Characterization of PEHD Films Using Uniaxial and Biaxial Testing

The bulge test is an experimental technique used in materials science and engineering research to determine the mechanical properties and deformation behavior of thin films or membranes subjected to biaxial stress conditions. It involves subjecting the film to a controlled pressure, which causes it to bulge outward. In this present work, commercially available polyethylene high density (PEHD) films were used for characterization under uniaxial and biaxial loading conditions. The films underwent initial characterization through tensile testing along both the longitudinal direction (MD) and the transverse direction (TD) through tensile testing. Subsequently, they were further characterized using the bulge test. The contrast between the uniaxial and biaxial behavior of the film has highlighted the shortcomings of relying solely on uniaxial tests to evaluate the mechanical properties of the films under realistic operating conditions.