<p>Doktorska disertacija razmatra primenu savremenih aditivnih proizvodnih tehnologija u postupku preciznog livenja ortopedskih implantata i njihov uticaj na skraćenje vremena i smanjenje tro&scaron;kova izrade topljivih modela. Konvencionalni postupak preciznog livenja ortopedskih implantata zahteva značajno vreme i tro&scaron;kove za izradu kalupa za topljive modele. U disertaciji je razvijena metoda za &bdquo;brzo precizno livenje&ldquo; kojom se elimini&scaron;e potreba za izradom kalupa za topljive modele ortopedskih implantata. Potrebno je utvrditi da li se pomoću predložene metode &bdquo;brzog preciznog livenja&ldquo; koja predstavlja integraciju aditivnih proizvodnih tehnologija i reverznog inženjerstva sa konvencionalnim preciznim livenjem, može dati značajniji doprinos daljem razvoju u oblasti izrade prilagođenih ortopedskih implantata.</p> / <p>The doctoral thesis discusses the application of modern additive manufacturing technologies in investment casting of orthopaedic implants and their impact on time and cost savings in meltable wax models development. The conventional procedure of investment casting of orthopaedic implants demands considerable time and costs when developing moulds for meltable wax models. The thesis shows a method of &ldquo;rapid investment casting&rdquo; developed to avoid the making the moulds for meltable wax models of orthopaedic implants. It is necessary to establish whether the proposed method of &ldquo;rapid investment casting&rdquo;, which integrates additive manufacturing technologies and reverse engineering with conventional investment casting, may give a significant contribution to further development of manufacturing of customized orthopaedic implants</p>

D. Tech. (Department of Electronic Engineering, Faculty of Engineering and Technology) --Vaal University of Technology / Opening up local markets for worldwide competition has led to the fundamental change in the development of new products. In order for the manufacturers to stay globally competitive, they should be able to attain and sustain themselves as ‘World Class Manufacturers’. These ‘World Class Manufacturers’ should be able to:  Deliver products in fulfilling the total satisfaction of customers.  Provide high quality products.  Offer short delivery time.  Charge reasonable cost.  Comply with all environmental concern and safety requirements. When a design is created for a new product there is great uncertainty as to whether the new design will actually do what it is desired for. New designs often have unexpected problems, hence prototypes are part of the designing process. The prototype enables the engineers and designers to explore design alternatives, test theories and confirm performance prior to standing production of new products. Additive Manufacturing (AM) technologies enable the manufacturers to produce prototypes and products which meet the requirements mentioned above. However the disadvantage of AM technologies, is that the printing material which is required is limited to that of the supplier. When uncommon printing materials must be used to manufacture a prototype or product, the 3D printing process stood out above the rest owing to its printing method. However the printing heads used in current commercially available 3D printers are limited to specific fluid properties, which limits new and unique powder binder combinations. Owing to the problem mentioned, the need arose to develop a more ‘rugged’ printing head (RPH) which will be able to print with different fluid properties. The RPH could then be used to print using unique and new powderbinder combinations. The RPH was designed and constructed using the solenoid inkjet technology as reference. In order to determine the effect which the fluid properties have on the droplet formation, fourteen different glycerol-water test solutions were prepared. The fluid properties were different for each of the glycerol-water solutions. The fluid properties included the viscosity, density and surface tension of the solution. The control parameters of the RPH were theoretically calculated for each of the glycerol-water solutions and nozzle orifice diameter sizes. The control parameters of the RPH included the critical pressure and time. Using an experimental setup, droplets ejected from the RPH could be photographed in order to be analysed. It was determined that the theoretically calculated critical times could not be used in the RPH, as the pulse widths were much lower than the recommended minimum valve pulse width of the solenoid valve used. The control parameters were then determined practically for each of the different glycerol-water solutions as well as for each nozzle orifice diameter size. The practically determined control parameters were also compared to that of the theoretically determined parameters. A mathematical model was formulated for each of the practically determined critical pressure and time parameters. Non-glycerol-water solutions were also prepared in order to determine whether the control parameters could be calculated using the practically determined mathematical models. It was found that the practically determined mathematical models, used to calculate the control parameters, could not be used with non-glycerol-water solutions. Using the practically determined mathematical models, the drop formation process of the non-glycerol-water solutions was not optimized and satellite droplets occurred. Although the practically determined models did not work for non-glycerol-water solutions, the methods used to determine the control parameters for the glycerol-water solutions could still be used to determine the practical critical pressure and time for Newtonian solutions.

No description available.

The aim of this thesis is ball screw service life measurement. Text is divided on two major parts, theoretical one and practical one. Theoretical part describes three basic methods of ball screws manufacturing – rolling, whirling and grinding. Subsequently, methods of heat treatment (inductive and laser hardening) are mentioned. Practical part is devoted to ball screw service life testing and evaluation of results. Tests were carried out on two sets of two ball screws. First set was manufactured by whirling and grinding followed by inductive hardening. Second set was manufactured by grinding followed by inductive hardening in one case and laser hardening in the second one. Test results were evaluated according to international standards.

Im Rahmen der vorliegenden Arbeit wurden Fertigungstechnologien zur kostengünstigen Herstellung eines neuartigen solarthermischen Kollektors entwickelt. Dieser Kollektor soll aus einem profilierten Grundkörper aus Schaumglas bestehen, welcher mit Flachglas abgedeckt ist. Die Herstellung des Schaumkörpers wurde betrachtet von der Auswahl der Rohstoffe, über die Entwicklung geeigneter Verfahrensparameter, bis zur Formgebung. Ein Schaumkörper mit profilierter Oberfläche konnte im Maßstab von 600 x 600 x 130 mm³ hergestellt werden. Zur Kosteneinsparung wurde hierfür ein Reststoff aus der Glas verarbeitenden Industrie verwendet. Um den Kollektor in ein hydraulisches System eingliedern zu können, wurde eine Technologie zur Einbindung von Rohrleitungsanschlüssen entwickelt. Emaillierte Rohrbögen aus Gusseisen konnten im Schäumungsprozess fest in den Schaumkörper integriert werden. Weiterhin wurden zwei Möglichkeiten zur Anbindung der Deckgläser untersucht. Dabei wurden mittels Klebung durch EVA-Folie eine höhere Verbundfestigkeit erreicht als mittels Löten durch Aluminium-Blech.:Inhaltsverzeichnis Vorwort 1 1 Einleitung 3 2 Solarkollektoren – Stand der Technik 5 2.1 Überblick 5 2.2 Flachkollektor 7 2.3 Zukünftige Entwicklung 16 3 Neuer Lösungsansatz 19 3.1 Konzept 19 3.2 Wirkungsgrad 21 3.3 Herstellkosten 23 4 Angewandte Messverfahren 24 5 Grundkörper des Kollektors 29 5.1 Grundlagen Schaumglas 29 5.1.1 Was ist Schaumglas 29 5.1.2 Schaumglasherstellung 30 5.1.3 Rohstoffe 33 5.1.4 Parameter der Schaumglasherstellung 37 5.2 Vorbetrachtung 42 5.3 Schäumen von Reststoffen 43 5.3.1 Charakterisierung der Rohstoffe 43 5.3.2 Schäumungsversuche 54 5.3.3 Einfluss der Rußart 61 5.3.4 Einfluss der Atmosphäre 63 5.3.5 Schäumungsverstärkung durch Oxidationsmittel 68 5.4 Eigenschaften 73 5.4.1 Schaumfestigkeit 73 5.4.2 Solare Absorption 94 5.4.3 Korrosionsbeständigkeit 104 5.5 Schäumungsform 113 5.5.1 Werkstoffauswahl 113 5.5.2 Charakterisierung von Calciumsilikatwerkstoffen 114 5.5.3 Entformbarkeit 118 5.5.4 Modellschäumung 122 5.6 Zusammenfassung und Ausblick 134 6 Anbindung weiterer Bauteile 137 6.1 Grundlagen der Materialverbindung 137 6.1.1 Anorganische Materialverbindung 137 6.1.2 Organische Materialverbindung 141 6.2 Vorbetrachtung 148 6.2.1 Rohrleitungsanschlüsse 148 6.2.2 Verbindung Grundkörper/ Deckglas 150 6.3 Einbindung der Rohrleitungsanschlüsse 155 6.3.1 Stand der Vorarbeiten 155 6.3.2 Emailliertes Gusseisen 157 6.3.3 Dauerbeständigkeit 166 6.4 Verbindung des Grundkörpers mit dem Deckglas 168 6.4.1 Stand der Vorarbeiten 168 6.4.2 Löten 169 6.4.3 Kleben 182 6.5 Zusammenfassung und Ausblick 185 7 Zusammenfassung 187 8 Ausblick 189 Literaturverzeichnis 191 Abkürzungs- und Symbolverzeichnis 200 Abbildungsverzeichnis 202 Tabellenverzeichnis 207 Anhang 209

The new reality is about connectivity. From social media to collaborative tools in work environments, people and their devices are highly intercommunicated. This reality also affects the manufacturing industry, which has been developing standards to keep up with technology and take advantage of it. These technologies are encompassed in what has been called Industry 4.0. Out of all the technologies, apart from artificial intelligence, the main drives of Industry 4.0 are considered by many studies augmented reality (AR) and industrial internet of things (IIoT). This thesis suggests that these drivers have been mostly tested either in an isolated fashion or with limited connectivity. The main objective is to explore the advantages of connecting AR, IIoT, and the main source of information in the manufacturing process: product lifecycle management (PLM) systems. Two sub-objectives are extracted from the main one: to study of value created from real-time role-dependent AR information displaying, and to study how the connection AR-IIoT-PLM can affect developing and deploying times of AR experiences. To achieve the mentioned objectives, a case of study is built, and the combined system implemented on it. Following design and creation methodology, an artefact is created, and conclusions are extracted from the design, implementation, and usage stages. Main results are an improvement in developing and deploying time of AR experiences, along with guidelines to extract as much value as possible from the implementation of a combined system of this sort. This thesis includes a discussion section, where the potential of the system is explained and framed within the near future of manufacturing companies.

No description available.

With the rise of smart manufacturing technologies and a shift towards a new industrial revolution, brings forth many new challenges, one of which is how to adapt and integrate these technologies into existing assembly lines. Scania CV AB has joined this race and, with the help of smart manufacturing solutions, works on increasing efficiency amongst its assembly lines. This thesis is aimed at creating concept designs using different smart manufacturing technologies in the assembly line of a pedal car, to evaluate and adapt the concept suited for a real assembly line. The thesis starts with studying the different smart manufacturing technologies to better understand them and the scientific methods used. This follows up with the methodology where several scientific methods such as morphological matrix and weight based decision making matrix are used to generate and evaluate different concept designs. This is followed by a qualitative analysis that helps in selecting the concept design that best suits the needs of the assembly line under consideration. The different concepts are visualized and the evaluation based on different parameters are discussed. This thesis lays a foundation to realize that an aggregate of an optimized process plan, a continuous improvement strategy and the right use of smart manufacturing technologies contributes to the productivity of the assembly line in the long run. / Med en ökning av smarta tillverkningsteknologier och ett skift mot en ny industriell revolution, kommer nya utmaningar. Av dessa utmaningar ifrågasätts hur man anpassar och kombinerar dessa olika teknologier gentemot existerande monteringslinjer. Scania CV AB har tagit del i denna resa och, med hjälp av smarta tillverkningslösningar, jobbar ständigt mot att effektivisera sina monteringslinjer. Detta examensarbete fokuserar på att använda olika och smarta tillverkningsteknologier i en monteringslina för tillverkning av en trampbil. Detta görs genom att evaluera och anpassa olika koncept som är lämpade för en verklig monteringslina. Examensarbetet börjar med en undersökning av nuläget för att få en bättre uppfattning om smarta tillverkningsteknologier samt de vetenskapliga metoder som används. Även här så undersöks referensprodukten - trampbil samt de olika programvarorna AviX, ExtendSim och LayCAD. Genom att ha satt tydliga arbetsmetoder och följt upp mot dessa så diskuterar och hänvisar nästa kapitel resultaten. Resultaten visar hur olika koncept har tagits fram samt vilka teknologier som går ihop med dessa. Fördelar, nackdelar och risker hos respektive teknologi har benämnts. Ett systematiskt arbetssätt har tagits fram mot hur man anpassar konceptet för monteringslinan av en trampbil till en verklig monteringslina, samt hur man har jobbat runt de restriktioner som uppkommit. Examensarbetet slutar med ett kapitel där slutsatserna, på en överskådlig nivå, tas fram. Hur dessa teknologier har kombinerats och evaluerats, samt att koncepterna som har tagits fram har lagt en grund för framtida projekt att följa upp emot.

Made available in DSpace on 2010-04-20T20:14:34Z (GMT). No. of bitstreams: 0 Previous issue date: 1995-05-15T00:00:00Z / Apresenta uma nova abordagem de mensuração de desempenho para as empresas manufatureiras, com ênfase nos princípios, critérios, modelos e metodologias para a implementação destes sistemas. Aborda o tópico das mudanças ocorridas no ambiente de negócios e do contexto específico do setor fabril, com miras a construir uma visão global dos eventos ocorridos na organização de trabalho, que permita a melhor compreensão do tema particular deste estudo. Apresenta uma metodologia proposta para a medição de desempenho nas indústrias.