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.

Most aircraft component are currently being manufactured by machining, forging, welding and also assembling such parts. However, the possibilities of cutting cost from a single component has brought about a growing trend towards looking into casting as a possible option for manufacturing aircraft parts. This thesis was done at the request of Saab Avitronics. It evaluates the possibilities of one aircraft part, a chassis for an electronic unit that was first designed to be machined from a blank, to be cast. The thesis goes through the multifaceted tasks of product development. Casting process selection, cast alloy selection as well as geometry modification were some of these tasks that were performed in this thesis. It also evaluates the performances of chosen casting processes, the design of gating systems as well as various process parameters set, by simulating the casting processes. The alloy chosen was A356.0 with a T6 temper and the casting processes chosen were plaster mold casting and rheocasting. The geometry of the original chassis, which had very thin sections and undercuts which were complex to cast, was modified and made easier to cast with an acceptable slight increase of mass and size. The modification done on the geometry as well as the gating systems used had proven to be worthwhile, as the simulation of both process showed that such a part can be casted with no crucial defects foreseen. However, probable cavities might occur at the very tip of the chassis’s thin-fins – that it has for carrying away heat. Minor subsurface porosities might also be formed, which would not impair the function of the chassis. The modified chassis was made as close to as finished piece as possible, for the purpose of reducing machining costs. The cost of producing such a part by casting was also seen to be much less than machining it from blank. This could be taken as rationale for casting the chassis with thicker sections, to avoid problems that may arise in casting, and to subsequently machine these faces later, as it would still be cheaper than machining the chassis from a blank.

<p>Most aircraft component are currently being manufactured by machining, forging, welding and also assembling such parts. However, the possibilities of cutting cost from a single component has brought about a growing trend towards looking into casting as a possible option for manufacturing aircraft parts.</p><p>This thesis was done at the request of Saab Avitronics. It evaluates the possibilities of one aircraft part, a chassis for an electronic unit that was first designed to be machined from a blank, to be cast. The thesis goes through the multifaceted tasks of product development. Casting process selection, cast alloy selection as well as geometry modification were some of these tasks that were performed in this thesis. It also evaluates the performances of chosen casting processes, the design of gating systems as well as various process parameters set, by simulating the casting processes.</p><p>The alloy chosen was A356.0 with a T6 temper and the casting processes chosen were plaster mold casting and rheocasting. The geometry of the original chassis, which had very thin sections and undercuts which were complex to cast, was modified and made easier to cast with an acceptable slight increase of mass and size. The modification done on the geometry as well as the gating systems used had proven to be worthwhile, as the simulation of both process showed that such a part can be casted with no crucial defects foreseen. However, probable cavities might occur at the very tip of the chassis’s thin-fins – that it has for carrying away heat. Minor subsurface porosities might also be formed, which would not impair the function of the chassis. The modified chassis was made as close to as finished piece as possible, for the purpose of reducing machining costs. The cost of producing such a part by casting was also seen to be much less than machining it from blank. This could be taken as rationale for casting the chassis with thicker sections, to avoid problems that may arise in casting, and to subsequently machine these faces later, as it would still be cheaper than machining the chassis from a blank.</p>

The master’s thesis deals with the analysis of casting technology of the selected aluminium casting. It is a casting of a part of CNC milling machine and it is cast by gravity casting into a permanent mold. The defects which are the cause of a high percentage of nonconforming production were analyzed. Furthermore, the master’s thesis includes a complete analysis of filling and solidification of this casting in the ProCast simulation program. Numerical simulation results are verified and improved. Then the causes of problematic casting defects are proven on several calculated variants. Measures are proposed to minimize the tendency to produce castings with defects leading to nonconforming production.