Method for producing a plastic granulate

US11241665B2 · kind B2 · utility

Assignee

• MAAG AUTOMATIK GMBH · DE

Inventors

• Horst Mueller · Rio Rancho, US
• Stefan Deiss · Harxheim, DE
• Frank Gloeckner · Aschaffenburg, DE
• Reinhardt-Karsten Muerb · Aschaffenburg, DE

Key dates

• Filing date: Oct 17, 2016
• Grant date: Feb 8, 2022
• Expiry date: Apr 16, 2037

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F26B2200/12
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a method for producing a plastic granulate (16), in which a process fluid (12) is contained in a process chamber (10) where an underwater granulation takes place and the process fluid in the process chamber has a temperature greater than 120° C. A process pressure of at least 2.0 bar is obtained in the process chamber, at which a granulation of the plastic strands (14) into plastic granulate occurs. From the process chamber, a mixture (18) of process fluid and plastic granulate is diverted into a first cooling zone (25) during cooling of the plastic granulate, while maintaining the process pressure. In a first separating device (22), the plastic granulate is separated from the process fluid under process pressure. In the process chamber, the process fluid has a temperature in the range from 120° C. to 160° C., and the process pressure obtained there is greater than the pressure of the vapour pressure curve of the process fluid. After separation from the process fluid in the first separating device, the plastic granulate is fed continuously in a line to a dealdehydization container (46).