Abstract: The plastic bag may include flexible thermoplastic sidewalls that have a pattern imparted onto them. The wrinkle pattern may be a plurality of linear ribs formed into the sidewall that may be arranged adjacent and parallel to one another. To impart the pattern to the sidewall, a thermoplastic web used to make the sidewall may be directed between a first cylindrical roller and a second cylindrical roller, each of which may have a plurality of spaced ridges extending about their peripheries. When the web is directed between the first and second rollers, the meshing of the ridges may form ribs into the web.

Abstract: A plastic bag with flexible sidewalls defining an interior volume for holding contents includes a reinforcing feature to resist puncture and/or rupture of the bag. The reinforcing feature may include reinforcing the portion of the bag proximate the bottom edge with additional or thicker thermoplastic material. In various embodiments, the reinforcing feature may be a strip of plastic material attached along a bottom edge of the bag, either internally or externally, to provide additional material resistant to puncture. In other embodiments, the sheet material used to produce the bag may be made with varying thicknesses. In addition, methods of manufacturing a bag with such reinforcing features in a high speed automated process are disclosed.

Abstract: Multi-layered bags include an outer layer or bag and an inner layer or bag that is shorter than the outer layer or bag. The shortened inner layer or bag can stretch or expand to the outer layer or bag when loaded with objects or otherwise strained. Such multi-layered bags can allow for a reduction in thermoplastic material without compromising the strength of the multi-layered bag. In various implementations, the inner layer or bag may be non-continuously laminated, continuously laminated, or joined only along one or more edges to the outer layer or bag. Implementations including non-continuous bonds securing the inner layer or bag to the outer layer or bag can provide additional strength to the bag. Methods of forming multi-layered bags with a shortened inner layer including inserting an inner layer within an outer layer and then joining the layers to form a bag.

Abstract: Methods for creating multi-layered bags with increased or maintained strength involve forming a ribbed pattern in one or more film layers of a multi-layered bag. The method also includes non-continuously laminating the film layers of the multi-layered bag together. In one or more implementation, a transverse direction ring rolling process forms the ribbed pattern and bonds the film layers together. In one or more additional implementations, the ribbed pattern and lamination are formed separately. Still further implementations include forming network patterns one or more film layers of a multi-layered bag. Multi-layered bags formed in accordance with one or more implementations of the present invention include one or more of increased strength or reduced basis weight.