In this study, the authors present a method to estimate the effect of heat treatment on the shrinkage behaviour of glasses. As a pre-requisite, sensitivity of the glass density as a function of glass fictive temperature is measured using the sink-float method and the slope of the relationship is used to determine the linear thermal strain proportionality factor. Evolution of the fictive temperature for different temperature-time history is measured using the infrared spectroscopy method and the results are used to estimate the structural relaxation parameters in the temperature range of interest. The overall shrinkage behaviour is predicted using the linear thermal strain actor and estimated change in fictive temperature due to thermal treatment. The predicted shrinkage behaviour is observed to be in good agreement with the independent dimensional change measurement performed on large glass sheets that have undergone similar thermal treatments.
