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US4781741A
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Process for producing spherical glass particles
Assignee: Osram Sylvania Inc
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Filing: 1987-09-28
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Granted: 1988-11-01
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Expires: 2007-09-28
Abstract
Abstract A process is disclosed for producing spherical glass particles. The process involves forming a high velocity stream of molten droplets of glass, directing said stream toward a repellent surface, impacting the molten droplets against the surface to form fragmented portions, and cooling the fragmented portions to form a glass powder consisting essentially of particles the major portion of which are glass spheres.
Inventors
- 👤 Walter A. Johnson
- 👤 Nelson E. Kopatz
- 👤 Lori S. Pruyne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:59
CPC Classifications
C; C03; C03B; C03B19/00; C03B19/10; C03B19/1005; C03B19/1015
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
112 words
A process for producing spherical glass particles, said process comprising: (a) entraining particles of glass in a non-reducing carrier gas; (b) forming a high velocity stream of molten droplets of said glass by feeding the entrained particles into a plasma; (c) passing said droplets through a gaseous atmosphere to cool and decrease the velocity of said droplets; (d) directing said stream toward a repellent surface; (e) impacting said molten droplets against said surface to form fragmented portions; and (f) cooling said fragmented portions to form a glass powder consisting essentially of particles the major portion of which are glass spheres having a particle size of less than about 25 micrometers in diameter.
Claim 2
Dependent Claim
112 words
A process for producing spherical glass particles, said process comprising: (a) entraining particles of glass in a non-reducing carrier gas; (b) forming a high velocity stream of molten droplets of said glass by feeding the entrained particles into a plasma; (c) passing said droplets through a gaseous atmosphere to cool and decrease the velocity of said droplets; (d) directing said stream toward a repellent surface; (e) impacting said molten droplets against said surface to form fragmented portions; and (f) cooling said fragmented portions to form a glass powder consisting essentially of particles the major portion of which are glass spheres having a particle size of less than about 25 micrometers in diameter.
Claim 3
Dependent Claim
20 words
A process of claim 1 wherein said glass is a non-metallic glass which forms an amorphous phase upon rapid cooling.
Claim 4
Dependent Claim
23 words
A process of claim 2 wherein said glass is selected from the group consisting of pyrex, quartz, soda lime, lead silicate, and borates.
Claim 5
Dependent Claim
18 words
A process of claim 1 wherein said spherical particles have a diameter of less than about 10 micrometers.
Claim 6
Dependent Claim
18 words
A process of claim 4 wherein said spherical particles have a diameter of less than about 1 micrometer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-01 | 1992-05-02 | 1992-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-01 | 1996-05-02 | 1996-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-01 | 2000-05-02 | 2000-11-01 | $7700.00 | Window Closed / Lapsed |