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Paint shop Process Improvement through Predictive Simulation
Machačová, Simona ; Hromková, Ivana (referee) ; Videcká, Zdeňka (advisor)
This thesis focuses on the use of simulation to optimise processes in a paint shop. The aim of the thesis is to analyse the existing production processes and suggest improvements using simulation. In the analytical part of the thesis, the processes in the paint shop are described in detail and Petri nets are used to describe the logic of the processes in the paint shop. In the design part of the thesis, the problem and objectives are formulated, and the design of the simulation model is presented. The design describes the elements and methods used in the Plant Simulation software in which the model is created. Furthermore, different scenarios are simulated to optimize the painting process and the deposition areas. The simulation results are compared with the actual state of the paint shop. Finally, the results are discussed and recommendations are proposed to optimize the paint shop processes using simulation. This work presents new approaches to process optimization in industrial manufacturing.
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An investigation of friction and lubrication of coated hip joint replacement
Balcárek, Ondřej ; Horák, Zdeněk (referee) ; Nečas, David (advisor)
The thesis focused on studying the effects of a new hydrogel coating and material combinations on the coefficient of friction and formation of lubricating film in the conformal contact of hip joint replacement. Experiments were conducted using a ball-on-cup configuration with a hip pendulum simulator. The formation of the lubricating film was observed using fluorescence microscopy. The results showed that the application of the coating did not have a clear impact on the coefficient of friction. However, for pairs with a coated cup, there was a reduction in CoF by approximately 20%. Generally, lower friction was observed when using a ceramic joint head. Surprisingly, even more interesting results were obtained in the lubrication analysis, where the use of metal heads led to a reduction in the thickness of the lubricating layer. Ceramic pairs exhibited very stable behavior. In addition to friction and lubrication, the topography of the implants was further evaluated, and their wettability was analysed. Although the polymer coating was expected to be highly hydrophilic, the surface properties were only slightly influenced, which partly explains why there was no significant improvement in the tribological behavior of the replacement. As the coating applied is already patented and its effectiveness in reducing wear has been clearly demonstrated, it is appropriate to investigate this issue further, with more attention being paid to long-term experiments. Based on the obtained data, it appears that the short-term benefits of the coating are practically negligible. However, it is important to highlight that, except for minor exceptions, the application of the coating did not lead to a deterioration of properties, which is a significant outcome of this work.
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Reducing friction losses of piston rings
Csintalan, Radoslav ; Novotný, Pavel (referee) ; Svída, David (advisor)
This diploma thesis deals with the possibilities of reducing the friction losses of the first sealing piston rings of the VW Group 1.5 TSI, 110kW engine. The first part of the thesis theoretically deals with the issue of piston rings in terms of their classification. Reduction of friction losses is ensured by PVD and PECVD coating technology. The second part of the thesis describes the production of coated piston rings. Measurements are performed on the created coatings, which are compared and evaluated in the conclusion at the end of the thesis.
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Preparation and characterisation of coatings for controlled-release fertilizers
Jašek, Vojtěch ; Sedláček, Petr (referee) ; Figalla, Silvestr (advisor)
The literary research of this Master's thesis is dedicated to controlled-release fertilizers (CRF). There is written the description of particular representatives of this kind of fertilizer and it also contains principles of nutrition's release mechanisms. Theoretical part is mainly focused on coated fertilizers, materials used for their production, coating technological processes and on a mathematical description of the diffusion transport which is the key of the mass transfer through polymer coatings. The laboratory preparation of innovative coatings based on modified vegetable oils is the main part of the experimental part of the thesis. It consists of the precursors' synthesis which can be applied on the fertilizer's surface in a liquid phase and polymerized by the UV-radiation in combination with an appropriate photoinitiator. There is described the synthesis of additional modifiers of precursors' viscosity and coatings' diffusive properties based on bio-source reactants such as sorbitol or ethyl lactate. The synthesized products are characterized by various methods such as volumetry, FTIR method or viscosimetry. The last part of the thesis contains the description of diffusive characteristics of coatings prepared out of the synthesized precursors.
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Verify the possibility of plasma treatment of printed circuit boards for subsequent surface treatment
Brokeš, Josef ; Košelová, Zuzana (referee) ; Otáhal, Alexandr (advisor)
This thesis deals with the regeneration and cleaning of printed circuit boards with emphasis on the use of plasma technology. Various surface cleaning methods, including manual cleaning, industrial washing and plasma treatment, were investigated and their effect on the subsequent quality of the paintwork. A systematic analysis of the effect of plasma treatment on the paint quality and functionality of the plates is also carried out, including an investigation of the possibility of regenerating older plates. This study provides a basis for further research and development in this area. The thesis also presents the design and implementation of a prototype plasma developer device for integration into a production line.
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Design of material for drawing tools
Petrecký, Adam ; Juliš, Martin (referee) ; Klakurková, Lenka (advisor)
Bachelor thesis deals with optimalization of material choice and its heat treatment for cold work forming tools. The thesis deals with specific failure of seizure during the cold forming of high strenght steel for automotive. First part deals with theory of cold forming and tool steels made for this purpose. The main goal of the thesis was to discover cause of the failure and deduce solution as choice of alternative material with its proper heat treatment and surface coating. Solution has to show higher lifespan and also has to deliver economical benefit.
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Material printing upscaling of chemical sensors to R2R techniques
Fanglová, Michaela ; Krystyník, Pavel (referee) ; Veselý, Michal (advisor)
The main task of the diploma´s thesis was to prepare mixtures for printing ozone and UVB sensors. Subsequently, to optimize the compositions and rheological properties of these mixtures for the preparation of chemical sensors for printing by production R2R machnies, including their calibration to detect required doses of ozone and UVB radiation. The experimental study focoused on the laboratory preparation of mixtures for chemical sensors and their subsequent conversion and printing on semi-operational and production R2R machines. The transfer of production to a larger scale was achieved through changes in the rheological properties of the compositions. The prepared ozone sensors were exposed to different ozone doses and their color change was monitored as a function of the ozone dose. The UVB sensors were calibrated to the required UVB dose and their colour response to the UVB dose was monitored.
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Porous-alumina-assisted formation of metal and metal-oxide nanostructures for use in advanced micro-devices
Kamnev, Kirill ; Mardare, Andrei Ionut (referee) ; Blanchar, Xavier Correig (referee) ; Mozalev, Alexander (advisor)
Anodizace kovů přes masku porézní anodické aluminy (PAA) je použita namísto nanoporézní anodizace nebo tradičních nanofabrikačních metod na výrobu nových nanostrukturovaných oxidů kovů se zdokonalenými parametry. Vylepšování vlastností oxidů ZrO2 a HfO2 nanostrukturováním vzbuzuje podstatný zájem kvůli aktivní komercionalizaci těchto oxidů kovů. Nanostrukturování ZrO2 a HfO2 anodizací je náročné kvůli včasné krystalizaci anodického oxidu a téměř nulovému transportnímu číslu kationtů. Tyto problémy jsou řešeny systematickým zkoumáním anodického chování dvouvrstev složených z tenké vrstvy Al nadeponované na vrstvě Zr nebo Hf. Po prvý krát je dosažen reprodukovatelný růst ZrO2 nanostruktur přes masku PAA, které plní póry PAA masky jenom částečně. Tyto vnořené ZrO2 nanostruktury se projevují zlepšeným dielektrickým výkonem v širokém rozsahu frekvencí s nízkými zbytkovými proudy a vysokými hodnotami průrazného napětí. Tyto vlastnosti z nich dělají atraktivní struktury pro použití v mokrých a hybridních elektrolytických kondenzátorech. Vrstvy s rovným povrchem, kompatibilní se standardními metodami nanofabrikace a obsahující ZrO2 nanostruktury kompletně plnící póry PAA masky, jsou syntetizovány kombinací anodizace přes masku PAA s částečným rozpuštěním PAA. Tyto vrstvy jsou použity v experimentálních MIM mikrokondenzátorech, které vykazují nízké zbytkové proudy, vysoké hodnoty průrazného napětí, vysoké hustoty energie, nízké hodnoty teplotního koeficientu kapacity a výbornou linearitu mezi kapacitou a napětím, což z nich dělá dokonalé kandidáty pro pasivní integraci zařízení na čipu. ZrO2 nanovrstvy připraveny anodizací přes masku PAA jsou, po prvý krát, schváleny k produkci osteogenních biokeramických povlaků. Tyto nanostrukturované biokeramické ZrO2 povlaky mohou modulovat interakce mezi buňkami a povrchem a zvyšovat mineralizaci osteoblastů 5 krát oproti rovné anodické ZrO2 vrstvě. Nanostrukturované HfO2 vrstvy připraveny anodizací přes masku PAA vykazují opakovatelné nízkovýkonové bipolární rezistivní spínání, což je dělá význačnými jako tuhé elektrolyty pro aplikace v memristorech. Anodizace Hf přes masku PAA v kombinaci s vhodnými chemickými modifikacemi povrchů je použita po prvý krát k vytvoření samouspořádaných nanostrukturovaných HfO2 povlaků, které jsou superhydrofóbní, odpuzují olej, jsou transparentní pro viditelné světlo a antireflexní, což je dělá velmi vhodnými pro pasivaci fotovoltaických zařízení.
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SMV-2022-43: Absorptivity and emissivity of materials for use in space
Králík, Tomáš
This contractual research was aimed at verifying the thermal radiation properties of the emissivity of coatings and covering foils for space probes. Half of the experiments were focused on thermal regulation coatings, the purpose of which is to passively maintain the optimal temperature of the device, the balance between thermal radiation and absorption of visible radiation. Some foils had unique thermochromic properties, where their thermal radiative properties change sharply with their own temperature. The second part of the research was focused on the effect of contamination of a clean metal surface with dust simulating lunar regolith on the absorption of thermal radiation. As part of this research, five differently contaminated surfaces were measured. This unique data will enable the contractor to better design apparatus for work on the surface of the Moon or other planets. The contractor selected and supplied\nsamples of materials in the form of foils and coated sheets, which had to be modified into a sample suitable for the apparatus operated at the ISI Brno. A material labelled EAC‐1A was used as a lunar regolith simulant. The goal of the project was to evaluate the so‐called total hemispheric emissivity or absorptivity in the temperature range from 20 K to 300 K.
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SMV-2022-09: Special coatings for a radio-frequency absorber
Frolec, Jiří
As part of the upcoming mission of the European Space Agency, the space-probe JUICE, the task of the Max Planck Institute for Solar System Research is to determine the thermal radiation properties of the coatings intended for the radio-frequency absorber of this probe. In frame of this project, there was an experimental verification of the relative rate of thermal radiation emission, so-called emissivity, of two different coatings deposited on the surface of the developed samples. The main output of the research is the low-temperature tests of these samples carried out using a unique measuring apparatus, cooled by a bath of liquid helium. The emissivity of thermal radiation of both surfaces was determined in the temperature range from 20 K to 300 K. As part of the project, we also assessed, in addition to the thermal-radiative properties, the mechanical stability of the sample at low temperatures. All data have been submitted to the Max Planck Institute in the form of research reports.
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