Method for making plastic overcaps using hot runner back-gated mold technology

• Main Authors: BUTLER THOMAS C, CONARD WILLIAM A, KEIRSTEAD EARLE, MCCLEERY FREDRICK S, KNIGHT ARTHUR G, ONZIK DAVID D, HOOVER WILLIAM C
• Format: Patent
• Language: English
• Published: 14.09.2005
• Edition: 7
• Subjects: ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS,e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES,DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; CONVEYING; HANDLING THIN OR FILAMENTARY MATERIAL; PACKAGES; PACKAGING ELEMENTS; PACKING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; STORING; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

The present invention is a method for making a plastic overcap using a mold tool stack. The mold tool stack has a core and a cavity plate forming a cavity therebetween. The core has a resin passageway therein with a gate in a top surface of the core. The gate has a valve proximate the top surface of the core to regulate resin flowing from the resin passageway and into the cavity. The steps of the mold method are as follows: the mold tool stack is closed to form the cavity; the valve is opened to allow resin to enter the cavity; the valve is closed; the resin is allowed to cool; and the mold tool stack is opened to allow removal of the plastic overcap from within the mold tool stack. The top side of the plastic overcap produced is blemish-free, facilitating placement of labels and other markings thereon.