STRETCHED FILMS WITH MAINTAINED TEAR RESISTANCE AND METHODS FOR MAKING THE SAME

摘要

Methods of stretching thermoplastic films in the machine direction include elongating the films in the machine direction without significantly reducing the films' machine-direction tear resistance. In one or more implementations, methods of stretching thermoplastic films include reducing the gauge of the films while substantially maintaining the films' machine-direction tear resistance. The methods can involve uniformly cold stretching the films by stretching the films to a draw of about one hundred and eighty percent, or less, of the films' original length.

主权项

1. A thermoplastic bag, comprising:
first and second sidewalls including blown, linear low-density polyethylene film continuously oriented in a machine direction and formed by stretching an un-stretched film; wherein:
the first and second sidewalls are joined along three edges;one or more of the first and second sidewalls has a machine direction tear resistance that is at least about 85 percent of a machine-direction tear resistance of the un-stretched film;one or more of the first and second sidewalls has a transverse tear resistance that is between about 87 percent and about 140 percent of a transverse direction tear resistance of the un-stretched film; andone or more of the first and second sidewalls has a gauge-by-weight that is less than a gauge-by-weight of the un-stretched film.