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US 2026/0115980 A1Published application
Device for preparation of expanded microspheres
AssigneeNouryon Chemicals International B.V.
InventorsPer Erik AJDÉN, Ulf Thomas HOLMLUND, Per Olov Fredrik SVENSSON
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Abstract
The present disclosure relates to a method and a device for producing expanded microspheres.
Claims15
A device for expanding unexpanded, thermally expandable microspheres comprising:
- a heating zone having an inlet and an outlet, wherein the inlet is configured to receive a slurry of unexpanded, thermally expandable microspheres;
- a first pump upstream of and in fluid communication with the heating zone inlet;
- an expansion zone with an inlet and an outlet, said inlet of the expansion zone being connected to the outlet of the heating zone, wherein the expansion zone is configured to be at a lower pressure than the heating zone;
- a flow control device downstream of and in fluid communication with the outlet of the expansion zone;
- a fluid inlet disposed between the outlet of the expansion zone and the flow control device;
- a fluid metering device configured to control an addition rate of a dilution liquid introduced at the fluid inlet;
- and
- a controller, wherein at least one of the first pump, the flow control device, and the fluid metering device is operatively linked to the controller, and wherein the controller is programmed to:
- receive at least a first flow rate signal related to a first flow rate generated by the first pump, a second flow rate signal related to a second flow rate generated by the flow control device, and a third flow rate signal related to a third flow rate of the dilution liquid,
- calculate the density of expanded microspheres in response to at least the first flow rate, the second flow rate, and the third flow rate, and
- control the density of the expanded microspheres by controlling at least one of the first flow rate, the second flow rate, and the third flow rate.
8 more elements
A process for expanding unexpanded, thermally expandable microspheres comprising a polymer encapsulating a blowing agent, wherein said blowing agent is a liquid having a boiling temperature not higher than the softening temperature of the polymer shell, the process comprising:
- feeding a slurry of unexpanded, thermally expandable microspheres into a heating zone using a first pump operating at a first pump speed to generate a first flow rate,
- heating the microspheres to a temperature above their softening temperature, while under a pressure sufficiently high to ensure they do not fully expand;
- passing the so-heated microspheres from the heating zone to an expansion zone, such that a pressure drop is created, resulting in a pressure in the expansion zone sufficiently low for the microspheres to expand,
- removing the expanded microspheres from the expansion zone and diluting the expanded microspheres with a dilution liquid introduced at a fluid inlet by a fluid metering device operating at a third flow rate to obtain a final slurry solid content value, and
- transporting the diluted expanded microspheres to a flow control device operating at a second flow rate;
- wherein a controller operatively linked to at least one of the first pump, the flow control device, and the fluid metering device, calculates the density of expanded microspheres in response to at least the first flow rate, the second flow rate, and the third flow rate, and controls the density of the expanded microspheres by controlling at least one of the first flow rate, the second flow rate, and the third flow rate.
3 more elements
Dependencies are inferred from the claim text.