FORMATION OF THROUGH HOLE IN RESIN MOLDING AND MOLDING DIE FOR RESIN MOLDING USED FOR FORMATION OF THROUGH HOLE

• Main Author: NEGI HIROSHI
• Format: Patent
• Language: English
• Published: 05.08.1997
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PROBLEM TO BE SOLVED: To provide a method for forming a through hole of desired shape and size and at the same time, manufacturing a resin molding by preventing resin waste produced by the formation of the through hole from remaining unremoved in the resin molding, and a molding die for the resin molding used for the method for forming the through hole. SOLUTION: A soft resin layer 28 positioned in a molding cavity 16 is tightly formed on the cavity face 20 of the molding cavity 16. Next, a sliding core 14 is moved backward from the cavity face 20 in such a state that the soft resin layer 28 is brought into contact with a cavity face constituting area 18 which constitutes part of the cavity face 20. In addition, the outer peripheral edge part 32 of the sliding core welding part 30 of the soft resin layer 28 welded to the cavity face constituting area 18 of the sliding core 14, is stretched into a thin wall part. Further, the sliding core welding part 30 is cut off the soft resin layer 28 by hardening the thin wall part by cooling.