US 5,871,112 A · Synthetic replacement for pulpboard in waxbond innerseals

Abstract

An innerseal is provided for sealing against the lip of a container opening under a cap. The innerseal includes a resiliently-compressible porous synthetic backing layer which fits within the cap, a foil layer, and a wax layer which initially holds the foil and backing layers together. Preferably, a heat-activatable adhesive layer is disposed against the foil layer. The cap is tightened so that the foil layer is pressed against the lip of the container opening. Then, heat is applied to melt the wax and to activate the adhesive layer. This molten wax is absorbed into the synthetic backing layer so that the backing layer and foil layer are separatable by a twisting of the cap. The synthetic backing layer provides improved strength and liquid resistance characteristics over pulpboard type seals, and is cuttable with less dust.

Claims13

Dependent claims

An innerseal for sealing over a container opening coverable by a cap and for providing a reusable seal between an underside of the cap and the container opening, the inner seal comprising:

a perforated synthetic foam backing layer attached to the underside of the cap;
a foil layer removably attached to the container opening;
and
a wax layer between the backing layer and the foil layer, the wax layer being meltable to infuse into the perforated backing layer so that the backing layer and foil layer are separable and so that the infusion of the wax into the perforated backing layer converts the perforated backing layer into a reusable seal between the underside of the cap and the container opening, and wherein, prior to melting, the wax layer holds the backing layer and foil layer together.

1 more element

Dependencies are inferred from the claim text.

Synthetic replacement for pulpboard in waxbond innerseals

Life of this patent

Synthetic replacement for pulpboard in waxbond innerseals

Life of this patent

Abstract

Claims13