US 5,240,133 A · Clamped-wave lid seal structure

Abstract

An article is disclosed comprising a lid engaged to a container by the formation of interlocking waves of lid material and container material at the junction of the lid and container. The interlocking waves are geometrically aligned relative to the interior of the container so as to maximize the burst strength of the container, and also to minimize the force required to peel the lid from the container. An unheated clamp head is used to clamp the lid structure immediately adjacent a heated seal head, the heated seal head being used to form the interlocking wave structure around the inside rim of the container. The clamp head prevents any melted portions of the container or lid from flowing to or towards the outside rim of the container, and thereby prevents the formation of similar interlocking waves about the outside rim of the container. Elimination of the interlocking waves about the outside rim of the container yields a clamped-wave seal structure having reduced peel initiation forces and reduced average peel forces, without affecting the resistance of the container/lid system to high burst pressures typically encountered under retort conditions.

Claims15

Dependent claims

An article comprising:

a container lid, and
a container with flange a portion of said flange formed from a second sheet of a second material, said flange shaped to operatively engage said lid, an inside rim defined at the interior junction of said lid to said container, an outside rim being defined at the exterior junction of said lid to said container, said lid and said flange operatively engaged to one another by interlocking waves formed at said inside rim, said lid and said flange bonded to each other across a sealed area defined from said interlocking waves toward said outside rim, a lid elevation change area defined outward from said interlocking waves toward said outside rim.

Dependencies are inferred from the claim text.

Clamped-wave lid seal structure

Life of this patent

Clamped-wave lid seal structure

Life of this patent

Abstract

Claims15