This master thesis deals with design of injection molding technology for plastic lamp shade made of polycarbonate labelled Lexan 925. The injection is performed into injection mold with hot runner system. Initially there is a general study related to plastic materials and injection molding technology. Further the study continues with technological solution of production of the lamp shade. The designed injection mold is two-plate, double cavity mold with two hot nozzles and is equipped with a thread-unscrewing machine. This thesis contains part of the documentation and item list of the injection mold, along with technical-economical evaluation of the developed solution.

The demand for bio-plastics is constantly growing, due to the increasing use of synthetic plastic, their non environmentally friendly properties and long degradation time. This thesis explored the possibility to use starch-lignosulfonate mixtures for food packaging. Films are prepared from potato starch and two different types of lignosulfonates, calcium and sodium respectively using mold casting. The films are compared to pure potato starch films in respect to their mechanical properties and moisture absorption. Characterization of the films is also conducted using scanning electron microscopy, energy-dispersive X- ray spectroscopy and light microscopy to see the interaction between the potato starch and lignosulfonates. The tensile test reveals that neither of the lignosulfonates do have a plasticizing effect on the potato starch films. The energy-dispersive X-ray spectroscopy conceded that the lignosulfonates are homogeneously dispersed throughout the film both on the surface and cross section. The moisture absorption test showed that the uptake of water does not decrease by adding lignosulfonates to the potato starch film. From these results it can be concluded that it is possible to produce films from potato starch and lignosulfonates in various ratios. But the potato starch:lignosulfonate films are not a viable option for food packaging due to their brittleness and high moisture uptake. / Efterfrågan på bioplast växer ständigt på grund av den ökande användingen av syntetiska plaster, deras icke miljövänliga egenskaper och den långa nedbrytningstiden. Denna avhandling undersöker möjligheten att använda blandningar av stärkelse-lignosulfonat i livsmedelsförpackningar. Potatisstärkelse och två olika typer av lignosulfonater med kalcium och natrium användes för att tillverka filmer genom formgjutning. Filmerna jämförs med filmer med ren potatisstärkelse, med avseende på deras mekaniska egenskaper och fuktabsorption. Karakterisering av filmerna genomförs även med hjälp av svepelektronmikroskop, energiröntgenspektroskopi och ljusmikroskopi för att se interaktionen mellan potatisstärkelse och lignosulfonater. Dragproverna visar att ingen av lignosulfonaterna har mjukgörande effekt på potatisstärkelsefilmerna. Energiröntgenspektroskopin visade att lignosulfonaterna är homogent dispergerade i hela filmen både på ytan och i tvärsnittet. Fuktabsorptionstestet visade att upptaget av vatten inte minskar genom tillsats av lignosulfonater i potatisstärkelse-filmen. Från dessa resultat kan man dra slutsatsen att det är möjligt att framställa filmer från potatisstärkelse och lignosulfonater i olika förhållanden. Men potatisstärkelse: lignosulfonatfilmer är inte ett hållbart alternativ för livsmedelsförpackningar på grund av sin sprödhet och höga fuktupptagning.

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It is well known that REMs are strong oxide and sulphide formers that can easily form large clusters which have harmful effect on the casting process as well as the quality of the final steel product. By adding these elements right before casting, the number of narrow transfer parts are eliminated (compared to if added in ladle) Also, the REM inclusions has less time to sinter together to form large clusters, preventing clogging. The general idea behind this alloying method in the continuous casting machine is to feed a wire of FeSiRE powder blend, coated with a metal strip, into the melt in the chilled Cu mold (CC mold) Adding REMs to the steel, in particular Ce, can increase the resistance to oxidation at high temperatures by improving the properties of the chromia layer. This is of big interest for SANDVIK as it can improve their corrosion resistant grades and may also, in the future, enable alloying in with other volatile elements such as Zr. This master thesis has the objective to find out the dissolution time of the wire, coated with three different metal strips; Steel, Cu and Al. The experiments were performed with steel grade 316L, provided by SMT, in a 2kg melt in a lab scaled induction furnace at 1500oC, 1510oC and 1530oC. The operations were performed both with and without FeSiRE powder inside. The results obtained with powder inside at 1500oC showed that the Al wire experienced the shortest dissolution time ( 0,5 to 1s) followed by Cu (≤10s) and Steel (18 to 20s). In addition to this, sampling procedures was implemented ( 1, 1, 3, 5 10 and 29mins after wire addition) in a depth of 40mm for each wire. Here, the yield of Ce 1 minute after wire addition was highest for the Steel wire (41.9%) followed by Cu wire (25%) and Al wire (<14.8%). From samples taken 1 and 5mins after wire addition in the Al wire experiment, inclusions were extracted and collected on a film filter after electrolytic extraction and filtration. The film filter was observed in SEM. The morphology and compositions were analysed and compared. It was found that Ce and La was present as Ce La oxy sulfides both individually and on Al Mg O clusters.

Aortic aneurysms are the 14th leading cause of death in the United States. Annually, abdominal aortic aneurysm (AAA) ruptures are responsible for 4500 deaths. There are another 45,000 repair procedures performed to prevent rupture, and of these approximately 1400 lead to deaths. With proper detection, the aneurysm may be treated using endovascular aneurysm repair (EVAR). Understanding how the flow of the blood within the artery is affected by the aneurysm is important in determining the growth of the aneurysm, as well as how to properly treat the aneurysm. The goal of this project was to develop a physical construct of the AAA, and use this construct to validate a computational model of the same aneurysm through flow visualization. The hypothesis was that the fluid velocities within the physical construct would accurately mimic the fluid velocities used in the computational model. The physical model was created from a CT scan of an AAA using 3D printing and polymer casting. The result was a translucent box containing a region in the shape of the aneurysm. Fluid was pumped through the construct to visualize and quantify the velocity of the fluid within the aneurysm. COMSOL Multiphysics® was used to create a computational model of the same aneurysm, as well as obtain velocity measurements to statistically compare to those from the physical construct. There was no significant difference between the velocity values for the physical construct and the COMSOL Multiphysics® model, confirming the hypothesis. This study used a CT scan to create an anatomically accurate model of an AAA that was used to validate a computational model using a novel technique of flow visualization. As EVAR technologies continue to progress, it will become increasingly important to understand how the blood flow within the aneurysm affects the growth and treatment of AAAs.

The arrival on the market of a new kind of CNC machines which can both add and remove material to an object paved the way to a new approach to the problem of repairing damaged components. The additive operation is performed by a Direct Laser Deposition (DLD) tool, while the subtractive one is a machining task. Up to now, repair operations have been carried out manually and for this reason they are errors prone, costly and time consuming. Refurbishment can extend the life of a component, saving raw materials and resources. For these reasons, using a precise and repeatable CNC machine to repair valuable objects is therefore very attractive for the sake of reliability and repeatability, but also from an economical and environmental point of view. One of the biggest obstacles to the automation of the repairing process is represented by the fact that the CAM software requires a solid CAD model of the damage to create the toolpaths needed to perform additive operations. Using a 3D scanner the geometry of the damaged component can be reconstructed without major difficulties, but figuring out the damage location is rather difficult. The present work proposes the use of octrees to automatically detect the damaged spot, starting from the 3D scan of the damaged object. A software named DUOADD has been developed to convert this information into a CAD model suitable to be used by the CAM software. DUOADD performs an automatic comparison between the 3D scanned model and the original CAD model to detect the damaged area. The detected volume is then exported as a STEP file suitable to be used directly by the CAM. The new workflow designed to perform a complete repair operation is described placing the focus on the coding part. DUOADD allows to approach the repairing problem from a new point of view which allows savings of time and financial resources. The successful application of the entire process to repair a damaged die for injection molding is reported as a case study. In the last part of this work the strategies used to apply new material on the worn area are described and discussed. This work also highlights the importance of using optimal parameters for the deposition of the new material. The procedures to find those optimal parameters are reported, underlying the pros and cons. Although the DLD process is very energy efficient, some issues as thermal stresses and deformations are also reported and investigated, in an attempt to minimize their effects.

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