US4163812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Container coating method
Assignee: WR Grace and Co
•
Filing: 1977-11-30
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Granted: 1979-08-07
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Expires: 1997-11-30
Abstract
Abstract A method for coating a slender, cylindrical container with a thin, resinous coating by spraying powdered resin is disclosed. The technique involves spraying of finely divided resin particles entrained in a gas stream at a substantially uniform rate at a velocity of from about 20 ft/min. to about 1000 ft/min. from a nozzle. The container may be sprayed by directing a continuous flow of resin particles at an accurate, predetermined rate into the container to deposit a substantially uniformly distributed coating. Alternatively, a pulse of a predetermined quantum of resin may be sprayed into a container. The resin particles are caused to adhere to the container by preheating the container, by inducing an electrostatic charge on the resin particles, or a combination of both. The coating may be matured by preheating the container to a high temperature or by postheating the coated container at temperatures in excess of about 300° F.
Inventors
- 👤 Robert G. Coucher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:07
CPC Classifications
B; B05; B05B; B05B7/00; B05B7/14; B05B7/1404; B05B12/00; B05B12/02; B05B12/06; B05B13/00; B05B13/06; B05B14/00; B05B14/10; B05D; B05D7/00; B05D7/22; B05D7/227; Y; Y02; Y02P; Y02P70/00; Y02P70/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A process of coating the interior of a cylindrical two-piece tin can container having an open end and a closed end with an ultra-thin, continuous, pore-free comestible coating comprising: (a) pneumatically conveying a finely divided thermosetting resinous powder from a powder feeding device to a spraying device at a substantially constant rate which deviates from the average less than about five percent by weight, (b) heating said container to a temperature above the softening point of the resin, and then, (c) pneumatically spraying into the interior of said container from a point external to said container a discrete quantum of said powder at a velocity of about 20 feet/min. to about 1600 ft./min. (d) heating said coating to cause said resinous particles to form a continuous uniform film of resin on the interior of said container.
Claim 2
Dependent Claim
136 words
A process of coating the interior of a cylindrical two-piece tin can container having an open end and a closed end with an ultra-thin, continuous, pore-free comestible coating comprising: (a) pneumatically conveying a finely divided thermosetting resinous powder from a powder feeding device to a spraying device at a substantially constant rate which deviates from the average less than about five percent by weight, (b) heating said container to a temperature above the softening point of the resin, and then, (c) pneumatically spraying into the interior of said container from a point external to said container a discrete quantum of said powder at a velocity of about 20 feet/min. to about 1600 ft./min. (d) heating said coating to cause said resinous particles to form a continuous uniform film of resin on the interior of said container.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein said powder is conveyed continuously at a rate of about 1 gram per minute to about 150 grams per minute.
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said resin is pulsed prior to being conveyed to a spray device.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein said pulse introduces a predetermined quantum of resin into said spraying device.
Claim 6
Dependent Claim
21 words
The process of claim 3 wherein said pulse of resin has a duration of about 1/10 second to about one second.
Claim 7
Dependent Claim
26 words
The process of claim 1 wherein said powder is conveyed continuously at a rate of about 25 grams per minute to about 100 grams per minute.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein said container is rotated rapidly about its longitudinal axis.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein said container is preheated to about 400° F.
Claim 10
Dependent Claim
31 words
The process of claim 1 wherein said resinous powder consists of particles having an average thickness of about 20 to about 30 microns and substantially no particles greater than 100 microns.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-08-06 | 1983-02-05 | 1983-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-08-06 | 1987-02-05 | 1987-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-08-06 | 1991-02-05 | 1991-08-07 | $7700.00 | Window Closed / Lapsed |