PNEUMATIC BURSTING CHARACTERISTICS OF PLASTICS FILMS

The bursting strength and inflated deflection of linear low density po lyethylene (LLDPE), oriented polypropylene (OPP), flexible poly(vinyl chloride) (PVC), poly(ethylene terephthalate) (PET), and polyurethane (PUR) films of different thicknesses were investigated with the pneuma tic bursting method. The study showed the bursting air pressure is dir ectly proportional to the thickness of LLDPE, OPP, and PET films. The effect of different membrane diameters on the change of the bursting p roperties in OPP and PUR film was also investigated. The results showe d that the bursting properties are inversely proportional to the membr ane diameter. Furthermore, biaxial stress-strain exerted on the pole r egion of the tested films was studied. The results denoted that the re lationship between the biaxial and uniaxial tensile stress-strain was considered for two types of film: 1) Film that presented an isotropic tensile behavior showed that the tangential stress-strain is higher th an the tensile stress-strain. 2) Film that presented an anisotropic te nsile behavior showed that the tangential stress-strain is determined by the weaker tensile stress-strain values between two directions.