초록 ▼

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 thermoplasti

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 multilayer strip of plastic material attached along a bottom edge of the bag, either internally or externally, to provide additional material resistant to puncture. The reinforcing feature may be adhesively bonded, heat bonded, or cold bonded to the bag sidewalls. 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.

대표청구항 ▼

1. A thermoplastic bag comprising: a first sidewall made of a flexible thermoplastic multilayer web material;a second sidewall of the flexible thermoplastic multilayer web material overlaid and joined to the first sidewall to provide an interior volume, the first and second sidewalls joined along a

1. A thermoplastic bag comprising: a first sidewall made of a flexible thermoplastic multilayer web material;a second sidewall of the flexible thermoplastic multilayer web material overlaid and joined to the first sidewall to provide an interior volume, the first and second sidewalls joined along a first side edge, an opposite second side edge, and a closed bottom edge, the first and second sidewalls un-joined along their respective top edges to define an opening opposite the bottom edge for accessing the interior volume;a multilayer non-porous thermoplastic reinforcing strip of the flexible thermoplastic multilayer web material disposed along the interior of the closed bottom edge; anda first plurality of discontinuous cold bonds securing the multilayer reinforcing strip directly to the first sidewall and a second plurality of discontinuous cold bonds securing the multilayer reinforcing strip directly to the second sidewall;wherein the multilayer reinforcing strip: extends from the first side edge to the opposite second side edge; andhas top edges positioned closer to the bottom edge of the bag than the top edges of the first and second sidewalls of the bag such that a majority of a bag body for holding contents is devoid of the multilayer reinforcing strip; and wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds are configured to de-bond and allow the reinforcing strip to act as a shock absorber as articles are added to the bag. 2. The thermoplastic bag of claim 1, wherein the multilayer web material has a BAB structure and the multilayer reinforcing strip has a B′A′B′ structure. 3. The thermoplastic bag of claim 2, wherein B′ is substantially the same material as B. 4. The thermoplastic bag of claim 2, wherein the multilayer web material has a combined B weight percentage of 30% to 50%. 5. The thermoplastic bag of claim 1, wherein the the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds securing the multilayer reinforcing strip directly to the first and second sidewalls consists of weak bonds. 6. The thermoplastic bag of claim 5, wherein the reinforcing strip is raised above the bag bottom edge and the weak bonds are configured to de-bond and allow the reinforcing strip to move downward and act as a shock absorber as articles are added to the bag. 7. The thermoplastic bag of claim 1, further comprising areas in which the reinforcing strip is not bonded to the first sidewall and the second sidewall dispersed about the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds securing the multilayer reinforcing strip directly to the first and second sidewalls. 8. A thermoplastic bag comprising: a first sidewall made of a flexible thermoplastic multilayer web material;a second sidewall of the flexible thermoplastic multilayer web material overlaid and joined to the first sidewall to provide an interior volume, the first and second sidewalls joined along a first sealed side edge, an opposite second sealed side edge, and a closed bottom folded edge, the first and second sidewalls un-joined along their respective top edges to define an opening opposite the bottom edge for accessing the interior volume; anda multilayer reinforcing strip of the flexible thermoplastic multilayer web material extending across the first and second sealed side edges from the bottom folded edge partially toward the opening;wherein the multilayer reinforcing strip is secured to the first sidewall by a first plurality of discontinuous cold bonds and wherein the multilayer reinforcing strip is secured to the second sidewall by a second plurality of discontinuous cold bonds;wherein the multilayer reinforcing strip: extends from the first side edge to the opposite second side edge; andextends between the bottom folded edge and the respective top edges a distance less than a half of a height of the first sidewall such that a majority of a bag body for holding contents is devoid of the multilayer reinforcing strip; and wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds are configured to de-bond and allow the reinforcing strip to act as a shock absorber as articles are added to the bag. 9. The draw tape bag of claim 8, wherein the sidewalls are formed with a plurality of patterns. 10. The thermoplastic bag of claim 8, wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds securing the reinforcing strip to the first sidewall and the second sidewall comprise ring roll bonds or SELFing bonds. 11. The thermoplastic bag of claim 8, wherein the reinforcing strip is additionally adhesively bonded to the first sidewall and the second sidewall. 12. The thermoplastic bag of claim 8, wherein the reinforcing strip is heat bonded to the first sidewall and the second sidewall along the side edges. 13. The thermoplastic bag of claim 8, wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds consists of weak bonds that are configured to break and absorb energy. 14. The thermoplastic bag of claim 8, wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds securing the reinforcing strip to the first and second sidewalls are positioned throughout the reinforcing strip and are surrounded by areas in which the reinforcing strip is not bonded to the first sidewall and the second sidewall. 15. A draw tape bag comprising: a first sidewall made of a flexible thermoplastic multilayer web material;a second sidewall of the flexible thermoplastic multilayer web material, overlaid and joined to the first sidewall to provide an interior volume, the first and second sidewalls joined along a first sealed side edge, an opposite second sealed side edge, and a closed bottom folded edge, the first and second sidewalls un-joined along their respective top edges to define an opening opposite the bottom edge for accessing the interior volume;a closure mechanism, the closure mechanism comprising a hem, one or more draw tape notches, and a draw tape within the hem, the hem being in at least one of the sidewalls and having a top length and extending along the open top end disposed opposite the bottom edge, the hem having a bottom length and a hem seal, the hem including the one or more draw tape notches and the draw tape;a folded multilayer reinforcing strip of the flexible thermoplastic multilayer web material extending from the first sealed side edge to the second sealed side edge and from the bottom folded edge toward the opening a distance less than half of a height of the first sidewall such that a top of the folded multilayer reinforcing strip is positioned more than half the height of the first sidewall from the closure mechanism such that a majority of a bag body for holding contents is devoid of the multilayer reinforcing strip; anda first plurality of discontinuous cold bonds securing the folded multilayer reinforcing strip directly to the first sidewall and a second plurality of discontinuous cold bonds securing the folded multilayer reinforcing strip directly to the second sidewall, the first and second plurality of discontinuous cold bonds being positioned throughout multilayer reinforcing strip and the first and second plurality of discontinuous cold bonds being configured to de-bond and allow the multilayer reinforcing strip to act as a shock absorber as articles are added to the bag. 16. The draw tape bag of claim 15, wherein the multilayer web material has a BAB structure and the multilayer reinforcing strip has a B′A′B′ structure. 17. The thermoplastic bag of claim 16, wherein B′ is substantially the same material as B. 18. The thermoplastic bag of claim 16, wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds securing the reinforcing strip to the first and second sidewalls are positioned throughout the reinforcing strip and are surrounded by areas in which the reinforcing strip is not bonded to the first sidewall and the second sidewall. 19. The draw tape bag of claim 15, wherein the reinforcing strip is substantially aligned with the bag bottom edge and the reinforcing strip is attached to the first and second bag sidewalls. 20. The thermoplastic bag of claim 15, wherein the reinforcing strip is raised above the bag bottom edge. 21. The draw tape bag of claim 15, wherein the first plurality of discontinuous cold bonds and the second plurality of discontinuous cold bonds consists of weak bonds that are configured to break and absorb energy.