Method of and system for injecting a fluid into a plastified mass in an extruder

US4381272A · kind A · utility

Assignee

• Battenfeld Maschinenfabriken GmbH · DE

Inventor

• Jurgen Ehritt · Hilchenbach, DE

Key dates

• Filing date: May 21, 1981
• Grant date: Apr 26, 1983
• Expiry date: May 21, 2001

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C2948/92828
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

An extruder system has an extruder provided internally with a worm. A source of an additive fluid under pressure is connected to a conduit opening into the barrel. An upstream valve and a downstream valve are provided in this conduit and a pressurizable fluid reservoir is provided in the conduit between the valves. The extruder is continuously rotated in the barrel to plastify a resin therein. The valves are alternatively opened and closed, that is one is open when the other is closed and vice versa, so that a fluid first flows from the source through the upstream valve into the reservoir and then from the reservoir through the downstream valve into the barrel to be mixed by the worm with the plastic resin therein. The reservoir can be a cylinder having a piston advanced when the downstream valve is opened to force the charge of additive fluid in the reservoir into the barrel.