Document VjQyk128EwQZ3ak3mVMqRd5aK

Materials and Design 53 (2014) 782-790 Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes Technical Report Functional and perceptive aspects of non-stick coatings for cookware Stefano Rossi a'*, Gianpietro Gai b, Roberto De Benedetto a Department of Industrial Engineering, University of Trento, via Mesiano 77, 38123 Trento, Italy hFaculty ofDesign and Art, Free University ofBozen, piazza Universitet 1, 39100 Hazen, Italy CrossMark ARTICLE INFO Article history: Received 28 March 2013 Accepted 24 July 2013 Available online 2 August 2013 ABSTRACT In this product design study the functional and perceptive properties characterizing non-stick coatings for cookware were investigated. The recent introduction of so-defined "ceramic" coatings allowed to offer consumers new perceptive experiences thanks to their light shade opposite to those typical of polytetrafluoroethylene (PTFE) coatings in dark colour. These innovations made possible to counteract the general decline in consumers interest towards non-stick aluminium cookware, due to news - later proved unfounded - about the alleged toxicity of PTFE, having these products a good market success. In this work a method was individuated for testing the non-stick properties of coatings in a more technical and repeatable way, compared to the standards usually adopted by the cookware manufacturers. The coatings were later mechanically damaged in order to simulate an intense use and the non-stick properties on these abraded surfaces were newly investigated. Ceramic coatings presented a reduced functionality compared to PTFE coatings with diminished non-stick properties both on new and damaged samples. 2013 Elsevier Ltd. All rights reserved. 1. Introduction Cookware present several characteristics that significantly differentiate one from another. This product differentiation has its origin from the necessity to satisfy the different customer requests, offering them a functional and aesthetically appealing product. The supply of non-stick cookware on the market has recently grown, presenting coatings and finishes of various kind. In fact, surface engineering have a key role to improvement the performance of engineering components [1]. These coatings are continuously more advanced from the technical point of view and they all have the nonstick capability as main purpose.In order to satisfy this aim they use various materials like polymeric coatings made of PTFE (commonly called Teflon) or, recently, ceramic coatings. Beside these systems, other types of cookware coatings have been tested in these years as -- for example -- Al--Cu--Fe--Cr quasicrystalline coating and PTFE impregnated aluminium 12-41. The frenzied life of the modern age has certainly facilitated the diffusion of non-stick aluminium cookware in kitchens all over the world. Non-stick coatings indeed can guarantee optimal thermal conductivity, like uncoated aluminium, but can also offer some additional benefits which now cannot be waived. Food does not stick to cookware, these are easy to clean and light courses can be prepared, without oil and butter abuse. The habit of considering non-stick cookware a must-have item in the kitchen, however, had * Corresponding author. Tel.: ; fax: +39 0461 281977. E-mail address: @ing.unitrLit (S. Rossi). 0261-3069/S - see front matter 2013 Elsevier Ltd. All rights reserved. http://dx.doLorg/10.1016/j.matdes 2013 07.079 a setback in early 2006, when spread the news of the alleged toxicity of Teflon" (commercial name for polytetrafluoroethylene products patented by DuPont). Teflon' is an organic auto-lubricant material, it is resistant to high temperatures and it is used for coating metal surfaces in order to provide non-stick properties [5-7]. To restrain this loss of interest towards non-stick aluminium products, many cookware manufacturers, especially the bigger ones, introduced the non-stick "ceramic" coated cookware. With this new kind of cookware, manufacturers could offer consumers original features to the industrial design point of view. These features can arouse in consumers feelings and emotions totally new compared to those provided by the PTFE coated cookware. In addition, the environmental sustainability of these new type of coatings in comparison with old "plastic" ones is highlighted. New "ceramic" coatings could also give impulse to non-stick market, with excellent economic results for manufacturers. However on the technical design side the functionality and other features of these coatings are still to be verified. Cookware manufacturers follow the standard AFNOR NF D 21-511 [8] to evaluate the non-stick properties of coatings. This standard provides two similar tests on brand-new coatings called "milk test" and "egg test". In the first one some milk is boiled on a gas cooker until the water component completely evaporates and then the remaining film is carbonized. The pan is then washed under running water and the non-stick property of the coating is classified in 4 different classes, depending on the ease whereby the film of milk is removed. In the "egg test" the method is similar but in this case an average-sized egg is cooked on an electric plate