Method for obtaining multilayered hollow plastic article

Claim 1

In the method of making a hollow plastic article wherein a parison is formed on a core in a parison mold by molding the plastic material around the core in the parison mold cavity and wherein the parison is subsequently expanded in a blow mold, the improvement which comprises: providing a preformed, drawn inner liner of organic plastic material; bringing said liner and core into axial alignment with each other; engaging said core and liner by relative axial movement between the core and liner to transfer said liner to said core; engaging said liner covered core and parison mold by relative axial movement between the core and parison mold; pressure molding an outer layer of organic plastic material around said liner in said parison mold to form a composite parison; providing a second mold; bringing the second mold and composite parison covered core into axial alignment with each other; engaging said second mold and composite parison covered core by relative axial movement between the second mold and core; freeing said composite parison from surface contact with said core in said second mold; bringing said freed parison on said core and said blow mold into axial alignment with each other; engaging said freed parison covered core and said blow mold by relative axial movement between the blow mold and core; axially extending said freed parison; and finally expanding said freed parison in said blow mold to form a multilayered, oriented, composite, hollow article, wherein the parison mold and core are maintained in axial alignment with each other, and wherein the liner, second mold, and blow mold are moved between said parison mold and core for axial alignment with said core.