Patent ID: 6949212
Filing Date: 2005-09-27
Classification: B29C,Y10S

Abstract:
1. A method of stretching a film, the method comprising: providing a stretcher comprising a plurality of gripping elements, opposing tracks along which the plurality of gripping elements travel, the opposing tracks defining a primary stretching region in which the tracks generally diverge to stretch a film held by the gripping elements, wherein each of the opposing tracks in the primary stretching region comprises at least one continuous rail extending the length of the track through the primary stretching region; and at least one track shape controller coupled to at least one of the continuous rails within the primary stretching region; activating at least one of the track shape controllers to apply a force to at least one of the continuous rails to modify a shape of at least one of the tracks; gripping opposing ends of a film using the gripping elements; conveying the film along the opposing tracks to the primary stretching region; and stretching the film within the primary stretching region.