US4391670A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low energy TMP furnish of improved strength by ozonation and press drying
Assignee: International Paper Co
•
Filing: 1981-10-07
•
Granted: 1983-07-05
•
Expires: 2001-10-07
Abstract
Abstract Press dried paper sheets from certain ozonated high yield pulps are disclosed. Such sheets show substantially improved strength over comparable sheets prepared from non-ozonated pulps and over non-press dried sheets from ozonated pulps.
Inventors
- 👤 Richard B. Phillips
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:53
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1073
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
83 words
A process for the preparation of linerboard from thermomechanical, high temperature mechanical and semichemical mechanical pulps comprising: (a) treating mechanical pulp selected from thermomechanical, semi-chemical mechanical, high temperature mechanical, or mixtures thereof with ozone; (b) forming a sheet having from about 30% to about 60% consistency from the ozone treated pulp of step a above; and (c) press drying the sheet formed in step b above at high temperatures and pressure until at least about 10% to about 15% moisture content is attained.
Claim 2
Dependent Claim
83 words
A process for the preparation of linerboard from thermomechanical, high temperature mechanical and semichemical mechanical pulps comprising: (a) treating mechanical pulp selected from thermomechanical, semi-chemical mechanical, high temperature mechanical, or mixtures thereof with ozone; (b) forming a sheet having from about 30% to about 60% consistency from the ozone treated pulp of step a above; and (c) press drying the sheet formed in step b above at high temperatures and pressure until at least about 10% to about 15% moisture content is attained.
Claim 3
Dependent Claim
22 words
A process as defined in claim 1 wherein the mechanical pulp is a mixture of thermomechanical pulp and high temperature mechanical pulp.
Claim 4
Dependent Claim
29 words
A process as defined in claim 2 wherein the thermomechanical pulp comprises southern softwood thermomechanical pulp and the high temperature mechanical pulp comprises southern hardwood high temperature mechanical pulp.
Claim 5
Dependent Claim
27 words
A process as defined in claims 1, 2, or 3 wherein the mechanical pulp comprises from about 40% to about 60% by weight southern softwood thermomechanical pulp.
Claim 6
Dependent Claim
29 words
A process as defined in claims 1, 2, or 3 wherein the mechanical pulp comprises from about 40% to about 60% by weight southern hardwood high temperature mechanical pulp.
Claim 7
Dependent Claim
29 words
A process as defined in claim 1 wherein the mechanical pulp comprises 60% by weight southern softwood thermomechanical pulp and 40% by weight southern hardwood high temperature mechanical pulp.
Claim 8
Dependent Claim
21 words
A process as defined in claim 1 wherein ozone consumption by the mechanical pulp is about 2.5% to 10% by weight.
Claim 9
Dependent Claim
19 words
A process as defined in claim 1 wherein cationic starch is added to the sheet formed in step b.
Claim 10
Dependent Claim
25 words
A process as defined in claim 8 wherein about 0.5% to 5% by weight cationic starch is added at the wet end during sheet formation.
Claim 11
Dependent Claim
15 words
A process as defined in claim 7 wherein ozone consumption is about 5% by weight.
Claim 12
Dependent Claim
14 words
A process as defined in claim 9 wherein about 1.0% cationic starch is added.
References Cited (Backward Citations)
US3319352A
Cited
US4196043A
Cited
US4040899A
Cited
US4011034A
Cited
US4120747A
Cited
US4123317A
Cited
US4080249A
Cited
US4145246A
Cited
US4216054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |