Experimental analysis of the thermoplastic film embossing process

Abstract

AbstractFilm embossing is a mechanical process in which a flat film is transformed into an embossed product. During the process, thermal and stress fields are applied to the polymer, causing changes in the microstructure and physical dimensions of the material. The engineering analysis of the process requires the study of various aspects relating to the characterization of the microstructure before and after embossing. A variety of experimental techniques were employed to characterize the properties and microstructure of embossed films in relation to: crystallinity, orientation, mechanical properties, and dimensions of the embossed films. Mathematical models were also developed to predict the temperature, stress, and deformation in the plastic films during embossing. The thermal treatment of the plastic film was shown to be the most significant factor in the process. The important aspects influencing the thermal treatment include the radiation heater temperature, preheat roll temperature, line velocity, and film thickness. In general, the heat transfer mathematical model predictions were in agreement with the experimental data. The stress and deformation analysis suggested that the embossing pressure and the rubber layer on the backup roll are significant factors in determining the dimensions and stress distribution in the nip region. © 1992 John Wiley & Sons, Inc.