In a previous paper, a model was developed to calculate energy efficiency and temperature profiles inside a polymer plate undergoing heat treatment. This model links up the radiator characteristics and the crystalline structures together with the material i.r. absorption behaviour. Here, to validate the model, we present a comparison between numerical simulation and experimental results carried out on poly(ethylene terephthalate) plates. Examples are then given which illustrate the possible applications of the model. Finally, simulation and experimental results on the crystalline fraction distribution inside the material are presented.