized. The finite element software (ANSYS) was used to design and optimize the filament orientations of the A-pillar. Actual parts from the proposed designs were fabricated using 3D printer and then tested. Consistent results have been observed between computational designs and experimental testing. It is recommended that the filament orientations in 3D-printing be “designed” or “tailored” by using laminate composite theory. The method would allow 3D printers to produce parts with optimal microstructure and mechanical properties to better satisfy the specific needs.

Ce travail est dédié à l'étude des mécanismes clés contrôlant l'écoulement linéaire et non-linéaire ainsi que l'état de dispersion des polymères fondus chargés avec des particules submicrométriques. La compréhension fondamentale est ensuite appliquée au procédé de moulage par injection céramique lors duquel un mélange-maître (i.e., une formulation complexe à base de polymères et avec un haut taux de charges de particules de céramique) est injecté dans un moule puis délianté et fritté. Un premier chapitre présente les caractéristiques principales du procédé, l'état de l'art de la compréhension des mécanismes concernés, ainsi que plus généralement, les forces d'interaction en jeu dans les polymères chargés. Ensuite, l'étude se focalise sur le polyéthylène chargé en zircone. Tout d'abord, le rôle de l'interface charge-matrice dans les propriétés rhéologiques et morphologiques est discuté. Il est montré qu'elles sont fortement influencées par la compatibilité de la charge avec la matrice. Une méthode expérimentale est développée pour ajuster la qualité de l'interface. En particulier, l'acide stéarique est déterminé comme étant le surfactant le plus efficace. La cinétique d'hydrophobisation des particules induite par l'estérification est analysée. Par la suite, les mécanismes de dispersion dans les polymères chargés sont explorés. Par exemple, il est conclu que l'acide stéarique et l'extrudeuse à fort cisaillement promeuvent la rupture et l'érosion des agglomérats. Leurs effets sur le comportement rhéologique (i.e., seuil de percolation, contrainte d'écoulement et modulus élastique dynamique) sont discutés. Enfin, la stabilité des polymères chargés, i.e., leur tendence à la floculation et à la ségrégation matrice-charge, est évaluée au repos et à haut taux de cisaillement. Deux méthodes expérimentales sont développées pour cette étude plus appliquée. Le rôle crucial de l'état de dispersion est notamment mis en avant / This work aims to investigate the relevant mechanisms controlling the linear and non-linear flow behaviors and dispersion state of molten polymers filled with submicrometer particles. The fundamental understanding is then applied to the Ceramic Injection Molding process, during which a feedstock (i.e., a complex polymer based formulation, highly filled with ceramic particles) is injected into a mold, debinded and sintered. A first chapter presents the key features of the process, a state of the art of the understanding of the involved mechanisms and more generally the interplaying interaction forces in filled polymers. Then, the study focuses on zirconia filled polyethylene. Firstly, the role of the filler-matrix interface in the rheological and morphological properties is discussed. It is shown that they are strongly influenced by the compatibility of the filler with the matrix. An experimental method is developed to adjust the interface quality. In particular, stearic acid is determined to be the most efficient surfactant. The kinetics of particles hydrophobization induced by the esterification is analyzed. Then, the dispersion mechanisms in filled polymers are explored. For instance, it is concluded that stearic acid and the high shear extruder promote the rupture and erosion of agglomerates. Their effects on the rheological behavior (i.e., percolation threshold, yield stress and dynamic storage modulus) are discussed. Finally, the stability of filled polymers, i.e., tendency to flocculation and filler-matrix segregation, is evaluated at rest and under high shear rates. Two experimental methods are developed for this more applied study. The crucial role of the dispersion state is for instance highlighted