US3908044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for coating a web
Assignee: Abitibi Paper Co Ltd
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Filing: 1973-11-15
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Granted: 1975-09-23
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Expires: 1993-11-15
Abstract
Abstract The invention provides a method and an apparatus for coating a moving web by passing the latter through a narrow die opening while maintaining a free flowing coating material between the die wall and the web surface being coated. The coating material wets both said die wall and the web surface. As the web passes through the die the coating material between the web surface and the die wall is sheared and a coating of same is applied to the web surface. The coated web is thereafter passed through a drying zone to effect the required degree of drying.
Inventors
- 👤 John R Gunning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:40
CPC Classifications
D; D21; D21H; D21H23/00; D21H23/02; D21H23/22; D21H23/32; D21H23/40; D21H5/00; D21H5/0005; D21H5/0012; D21H5/0015
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
175 words
A METHOD OF COATING A FLEXIBLE WEB COMPRISING THE FOLLOWING STEPS: A. PASSING THE WEB THROUGH RESERVOIR MEANS CONTAINING A LIQUID COATING MATERIAL FOR WETTING THE WEB SURFACE BY THE COATING MATERIAL, B. SUBSEQUENT TO STEP (A), PASSING THE WEB THROUGH A DIE OPENING DEFINED BY SPACED DIE WALLS IN COMMUNICATION WITH THE RESERVOIR MEANS FOR BEING WETTED BY THE COATING MATERIAL, C. THROUGHOUT THE COATING OPERATION, MAINTAINING THE DIE WALLS ALONG THEIR ENTIRE EXTEND IN PERFECT PARALLELISM WITH RESPECT TO ONE ANOTHER AND WITH A SPACING HAVING A PREDETERMINED VALUE RANGING IN MAGNITUDE FROM ABOUT 0.003 INCH TO ABOUT 0.020 INCH, D. AS A PART OF STEP (B), MAINTAINING THE WEB AT A PREDETERMINED, PARALLEL-SPACED RELATIONSHIP THROUGHOUT SUBSTANTIALLY THE ENTIRE EXTENT OF THE DIE WALLS FOR EFFECTING COATING BY SHEARING THE COATING MATERIAL IN CONTACT WITH THE WEB SURFACE IN A DIRECTION PARALLEL THERETO, WHILE AVOIDING WEDGING OF THE COATING MATERIAL BETWEEN THE DIE WALLS AND THE WEB, AND C. SUBSEQUENT TO STEPS (B) AND (D), PASSING THE COATED WEB THROUGH A DRYING ZONE.
Claim 2
Independent Claim
175 words
A METHOD OF COATING A FLEXIBLE WEB COMPRISING THE FOLLOWING STEPS: A. PASSING THE WEB THROUGH RESERVOIR MEANS CONTAINING A LIQUID COATING MATERIAL FOR WETTING THE WEB SURFACE BY THE COATING MATERIAL, B. SUBSEQUENT TO STEP (A), PASSING THE WEB THROUGH A DIE OPENING DEFINED BY SPACED DIE WALLS IN COMMUNICATION WITH THE RESERVOIR MEANS FOR BEING WETTED BY THE COATING MATERIAL, C. THROUGHOUT THE COATING OPERATION, MAINTAINING THE DIE WALLS ALONG THEIR ENTIRE EXTEND IN PERFECT PARALLELISM WITH RESPECT TO ONE ANOTHER AND WITH A SPACING HAVING A PREDETERMINED VALUE RANGING IN MAGNITUDE FROM ABOUT 0.003 INCH TO ABOUT 0.020 INCH, D. AS A PART OF STEP (B), MAINTAINING THE WEB AT A PREDETERMINED, PARALLEL-SPACED RELATIONSHIP THROUGHOUT SUBSTANTIALLY THE ENTIRE EXTENT OF THE DIE WALLS FOR EFFECTING COATING BY SHEARING THE COATING MATERIAL IN CONTACT WITH THE WEB SURFACE IN A DIRECTION PARALLEL THERETO, WHILE AVOIDING WEDGING OF THE COATING MATERIAL BETWEEN THE DIE WALLS AND THE WEB, AND C. SUBSEQUENT TO STEPS (B) AND (D), PASSING THE COATED WEB THROUGH A DRYING ZONE.
Claim 3
Dependent Claim
114 words
means for maintaining unchanged said predetermined spacing during the coating operation; c. drier means situated downstream of said coating die with respect to the direction of web advance for removing moisture from the coated web; and d. guiding means for passing the web in a path of travel in succession through said reservoir means for wetting the web surface with the coating material, through said die opening and through said drier means; said guiding means causing the web to pass in a predetermined spaced relationship to said walls in parallelism thereto throughout substantially the entire extent of said walls to effect coating of said web by shearing of the coating material by said walls.
Claim 4
Dependent Claim
114 words
means for maintaining unchanged said predetermined spacing during the coating operation; c. drier means situated downstream of said coating die with respect to the direction of web advance for removing moisture from the coated web; and d. guiding means for passing the web in a path of travel in succession through said reservoir means for wetting the web surface with the coating material, through said die opening and through said drier means; said guiding means causing the web to pass in a predetermined spaced relationship to said walls in parallelism thereto throughout substantially the entire extent of said walls to effect coating of said web by shearing of the coating material by said walls.
Claim 5
Dependent Claim
90 words
The method according to claim 1, further including the step of maintaining said reservoir means with the coating material immediately adjacent the entrance to said die opening thus generating flow of the coating liquid from the reservoir means into the regions intermediate the web surfaces and the walls of the coating die, which flows of material into said regions generate hydraulic forces tending to center the web between the walls of the die opening to provide for equal thicknesses of coating to be applied to both surfaces of said web.
Claim 6
Dependent Claim
11 words
The method according to claim 2 wherein said walls are planar.
Claim 7
Dependent Claim
24 words
The method according to claim 1 wherein the rate of shear of said coating material is from about 1000 to about 600,000 sec 1.
Claim 8
Dependent Claim
11 words
The method according to claim 1 wherein the web comprises paper.
Claim 9
Dependent Claim
23 words
The method according to claim 2 wherein the rate of shear of said coating material is not greater than about 600,000 sec 1.
Claim 10
Dependent Claim
33 words
Apparatus for coating a flexible web advanced through the apparatus, comprising: a. reservoir means for accommodating a liquid coating material; b. a coating die connected to said reservoir means; said coating die including
Claim 11
Dependent Claim
33 words
Apparatus for coating a flexible web advanced through the apparatus, comprising: a. reservoir means for accommodating a liquid coating material; b. a coating die connected to said reservoir means; said coating die including
Claim 12
Dependent Claim
18 words
Apparatus as defined in claim 1, including adjusting means for setting said predetermined spacing to a selected magnitude.
Claim 13
Dependent Claim
114 words
Apparatus according to claim 7, said coating die being arranged relative to the guiding means for passing the web in the path of travel such that the web passes intermediate the space apart walls in parallelism thereto, said reservoir means being disposed immediately in advance of the die opening through which reservoir the web passes thus generating flow of the coating liquid from the reservoir into the regions intermediate the web surfaces and the parallel walls of the coating die which flows of material generate hydraulic forces tending to effect centering of the web being the parallel walls of the die whereby to apply equal coating thicknesses to both of the opposed web surfaces.
Claim 14
Dependent Claim
47 words
Apparatus according to claim 7, further including means for moving the web at a speed such, and wherein the die walls are spaced from the web surface sufficiently that, a rate of shear of said coating material from about 1000 to about 600,000 sec 1 is produced.
Claim 15
Dependent Claim
25 words
Apparatus according to claim 7 wherein the guiding means for passing the web is arranged such that its path of travel is directed verticaLly downwardly.
Claim 16
Dependent Claim
17 words
Apparatus according to claim 7 wherein the die walls are made of a hard, abrasion resistant material.
Claim 17
Dependent Claim
13 words
Apparatus according to claim 7 wherein the die walls are flat or planar.
Claim 18
Dependent Claim
20 words
Apparatus according to claim 7 wherein the distance between said die walls is from about 0.008 to about 0.011 inch.
References Cited (Backward Citations)
US2766721A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |