Optimization of a glass annealing process: a statistical and materials science approach to a glass containers manufacturing case application

Abstract

Annealing is one of the most important processes to manufacture glass since it provides relaxation to the SiO2 vitreous network and therefore it determines important mechanical properties required for doing this material useful. However, this process is also expensive due to there are involved high quantities of energy and time to carry it out, and for these reasons there is into the glass industry a paradigm regarding possible issues involved with the changing of variables to improve the process at the technical level without affecting the glass quality. In this order of ideas, progressive decreases of both, temperature and time were performed into an actual lehr, aiming to measure, to analyze and to compare the values of stress obtained from the actual and the proposed processes, all of this using the ASTM C336-71 and the ASTM C148-14 standards, as well as using statistical tools such as: Design of Experiments (DOE) and Analysis of Variance (ANOVA). As results were obtained non-significant statistical changes between the values of stress obtained for the majority of decreases performed, which allows to think about these decreases as an option for the high glass industry costs.