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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.
41

Hybridní biopolymerní kompozity pro 3D tiskové aplikace / Hybrid biopolymer composites for 3D printing applications

Menčík, Přemysl January 2019 (has links)
This dissertation work deals with the thermic and the mechanical behavior of plasticized bio-plastics and bio-composites for the 3D printing applications. The influence of plasticizer chemical structure on thermic and mechanical properties of plasticized polymeric blends from the poly-3-hydroxybutyrate and the poly lactic acid was investigated. Used plasticizers are based on derivative of citric acid. The influence of plasticizers on polymeric matrix and their compatibility was estimated by gear torque rate of melt mixer, respectively rate of plasticizer migration from the material during higher temperature. The plasticizer structure influence on the glass transition temperature and on the kinetics of crystallization of plasticized material was investigated by modulated differential scanning calorimetry. The behavior of material during 3D printing was also observed. Mechanical properties of printed samples, especially their elongation at break, were determined by tensile tests. The largest softening effect was observed using tributylcitrate plasticizer, where the glass temperature decreased by 35 °C and elongation at break increased by 150% compared to non-plasticized reference material. This plasticized polymeric blend showed also sufficient 3D printing properties and was used as the matrix for composites in the next part of this work. Composites were filled by kaolin, limestone, halloysit, fumed silica, talc, magnesium hydroxide and chopped flax fibers. Particle distribution in composites in dependence of used surface treatment of filler was observed by scanning electron microscopy. The influence of composite filler on rheological properties, crystallization kinetics and thermal stability of composites, was observed by viscometry and differential scanning calorimetry. Their mechanical properties and heat deflection temperature were observed on samples prepared by 3D print. Kaolin in composite material showed homogeneous particle distribution and insignificant nucleation effect and influence on thermic stability. Composite filled by kaolin also showed 18% smaller warping during 3D printing compared to non-filled reference. Consequently kaolin was evaluated as suitable inorganic filler for bioplastic composite intended for 3D print and this composite was used in the following part of this thesis. Method of mathematical prediction of Young's modulus was described for composite samples prepared by 3D print. Composites filled by one type of filler – kaolin, or limestone, resp. by combination of both fillers were investigated on the basis of the micromechanic Halpin-Tsai model modified by the semiempiric multiparametric Cerny's equation. Additive and combinational method of Young's modulus evaluation is used for composites with hybrid filling. Deflection of measured and theoretical Young's modulus value of composite filled with kaolin was decreased by established correction from 21% to 1% and for composites filled with limestone from 13% to 9%. In this manner it is possible to predict the Young's modulus of the samples prepared by 3D print.
42

Technologie výroby kopie osobního automobilu pomocí digitalizace / Manufacturing technology of a car copy by digitizing method

Eis, Jiří January 2010 (has links)
This thesis, maked as diploma project at VUT Brno, summarize in teoretical part most used methods, technology of reverse engineering and rapid prototyping, including their using in practice. Experimental part discussed about aplication of this technologies on practical example. Tendency of thesis was creation of digitized model of a car by optical scanner ATOS and photogrammetry system TRITOP, including modifications and processing of get data, which will use to verification of model by FDM technology.
43

Návrh technologie výroby formy na odlévání dílu v malosériové výrobě / Design of technology for a mould manufacturing for casting in short run production

Pivoda, Miroslav January 2010 (has links)
The aim of thesis is to describe the basic methods called Rapid Prototyping in theory and using one of them to create master model. Master model will be used to create silicone mould where a limited series of wax models will be by means of vacuum casting chamber. They will also be used to make ceramic form in which the final pad will be cast from freely accessible materials. After processing it the suitability of the proposed technologies for the production of the part in question will be assessed.
44

Experimentální biomechanická protéza ruky / Experimental biomechanical hand prosthesis

Lux, Martin January 2012 (has links)
This masters thesis deals with experimental biomechanical hand prosthesis designing and its realization in shape of prototype. Hand prosthesis sizing corresponds with adult man hand. Prosthesis functionality is selected with respect to search analysis results, to provide sufficient options to grip different objects. Hand design, including technical documentation, is completely made in Autodesk Inventor 2012. Main parts of prototype are made with using rapid - prototyping technologies. Used materials for parts made by this way are ABS plastics and plaster powder. Firgelli linear actuators (product line L) are used as drive for electrical controlled fingers. Prototype control is realized by PCI card and program, which has been written in LabView.
45

Návrh temperovaného stolu pro FDM 3D tiskárnu s využitím simulace MKP / Design of heated print bed for FDM 3D printer with FEM simulation

Bartoš, Radko January 2014 (has links)
Master´s thesis deals with desing of a heated bed for FDM 3D printer using the finite element method. It is briefly described the history of RepRap printers, construction and mechanical parts. Are discussed two methods of heating, heated by PCB boards and using power resistors. Furthermore is work closely focused on power resistors. There are presented methods and procedures which leads to an optimal distribution of heated components on the board of heated bed. In conclusion are presented results of testing which are compared with the simulations in ANSYS.
46

Konstrukce 3D tiskárny pro materiály s vyšší pevností / Design of 3D printer for high strength materials

Žlebek, Michal January 2015 (has links)
Thesis deals with FDM 3D printing method and testing capabilities of optimum printing conditions for different materials. The aim of this work is to design and manufacture of experimental device that enables printing to investigate these conditions. A device designed in this work was named UK3DP and allows dual color object printing with maximum dimensions of the square base of 150 mm and a height of 150 mm. Before printing, the user can set almost all parameters affecting the printing process, including air temperature in heated chamber that is part of it. To verify the functionality several materials are tested, including ABS, PC and PEI. It also describes basic verification of the influence of selected parameters on the print result. Performs tensile tests confirming the influence of ambient temperature during printing on the quality of fiber connections, examines the final quality of the surface for each layer height and compares the resulting deformation of printed objects with other printers. The result of this work is a 3D printer capable of testing printing conditions for both existing and new types of materials with a range of user adjustable parameters.
47

Vliv průměru trysky na kvalitu tisku 3D tiskárny / Effect of the diameter of the nozzle on the 3D printer print quality

Kutil, Jaroslav January 2016 (has links)
The matter of this thesis is to find the influence of the diameter of the nozzle on the 3D printer´s print quality. The first part briefly characterizes the Rapid Prototyping technology and describes the RepRap project. The second part describes the construction of the experimental FMD 3D printer. The following section deals with technical printing parametres and their influence on the printed product. The experimental part of the thesis is focused on the impact of the discharge nozzle diameter on the mechanical properties, surface quality and shape accuracy of the final product and on the following recommendations of operational parametres.
48

Vývoj 3D FDM tiskárny implementace na trh / Development of FDM 3D printer and implementation on the market

Bouchal, Petr January 2016 (has links)
The result of this thesis is to create an overview of available 3D printing technologies, design a 3D FDM printer, create an instructional manual on the assembling and create a business model of a 3D printing company.
49

3D tiskárna / 3D Printer

Ctibor, Jiří January 2016 (has links)
Master thesis deals with topic about 3D printers, concretely making hardware of control and power electronic for FDM 3D printer. The work could offer an overview about basic 3D printing technologies after reading. More information could be read about FDM technology, which is used in our printer, also with description of all important components. The furthest is discussed about electronic drives. If reader is interested in this topic, part of this thesis is schematic design of control electronics, which can be used to build own boards. Design of printed circuit boards is not present in attachment and can be obtained by contacting the author. For own control is used one of the open source control software. Mechanical problems and also mechanical design is done in parallel thesis by other student of Faculty of mechanical engineering.
50

Návrh duální tiskové hlavy pro FDM 3D tiskárnu / Design of dual hot-end for FDM 3D printer

Prouza, Tomáš January 2016 (has links)
This master thesis is focused on a research in the field of 3D printing technology. During the research a particular technology, being regularly applied by the RepRap printers, is described. Mentioned technology is tested on a Rebel II printer model. The findings are applied to the dual 3D extruder design project. This dual 3D extruder is designed and made in two basic options, where the first option discovers the shortcomings and the second option is modified and tested. In the following step, assessment of applicability, functionality, as well as economic analysis of production of this dual 3D extruder is made.

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