主权项 |
1. A flexible packaging structure for a microwavable package, in which the structure has a built-in vent feature, the packaging structure comprising:
an outer structure joined in face-to-face relation with an inner structure, each of the outer and inner structures comprising one or more layers of flexible packaging material; a continuous outer score line formed through the thickness of the outer structure, but not breaching the inner structure, the outer score line having a generally U- or V-shaped configuration so as to define an outer flap that can be lifted out of the plane of the outer structure, by pivoting about a fixed end of the outer flap defined by two ends of the outer score line; a continuous inner score line formed through the thickness of the inner structure but not breaching the outer structure, to define an inner flap or plug that can be lifted out of the plane of the inner structure, the inner score line having a smaller foot print than and being wholly contained within the area bounded by the outer score line, such that there is a marginal region bounded by the inner and outer score lines; a localized patch of pressure-sensitive adhesive (PSA) disposed between the inner and outer structures, registered with the inner and outer score lines, so that the PSA is present between the two structures in the marginal region, the PSA allowing the outer flap to be lifted away from the underlying inner structure, with the inner flap or plug remaining adhered to the outer flap via the PSA, thereby causing an opening to be formed through the structure. |