Next Generation Kettle : A Realisation of an Induction Cooktop Kettle with Automatic Deactivation

Sammanfattning: In 2018 KTH alumni Frida Bylund and Linnea Kåwe investigated, on behalf of C3 Scandinavian lifestyle, a new way of boiling water on an induction cooktop. The idea was to develop an induction kettle that shuts itself off when the water reaches 100°C. This product would fulfil the user desire to keep their kitchen counter minimalistic and clean from clutter and home appliance products. This thesis is a continuation of Bylund and Kåwe’s work and carried out together with Svensk konstruktionstjänst AB. The mechanism of the product was to be evaluated and developed, resulting in a refined solution. A repetitive prototype was to be built to present and ensure the functionality of the mechanism. Furthermore, a design concept was to be realised as renderings and a physical model, which included the mechanism. The project was divided into four phases: Frame of reference, Development of the mechanism, Evaluation of final prototype, Industrial design Proposal. The first phase consisted of testing and evaluating Bylund and Kåwe’s mechanism. Furthermore, a literature study was conducted to examine key components and materials for the product. The second phase consisted of generating concepts for the mechanism using the methods; Crazy eight´s, Brainstorming/Braindrawing, Structural and Shape variation and Negative brainstorming. The concepts were evaluated with the Weight criteria matrix to find the most suitable solution. The third phase consisted of building a robust and repetitive prototype which could be tested with users as well as evaluated against the requirements specification. The user tests were carried out with the Think aloud method and Semi structured interviews. Finally, a design proposal for the product was designed and presented with renderings and a physical model in the fourth phase. A solution for the mechanism was found and the functional prototype was successful. It could boil water 20 times in a row over the course of three days without failure - half a liter of water boiled in 4 minutes and 45 seconds. However, the prototype was only able to manage about 1000W which resulted in a long boiling time. The power drop was partly because the jug was convex in the bottom which created an unwanted distance to the induction cooktop, hence decreasing the transferred power. The second reason was most likely that the ferrous material, which established contact with the induction cooktop, had lost some of its magnetic properties during manufacturing of the prototype. If a better jug and ferrous material for the induction cooktop could be manufactured, the prototype would perform better. An induction kettle could be more sustainable than an electric kettle since it does not consist of electrical components. An eco-analysis was conducted to compare the design suggestion of the induction kettle with an electric kettle. The simplified life-cycle assessment showed that the induction kettle had better end of life potential than an electric kettle, however the materials selected for the induction kettle proved to be on the critical materials list which made the carbon footprint of the induction kettle higher than expected. This could be lowered if the induction kettle does not require virgin materials for its components. The purpose and the goal for the project was reached, a solution for the mechanisms was found and evaluated - the mechanism proved to be robust enough to further develop the product. Areas of future work were found; The housing and other plastic components has to be investigated further and the tolerances of the mechanism has to be customised for the solution.