Apparatus for the punching and removing of the sprue in an injection molding tool

US4715806A · kind A · utility

Assignee

• Krauss-Mafei AG · DE

Inventors

• Ernst Ehrler · Munich, DE
• Martin Eichlseder · Tettenweis, DE
• Edmund Theiss · Freising, DE

Key dates

• Filing date: Nov 18, 1985
• Grant date: Dec 29, 1987
• Expiry date: Nov 18, 2005

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S425/81
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A sprue part is cut and removed from the injection mold part during the manufacture of information storage disks by an injection molding process. The highly sensitive molding of an information storage disk is protected from damage by the sprue and the deposition of dust particles during stripping by this process. The sprue is punched into a part serving as the die of the injection molding tool and subsequently removed, in particular by suction, through an orifice leading from inside the part, together with the dust particles generated in the punching process. Preferably, the sprue is punched out and removed with the injection molding tool closed. The injection molding tool must be opened only after the sprue and the dust have already been removed, thus ensuring that the molded product has an especially good quality.