US3729648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for treating a web
Assignee: Eastman Kodak Co
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Filing: 1971-09-30
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Granted: 1973-04-24
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Expires: 1991-09-30
Abstract
Abstract An improved method and apparatus for substantially eliminating non-uniform charge patterns from a surface of a corona-treated web, particularly for enhancing the surface''s coatability, is disclosed. The improved method and apparatus employs the technique of ''''flooding'''' the surface with charge of one polarity from a first electrode so as to generally uniformly charge the surface, and thereafter removing the charge imparted to the surface by applying an equal but opposite charge from a second electrode. To ensure positive control between the amount of charge added to the surface and the amount removed, the invention proposes that the first and second electrodes be connected to a single source of DC power and that the web, when treated in accordance with the invention, be supported by an electrically conductive roller which is electrically isolated from ground.
Inventors
- 👤 W Kerr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:59
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03C1/91; G03C1/915; B; B29; B29C; B29C59/00; B29C59/10; D; D06; D06M; D06M10/00; D06M10/02; D06M10/025; G03C1/74; B29K; B29K2995/00; B29K2995/0003; B29K2995/001; D06M2101/00; D06M2101/16; D06M2101/18; D06M2101/20; D06M2101/22; D06M2101/26; D06M2101/28; D06M2101/30; D06M2101/32; D06M2101/34; D06M2200/00; D06M2200/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
176 words
An apparatus for treating a moving web, which apparatus comprises: a. an electrical source of DC potential, b. a first electrode means coupled to one pole of said source, said first electrode means being positioned in facing relationship to one side of said web so as to generally uniformly electrically charge the said one side, and c. a second electrode means coupled to aN opposite pole of said source, said second electrode means being positioned in facing relationship to said one side of said web so as to substantially remove the charge imparted to the said one side by said first electrode; and the improvement which comprises: d. means for supporting said web, said supporting means including an electrically conductive support member which is isolated from ground and which is adapted to contact the opposite side of said web, said member being charged by said source to a potential between those applied to said first and second electrodes, and said member cooperating with said electrodes so as to comprise a common counter electrode for said electrodes.
Claim 2
Independent Claim
176 words
An apparatus for treating a moving web, which apparatus comprises: a. an electrical source of DC potential, b. a first electrode means coupled to one pole of said source, said first electrode means being positioned in facing relationship to one side of said web so as to generally uniformly electrically charge the said one side, and c. a second electrode means coupled to aN opposite pole of said source, said second electrode means being positioned in facing relationship to said one side of said web so as to substantially remove the charge imparted to the said one side by said first electrode; and the improvement which comprises: d. means for supporting said web, said supporting means including an electrically conductive support member which is isolated from ground and which is adapted to contact the opposite side of said web, said member being charged by said source to a potential between those applied to said first and second electrodes, and said member cooperating with said electrodes so as to comprise a common counter electrode for said electrodes.
Claim 3
Dependent Claim
31 words
The invention according to claim 1 wherein the first and second electrode means are spaced from said one side of said web, and said support member is comprised of a roller.
Claim 4
Dependent Claim
31 words
The invention according to claim 1, in combination with apparatus for corona-treating the web, the corona-treating apparatus being adapted to corona-treat the web at a location upstream of the support member.
Claim 5
Dependent Claim
31 words
The invention according to claim 3, in combination with means for coating the web, the coating means being adapted to coat the web at a location downstream of the support member.
Claim 6
Dependent Claim
16 words
The invention according to claim 1, wherein said electrically conductive support member is insulated from ground.
Claim 7
Dependent Claim
70 words
The invention according to claim 1, wherein a switch is electrically connected to the electrically conductive support member, the switch including at least three positions which comprise: a. means to bias the support member to a first pole of the DC source, b. means to bias the support member to a second pole of the DC source, and c. an open position wherein the support member is insulated from ground.
Claim 8
Dependent Claim
176 words
A process for the preparation of a web for deposition of a coating thereon, the web including a non-uniform distribution of electric charge that is to be substantially removed from the web prior to coating, the process including the steps of: a. providing an electrical source of DC potential, the source having first and second electrodes with the DC potential applied between the electrodes; b. exposing one side of the web to the first electrode so as to generally uniformly electrically charge the said one side; and c. exposing the said one side to the second electrode so as to remove the charge imparted to the said one side in step (b), and the improvement which comprises: d. supporting the web so that the opposite side thereof is in contact with an electrically conductive support member that is isolated from ground, said support member being charged by said source to a potential between those applied to said first and second electrodes, whereby said support member comprises a common counter electrode for said first and second electrodes.
Claim 9
Dependent Claim
176 words
A process for the preparation of a web for deposition of a coating thereon, the web including a non-uniform distribution of electric charge that is to be substantially removed from the web prior to coating, the process including the steps of: a. providing an electrical source of DC potential, the source having first and second electrodes with the DC potential applied between the electrodes; b. exposing one side of the web to the first electrode so as to generally uniformly electrically charge the said one side; and c. exposing the said one side to the second electrode so as to remove the charge imparted to the said one side in step (b), and the improvement which comprises: d. supporting the web so that the opposite side thereof is in contact with an electrically conductive support member that is isolated from ground, said support member being charged by said source to a potential between those applied to said first and second electrodes, whereby said support member comprises a common counter electrode for said first and second electrodes.
Claim 10
Dependent Claim
15 words
The invention according to claim 7 wherein a side of said web is a dielectric.
Claim 11
Dependent Claim
22 words
The invention according to claim 8 wherein the non-uniform distribution of electric charge was placed on the web during a corona-treatment process.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |