Bag

摘要

A thermoplastic bag may include a sidewall that may have a plurality of first and second ribs formed therein. The first ribs may be longer in length but shorter in height than the second ribs. The second ribs may be arranged in discrete networks that appear superimposed over the first ribs. The second ribs may normally remain in a bent-over configuration. When a force is applied, the second ribs may expand the area of the sidewall so that the bag may easily accommodate large objects. To produce the bag, a thermoplastic web may be directed between opposing first and second rollers. One of the rollers may include ridges that may have first and second segments of differing heights that correspond to the differing heights of the first and second ribs. The formation of the first ribs may increase the width of the web.

主权项

1. A thermoplastic bag comprising:
a first sidewall of pliable thermoplastic material; a second sidewall of pliable thermoplastic material overlaid and joined to the first sidewall along a first side edge, a second side edge, and a bottom edge extending between the first and second side edges to provide an interior volume, the interior volume accessible via an opening provided by un-joined first and second top edges of the respective first and second sidewalls; wherein the first sidewall includes a first section having no ribs, and a second section having a plurality of first ribs parallel to one another and a plurality of second ribs parallel to one another wherein:
the second ribs are arranged in differentiated networks aligned with the first ribs,anda combination of a set of the first ribs and a set of the second ribs intermittently dispersed between the set of first ribs extend from the first side edge continuously to the second side edge, the set of second ribs being co-linear with the set of first ribs; wherein the second section provides both increased stretching and decreased thickness compared to the first section; and the first ribs and the second ribs are formed by passing the first and second sidewalls through a single pair of intermeshing rollers having a roller with a plurality of teeth that each include both a first plurality of first ring rolling elements that create the first ribs and a second plurality of SELFing elements that create the second ribs.