{"id":28949,"date":"2022-06-02T09:44:32","date_gmt":"2022-06-02T08:44:32","guid":{"rendered":"https:\/\/www.he-arc.ch\/?post_type=he-arc_project&p=28949"},"modified":"2022-06-02T10:50:18","modified_gmt":"2022-06-02T09:50:18","slug":"ecological-impact-of-a-mechanical-swiss-watch","status":"publish","type":"he-arc_project","link":"https:\/\/www.he-arc.ch\/en\/projets-recherche\/ecological-impact-of-a-mechanical-swiss-watch\/","title":{"rendered":"Ecological impact of a mechanical Swiss watch"},"content":{"rendered":"\n

Context and challenges<\/h3>\n\n\n\n

This project is a case study of a hypothetical watch piece, aiming to represent a typical Swiss watch.<\/p>\n\n\n\n

The analysis was performed with the help of the Granta Edupack software, courteously provided by Ansys and in collaboration with a class of engineering students in Industrial Design Engineering led by David Weber, scientific assistant in the watchmaking research department of HE-Arc.<\/p>\n\n\n\n

Understanding how and where the watch industry uses energy is essential to identify areas that contribute most to the emission and find innovative solutions to reduce their footprint.<\/p>\n\n\n\n

Methodology<\/h3>\n\n\n\n

As the main goal of this study is to evaluate the impact of each component of the watch in the global energy consumption, the estimation made in this study is a partial eco-audit. Contrary to a global study, only embodied material energy and manufacturing processes were considered. Transportation between each step, use, maintenance and recycling were not considered because we estimate that their analysis would have relied upon too many hypotheses.<\/p>\n\n\n\n

We calculated the total required energy and emitted CO2<\/sub> by adding values contributed by:<\/p>\n\n\n\n

– initial material production, defined as \u201cEmbodied energy & CO2<\/sub> footprint of primary production\u201d in Granta Edupack<\/p>\n\n\n\n

– manufacturing of each component or \u201cMaterial processing energy & CO2<\/sub>\u201d in the Granta Edupack database.<\/p>\n\n\n\n

Results<\/h3>\n\n\n\n

We calculated that the total energy required for one watch to be 22.20\u00b1 1.03 MJ. This is equivalent to heating 66 liters of water from 20\u00b0C to 100 \u00b0C. The total CO2<\/sub> emitted is 1.52\u00b10.08 kg, that corresponds to 12.9 km driven by a modern car emitting 118 grams of CO2<\/sub> per kilometer.<\/p>\n\n\n\n

The evaluation of micro-machining and special processes as used in the watchmaking industry may differ from the mean values used in the Granta database for standard mechanical machining. Therefore, the proportion between parts footprints is more pertinent than the absolute amount of energy and CO2<\/sub> calculated in this study.<\/p>\n\n\n\n

Our study revealed that:<\/p>\n\n\n\n