Die cut resealable laminated lidding film

Abstract

A lidding film and method of manufacture thereof includes a laminated web having upper and lower film layers joined by a central PSA layer. At least one laser creates a “kiss” cut through one but not both of the film layers to form a first flap. A second laser can form a second, larger flap in the other film layer. Separating the film layers or pulling back the second flap also pulls back the first flap, creating an opening and leaving a PSA coated margin for resealing. One or more score cuts through only the upper layer, proximal to the apex can facilitate lifting of the flaps. A second plurality of score cuts through only the lower layer proximate but not overlapping the first plurality can further facilitate the flap lifting. The score cuts and/or printing over the die cuts can provide tamper evidence.

I claim: 
     
         1 . A method of manufacturing a laminated lidding film with peel back resealable flap, the method comprising:
 providing a laminated web comprising a first film layer on a first side of the laminated web, a second film layer on a second side of the laminated web, and a pressure sensitive adhesive (PSA) layer sandwiched between the first and second film layers, wherein the PSA layer adheres the first and second film layers to each other;   causing a first laser beam directed at the first film layer from the first side of the laminated web to die cut a first flap outline through the first film layer, thereby defining a first flap formed within the first film layer of the laminate web; and   causing a second laser beam directed at the second film layer from the second side of the laminated web to die cut a second flap outline through the second film layer, thereby defining a second flap formed within the second film layer of the laminate web and overlapped by the first flap;   wherein:
 neither of the flap outlines penetrates through both of the film layers of the laminate web; and 
 the first and second flaps are complementary in shape, but the first flap is larger than the second flap, so that the first flap extends beyond the second flap over a margin region of the second film layer of the laminate web; and 
 separating the first flap from the first film layer at an apex of the first flap and pulling the first flap away from the laminated web causes the second flap to remain laminated to the first flap and to also be pulled away from the laminated web, so that the margin region of the second film layer is exposed, and so that an opening is formed in the lidding film in a region thereof that was formerly occupied by the second flap. 
   
     
     
         2 . The method of  claim 1 , wherein one but not both of the flap outlines further penetrates through the PSA layer, and wherein separating the first flap from the first film layer of the laminate web a margin portion of the PSA layer remains bonded to either the margin region or to a corresponding region of the first flap. 
     
     
         3 . The method of  claim 1 , wherein the first and second flap outlines are cut simultaneously. 
     
     
         4 . The method of  claim 1 , wherein the first and second flap outlines are cut sequentially. 
     
     
         5 . The method of  claim 1 , wherein the first and second flap outlines are cut while the web is in motion. 
     
     
         6 . The method of  claim 1 , wherein the flap outline further penetrates through the PSA layer, and wherein a margin portion of the PSA layer remains bonded to either the margin region or to a corresponding region of the first film layer. 
     
     
         7 . The method of  claim 1 , further comprising causing the first laser beam to further create a score cut penetrating through the first film layer but not through the second film layer of the laminate web, the score cut being located proximal to the apex of the first flap but outside of the first flap. 
     
     
         8 . The method of  claim 1 , further comprising causing the first laser beam to further create a first plurality of score cuts penetrating through the first film layer but not through the second film layer of the laminate web, the first plurality of score cuts being proximal to the apex of the first flap and within the first flap. 
     
     
         9 . The method of  claim 8 , further comprising causing the second laser beam to create a second plurality of score cuts penetrating through the second film layer but not through the first film layer of the laminate web, the second plurality of score cuts being proximal to but not overlapping the first plurality of score cuts. 
     
     
         10 . The method of  claim 1 , further comprising:
 temporarily delaminating the first and second film layers of the laminate web from each other;   deadening the PSA layer in a pull-tab region within the first flap and proximate the apex of the first flap; and   re-laminating the first and second film layers of the laminate web to each other, whereby the pull-tab region of the first film layer remains weakly attached to or detached from the PSA layer.   
     
     
         11 . A method of manufacturing a laminated, resealable lidding film, the method comprising:
 providing a laminated web comprising a first film layer on a first side of the laminated web, a second film layer on a second side of the laminated web, and a pressure sensitive adhesive (PSA) layer sandwiched between the first and second film layers and laminating the first and second film layers to each other; and   causing a laser beam directed at the second film layer from the second side of the laminated web to die cut a flap outline through the second film layer without penetrating through the first film layer, thereby defining a flap formed within the second film layer that is separated from a boundary of the second film layer of the laminate web by a margin region;   wherein at least partially separating the first film layer from the second film layer and pulling the first film layer partially away from the second film layer of the laminate web causes an underlying portion of the flap to remain laminated to the first film layer and to be pulled away from the margin region of the second film layer, so that an opening is formed in the lidding film in a region thereof that was formerly occupied by the underlying portion of the flap.   
     
     
         12 . The method of  claim 11 , wherein the flap outline further penetrates through the PSA layer, and wherein upon separating the first film layer from the margin region a margin portion of the PSA layer remains bonded to either the margin region or to a corresponding region of the first film layer of the laminate web. 
     
     
         13 . The method of  claim 11 , wherein the flap outline is cut while the web is in motion. 
     
     
         14 . The method  claim 11 , further comprising:
 temporarily delaminating the first and second film layers of the laminate web from each other;   deadening the PSA layer in a pull-tab region of the lidding film proximate a boundary of the lidding film; and   re-laminating the first and second film layers to each other, whereby the first and second film layers remain weakly attached to each other or are detached from each other in the pull-tab region.   
     
     
         15 . A laminated lidding film with peel back resealable flap, comprising:
 a first film layer on a first side of the laminated lidding film;   a second film layer on a second side of the laminated lidding film;   a pressure sensitive adhesive (PSA) layer sandwiched between the first and second film layers and laminating the first and second film layers to each other;   a first flap outline die cut through the first film layer of the laminated lidding film and defining a first flap formed within the first film layer; and   a second flap outline die cut through the second film layer of the laminated lidding film and defining a second flap formed within the second film layer of the laminated lidding film and overlapped by the first flap;   wherein:
 the first and second flaps are complementary in shape, but the first flap is larger than the second flap, so that the first flap extends beyond the second flap over a margin region of the second film layer; and 
 separating the first flap from the first film layer of the laminated lidding film at an apex of the first flap and pulling the first flap away from the laminated web causes the second flap to remain laminated to the first flap and to also be pulled away from the laminated web, so that the margin region of the second film layer is exposed, and so that an opening is formed in the lidding film in a region thereof that was formerly occupied by the second flap. 
   
     
     
         16 . The film of  claim 15 , wherein one but not both of the flap outlines further penetrates through the PSA layer, and wherein upon separating the first flap from the first film layer of the laminated lidding film a margin portion of the PSA layer remains bonded to either the margin region or to a corresponding region of the first flap. 
     
     
         17 . The film of  claim 15 , further comprising a score cut penetrating the first film layer of the laminate lidding film but not the second film layer, the score cut being located proximal to the apex of the first flap but outside of the first flap. 
     
     
         18 . The film of  claim 15 , further comprising a first plurality of score cuts penetrating the first film layer but not the second film layer, the score cuts being proximal to the apex of the first flap and within the first flap. 
     
     
         19 . The film of  claim 18 , further comprising a second plurality of score cuts penetrating the second film layer of the laminated lidding film but not the first film layer, the second plurality of score cuts being proximal to but not overlapping the first plurality of score cuts. 
     
     
         20 . A laminated lidding film with peel back resealable flap, comprising:
 a first film layer on a first side of the laminated lidding film;   a second film layer on a second side of the laminated lidding film;   a pressure sensitive adhesive (PSA) layer sandwiched between the first and second film layers and laminating the first and second film layers to each other; and   a flap outline die cut through the second film layer of the laminated lidding film but not through the first film layer and defining a flap formed within the second film layer that is separated from a boundary of the second film layer by a margin region;   wherein at least partially separating the first film layer of the laminated lidding film from the second film layer of the laminated lidding film and pulling the first film layer partially away from the second film layer causes an underlying portion of the flap to remain laminated to the first film layer and to be pulled away from the margin region of the second film layer, so that an opening is formed in the lidding film in a region thereof that was formerly occupied by the underlying portion of the flap.   
     
     
         21 . The film of  claim 20 , wherein the flap outline further penetrates through the PSA layer, and wherein upon separating the first film layer of the laminated lidding film from the margin region a margin portion of the PSA layer remains bonded to either the margin region or to a corresponding region of the first film layer.