US4828650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment of paper products having milk and other additives
Assignee: International Paper Co
•
Filing: 1987-09-30
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Granted: 1989-05-09
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Expires: 2007-09-30
Abstract
Abstract The stiffness, wet strength and bursting strength of paper is improved by adding a latex such as milk to the paper and then subjecting the paper to steps of high temperature treatment and immediate rewetting.
Inventors
- 👤 Dinkar G. Wagle
- 👤 Vacheslav M. Yasnovsky
- 👤 Jeffery R. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:31
CPC Classifications
D; D21; D21H; D21H25/00; D21H25/04; D21H25/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
99 words
A method of improving the stiffness, wet strength and opacity of a kraft paper product while maintaining acceptable flexibility thereof, comprising steps of applying an additive selected from the group consisting of (a) milk and (b) a mixture of equal proportions of potato starch in 8% aqueous solution and acrylic latex in 50% solution to said product, then heat treating said product at an internal temperature of at least 400° F. for a period of time sufficient to increase the wet strength thereof, and then rewetting the product immediately after said heat treating step before the product cools substantially.
Claim 2
Independent Claim
99 words
A method of improving the stiffness, wet strength and opacity of a kraft paper product while maintaining acceptable flexibility thereof, comprising steps of applying an additive selected from the group consisting of (a) milk and (b) a mixture of equal proportions of potato starch in 8% aqueous solution and acrylic latex in 50% solution to said product, then heat treating said product at an internal temperature of at least 400° F. for a period of time sufficient to increase the wet strength thereof, and then rewetting the product immediately after said heat treating step before the product cools substantially.
Claim 3
Dependent Claim
27 words
The method of claim 1, wherein the product has an initial moisture content in the range of 1.0 to 20% by weight before said heat treating step.
Claim 4
Dependent Claim
21 words
The method of claim 1, wherein the moisture content of said product after rewetting is between 1.0 and 20% by weight.
Claim 5
Dependent Claim
37 words
The method of claim 1, wherein said heat treating step comprises heating said product to within the range of 400° F. to 482° F., for a length of time in the range of 0.5 to 120 seconds.
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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |