Pelletizing die with even heat distribution and with polymer channel to orifice transition zone, process for orifice thermal stabilization and process for forming a pelletizing die with brazing and thin hard face layer

US6976834B2 · kind B2 · utility

Assignee

• BORSIG GMBH · DE

Inventors

• Clifton T. Knight · Houston, US
• Judeth Brannon Corry · Houston, US
• Jürgen BLUM · Velten, DE
• Andreas Grundmann · Berlin, DE
• Dieter Bormann · Kelkheim, DE
• Andreas Forster · Schweinfurt, DE

Key dates

• Filing date: Jul 9, 2001
• Grant date: Dec 20, 2005
• Expiry date: Feb 9, 2022

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/919
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A pelletizing die includes a pelletizing die member with a die exit side exposed to cooling fluid and a die entry side for receiving polymer fed thereto. The die member has a plurality of polymer channels and a plurality of extrusion orifices connected to a respective one of the channels to form a extrusion orifice section. A heating medium system has additional heating medium conduits between channels and a supply and intermediate header for heating the channels (radially from each side) and providing once in and once out heating medium flow. The die member may be formed by high temperature brazing of components using coordinated solder (Ni based or gold-nickel) and component heat treatment temperature. A thin hard face coating may be provided on raised extrusion orifice ring faces around each extrusion orifice section.