Patch Bag Having Separated Tear Initiators

Abstract

A patch bag has a heat-shrinkable patch adhered to a heat-shrinkable bag and a skirt between a heat seal and an edge of the bag. The bag is made from a multilayer film with at least one film layer comprising an incompatible polymer blend so that after shrinking the film exhibits controlled tear direction. The bag skirt has a bag tear initiator for initiating a controlled direction tear to the opposite side of the bag. The patch has an edge with a patch tear initiator separated from the bag tear initiator but positioned along a tear line emanating from bag tear initiator, so that upon tearing the shrunken bag, the controlled tear propagates into the patch tear initiator and thereafter the shrunken bag and the shrunken patch tear together towards an opposite edge of the patch.

What is claimed is: 
     
         1 . A patch bag comprising a heat-shrinkable patch adhered to a heat-shrinkable bag having an open top and a top edge, a closed bottom and a bottom edge, a first side edge, a second side edge, a first lay-flat side, a second lay-flat side, a heat seal of a region of the first lay-flat side to a region of the second lay-flat side, a first tear initiator in the first lay-flat side in a bag skirt outward of the heat seal or in a bag header between the patch and the top edge of the bag, a second tear initiator in the second lay-flat side in the bag skirt outward of the heat seal or in the bag header between the patch and the top edge of the bag, with at least a portion of the heat-shrinkable patch being adhered to an outside surface of the first lay-flat side of the bag, with the patch having a patch tear initiator located on an edge of the patch in a location separated from the first tear initiator, the patch tear initiator being aligned with an MD or TD tear line extending from the first bag tear initiator, with the heat shrinkable bag comprising a multilayer film having at least one layer comprising an incompatible polymer blend. 
     
     
         2 . The patch bag according to  claim 1 , wherein the incompatible polymer blend comprises at least one member selected from the group consisting of:
 (A) a blend of from 80 to 60 wt % ethylene homopolymer and/or ethylene/α-olefin copolymer with from 20 to 40 wt ethylene/unsaturated ester copolymer having an unsaturated ester content of at least 10 wt %;   (B) a blend of ionomer resin with ethylene/unsaturated ester copolymer, and/or polybutylene, and/or propylene homopolymer and/or propylene copolymer;   (C) a blend of homogeneous ethylene/α-olefin copolymer with recycled polymer blend comprising ethylene homopolymer, propylene homopolymer, ethylene copolymer, propylene copolymer, polyamide, ethylene/vinyl alcohol copolymer, ionomer resin, anhydride-modified ethylene/α-olefin copolymer, and/or antiblock;   (D) a blend of from 10 to 75 wt % ethylene/unsaturated ester copolymer with from 90 to 15 wt % polypropylene and/or propylene/ethylene copolymer, and/or polybutylene, and/or modified ethylene/α-olefin copolymer, and/or styrene homopolymer, and/or styrene/butadiene copolymer;   (E) a blend of ethylene/norbornene copolymer with ethylene/unsaturated ester copolymer and/or polypropylene and/or polybutylene;   (F) a blend of from 90 to 15 wt % ethylene/α-olefin copolymer with from 10 to 75 wt % polypropylene and/or polybutylene and/or ethylene/norbornene;   (G) a blend of from 90 to 25 wt % homogeneous propylene homopolymer and/or homogeneous propylene copolymer with from 10 to 75 wt % homogeneous ethylene/α-olefin copolymer and/or ethylene/unsaturated ester copolymer;   (H) a blend of propylene homopolymer and/or propylene/ethylene copolymer and/or polybutylene with ethylene/methyl acrylate copolymer and/or ethylene/acrylic acid copolymer and/or ethylene/butyl acrylate copolymer;   (I) a blend of polyamide with polystyrene and/or ethylene/α-olefin copolymer and/or ethylene/vinyl acetate copolymer and/or styrene/butadiene copolymer;   (J) a blend of polyamide 6 and polyamide 6I6T;   (K) a blend of a thermoplastic polymer and a filler, wherein the filler is present in an amount of at least 5 wt %, based on layer weight.   
     
     
         3 . The heat-shrinkable patch bag according to  claim 1 , wherein the bag is an end-seal bag comprising a seamless tubing with the first and second bag side edges being folded edges, with the heat seal being an end seal across a bottom of the bag, with the skirt being outward of the end seal, with the patch tear initiator being aligned with the MD tear line extending from the first tear initiator. 
     
     
         4 . The heat-shrinkable patch bag according to  claim 1 , wherein the bag is a side-seal bag having an open top, a folded bottom edge, first side seal along the first side edge, second side seal along the second side edge, with respective first and second bag skirts outward of respective first and second side seals, with the first and second tear initiators being in the first bag skirt and outward of the first side seal, with the patch tear initiator being aligned with the MD tear line extending from the first tear initiator. 
     
     
         5 . The heat-shrinkable patch bag according to  claim 1 , wherein the bag is a pouch having a bottom seal which is a heat seal of the first lay-flat side to the second lay-flat side along the bottom edge, with a bottom skirt between the bottom edge and the bottom seal, and a first side seal which is a heat seal of the first lay-flat side to the second lay-flat side along the first side edge with a first side skirt between the first side seal and the first side edge, a second side seal which is a heat seal of the first lay-flat side to the second lay-flat side along the second side edge with a second side skirt between the second side seal and the second side edge, with the first and second tear initiators being in the same skirt. 
     
     
         6 . The heat-shrinkable patch bag according to  claim 1 , wherein the bag is a backseamed bag having a bottom seal which is a heat seal of the first lay-flat side to the second lay-flat side along the bottom edge, with a bottom skirt between the bottom edge and the bottom seal, with the backseamed bag having a backseamed seal which is a heat seal of the multilayer film to itself, with the backseam seal being on the second lay-flat side of the bag and the backseam running from the bottom edge of the bag to the top edge of the bag. 
     
     
         7 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch comprises a plurality of tear initiators, with one of the tear initiators being aligned with an MD or TD tear line extending from the first bag tear initiator. 
     
     
         8 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch tear initiator is V-shaped or Y-shaped. 
     
     
         9 . The heat-shrinkable patch bag according to  claim 1 , wherein the bag film is a multilayer film comprising an outer seal and meat contact layer which is an inside layer of the bag and which comprises ethylene/α-olefin copolymer, an outer abuse layer which is an outside layer of the bag and which comprises ethylene/α-olefin copolymer, an internal O 2 -barrier layer, a first tie layer between the seal layer and the O 2 -barrier layer, a second tie layer between the O 2 -barrier layer and the abuse layer, a first incompatible polymer blend layer between the seal layer and the first tie layer, and a second incompatible polymer blend layer between the abuse layer and the second tie layer, wherein first and second incompatible polymer blend layers comprise a blend of from 60 to 80 wt % ethylene/α-olefin copolymer and 40 to 20 wt % ethylene/unsaturated ester copolymer having an unsaturated ester content of at least 10 wt %, based on polymer weight, with the amount of incompatible polymer blend in the film being from 30 to 70 wt %, based on total film weight, and
 the patch comprises self-welded multilayer film having an outer layer comprising ethylene/α-olefin copolymer, self-weld layer comprising an ethylene unsaturated ester or ethylene/unsaturated acid copolymer, and an intermediate layer between the self weld layer and the outer layer comprising ethylene/α-olefin copolymer. 
 
     
     
         10 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch is positioned inward of the heat seal and does not extend to the heat seal. 
     
     
         11 . The heat-shrinkable patch bag according to  claim 1 , wherein the first tear initiator is placed in a central region of the bag, and the second tear initiator is placed in the central region of the bag, with the central region extending up to 70% of a bag dimension transverse to a centerline. 
     
     
         12 . The heat-shrinkable patch bag according to  claim 1 , wherein the skirt further comprises a grip assister, and at least a portion of the skirt or header is heatset in order to reduce the shrinkage of the skirt or header upon shrinking the film around the product. 
     
     
         13 . The heat-shrinkable patch bag according to  claim 12 , wherein the heatset portion is in the skirt and the heatset portion comprises at least one supplemental heat seal of at least a portion of the first lay-flat side of the skirt to a portion of the second lay-flat second side of the skirt. 
     
     
         14 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch covers at least a portion of the heat seal and a portion of the patch covers a portion of the skirt, with the portion of the patch covering the skirt having an edge inside an outer edge of the skirt. 
     
     
         15 . The heat-shrinkable patch bag according to  claim 1 , wherein the multilayer film has Peak Load Impact Strength, determined using ASTM D 3763-95A, of at least 50 Newtons per mil, and the multilayer film has thickness of from 1.5 to 5 mils. 
     
     
         16 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch does not have a line of weakness aligned with the patch tear initiator. 
     
     
         17 . The patch bag according to  claim 1 , wherein the first tear initiator and the second tear initiator are coincident or substantially coincident. 
     
     
         18 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch comprises a heat shrinkable film that does not comprise an incompatible polymer blend. 
     
     
         19 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch comprises a heat shrinkable film containing an incompatible polymer blend. 
     
     
         20 . The heat-shrinkable patch bag according to  claim 1 , wherein the patch is a first patch adhered to a first lay-flat side of the bag, with the patch tear initiator being a first patch tear initiator in the first patch, with the first patch tear initiator being aligned with the first bag tear initiator, with the patch bag further comprising and a second patch adhered to a second lay-flat side of the bag, the second patch having a second patch tear initiator which is aligned with the second bag tear initiator.