Method for operating an injection moulding machine

US11052591B2 · kind B2 · utility

Assignee

• Kraussmaffei Technologies GMBH · DE

Inventors

• Reinhard Schiffers · Munich, DE
• Stefan Kruppa · Munich, DE
• Stefan Moser · Hallbergmoos, DE
• Matthias Busl · Karlsfeld, DE
• Johannes Wortberg · Bochum, DE

Key dates

• Filing date: Jul 19, 2016
• Grant date: Jul 6, 2021
• Expiry date: Mar 22, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2945/76933
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

In a method for operating an injection moulding machine in the absence of a backflow barrier, plastic melt is injected by a plasticising device into a cavity in a screw antechamber of a plasticising screw adapted to rotate about a longitudinal axis and to move translationally by a drive unit during an injection phase and a holding-pressure phase. A rotational drive of the drive unit is controlled such that a speed of the plasticising screw causes overlay of a backflow of the plastic melt from the screw antechamber back into screw threads of the plasticising screw by an opposing delivery flow as a result of a rotation of the plasticising screw due to a translational injection movement of the plasticising screw. A differential flow is established from the backflow and the opposing delivery flow and influenced at least during the injection phase by influencing the speed of the plasticising screw.