Color Measurements and Development in Electroplating Trades

Tuesday, 3 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
W. Giurlani (Department of Chemistry - University of Florence), S. Freschi (Freschi & Vangelisti srl), A. De Luca, A. Giaccherini (Department of chemistry - University of Florence), and M. Innocenti (CNR-ICCOM)
The color measurement is a fundamental step in quality control at the end of the assembly line and in the research and development process for a variety of industrial fields: printings, textiles, automotive and last, but not least, electroplating. The precise color determination and realization has a central importance in the fashion division of electroplated bijoux. Even if color measurement could appear to be a simple operation, that’s not the case. Indeed, variation in surface roughness, ambient illumination, instruments and methods could affect drastically the reproducibility of analysis. Often, especially in industrial environment, these variables are underestimated resulting in communication problems between producer and customer. The purpose of this study, focused on the fashion applications, is to take an overview of conditions and techniques of color evaluation, effectively implemented from companies, and to find out the most accurate, and at the same time economically sustainable one. To reach this goal all the measurements are taken by keeping in mind the CIE’s (Commission Internationale de l’Eclairage - International Commission on Illumination) recommendations about standard observers, illuminants and operative conditions for reflective samples. The accuracy and affidability of a commercial colorimeter, general used in quality control, have been evaluated by comparison with a much more expensive UV-VIS laboratory spectrophotometer, which provides exact results. All specimens have been prepared by electrodeposition from different standards solutions commonly used in the electroplating area. Furthermore, is object of the study also the diverse colors obtained from the same electroplating bath by changing the operating condition, like pH, current density, additives, as well as metal ions composition.