Flexible packaging structure with built-in tamper-evidence features and method for making same
A flexible packaging laminate has built-in opening/reclose and tamper-evidence features by forming the laminate from an outer structure joined in face-to-face relation to an inner structure. Score lines are formed in both structures to enable an opening to be formed through the laminate by lifting a flap or the like out of the plane of the laminate. The score line through the outer structure defines a larger opening than the score line through the inner structure, such that a marginal region of the outer structure extends beyond the edge of the opening portion of the inner structure. A pressure-sensitive adhesive is used to re-adhere the marginal region to an underlying surface of the inner structure adjacent the opening through the laminate. The outer score line includes at least one tab positioned within a heat seal region of the laminate.
1. A method of making a flexible package comprising
applying a pressure-sensitive adhesive onto one surface of a first structure comprising at least one layer of flexible material;
adhesively joining the first structure to a second structure so as to form a laminate, the second structure comprising at least one layer of flexible material, wherein one of the first and second structures comprises an outer structure and the other comprises an inner structure;
advancing the laminate to a scoring station at which an outer score line is formed through the thickness of the outer structure and an inner score line is formed through the thickness of the inner structure in registration with the outer score line, the outer score line delineating a tab and an outer opening portion of the outer structure that is separable from the outer structure along the outer score line, the inner score line delineating an inner opening portion of the inner structure that is affixed to the outer opening portion and is separable from the inner structure along the inner score line, wherein a region of the outer opening portion between the outer and inner score lines is attached to an underlying surface of the inner structure via the pressure-sensitive adhesive, the outer opening portion being peelable from the underlying surface of the inner structure so as to cause the inner opening portion to also be peeled back to create an opening in the laminate, and the outer opening portion being re-attachable to the underlying surface of the inner structure via the pressure-sensitive adhesive for reclosing the opening; and
sealing at least one end of the laminate to form an end seal such that the tab is disposed at least partially within the end seal.
2. The method of claim 1 , wherein an edge of the tab is aligned with an edge of the package.
3. The method of claim 1 , wherein the tab is free from adhesion or lamination to the inner structure.
4. The method of claim 1 , wherein the sealing step comprises heat sealing the at least one end of the laminate.