The effect of processing conditions on the microstructure of embossed polyethylene films

Abstract

Film 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 Lo 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 techniques were employed to characterize the properties and microstructure of the embossed film in relation to: crystallinity, orientation, mechanical properties, and dimensions of the embossed films. The thermal treatment of the polymer film was shown to be the most significant factor in the process. By controlling the thermal treatment of the film, it is possible to manipulate the properties and dimensions of the embossed film. The important aspects: influencing thermal treatment include the radiation heater temperature, preheat roll temperature, line velocity, and film thickness. The initial film orientation and embossing pressure have a minor effect on the final properties of the embossed film. The main effect of the embossing pressure is on the bulk thickness of the embossed film.

Computer simulation of the film blowing process incorporating crystallization and viscoelasticity

“…Kamal et al (1988) and Haber and Kamal (1992) used Wide angle X-ray diffraction, infrared spectroscopy, sonie modulus, birefringence, differential scanning calorimetry, density column, and tensile tests to characterize LDPE films blown at two different blow-up ratios: 4 and 2. The thickness was kept constant for these samples.…”