ALEXANDRIA, Va., Sept. 23 -- United States Patent no. 12,420,985, issued on Sept. 23, was assigned to YOSHINO KOGYOSHO Co. LTD. (Tokyo).
"Method of injection molding preform" was invented by Hiroshi Hosokoshiyama (Tokyo), Junichi Chiba (Tokyo) and Seiji Iso (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method of injection molding a test tube-shaped preform for biaxial stretch blow molding includes supplying a major material resin from outer and inner flow paths to a combined flow path for a predetermined time and rate. For a period of time within a range of the predetermined time period during which the major material resin is supplied, the intermediate layer resin is simultaneously supplied from t...