DEFORMATION BEHAVIOR OF POLYETHYLENE FILMS

Abstract

The deformation of polyethylene films with spherulites was investigated by electron and polarising microscope. A linear polyethylene, Hizex 5000 was disolved in xylene at above 120°C and films were prepared on a piece of hot glass at 110°C and then cooled slowly to room temperature. (for 2-3 hours). The sperulitic films were drawn with various ratio at 20°C and 60°C. The deformation behaviour of the films at room temperature depends on the crystallization condition.The results obtained are as follows., 1) No deformation of spherulites was observed by polarising microscope in the range within the elastic limits at 20°C and 60°C.2) In the range where the strain is proportional to stress, the deformation of spherulites starts from the center at both temperature.3) In the high stretching the extinction ring was observed in the necking part. This indicates that the crystal lamellae remains without unfolding.4) When cross nicol is set in the direction of 45° to the drawing direction, the angle between the cross extinction lines observed in necking part becomes smaller than 90°.5) In lower stretching the extension of spherulite is of affine deformation.