Influence of Annealing on Crystalline Orientation of HDPE Cast Films with Row-Nucleated Lamellar Structure

Cast films of high density polyethylene (HDPE) were prepared by extrusion followed by stretching using a chill roll. The applied draw ratios were 10, 15 and 35. Afterwards, the effect of annealing on crystalline orientation of these HDPE cast films, was investigated. The microstructure development of the lamellarstructure of the HDPE cast films was detected before and after annealing by Fourier transform infrared (FTIR). Herman orientation function of crystalline phase was calculated using dichroic ratio (D). In comparison to the non-annealed films, a significant improvement in the orientation of crystalline phase was observed when the cast films were annealed at 120 °C in a temperature controlled oven.

Keywords:

High density polyethylene , Cast film , Crystalline orientation , Dichroic ratio , Annealing