Patent ID: 8268216

Claim:
A process of forming a closure adapted to be coupled to a filler neck of a container to close a mouth opening into a passageway formed in the filler neck and to establish a sealed connection between the closure and the filler neck, the process comprising the steps of providing a cap formed to include an interior region, depositing a gob of plastics material onto an interior deck of the cap to locate the gob of plastics material in the interior region of the cap, and moving a liner-forming die having a one-piece mold face into the interior region of the cap to cause the one-piece mold face to engage and compress the gob of plastics material to cause plastics material in the gob to flow in a mold chamber defined between the liner-forming die and the interior deck of the cap to form a compression-molded seal liner on the interior deck of the cap in the interior region of the cap, wherein the compression-molded seal liner includes a membrane and an annular sealing rim surrounding the membrane and mating with a perimeter portion of the membrane and the one-piece mold face is formed to include a membrane-forming surface, an annular sealing rim-forming trench surrounding the membrane-forming surface, and channel means arranged to interrupt the membrane-forming surface for receiving a portion of the plastics material in the gob and conducting the portion in radially outward directions toward the annular sealing rim-forming trench of the one-piece mold face and a perimeter edge of the interior deck during movement of the one-piece mold face toward the interior deck to cause the membrane-forming surface to be covered completely with plastics material and to cause plastics material to flow into the annular sealing rim-forming trench to form the annular sealing rim therein.