US4324753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing an air laid paper web utilizing microencapsulated hydrogen bond promoting material
Assignee: Individual
•
Filing: 1980-11-03
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Granted: 1982-04-13
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Expires: 2000-11-03
Abstract
Abstract A method of forming an air laid web of hydrogen bonded wood pulp fibers is disclosed. More specifically, a paper producing method is disclosed wherein microencapsulated hydrogen bond promoting material is thoroughly premixed with wood pulp fibers. The mixture is then air laid on a moving screen to form a three dimensional continuum. The microcapsules may then be ruptured by heat and/or pressure to release the hydrogen bond promoting material evenly throughout the continuum. The continuum may then be heated or pressed to further consolidate the web.
Inventors
- 👤 Robert A. Gill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:57
CPC Classifications
D; D21; D21H; D21H5/00; D21H5/26; D21H5/2607; D21H5/2628; D21H23/00; D21H23/02; D21H23/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
A method of producing a web of hydrogen-bonded wood pulp fibers comprising the steps of: forming a suspension of wood pulp fibers in air; mixing a hydrogen-bond promoting agent in the form of microcapsules into said suspension; depositing the wood pulp and microcapsule mixture on a moving screen to form a continuous web; and rupturing said microcapsules to release said bonding agent so that hydrogen-bonds are formed between said wood pulp fibers within said web.
Claim 2
Independent Claim
75 words
A method of producing a web of hydrogen-bonded wood pulp fibers comprising the steps of: forming a suspension of wood pulp fibers in air; mixing a hydrogen-bond promoting agent in the form of microcapsules into said suspension; depositing the wood pulp and microcapsule mixture on a moving screen to form a continuous web; and rupturing said microcapsules to release said bonding agent so that hydrogen-bonds are formed between said wood pulp fibers within said web.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein after said microcapsules are ruptured, said wood fibers are permitted to consolidate for a predetermined time period.
Claim 4
Dependent Claim
22 words
The method of claim 2 further comprising the step of heating said web to dry and further consolidate said wood pulp fibers.
Claim 5
Dependent Claim
33 words
The method of claim 1 wherein said hydrogen-bond promoting agent is encapsulated in a polymer which ruptures under pressure and said rupturing step includes applying pressure to said web to rupture said microcapsules.
Claim 6
Dependent Claim
12 words
The method of claim 4 wherein said pressure is exerted by rollers.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein said hydrogen-bond promoting agent is encapsulated in a thermoplastic material and said rupturing step comprises heating said web to rupture said microcapsules.
Claim 8
Dependent Claim
24 words
The method of claim 1 wherein said wood pulp fibers are manufactured from cellulose pulp which is stripped into said fibers in a defiberator.
Claim 9
Dependent Claim
28 words
The method of claim 1 wherein said suspension of wood pulp fibers in air is formed in a distributor which spins said fibers and blows them with air.
Claim 10
Dependent Claim
20 words
The method of claim 8 wherein said microcapsules are introduced to said suspension while said suspension is in said distributor.
Claim 11
Dependent Claim
26 words
The method of claim 1 wherein the depositing of the wood pulp and microcapsules on said moving screen is facilitated by providing suction through said screen.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein said hydrogen-bond promoting agent is water.
Claim 13
Dependent Claim
12 words
The method of claim 1 wherein said hydrogen-bond promoting agent is ammonia.
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) | 1985-04-12 | 1985-10-12 | 1986-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-12 | 1989-10-12 | 1990-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-12 | 1993-10-12 | 1994-04-13 | $7700.00 | Window Closed / Lapsed |