Patent US4957578A successfully refreshed from Google Patents.
US4957578A
Expired / Lapsed
US
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Process for producing a paperboard product for premium packaging applications
Assignee: WestRock MWV LLC
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Filing: 1989-03-22
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Granted: 1990-09-18
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Expires: 2009-03-22
Abstract
Abstract A process is disclosed for preparing a high quality paperboard product with high brightness and a defect-free glossy surface. The product comprises a structure consisting essentially of a paperboard substrate onto one surface of which there is first applied a coating of a pigmented polyolefin and a subsequent coating of a clear polymeric material such as a polyester. The brightness and loss achieved for the paperboard product is superior to conventional coated paperboard, cast coated paperboard, or other laminated paperboards currently in use.
Inventors
- 👤 Todd H. Huffman
- 👤 Debora F. Massouda
- 👤 Thomas S. Williams, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:18
CPC Classifications
D; D21; D21H; D21H19/00; D21H19/10; D21H19/14; D21H19/24; D21H19/28; D21H19/36; D21H19/44; D21H19/56; D21H19/80; D21H19/82; D21H19/826; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24876; Y10T428/24893; Y10T428/24901; Y10T428/31504; Y10T428/31507; Y10T428/31678; Y10T428/31681; Y10T428/31725; Y10T428/31739; Y10T428/31786
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
198 words
A process for producing a paperboard product having a brightness of at least about 83 TAPPI Brightness and a Hunter gloss of 100-plus at an angle of 60 degrees suitable for use as a premium packaging material comprising the steps: (a) applying a surface treatment to one surface of a paperboard substrate to improve its adhesion to a subsequent coating layer; (b) passing the treated paperboard into a nip formed between a chill roll and a backup roll while simultaneously extruding onto the treated surface of the paperboard a polyolefin coating selected from the group consisting of polyethylene, low density polyethylene, linear low density polyethylene, and polypropylene containing a bright, white pigment; (c) applying a surface treatment to the exposed surface of said polyolefin coating to improve its adhesion to a subsequent coating layer; and, (d) passing the treated and coated paperboard into a second nip formed between a chill roll and a backup roll while simultaneously extruding onto the treated surface of said pigmented polyolefin coating a clear coating of a polyester material selected from the group consisting of polyethylene terephthalate (PET), glycol-modified PET, acid-modified PEt, polybutylene terephthalate, polycarbonate and nylon to produce a defect-free, glossy surface.
Claim 2
Dependent Claim
198 words
A process for producing a paperboard product having a brightness of at least about 83 TAPPI Brightness and a Hunter gloss of 100-plus at an angle of 60 degrees suitable for use as a premium packaging material comprising the steps: (a) applying a surface treatment to one surface of a paperboard substrate to improve its adhesion to a subsequent coating layer; (b) passing the treated paperboard into a nip formed between a chill roll and a backup roll while simultaneously extruding onto the treated surface of the paperboard a polyolefin coating selected from the group consisting of polyethylene, low density polyethylene, linear low density polyethylene, and polypropylene containing a bright, white pigment; (c) applying a surface treatment to the exposed surface of said polyolefin coating to improve its adhesion to a subsequent coating layer; and, (d) passing the treated and coated paperboard into a second nip formed between a chill roll and a backup roll while simultaneously extruding onto the treated surface of said pigmented polyolefin coating a clear coating of a polyester material selected from the group consisting of polyethylene terephthalate (PET), glycol-modified PET, acid-modified PEt, polybutylene terephthalate, polycarbonate and nylon to produce a defect-free, glossy surface.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the chill roll in step (b) has a matte finish.
Claim 4
Dependent Claim
25 words
The process of claim 2 wherein the white pigment in step (b) is selected from the group consisting of titanium dioxide, calcium carbonate and clay.
Claim 5
Dependent Claim
22 words
The process of claim 3 wherein the amount of pigment included in the pigmented coating of step (b) ranges from about 1-12%.
Claim 6
Dependent Claim
28 words
The process of claim 4 which includes the additional step: (e) applying a surface treatment to the exposed surface of said clear polyester coating to improve its glueability.
Claim 7
Dependent Claim
13 words
The process of claim 5 wherein the paperboard substrate comprises clay coated paperboard.
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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) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |