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US 12,496,753 B2Granted
Production of high temperature polymer based pellets by underwater pelletization at elevated water temperature to produce (rigid) bead foams
AssigneeEvonik Operations GmbH
InventorsChristian Traßl, Melanie Niepert, Florian Hopf, Denis Holleyn, Mona Ganglauf
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Abstract
A process can be used for producing (rigid) particle foams from polymer compositions containing at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. with an underwater pelletization system.
Claims11
A process for preparing expandable pellets with an underwater pelletization system from a polymer composition comprising at least one polymer having a glass transition temperature according to ISO 11357-2 published:
- 2014-07 of at least 180° C., the process comprising:
- a) conveying a polymer melt of the polymer composition from an extruder into a first water circuit that is pressurized, with a gauge pressure being within a range from 0.2 to 30 bar and a water temperature in the first water circuit being within a range from 105° C. to 180° C., and
- b) pelletizing,
- wherein the polymer composition comprises a blowing agent,
- further comprising:
- c) supplying a pelletized material from b) to a second water circuit that has a temperature below 100° C. and is operated
- 1) unpressurized, or
- 2) under a gauge pressure within a range from 0.2 to 30 bar.
5 more elements
Dependencies are inferred from the claim text.