Composite lid

Claim 1

A composite lid for use in a sealable closure arrangement with a container having a rim surface formed of a heat sealable material, said lid comprising: (a) an annular rim formed of molded plastic and including: (i) a horizontally disposed, radially inner ledge; (ii) a vertically disposed, radially outer skirt formed integrally with an outer portion of said ledge; (b) a central panel formed of a sheet of relatively thin printable sheet material, such as paperboard, and having a marginal area bonded to the underside of said rim ledge; (c) a membrane formed of an upper layer of Saran and a lower layer of polyethylene, said lower layer of polyethylene being compatible with the material of said container rim; (d) a temporary adhesive of a wax type material filled with metal particles disposed between said upper layer of Saran and said central panel at a marginal area thereof above the sealing area of the container rim, said membrane having the marginal area of its upper side of said upper layer of Saran releasably secured to the underside of said central panel by said temporary adhesive which will maintain said membrane and central panel attached to each other during formation of the lid in an insert molding process but which will deteriorate when the underside of said membrane is releasably attached to said container rim by radio generated frequency sealing.