INJECTION MOLD

• Main Author: NAKAJIMA NOBORU
• Format: Patent
• Language: English
• Published: 29.06.1999
• 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 enhance the quality of a molded product by preventing the generation of a dimple like sink in the surface of the molded product. SOLUTION: In an injection mold wherein a cavity 5 for molding a molded product and the runner 7 injecting a resin into the cavity 5 are formed between a plurality of the split respective molds 2, 3 of a mold main body 1 and the cavity 5 and the runner 7 are connected by a tunnel gate 6, a back flow blocking means 10 blocking the back flow of the resin by cooling the resin in the tunnel gate 6 is provided on the way of the tunnel gate 6 and, since the resin is not drawn into the cavity 5 even if the resin in the tunnel gate 6 or the runner 7 is cooled to be contracted in vol., a dimplelike sink is not generated in the surface of the molded product.