Patent US4969975A successfully refreshed from Google Patents.
US4969975A
Expired / Lapsed
US
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Process for forming a sheet of material
Assignee: Wiggins Teape Group Ltd
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Filing: 1989-02-24
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Granted: 1990-11-13
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Expires: 2009-02-24
Abstract
Abstract A process for forming a homogeneous sheet from particulate elements, (as herein defined), at least some of which have an inherent vertical mobility (as herein defined) in water at normal temperature and pressure of from about 1 to about 21 cms/sec, which comprises the steps of forming a foamed dispersion of said particulate elements, and depositing and draining said dispersion on a foraminous support.
Inventors
- 👤 Ian S. Biggs
- 👤 Bronislaw Radvan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:25
CPC Classifications
D; D21; D21F; D21F11/00; D21F11/002; D21F1/00; D21F1/34
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
59 words
A process for forming a homogeneous sheet from particulate elements at least some of which have an inherent vertical mobility in water at normal temperature and pressure of from about 5 to about 21 cms/sec, which comprises the steps of forming an aqueous foamed dispersion of said particulate elements, and depositing and draining said dispersion on a foraminous support.
Claim 2
Dependent Claim
59 words
A process for forming a homogeneous sheet from particulate elements at least some of which have an inherent vertical mobility in water at normal temperature and pressure of from about 5 to about 21 cms/sec, which comprises the steps of forming an aqueous foamed dispersion of said particulate elements, and depositing and draining said dispersion on a foraminous support.
Claim 3
Dependent Claim
21 words
A process as claimed in claim 1 in which said particles have vertical mobilities of not more than about 13 cms/sec.
Claim 4
Dependent Claim
15 words
A process as claimed in claim 1 in which said particulate elements comprise metallic particles.
Claim 5
Dependent Claim
25 words
A process as claimed in claim 1 in which a plurality of kinds of particulate elements are included and which have different inherent vertical mobilities.
Claim 6
Dependent Claim
25 words
A process as claimed in claim 4 in which the particulate elements comprise a mixture of elements which rise and elements which settle in water.
Claim 7
Dependent Claim
57 words
A process as claimed in any one of the preceding claims 1 to 5 in which the foamed dispersion is aqueous and has a viscosity of at least 22 second when measured by Form Cup Type B-4 at 20° C. according to British Standard No. BS1733 or an equivalent viscosity as determined according to British Standard BS3900-A6.
Claim 8
Dependent Claim
37 words
A process as claimed in any one of claims 1 to 5 in which the foamed dispersion has an air content of at least 55% and is comprised of bubbles having an average size of 0.2 mm.
Claim 9
Dependent Claim
21 words
A process as claimed in claim 7 in which the foamed dispersion has an air content of at least about 65%.
Claim 10
Dependent Claim
17 words
A sheet formed by the process set forth in any one of the claims 1 to 5.
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |