Patent US4657783A successfully refreshed from Google Patents.
US4657783A
Expired / Lapsed
US
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Process and apparatus for coating paper
Assignee: Arjo Wiggins Ltd
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Filing: 1985-01-25
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Granted: 1987-04-14
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Expires: 2005-01-25
Abstract
Abstract A process for effecting the high speed coating (as herein defined) of both sides of a lightweight paper sheet (as herein defined) with coatings of low dry coatweight (as herein defined), while maintaining good coating pattern and control over the degree of curl in the sheet when dried, comprising the steps of: moving an endless transfer surface sequentially through first, second and third stations, at first station, forming on said transfer surface a smooth continuous film of a first coating mix having a predetermined fluid content and rheology, at the second station, bringing a first side of said paper sheet into contact with said transfer surface and simultaneously subjecting the sheet to pressure against said transfer surface without substantial sheet distortion, so as to promote substantially complete absorption by the sheet of the solvent or dispersion medium of the first coating mix while in engagement with the transfer surface and prior to passage of the sheet and transfer surface through the third station. at the third station, applying to the second side of the sheet a second coating mix having a predetermined fluid content and rheology optionally differing from that of the first coating mix, and separating the sheet from the transfer surface for drying.
Inventors
- 👤 Christopher F. Tatt
- 👤 Kenneth Richards
- 👤 Michael R. Chamberlain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:31
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/28; B05C; B05C1/00; B05C1/04; B05C1/08; B05C1/12; B05C9/00; B05C9/04; B41; B41M; B41M5/00; B41M5/124; B41M5/1246; D; D21; D21H; D21H23/00; D21H23/02; D21H23/22; D21H23/70; D21H23/72; D21H5/00; D21H5/0005; D21H5/005; D21H5/0052; B05D2252/00; B05D2252/02; B05D2252/10
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
200 words
A process for effecting the high speed coating of both sides of a lightweight paper sheet with coating of low dry coatweight, whilst maintaining good coating pattern and control over the degree of curl in the sheet when dried, comprising the steps of: moving an endless transfer surface sequentially through first, second and third stations, at the first station, forming on said transfer surface a smooth continuous film of a first coating mix having a predetermined fluid content and rheology, at the second station, bringing a first side of said paper sheet into contact with said transfer surface and simultaneously subjecting the sheet to pressure of about 0.5 kilograms per linear centimeter with a pressure roll which is softer than said transfer surface without substantial sheet distortion, so as to promote substantially complete absorption by the sheet of the fluid content of the first coating mix whilst in engagement with the transfer surface and prior to passage of the sheet and transfer surface through the third station, at the third station, applying to the second side of the sheet a second coating mix having a predetermined fluid content and rheology, and separating the sheet from the transfer surface for drying.
Claim 2
Dependent Claim
200 words
A process for effecting the high speed coating of both sides of a lightweight paper sheet with coating of low dry coatweight, whilst maintaining good coating pattern and control over the degree of curl in the sheet when dried, comprising the steps of: moving an endless transfer surface sequentially through first, second and third stations, at the first station, forming on said transfer surface a smooth continuous film of a first coating mix having a predetermined fluid content and rheology, at the second station, bringing a first side of said paper sheet into contact with said transfer surface and simultaneously subjecting the sheet to pressure of about 0.5 kilograms per linear centimeter with a pressure roll which is softer than said transfer surface without substantial sheet distortion, so as to promote substantially complete absorption by the sheet of the fluid content of the first coating mix whilst in engagement with the transfer surface and prior to passage of the sheet and transfer surface through the third station, at the third station, applying to the second side of the sheet a second coating mix having a predetermined fluid content and rheology, and separating the sheet from the transfer surface for drying.
Claim 3
Dependent Claim
202 words
Apparatus for forming a low coatweight coating on each side of a lightweight paper sheet whilst predetermining the degree of curl in the sheet when dried, comprising a backing roll for supportive engagement with a first side of a paper sheet and transferring thereto a film coating mix, means for forming a continuous film of the first coating mix on said backing roll, a trailing blade metering device for metering and smoothing the film on the backing roll, a pressure roll forming a nip with the backing roll, the pressure roll having a softer surface than the backing roll, the pressure and backing rolls being adapted to apply a nip pressure of about 0.5 kilograms per linear centimeter transversely of the sheet so as to conform the sheet, without substantial distortion, to the profile of the backing roll and so as to promote absorption by the paper sheet of the fluid content of the film, and means for applying a coating of a second coating mix to the second side of the sheet while the sheet engages the backing roll after the fluid content of the film has been absorbed, the means for applying the coating being spaced from the pressure roll.
Claim 4
Dependent Claim
202 words
Apparatus for forming a low coatweight coating on each side of a lightweight paper sheet whilst predetermining the degree of curl in the sheet when dried, comprising a backing roll for supportive engagement with a first side of a paper sheet and transferring thereto a film coating mix, means for forming a continuous film of the first coating mix on said backing roll, a trailing blade metering device for metering and smoothing the film on the backing roll, a pressure roll forming a nip with the backing roll, the pressure roll having a softer surface than the backing roll, the pressure and backing rolls being adapted to apply a nip pressure of about 0.5 kilograms per linear centimeter transversely of the sheet so as to conform the sheet, without substantial distortion, to the profile of the backing roll and so as to promote absorption by the paper sheet of the fluid content of the film, and means for applying a coating of a second coating mix to the second side of the sheet while the sheet engages the backing roll after the fluid content of the film has been absorbed, the means for applying the coating being spaced from the pressure roll.
Claim 5
Dependent Claim
41 words
A process for effecting the high speed coating of both sides of a lightweight paper sheet as claimed in claim 1 in which the fluid content and rheology of the second coating mix differ from that of the first coating mix.
Claim 6
Dependent Claim
34 words
Apparatus as claimed in claim 2 in which the means for applying the first and second coating mixes to the applicator roll and the second side of the paper comprise gate or applicator rolls.
Claim 7
Dependent Claim
32 words
Apparatus as claimed in claim 2 in which the means for applying the first and second coating mixes to the applicator roll and the second side of the paper comprise fountain applicators.
Claim 8
Dependent Claim
18 words
Apparatus as claimed in claim 4 in which the metering means are bent, soft or flexible blade configurations.
Claim 9
Dependent Claim
13 words
Apparatus as claimed in claim 6 in which a trailing blade is utilized.
Claim 10
Dependent Claim
14 words
Apparatus as claimed in claim 2 in which the metering means include metering rolls.
Claim 11
Dependent Claim
14 words
Apparatus as claimed in claim 2 in which the metering means include metering rolls.
Claim 12
Dependent Claim
18 words
Apparatus as claimed in claim 5 in which the metering means are bent, soft or flexible blade configurations.
Claim 13
Dependent Claim
34 words
Apparatus as claimed in claim 2 in which the means for applying the first and second coating mixes to the applicator roll and the second side of the paper comprise gate or applicator rolls.
Claim 14
Dependent Claim
32 words
Apparatus as claimed in claim 2 in which the means for applying the first and second coating mixes to the applicator roll and the second side of the paper comprise fountain applicators.
References Cited (Backward Citations)
US2325798A
Cited
US2676563A
Cited
US2670564A
Cited
US3293067A
Cited
US3908042A
Cited
GB1419316A
Cited
GB1404616A
Cited
US4198446A
Cited
US4354449A
Cited
US4357370A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |