Method and apparatus for producing plastic objects with solid sections and hollow sections

US6143237A · kind A · utility

Assignee

• Battenfeld GmbH · DE

Inventors

• Helmut Eckardt
• Jurgen Ehritt · Hilchenbach, DE
• Alfons Seuthe · Meinerzhagen, DE
• Michael Gosdin · Meinerzhagen, DE

Key dates

• Filing date: Apr 28, 1998
• Grant date: Nov 7, 2000
• Expiry date: Apr 28, 2018

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C45/1711
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A method and an apparatus are disclosed for producing plastic objects with solid regions and hollow regions. The method has the following steps: a) blocking off a part of the cavity (2) of a molding tool (1), so that little or no plastic melt can reach the blocked-off region (8); b) injecting plastic melt into the unblocked region (9) of the cavity (2) of the molding tool (1); c) releasing the blockage, so that plastic melt can reach the previously blocked-off region (8) of the cavity (2); d) injecting a pressurized gas into the melt by means of at least one fluid injection nozzle (7), so that the melt injected into the molding tool is distributed into the desired regions of the cavity (2) while forming a hollow space and is pressed against the cavity walls of the molding tool (1); e) allowing the molded part (6) to cool; f) relieving the cavity (2) of the pressure of the pressurized fluid; and g) demolding the molded part. The advantage achieved thereby is that solid regions and hollow regions are formed in the molded part in a predetermined manner.