The following report refers to a thesis project at the undergraduate level in innovation and product design, at Mälardalen university. The project has been carried out for Mälardalen University's workshop, which needs a machine that can recycle PLA waste. The work involved developing a concept that is economically defensible and performs at the same level as existing machines in the surrounding price range. The problem statements to be answered are the following:• What components are required for extrusion of PLA?• Which inclination is the most efficient for extrusion of PLA?The product development process described in Ulrich and Eppinger (2014), the 6 product development phases, has been the basis for the execution of this thesis project. The client's wishes, which were divided into two different categories, absolute requirements, and desirable requirements, were fulfilled in part through a theoretical concept that will later result in a physical concept.A decision matrix was drawn up to be able to decide which concept the thesis project should continue with. Concept 3 became the concept that received the most points in the matrix. The concept was based on different inclinations of the machine, and which would be most efficient in terms of time and as few components as possible. This concept was further developed in the CAD program Solidworks with a vertical setup with all the components. The vertical design means that the PLA wire does not need to be actively cooled but is instead cooled in room temperature. The total cost for the components that were ordered was around SEK 6400 (excluding what the school already has). In terms of price, this is far below the machine that is between the cheapest and the most expensive machine.The theoretical part of the work has been delivered to Henrik Lekryd and it has been well received. But no physical machine has yet been built because the ordered components have had a long delivery time. This will happen in the near future.The second question has not been answered either, as this requires a physical machine to finally calculate the machine's capacity in the selected slope (vertically). The vertical slope was chosen so that there is not a need for additional components for cooling filaments, such as water baths or fans.For further work, it is recommended, among other things, that a physical prototype is built to see what problems may arise and see the shortcomings in the selected components. A gearbox may need to be used to not overload the stepper motor. For a more durable and stable machine, metal is a better material to build the frame of, than the theoretically proposed material, MDF. / Följande rapport är avser ett examensarbete som har utförts på grundnivå på högskoleingenjörsprogrammet, inom innovation och produktdesign vid Mälardalens Högskola. Projektarbetet har utförts åt Mälardalens Högskolas verkstad som är i behov en maskin som kan återvinna PLA-skräp. Arbetet innebar att ta fram ett koncept som är ekonomiskt försvarbart och presterar på samma nivå som befintliga maskiner i kringliggande prisklass. De frågeställningar som ska besvaras är följande:• Vilka komponenter krävs för extrudering av PLA?• Vilken lutning är mest effektiv för extrudering av PLA?Produktutvecklingsprocessen som beskrivs i Ulrich och Eppinger (2014), de 6 produktutvecklingsfaserna, har varit grunden för utförandet av detta projektarbete. Uppdragsgivarens önskemål som delades upp i två olika kategorier, absoluta krav och önskvärda krav, uppfylldes delvis genom ett teoretiskt koncept som i senare skede ska resultera i ett fysiskt koncept.En beslutmatris uträttades för att kunna ta ett beslut kring vilket koncept som projektarbetet ska fortsätta med. Koncept 3 blev det koncept som fick flest poäng i matrisen. Koncepten byggde på olika lutningar av maskinen och vilket som skulle vara mest effektivt tidsmässigt och med så få komponenter som möjligt. Detta koncept vidareutvecklades i CAD-programmet Solidworks med en vertikal uppsättning av alla komponenter. Den vertikala designen innebär att filamentet inte behöver kylas ner aktivt, utan den kyls ner i rumstemperatur. Den totala kostnaden för de komponenter som beställdes blev cirka 6400kr (exklusiv det som skolan redan har). Detta hamnar prismässigt, långt under den maskin som är mellan den billigaste och den dyraste maskinen.Den teoretiska delen av arbetet har levererats till Henrik Lekryd och det har mottagits väl. Men någon fysisk maskin har ännu inte byggts eftersom de beställda komponenterna har haft lång leveranstid. Detta kommer att ske inom en snar framtid.Den andra frågeställning har inte heller besvarats eftersom för detta krävs en fysisk maskin för att slutligen räkna ut maskinen kapacitet i den valda lutningen (vertikalt). Den vertikala lutningen valdes för att inte behöva använda fler komponenter för kylning av filament, såsom vattenbad eller fläkt.För fortsatt arbete rekommenderas bland annat att en fysisk prototyp byggs för att se vilka problem som kan dyka upp och se bristerna i de valda komponenterna. En växellåda kan komma att behöva användas för att inte belasta stegmotorn. För en tåligare och stadigare maskin är metall ett bättre material att bygga ramen av än det i teoretiskt föreslagna materialet, MDF.

The relative share of natural rubber in the world's total rubber consumption had been decreasing from 75 percent in 1948- 1949 to 44.4 percent in 1965. Since the production of natural rubber has been rising over the same period , some predictions have been made indicating that there will be a surplus of production over consumption of natural rubber in the near future. In the world output of natural rubber industry, Thailand ranks third, being surpassed only by Malaysia and Indonesia. Of all the exports of Thailand, rubber ranks second in value and is exceeded only by rice. Almost all of the rubber plantations are less than 8 acres in size and the prewar stock will give a low yield. The purpose of this study is to evaluate such predictions. An attempt is also made to show that the rising relative share of synthetic rubber in the world's total rubber consumption has been primarily due to the inability of the producers of natural rubber to increase supply in pace with the increasing demand for rubber and with the technological advances in the synthetic rubber industry. The study revealed that the United States and Western Europe can be expected to continue to exercise a great influence in the future rubber market as the industrial consumers absorb nearly 50 percent of the world's total rubber consumption. In addition, the United States is expected to play a vital role as the major producer of synthetic rubber, which appears to be a critically important fact or in determining the future prospects regarding the demand for natural rubber. It is concluded that the techniques of replanting and new planting or both, using the best available high yielding clones would enable natural rubber producers to reduce the cost of production enough to meet the keen price competition from synthetic rubber. In the face of the threatening competition from synthetic rubber, the success of the natural rubber industry may be measured by the extent of realization of effective and unremitting efforts by the natural rubber industry. The future of the natural rubber industry in Thailand, then, depends first on how fast production could be stepped up; secondly how fast the cost of production could be reduced by replanting with high yielding clone; and thirdly on the world price of natural rubber. The projection of natural rubber production during the year 1970 indicates that all rubber produced will be sold. Synthetic rubber will be used to meet excess demand for new rubber during this period. But some surplus of the natural rubber will occur during the year 1975. The future of the natural rubber industry depends to a large degree on lowered costs of production with replanting and planting with high yielding trees, and improving the quality and marketing. In conclusion, the planting scheme now being undertaken in the natural rubber producing countries, will be of advantage not only at the present but also in the future.

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The aim of the thesis was to recycle a common carpet waste containing polyamide 6 (PA6) and polypropylene (PP) polymers with thermomechanical recycling. The produced products were compared to neat polymer materials. The recycled material underwent the thermomechanical process which includes shredding and extruding. The created filament was analyzed using various analysis techniques including FTIR, SEM, DSC and tensile testing for the mechanical properties. The filament was later evaluated with a 3D printer to see if a product could be made from the material. Filament containing recycled carpet material was used to create a 3D printed product, thus the method seems promising. The results from the structural analysis techniques showed that degradation of the polymers occurred after multiple recycling cycles, mostly of the PA6 polymer. The mechanical properties with the addition of recycled carpet to a blend of neat materials show similar properties when compared to only neat material. In conclusion, it is possible to 3D print recycled carp inted product so the method seems viable for future applications. / Syftet med avhandlingen var att återvinna en vanlig matta som innehåller polyamid-6- och polypropenpolymerer med termomekanisk återvinning och jämföra produkten med rena polymermaterial. Det återvunna materialet tillverkades med den termomekaniska processen som inkluderar malning och strängsprutning (extrudering). Filamentet analyseras med olika analystekniker inklusive FTIR, SEM, DSC och dragprovning för mekaniska egenskaper. Filamentet testas sedan med en 3D-skrivare för att se om en produkt kan tillverkas av materialet. Filamentet med återvunnen matta användes för att skapa en 3D-skriven produkt, därför verkar metoden lovande. Resultaten från analysteknikerna visade polymererna bröts ner efter flera återvinningscykler, mestadels av PA6-polymeren. De mekaniska egenskaperna med tillsats av återvunnet matta till en blandning av rena material visar liknande egenskaper jämfört med endast rena material. Sammanfattningsvis är det möjligt att 3D-skriva med återvunnet mattfilament för att skapa en 3D-skriven produkt, metoden verkar lovande.

The industrial demand for high strength-to-weight ratio materials is increasing due to the need for high performance components. Epoxy polymers, although often used in fiber-reinforced polymeric composites, have an inherent low toughness that further decreases with decreasing temperatures. Second-phase additives have been effective in increasing the toughness of epoxies at room temperature; however, the mechanisms at low temperatures are still not understood. In this study, the deformation mechanisms of a DGEBA epoxy modified with MX960 core-shell rubber (CSR) particles were investigated under quasi-static tensile and impact loads at room temperature (RT) and liquid nitrogen (LN2) temperature. Overall, the CSR had little effect on the tensile properties at RT and LN2 temperature. The impact strength decreased from neat to 3 wt% but increased from neat to 5 wt% at RT and LN2 temperature, with a higher impact strength at RT at all CSR loadings. The CSR particles debonded in front of the crack tip, inducing voids into the matrix. It was found that an increase in shear deformation and void growth likely accounted for the higher impact strength at 5 wt% CSR loading at RT while the thermal stress fields due to the coefficient of thermal expansion mismatch between rubber and epoxy and an increase in secondary cracking is likely responsible for the higher impact strength at 5 wt% tested at LN2 temperature. While a large toughening effect was not seen in this study, the mechanisms analyzed herein will likely be of use for further material investigations at cryogenic temperatures.

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The microalgae Scenedesmus Bloom are grown in sewage environment and contains, among other things, polymers of saccharides. The polysaccharides can possibly be extracted and used for the manufacturing of plastic material. The algae have a strong cell wall, can grow fast in severe external conditions and shows good ability to capture carbon dioxide. This study attempts to extract polymers from the algae, which will be used to create plastic films based on the microalgae. Analyses were made to determine which method gave the best results. The extraction methods that were performed were acid hydrothermal extraction, ultrasonic extraction and a combination of both methods. Before the extraction took place, preparation of the algae was performed. The preparation consisted of grinding the algae and washing the algae with acetone. The washing methods used in this study showed to not have a big influence and was therefore considered unnecessary. After the extraction, methods as dialysis and freezedrying were performed, for purification and drying of the extracted material. Finally, plastic films were made by a mixture of the extracted material and carboxymethylcellulose sodium salt. Successful films were created from extracted material from washed algae that had undergone ultrasonic extraction and from unwashed algae that had undergone the acid hydrothermal extraction. The study showed that washed algae that had undergone ultrasonic extraction gave the best results. The created films were very brittle and without the addition of any additives, no useful applications could be found. / Mikroalgen Scenedesmus Bloom odlas i avloppsmiljö och innehåller, bland annat, polymerer av sackarider. Polysackariderna kan eventuellt extraheras och användas för tillverkning av plastmaterial. Algerna har en stark cellvägg, kan växa i svåra yttre förhållanden och visar god förmåga på att fånga koldioxid. I denna studie görs försök att extrahera polymerer från algerna för att sedan tillverka plastfilmer baserade på mikroalgerna. Analyser gjordes för att bestämma vilken metod som gav de bästa resultaten. De extraktionsmetoder som utfördes var hydrotermisk extraktion med syra, ultraljudsextraktion och en kombination av båda metoderna. Innan extraktionsmetoderna ägde rum, utfördes förbehandling på algerna, vilket bestod av malning och tvättning med aceton. De tvättningsmetoder som användes i denna studie visade sig ha en tämligen liten effekt och ansågs därför som onödiga. Efter extraktionsmetoderna utfördes även metoder som dialys och frystorkning för rening och torkning av det extraherade materialet från algerna. Slutligen framställdes plastfilmer genom en blandning av det extraherade materialet och karboximetylcellulosa. Lyckade filmer skapades från extraherat material från tvättad alg som genomgått ultraljudsextraktion och från otvättad alg som genomgått hydrotermisk extraktion med syra. Det visade sig att tvättad alg som genomgått ultraljudsextraktionen gav bäst resultat. Plastfilmerna var mycket spröda och utan tillsatser kunde inga direkta tillämpningar ses.

This dissertation presents the results of a study performed to investigate methods for increasing the damping capacity of concrete. A variety of additives, both particle and latex based, were added to standard concrete mixtures by replacing up to 20% of the fine aggregate to measure their effects on strength, stiffness, damping, and air content. The additives included rubber particles from recycled tires, calcium carbonate particles, styrene butadiene rubber (SBR) latex, and a commercially available product named ConcreDamp which contains vegetable gum suspended in styrene butadiene latex. An initial investigation resulted in the observation that all of the additives with the exception of the SBR latex would both increase air content and decrease compressive strength. As a result, combinations of additives were investigated to see if both the mechanical and dynamic properties could be improved. The addition of steel fibers to mixtures with ground rubber were found to significantly increase air content which offset any gains in compressive strength. The combination of ground rubber and latex was shown to improve both increase compressive strength and reduce air content. The study advanced to investigate the effects of rubber size on air content, strength, and damping. It was found that for the same volume of rubber, a larger rubber particle would decrease air content, decrease compressive strength, and improve damping. The results of this study show that the best performing additive was the vegetable gum latex which improved the concrete damping by a factor of 2 when added as 15% of the fine aggregate. Additionally, an equation is presented for calculating a strength reduction factor for concrete containing rubber particles of different sizes. Finally, two full scale footbridge laboratory specimens were tested to investigate the effect of increased material damping at the structural level. One footbridge was constructed using a base concrete mixture without damping admixtures. The second was constructed with a concrete mixture that contained a replacement of 15% of the fine aggregate with ground rubber. The results were used to create a finite element model in SAP2000 that was used to predict the effects that high damping concretes would have on the footbridge specimen. / Ph. D.