Matching Items (3)
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- All Subjects: Plastics
- Genre: Academic theses
- Genre: Masters Thesis
- Creators: Allenby, Braden
- Member of: Theses and Dissertations
Description
With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that mimic the strength characteristics of a comparable part of the same design and materials created using injection molding. In achieving this goal the production cost can be reduced by eliminating the initial investment needed for the creation of expensive tooling. This initial investment reduction will allow for a wider variant of products in smaller batch runs to be made available. This thesis implements the use of ultraviolet (UV) illumination for an in-process laser local pre-deposition heating (LLPH). By comparing samples with and without the LLPH process it is determined that applied energy that is absorbed by the polymer is converted to an increase in the interlayer temperature, and resulting in an observed increase in tensile strength over the baseline test samples. The increase in interlayer bonding thus can be considered the dominating factor over polymer degradation.
ContributorsKusel, Scott Daniel (Author) / Hsu, Keng (Thesis advisor) / Sodemann, Angela (Committee member) / Kannan, Arunachala M (Committee member) / Arizona State University (Publisher)
Created2017
Description
Plastic is a valuable part of the consumer economy, but it creates negative environmental externalities throughout its lifecycle. To reduce these effects, a sustainable circular economy is needed, where more plastic is diverted from landfill or environmental sinks through reduction, reuse, recycling, or composting, while addressing social needs. Although many different stakeholders (industry, academia, policymakers) are calling for a sustainable circular economy for plastics, globally, less than 20% of plastic is recycled with no data on reduction and reuse. In this dissertation, a mixed methods approach is used to suggest how organizations related to the plastic industry can implement a sustainable circular economy. The first chapter identifies how firms across the plastic value chain can innovate to adopt a sustainable circular flow. A systematic review reveals over 300 examples, which are used to create a material flow typology. Findings summarize five critical points of innovation and indicate that innovation adoption is low. More concerted efforts are needed to improve innovation adoption and there is a need to shift innovation focus from resource efficiency to sustainability. The second chapters studies U.S. plastic recyclers’ price signals to generate evidence for favorable recycling policies. A hedonic analysis reveals recyclers preferences for recyclability – plastic properties that enable recycling. Results suggest that adequate recycling infrastructure and absence of virgin plastic can play an important role in facilitating more recycling. In the third paper, the role of governments as consumers is studied. As the largest consumers in a market, governments can signal a large demand for circular products and services, however public administration literature has paid limited attention to it. A theoretical framework is created to fill the knowledge gap and suggest how governments can use sustainable public procurement for a circular economy. A systematic literature review of the top ten public administration journals over 32 years reveals critical knowledge gaps and the potential for important sustainable public procurement research
ContributorsHafsa, Fatima (Author) / Englin, Jeffrey (Thesis advisor) / Abbott, Joshua K (Committee member) / Darnall, Nicole (Committee member) / Dooley, Kevin J (Committee member) / Arizona State University (Publisher)
Created2022
Description
This thesis examines the composition, flow rate, and recyclability of two abundant materials generated in modern society: municipal sewage sludge (SS) generated during conventional wastewater treatment, and single-use plastic packaging (specifically, plastic bottles) manufactured and dispersed by fast-moving consumer goods companies (FMCG). The study found the presence of 5 precious metals in both American and Chinese sewage sludges. 13 rare elements were found in American sewage sludge while 14 were found in Chinese sewage sludge. Modeling results indicated 251 to 282 million metric tons (MMT) of SS from 2022 to 2050, estimated to contain some 6.8 ± 0.5 MMT of valuable elements in the USA, the reclamation of which is valued at $24B ± $1.6B USD. China is predicted to produce between 819 - 910 MMT of SS between 2022 and 2050 containing an estimated 14.9 ± 1.7 MMT of valuable elements worth a cumulative amount of $94B ± 20B (Chapter 2 and 3). The 4th chapter modeled how much plastic waste Coca-Cola, PespiCo and Nestlé produced and globally dispersed in 21 years: namely an estimated 126 MMT ± 8.7 MMT of plastic. Some 15.6 MMT ± 1.3 MMT (12%) is projected to have become aquatic pollution costing estimated at $286B USD. Some 58 ± 5 MMT or 46% of the total mass were estimated to result in terrestrial plastic pollution, with only minor amounts of 9.9 ± 0.7 MMT, deemed actually recycled. Absent of change, the three companies are predicted to generate an additional 330 ± 15 MMT of plastic by 2050, thereby creating estimated externalities of $8 ± 0.4 trillion USD. The analysis suggests that a small subset of FMCG companies are well positioned to change the current trajectory of global plastic pollution and ocean plastic littering. Chapter 5 examined the barriers to Circular Economy. In an increasingly uncertain post pandemic world, it is becoming progressively important to conserve local resources and extract value from materials that are currently interpreted a “waste” rather than a current or potential future resource.
ContributorsBiyani, Nivedita (Author) / Halden, Rolf U. (Thesis advisor) / Allenby, Braden (Committee member) / Jalbert, Kirk (Committee member) / Arizona State University (Publisher)
Created2022