US4298440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the corona discharge treatment of webs, and webs treated therewith
Assignee: British Cellophane Ltd
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Filing: 1980-01-25
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Granted: 1981-11-03
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Expires: 2000-01-25
Abstract
Abstract Apparatus for the corona discharge treatment of a travelling web such as a plastics or cellulose film comprises a pair of spaced conductors with an associated alternating voltage power supply set at such a distance apart that the possibility of spark or arc discharge is avoided, at least one conductor having mounted thereto an electrode member extending towards the other conductor to define a gap across which a corona discharge can be formed. The electrode member consists of a dielectric material having a dielectric constant of at least 8, preferably at least 80, and may consist of a plate with an edge directed towards the other conductor. Preferably the plate is formed of one or more ceramic tiles based upon a titanium and/or zirconium compound. In another form the electrode member consists of a row of rods or two or more rows of spaced rods in staggered relationship.
Inventors
- 👤 John L. L. Hood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:08
CPC Classifications
H; H01; H01T; H01T19/00; Y; Y10; Y10S; Y10S422/00; Y10S422/907
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
113 words
Apparatus for the corona discharge treatment of a travelling web comprising means defining a gap wherein a corona discharge may be formed, and through which the travelling web may be drawn, a pair of spaced electrical conductors for supplying power for the discharge to the said gap defining means, and a power source for supplying an alternating electrical voltage across the conductors, the means defining the gap including an electrode member mounted in electrical contact to at least one of the conductors, the electrode member being formed from a dielectric material having a dielectric constant of from 80 to 750, and the conductors being sufficiently spaced apart to preclude an arc discharge therebetween.
Claim 2
Dependent Claim
113 words
Apparatus for the corona discharge treatment of a travelling web comprising means defining a gap wherein a corona discharge may be formed, and through which the travelling web may be drawn, a pair of spaced electrical conductors for supplying power for the discharge to the said gap defining means, and a power source for supplying an alternating electrical voltage across the conductors, the means defining the gap including an electrode member mounted in electrical contact to at least one of the conductors, the electrode member being formed from a dielectric material having a dielectric constant of from 80 to 750, and the conductors being sufficiently spaced apart to preclude an arc discharge therebetween.
Claim 3
Dependent Claim
28 words
Apparatus as claimed in claim 1 in which only one of the said conductors has an electrode member mounted thereto and the other conductor is a rotatable drum.
Claim 4
Dependent Claim
15 words
Apparatus as claimed in claim 1 in which the dielectric material is a ceramic material.
Claim 5
Dependent Claim
17 words
Apparatus as claimed in claim 3 wherein said ceramic material is formed of a transition metal compound.
Claim 6
Dependent Claim
23 words
Apparatus as claimed in claim 4 wherein said transition metal compound is selected from the group consisting of titanium compounds and zirconium compounds.
Claim 7
Dependent Claim
31 words
Apparatus as claimed in claim 5 wherein said transition metal compound is selected from the group consisting of titanium dioxide, barium titanate, barium aluminium titanate, barium titanate zirconate or calcium titanate.
Claim 8
Dependent Claim
22 words
Apparatus as claimed in claim 1 in which the electrode member comprises a plate having an edge directed towards the other conductor.
Claim 9
Dependent Claim
17 words
Apparatus as claimed in claim 7 in which the electrode member comprises a series of abutting tiles.
Claim 10
Dependent Claim
25 words
Apparatus as claimed in claim 7 in which the abutting faces of the tiles are set at an angle to provide a degree of overlap.
Claim 11
Dependent Claim
17 words
Apparatus as claimed in claim 1 in which the electrode member comprises a series of abutting rods.
Claim 12
Dependent Claim
31 words
Apparatus as claimed in claim 8 or claim 10 in which the electrode member is glazed with a nonconductive glaze except for the end in electrical contact with the supporting conductor.
Claim 13
Dependent Claim
34 words
Apparatus as claimed in claim 1 in which the electrode member comprises two or more staggered rows of spaced rods, the spacing of the rods being less than the diameter of a single rod.
Claim 14
Dependent Claim
35 words
Apparatus as claimed in claim 1 in which the power source is such as is capable of supplying a voltage of from 6 to 20 Kilovolts at a frequency of from 2 to 50 Kilohertz.
Claim 15
Dependent Claim
16 words
Apparatus as claimed in claim 1 wherein the conductors are spaced by at least 35 millimeters.
Claim 16
Dependent Claim
80 words
A process for the treatment of a travelling web material with a corona discharge comprising forming a corona discharge in a gap between an electrode member having a dielectric constant of from 80° to 75° in electrical contact with an electrical conductor, and a second electrical conductor, supplying the electrical conductors with an alternating electrical voltage, the two electrical conductors and being sufficiently spaced apart to preclude an arc discharge between them, and passing the web material through the gap.
Claim 17
Dependent Claim
80 words
A process for the treatment of a travelling web material with a corona discharge comprising forming a corona discharge in a gap between an electrode member having a dielectric constant of from 80° to 75° in electrical contact with an electrical conductor, and a second electrical conductor, supplying the electrical conductors with an alternating electrical voltage, the two electrical conductors and being sufficiently spaced apart to preclude an arc discharge between them, and passing the web material through the gap.
Claim 18
Dependent Claim
17 words
A process as claimed in claim 15 in which the travelling web material is a plastics film.
References Cited (Backward Citations)
GB771234A
Cited
GB765545A
Cited
US3291711A
Cited
US3397136A
Cited
US3409537A
Cited
US3600122A
Cited
GB1228987A
Cited
GB1373235A
Cited
US4024038A
Cited
GB1448385A
Cited
US4057723A
Cited
US4145386A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |