Abstract: In this paper, a bi-axially stretching was applied on a commercial polypropylene film and relationship between the stretching ratio and the properties was established. It showed that with increasing MD stretching, the film Haze was declining and the film gloss was improved. While, with increasing TD stretching, the film TD tensile strength increased linearly. The TD stretching ratio remarkably affected the properties of BOPP film.

Key words: polypropylene, film, bi-axially stretching, stretching ratio