US 12,226,938 B2
Device for preparation of expanded microspheres
Jan Nordin, Kvissleby (SE); and Per Ajdén, Bergeforsen (SE)
Assigned to NOURYON CHEMICALS INTERNATIONAL B.V., Arnhem (NL); and CONSTRUCTION RESEARCH TECHNOLOGY GMBH, Trostberg (DE)
Appl. No. 17/045,388
Filed by NOURYON CHEMICALS INTERNATIONAL B.V., Arnhem (NL); and CONSTRUCTION RESEARCH TECHNOLOGY GMBH, Trostberg (DE)
PCT Filed Mar. 29, 2019, PCT No. PCT/EP2019/058042
§ 371(c)(1), (2) Date Oct. 5, 2020,
PCT Pub. No. WO2019/192936, PCT Pub. Date Oct. 10, 2019.
Claims priority of application No. 18165829 (EP), filed on Apr. 5, 2018.
Prior Publication US 2021/0146580 A1, May 20, 2021
Int. Cl. B29C 44/34 (2006.01); B01J 13/20 (2006.01); B29K 101/12 (2006.01); B29K 105/00 (2006.01)
CPC B29C 44/3461 (2013.01) [B01J 13/20 (2013.01); B29K 2101/12 (2013.01); B29K 2105/0076 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A device for expanding unexpanded, thermally expandable, thermoplastic microspheres, comprising:
a heating zone having an inlet, and an outlet;
a pump upstream of and in fluid communication with the heating zone for feeding a slurry of unexpanded, thermally expandable, thermoplastic microspheres into the heating zone, wherein the pump is capable of generating above-atmospheric pressure in the heating zone;
an element for heating the heating zone to soften the microspheres fed into the heating zone;
an expansion zone with an inlet and an outlet, said inlet of the expansion zone being connected to the outlet of the heating zone in such a way that a pressure drop is created across the expansion zone inlet, such that a pressure in the expansion zone is at a lower pressure than the heating zone for expanding the microspheres in the expansion zone;
a distribution pipe located downstream of the expansion zone with a first inlet in fluid communication with the outlet of the expansion zone, a second inlet configured to be fluidly coupled to a cooling medium source and an outlet; and
an adjustable back pressure generator disposed in the distribution pipe for creating a variable counter pressure to influence the pressure in the expansion zone.