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Patent US4619734A successfully refreshed from Google Patents.
US4619734A
Expired / Lapsed
US
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Sanitary paper web having high bulk, bulk softness and surface softness and method of manufacturing said web
Assignee: Valmet Technologies Oy
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Filing: 1984-10-16
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Granted: 1986-10-28
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Expires: 2004-10-16
Abstract
Abstract In order to achieve a sanitary paper web having high bulk, bulk softness and surface softness it is proposed according to the invention that said web contains expanded microspheres (11) of thermoplastic material in an amount of from 1 to 10% based on the weight of the dry web.
Inventors
- 👤 Ingmar A. Andersson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:55
CPC Classifications
A; A47; A47K; A47K10/00; D; D21; D21F; D21F11/00; D21F11/14; D21H; D21H21/00; D21H21/14; D21H21/22; D21H21/50; D21H21/52; D21H21/54; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24446; Y10T428/24455; Y10T428/24463; Y10T428/25; Y10T428/254
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
58 words
A sanitary paper web having high bulk, bulk softness and surface softness, and comprising a creped sanitary paper web and expanded microspheres of thermoplastic material incorporated therein in an amount from 1 to 10% based on the weight of the dry web, said web having a high bulk value of at least about 4.0×10 -3 m 3 /kg.
Claim 2
Dependent Claim
58 words
A sanitary paper web having high bulk, bulk softness and surface softness, and comprising a creped sanitary paper web and expanded microspheres of thermoplastic material incorporated therein in an amount from 1 to 10% based on the weight of the dry web, said web having a high bulk value of at least about 4.0×10 -3 m 3 /kg.
Claim 3
Dependent Claim
36 words
A creped sanitary paper web according to claim 1, wherein a major proportion of the microspheres is located in a central region of the web when viewed in the direction of the thickness of the web.
Claim 4
Dependent Claim
35 words
A creped sanitary paper web according to claim 2, wherein the web is multi-layered, and comprises two surface layers and at least one inner layer in which the major proportion of the microspheres is located.
Claim 5
Dependent Claim
34 words
A creped sanitary paper web according to claim 3, wherein the pulp fibers in the two surface layers are derived mainly from hardwood and those in said inner layer are derived mainly from softwood.
Claim 6
Dependent Claim
30 words
A creped sanitary paper web according to any one of claims 1-4, wherein at least 90% of the expanded microspheres have a size in the range from about 10-100 μm.
Claim 7
Independent Claim
187 words
A method of manufacturing a sanitary paper web having high bulk, bulk softness and surface softness comprising the steps of forming a slurry of fibrous stock containing microspheres of thermoplastic material expandable by heating, in an amount of from 1 to 10% based on the weight of dry fibers in the web to be formed, dewatering the slurry in the wet end of a paper machine to form a sanitary paper web, and thereafter, while retaining a considerable proportion of the bulk of the sanitary paper web thus formed, transferring the web from the wet end to the drying section of the paper machine and there drying the sanitary paper web containing the expandable microspheres on a Yankee cylinder dryer at a temperature and for a period of time sufficient to expand at least a main proportion of the microspheres while preventing additional fiber bonds and creping the sanitary paper web off of the Yankee cylinder to thereby provide a creped sanitary paper product having enhanced bulk, enhanced bulk softness and enhanced surface softness and a bulk value of at least about 4.0×10 -3 m 3 /kg.
Claim 8
Independent Claim
187 words
A method of manufacturing a sanitary paper web having high bulk, bulk softness and surface softness comprising the steps of forming a slurry of fibrous stock containing microspheres of thermoplastic material expandable by heating, in an amount of from 1 to 10% based on the weight of dry fibers in the web to be formed, dewatering the slurry in the wet end of a paper machine to form a sanitary paper web, and thereafter, while retaining a considerable proportion of the bulk of the sanitary paper web thus formed, transferring the web from the wet end to the drying section of the paper machine and there drying the sanitary paper web containing the expandable microspheres on a Yankee cylinder dryer at a temperature and for a period of time sufficient to expand at least a main proportion of the microspheres while preventing additional fiber bonds and creping the sanitary paper web off of the Yankee cylinder to thereby provide a creped sanitary paper product having enhanced bulk, enhanced bulk softness and enhanced surface softness and a bulk value of at least about 4.0×10 -3 m 3 /kg.
Claim 9
Dependent Claim
33 words
A method according to claim 6 wherein a major proportion of the microspheres is located in a central region of the web when viewed in the direction of the thickness of the web.
Claim 10
Dependent Claim
32 words
A method according to claim 7, wherein said web is multi-layered and comprises two surface layers and at least one inner layer, in which a major proportion of the microspheres is located.
Claim 11
Dependent Claim
27 words
A method according to claim 8, wherein hardwood pulp fibers are used for the two surface layers and softwood pulp fibers are used for said inner layer.
Claim 12
Dependent Claim
35 words
A method according to claim 7, wherein the step of dewatering the slurry to form a sanitary paper web comprises dewatering a multi-layered stock flow from a multiple layer head box between two forming wires.
Claim 13
Dependent Claim
24 words
A method according to claim 6, wherein at least 90% of the expandable microspheres have a size in the range from about 5-30 μm.
Claim 14
Dependent Claim
65 words
A method according to claim 7, wherein the step of dewatering the slurry to form a sanitary paper web comprises dewatering a multi-layered stock flow between an outer forming wire and an inner felt in a curved forming zone of a twin-wire paper machine and wherein the inner layer of the flow in relation to the curvature of the forming zone contains the expandable microspheres.
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) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |