During the use phase of products, a series of obsolescing factors contribute to why a product is disposed of. Currently the visual state of a product is considered primarily in terms of aesthetic obsolescence which is synonymous with influential factors such as changes in fashion or personal preferences in style. The physical condition of a product is not commonly understood within the context of product replacement and the physical changes due to use are not understood fully. The research contributes to and provides original empirical research findings for the current literature on product lifetime extension, material semantics, the circular economy, emotionally durable design and material culture. Through an initial exploratory study (Photographic Analysis (PA) Study) of previously unexplained types of wear and damage that occur on portable electronic devices a taxonomy of damage (TOD) was established which provided the nomenclature for further studies. The second study (Retrospective Assessment (RA) Study) established the attitudes to wear based on the wear type, location, material and the stage during ownership that the wear occurred at. The RA Study highlighted the differences in the attitudinal responses to differing types of wear and damage and identified the differences in the temporal assessments of wear and damage. A third study (Real Time Assessment (RTA) Study) aimed to confirm or repudiate the findings found in the RA Study. The focus during the study was attitudes to the wear and damage in relation to the differences in materials, the location of the wear and the type of wear and damage was also looked at and led to a fuller understanding of how products and materials are perceived during the use phase; a stage of the product lifetime that is not currently well understood in terms of users aesthetic or cosmetic sensibilities. The final study (Semantic Perception of Materials (SPM) Study) focused on the visual and tactile perceptions of materials. The study established attitudinal perceptions of wear and damage of materials with a quantitative research methodology which has produced a better understanding of material semantics within the context of electronic objects. Through the four studies, discussion topics arose and major findings of the doctoral study were drawn out and seen to be interesting enough for further research and study. These discussions include the importance of including cosmetic obsolescence into the lexicon of product obsolescence and product lifetime extension literature, the differences in the perceptions of materials when they are within the context of a product or being assessed as samples, how differing product contexts affect user perceptions of wear and damage on materials and the potential inclusion of a material wear index that could inform the material selection process that goes further than the technical aspects outlined in current material selection tools and literature.

This thesis is being conducted by two final year Bachelor degree students, collaborating with a Swedish fashion brand producing leather sneakers with the aim to investigate the most common wear and tear of shoes in metropolitan and suburban environments. Shoes are readily known for having a relatively short product lifecycle and with few alternatives to prolong the materials usefulness at the end. Furthermore consumers find that the main problems that make them not want to repair, are mainly financial reasons and a lack of knowledge in repair methods. This study has conducted a survey to gain information of the most common wear and tears regarding shoes in order to meet what the consumers want for products in a repair kit. The study involved a qualitative interview about material expertise about the shoes used in this study with selected and qualified respondents from the fashion brand company. The data collected was sufficient to create a product list for a repair-kit and shows a PU-solution to repair damaged leather, heel patches to repair ripped lining, a cyanoacrylate glue to mend detached/broken outsoles and an informational manual should be the main components for the repair kit. This study is designed to work as a future recommendation specification of requirements to the company this study is collaborating with to prolong the time of usage for the shoes.

In order to meet the needs of the generations to come and to achieve the global target of maximum climate change of 1.5 degrees, we need to transform the way the society consumes natural resources. The purpose of this research is to effectively align the needs of the businesses and customers alike to accelerate a market-driven resource efficiency. We also intended to investigate what the opportunities presented to businesses are, in order to achieve environmental and economic sustainability by extending the product lifetime and improving accessibility of spares/repairs/upgrades, etc. for their products. We performed an extensive review of literature in the past two decades which describe product lifetime, obsolescence of products and the various reasons of obsolescence in the larger picture. The study is a mixed approach as we gathered data from the partner businesses by way of semi-structured interviews at the management level. We carried out a survey with a potential consumer group of these products and analysed the requirements and habits of the market. Our findings suggest that the primary driving causes for optimizing the product lifetimes of the products have been ethical and social responsibilities of the businesses. Businesses acknowledge that legislative and market pressure has increased over the past half-decade but hasn’t been enough to motivate the investments required to restructure products and business models. Businesses need to improve the statistical data they acquire from products after they have been sold, in order to facilitate the streamlining of the reverse supply chains. Lastly, we have found that the top management is committed and engaged to change the way the business functions, but the ground functions are either not aware or trained to effectively implement the changes. Future research could investigate the readiness of businesses to transition to a more closed-loop business model by way of improving information flow through the lifetime of the product. / För att bemöta kraven hos de kommande generationer och för att uppnå det globala målet om en maximal klimatförändring på 1,5 grader, måste det ske en förändring på hur samhället konsumerar naturresurser. Syftet med denna forskning och studie är att effektivt anpassa behoven hos såväl kunden som företag för att påskynda en marknadsdriven resurseffektivitet. Med denna studie har vi också för avsikt att undersöka vilka möjligheter som erbjuds till företag, för att uppnå miljömässig och ekonomisk hållbarhet genom att förlänga produktens livslängd och förbättra cängligheten för reservdelar/reparationer/uppgraderingar etc. av deras produkter. Vi gjorde en omfattande litteraturgenomgång av forskning under de senaste två decennierna som beskriver produktens livslängd, produkters inkurans och de olika orsakerna till inkurans i den större bilden. Detta hjälpte oss att ta fram en konkret definition av produktens livslängd och hur den kan förbättras med bättre material, design och ökade återvinnings aktiviteter på produktnivå. Våra resultat tyder på att de främsta drivande orsakerna till att optimera produkt livslängden för produkterna i fråga har varit företagens etiska och sociala ansvar. Företagen erkänner att lagstiftnings- och marknads trycket har ökat under de senaste 5 åren, men det har inte varit tillräckligt för att motivera de investeringar som krävs för att omstrukturera produkter och affärsmodeller. Företag måste förbättra de statistiska uppgifter som de skaffar från produkter efter att de har sålts, för att underlätta effektiviseringen. Slutligen har vi funnit att den högsta ledningen är engagerad i att förändra hur verksamheten fungerar, men markfunktionerna är antingen inte medvetna eller utbildade för att effektivt implementera förändringarna. Framtida forskning skulle kunna undersöka företagens beredskap att övergå till en mer sluten affärsmodell genom att förbättra informationsflödet genom produktens livslängd.

<p dir="ltr"><a href="" target="_blank">The electrification of the transportation sector is pivotal in reducing greenhouse gas emissions and decreasing dependence on fossil fuels. Central to this transition are battery electric vehicles (BEVs) and other clean energy technologies, which rely heavily on critical materials (CMs) such as cobalt, lithium, neodymium, and nickel. </a>These materials are essential for the performance of batteries, advanced electronics, and other components in BEVs. <a href="" target="_blank">However, the limited availability of these CMs poses potential constraints on the widespread adoption of such technologies.</a></p><p dir="ltr">This research delves into the implications of widespread BEV adoption on the demand for CMs in the United States, with a focus on both light-duty vehicles (LDVs) and medium- and heavy-duty vehicles (MHDVs). Various market penetration scenarios were analyzed, revealing that while MHDVs require more CMs per vehicle, the sheer volume of LDV sales drives the overall CM demand, particularly in a scenario with 100% BEV adoption. Key findings highlight that cobalt, graphite, lithium, neodymium, and nickel are critical for BEVs, whereas palladium and rhodium are more crucial for internal combustion engine vehicles (ICEVs). Also explored is the impact of lightweighting on LDVs, revealing that while substituting steel with aluminum increases the total CM quantity per vehicle, it reduces the vehicle's mass, operational energy consumption, and the demand for high-concern battery-related CMs. Additionally, changing the battery cathode chemistry from NMC622 to LFP significantly reduces CM use but increases the demand for strategic materials like copper and phosphorus due to the lower energy density of LFP-based batteries.</p><p dir="ltr">The research also highlights the importance of rare earth permanent magnets (REPMs), <a href="" target="_blank">particularly Neodymium-Iron-Boron (NdFeB) magnets, in clean energy technologies such as electric vehicles and wind turbines.</a> Neodymium, a critical material, faces supply chain risks. To lessen these risks, circular economy strategies have been proposed, including the recovery of needed materials from end-of-life (EoL) products. <a href="" target="_blank">A dynamic material flow analysis (MFA) model was developed to forecast such EoL flows for products containing REPMs and assess the recoverable neodymium from these EoL products. </a>The results indicate that even a modest recycling efficiency of 15% could meet 12% of the Nd demand for EVs by 2050, with reuse meeting up to 70% of the demand.</p><p dir="ltr">With the dynamic MFA model showing that circular economy principles could meet up to 70% of future neodymium demand in 2050, the next step was to investigate the techno-economic feasibility of recycling REPMs. A techno-economic assessment model was developed for establishing a magnet-to-magnet recycling facility for REPMs. Results revealed a net present value (NPV) of $8,867,111 over 20 years, a payback period of 3 years, and an internal rate of return (IRR) of 53%, providing a compelling case for investment in recycling infrastructure. Sensitivity analyses point to the selling price of recycled magnets, feedstock purchase price, facility throughput, and labor costs as the most influential factors on profitability.</p><p dir="ltr"><a href="" target="_blank">Additionally, this research explored the challenges and opportunities in the disassembly and recycling of EoL EV components, particularly traction motors containing REPMs. The complexity of disassembly, driven by varying component sizes and designs, is identified as a significant barrier. By evaluating manual disassembly times and proposing potential automation solutions, the study aims to streamline the disassembly process, thus facilitating more efficient recycling and remanufacturing operations.</a></p><p dir="ltr">The key contributions of this research are summarized as follows:</p><p dir="ltr">· Evaluated the vehicle CM demand of ICEVs and BEVs for LDVs and MHDVs and explored the impact of lightweighting and changing the battery cathode chemistry from NMC622 to LFP on CM demands.</p><p dir="ltr">· Developed a dynamic material flow analysis (MFA) model to forecast end-of-life (EoL) flows of products containing REPMs and assess the recoverable neodymium from these EoL products.</p><p dir="ltr">· Developed a techno-economic assessment (TEA) model to evaluate the viability of a magnet-to-magnet recycling facility.</p><p dir="ltr">· Performed disassembly analysis to assess the ease with which EoL BEV transmissions can be disassembled with a specific focus on the retrieval of traction motors (which house the REPMs) for potential reuse or remanufacturing.</p>