Study for the development of an endurance testing method for washing machines

摘要

This study is part of a technical support contract signed between DG Environment and DG Joint Research Centre, regarding Environmental Footprinting, material efficiency in product policy and the European Platform on LCA (2013-2017). In particular, Task and Deliverable 8 are entitled “Develop/test potentially standardized method on material efficiency, to be applied to relevant product groups” and aim at developing feasibility studies on potentially standardized methods for assessing durability of products. The main objective of this report consists of outlining and testing a procedure for assessing durability of electric washing machines for household use. In particular the report will: •investigate existing endurance tests, •define whether such endurance tests can be suitable for a possible standardised testing procedure,•develop and test a durability procedure on exemplary washing machines, and•assess the durability procedure and provide guidelines for future development. Chapters 2 and 3 of the present report concern I) a literature review, with a focus on the state of the art of washing machine durability, the average usage in Europe, frequent failure modes and different existing theories behind durability tests; II) the study of existing international standards, currently dealing with safety of electronic devices and household appliances, endurance requirements for washing machine parts and guidelines to assess the performance during the washing cycle; III) comments and feedback from experts that were contacted during the study in order to gather information about tests, non-disclosed procedures, failure mode statistics and possible answers to the question of methods able to measure or to verify durability.Chapter 4 provides the scientific background about the dynamics of a horizontal axis washing machine, which can be seen physically as a vibrating system where the tub (including the drum) is fixed with springs on the top of the housing.Finally, a novel procedure for durability testing is proposed in chapter 5. The proposed method is a first attempt to find a framework in which several washing machine types can fit in and, eventually, a point of discussion for further improvements and diversification. The results of the proposed method are presented in chapter 6 and discussed in chapter 7.