MATERIALS SELECTION TOOLS IN PROFESSIONAL APPLIANCES: HYPOTHESIS TO ESTIMATE MATERIALS’ PERFORMANCE AND IMPACT ON INDUSTRIAL PROCESSES

Concept: The use of materials selection in professional appliances increased in recent times, thanks to its potential pre-evaluation of materials’ performance and impact on industrial production processes. Materials selection permits cost reduction in preventive tests, introduction of innovative materials and technologies, materials optimization and decreasing of failures. Through a collaboration among Politecnico di Milano (Department of Design and Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”) and Electrolux Professional S.p.A. (Global Research & Development, Innovation & Technologies Area), an evaluation of materials’ tangible and intangible properties has been developed using non-traditional methods. In the first part, this work evidences the major limits and critical points of the materials’ selection tools currently and most commonly proposed in industrial applications. Within these, the main key points highlighted are the translation and connection of quantitative and qualitative properties and the risk associated to the materials selection process reliability. In a second step, some ameliorative hypotheses are built to overcome these limits, using a repeatable and suitable method for different materials selection cases. Motivations and objectives: From the critical analysis of Ashby and Karana materials selection processes emerged a critical issue: the need of a unique language to evaluate the different properties commonly investigated in a materials selection conducted both from engineers and designers. The nontraditional materials selection methodology would offer a complete evaluation of different properties: material’s technical properties (e.g. mechanical, thermal and process parameters), durability (e.g. food chemicals and detergents), food-material compliance and intangible properties (e.g. customer perception). The need of a unique materials selection method, able to convert quantitative to qualitative evaluation of properties and to estimate the risk associated to the materials selection reliability, driven the research. A procedure, which evaluates components’ life and possible failure modes (based on DOE), is under development in order to integrate these information into the future products development. Results and discussion: The research presents the development of the materials selection methodology under considerations supported by a case study focused on durability properties of materials. Each professional appliance can be seen as an input-output system constituted by materials and components that interact and have an effect on materials and components, generating different outputs. Failures are possible outputs, due to different factors, and decrease the efficiency of the system, reducing the guaranteed performances. As regards the perception of the same professional appliances by the users, their quality is unconsciously rated on the basis of visual, haptic and auditory feedback generated during the user-product interaction. The “Sensory Metrology” has been selected as appropriate method in investigating both physical properties of the materials, and in evaluating the relation with some descriptors (e.g. adjectives) associated to the perception of quality and robustness of the whole appliance.