Patent ID: 7704440

Claim:
A method of forming a fill nipple for a polymeric fuel tank, comprising the steps of: providing a mold having at least one mold cavity with a shape adapted to define the desired shape of the fill nipple including a side wall and an outwardly extending section to define an outwardly extending flange on the fill nipple and at least one slide of the outwardly extending section movable relative to the mold cavity; disposing in the mold cavity a cylindrical parison having a wall having an inner layer of a polymeric material through which hydrocarbons can permeate, an outer layer of an HDPE polymeric material and a substantially continuous hydrocarbon vapor barrier layer of a polymeric material between and adhered to the inner and outer layers of material, the polymeric material of the vapor barrier layer having a different composition than the polymeric material of the inner and outer layers; expanding the parison within the mold cavity so that the parison wall conforms to the contour of the mold cavity such that the parison includes a side wall portion and a pair of spaced outwardly extending wall portions in the outwardly extending section of the mold cavity; and moving the slide relative to the mold cavity to compress and form the outwardly extending wall portions into a flange section of the fill nipple wherein the flange section includes two vapor barrier layers within the flange section and continuous with the vapor barrier layer in the side wall of the fill nipple.