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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.
231

Optimalizace uspořádání lisovací linky na výrobu reflektorů ve firmě Automotive Lighting / Optimum layout of pressing line for the production of reflectors at Automotive Lighting

Šťastný, Michal January 2012 (has links)
This thesis deals with optimization of a press line part for the manufacture of reflectors present at the Automotive Lighting Company, Jihlava. The first part focuses on describing the current workplace layout of the press line. The workplaces are located inconveniently and thus require a larger number of operators and a considerable amount of manual work. The second part of the thesis proposes layout solutions for the injection presses and for other machine parts. At the same time, a smoother transition design is proposed for the press line and for the manufacturing section that follows. Based on an evaluation of selected criteria, the optimum version is chosen, thereby adding to the efficiency of the molding process by reducing the number of operators required, by lowering the proportion of manual work relative to other activities, and by limiting the risk of poor quality. The conclusion of the thesis sums up the necessary investment costs and offers an economic assessment of introducing the selected press line arrangement to operation.
232

Návrh a posouzení uspořádání nové lakovací linky ve společnosti Automotive Lighting / Design and assessment of a new paint line arrangement at Automotive Lighting

Bouček, Filip January 2013 (has links)
The thesis deals with the design and arrangement of a new paint line at company Automotive Ligting s.r.o in Jihlava. It deals with design of several possible options of arrangement of machines that are required for the processing of polycarbonate granules and their conversion into acrylic glass using two-component injection molding. The glass is then coated with the coating line which is part of the arrangement included in this project. Design of the individual sites and their organization is based on both the company's requirements and the principles of technological design. The best of the three options is analyzed in detail and evaluated from the economic point of view.
233

Racionalizace technologie výroby forem / Rationalization technology of production forms

Kalous, Ondřej January 2014 (has links)
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.
234

Technologie výroby plastového držáku střešního nosiče / Production technology of plastic holder roof rack

Nevřivý, Lukáš January 2016 (has links)
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.
235

Welding of foam injection molded parts – Analysis of the process - material - structure - property relations

Hofmann, Karoline, Brütting, Christian 13 December 2019 (has links)
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.
236

Integrative Prozess- und Bauteilsimulation für kurzfaserverstärkte Spritzgießbauteile

Müller, Sascha, Iwan, Sebastian, Meyer, Marcel, Kroll, Lothar 08 June 2017 (has links)
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.
237

Mechanical, Microstructural and Corrosion performance for MIM materials based on coarse (-45µm) powders of ferritic stainless steel

Afraz, Syed Ali January 2012 (has links)
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.
238

Dispersion de particules de zircone dans les polyoléfines : rhéologie et application au moulage par injection céramique / Dispersion of zirconia particles in polyolefins : rheology and application to ceramic injection molding

Auscher, Marie-Camille 02 October 2017 (has links)
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
239

A Development of a Mobile Application for Monitoring Siemens S7-1200 Controller Variables Through Firebase

Diaz, Alexander, Rivera, Steven, Vinces, Leonardo, Del Carpio, Christian 01 January 2021 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Production systems need to be monitored because failure to do so can cause a delay in production due to a lack of remote monitoring. There are solutions that provide this information, but they are limited, because they are owned and very expensive solutions. This paper proposes the development of a mobile application for the monitoring of S7-1200 programmable controller variables through Firebase. The goal is to use open-source-type tools to develop a real-time variable monitoring application of a programmable controller capable of hosting a Web server, and the sent data to the Firebase cloud, in order to avoid modifying the driver software and the data stored in memory. The implemented system of sending, handling and presenting variables is developed with tools of open source type, since they have as an advantage to have greater freedom in programming, unlike proprietary solutions or services. The tests were performed on the Siemens S7-1200 controller with a plastic injection molding machine. / Revisión por pares
240

Analyse der numerischen Approximation von 2,5D und 3D Modellen beim Füllvorgang des Spritzgießens

Baum, Markus, Anders, Denis, Reinicke, Tamara 24 May 2023 (has links)
Dieser Beitrag untersucht die Gültigkeit von 2,5D und 3D Simulationsmodellen des Füllvorgangs beim Spritzgießen. Zur numerischen Approximation dieser Ansätze wird für das 2,5D Verfahren die Software Cadmould 3D-F und für das 3D Verfahren Ansys CFX verwendet. Um das nicht newtonsche Viskositätsverhalten der Polymerschmelze abzubilden, wird in beiden Simulationen ein geeignetes Viskositätsmodell verwendet. Die Ergebnisse des numerischen Füllvorgangs werden anschließend mit experimentellen Daten validiert. / This article examines the validity of 2.5D and 3D simulation models of the filling process in injection molding. To numerically approximate these approaches, the software Cadmould 3D-F is used for the 2.5D method and Ansys CFX for the 3D method. To represent the non-Newtonian viscosity behavior of the polymer melt, a suitable viscosity model is used in both simulations. The results of the numerical filling process are then validated with experimental data.

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