US4513106A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for expanding microspheres
Assignee: Kemanord AB
•
Filing: 1983-11-22
•
Granted: 1985-04-23
•
Expires: 2003-11-22
Abstract
Abstract A process for expanding expandable thermoplastic microspheres containing a blowing agent which will be volatilized at heating. A slurry of the unexpanded spheres is fed to a pressure zone together with steam whereby volatilization of the blowing agent occurs in the zone and the expanded microspheres are then allowed to leave the zone at a considerable pressure drop.
Inventors
- 👤 Anders Edgren
- 👤 Jan Soderberg
- 👤 Bengt Bergstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:12
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/18; B01J19/20; C; C08; C08J; C08J9/00; C08J9/22; C08J9/228; C08J9/32; Y; Y10; Y10S; Y10S264/00; Y10S264/09
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A method for expanding expandable organic thermoplastic microspheres containing a blowing agent, able to be vaporized upon heating, comprising the steps of (a) providing a pumpable slurry of the unexpanded microspheres in an inert liquid, (b) feeding the slurry into a pressure zone in which a pressure above the surrounding pressure is maintained, (c) feeding to the pressure zone steam of a temperature and in an amount sufficient for heating the microspheres above the vaporization temperature of the blowing agent, at the pressure in the pressure zone, to thereby partially expand the microspheres, (d) allowing the partially expanded microspheres to leave the pressure zone under a pressure drop whereby the spheres are further expanded and accelerated into a stream with a velocity of at least 1 meter per second, (e) injecting the accelerated stream into gas volume whereby the stream is disintegrated and cooled, and (f) separating essentially uniformly expanded and non-agglomerated spheres from the gas.
Claim 2
Independent Claim
156 words
A method for expanding expandable organic thermoplastic microspheres containing a blowing agent, able to be vaporized upon heating, comprising the steps of (a) providing a pumpable slurry of the unexpanded microspheres in an inert liquid, (b) feeding the slurry into a pressure zone in which a pressure above the surrounding pressure is maintained, (c) feeding to the pressure zone steam of a temperature and in an amount sufficient for heating the microspheres above the vaporization temperature of the blowing agent, at the pressure in the pressure zone, to thereby partially expand the microspheres, (d) allowing the partially expanded microspheres to leave the pressure zone under a pressure drop whereby the spheres are further expanded and accelerated into a stream with a velocity of at least 1 meter per second, (e) injecting the accelerated stream into gas volume whereby the stream is disintegrated and cooled, and (f) separating essentially uniformly expanded and non-agglomerated spheres from the gas.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the pressure drop at the outflow of the slurry exceeds 0.05 MPa.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the pressure drop at the outflow of the slurry exceeds 0.1 MPa.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein the content of microspheres in the slurry fed to the pressure zone is between 5 and 45 percent by weight.
Claim 6
Dependent Claim
18 words
The method of claim 4 wherein the content of microspheres is between 5 and 45 percent by weight.
Claim 7
Dependent Claim
31 words
The method of claim 1 wherein the initial dry content and the amount of steam are selected to give a microspheres content in the outgoing mixture exceeding 10 percent by weight.
Claim 8
Dependent Claim
18 words
The method of claim 6 wherein the microsphere content in the outgoing mixture exceeds 15 percent by weight.
Claim 9
Dependent Claim
15 words
The method of claim 1 wherein an inert gas is fed into the pressure zone.
References Cited (Backward Citations)
US2944292A
Cited
US3914360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |