US5527429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing paper for filter bags, apparatus for implementing the method, and product obtained thereby
Assignee: Papeteries de Cascadec
•
Filing: 1993-05-12
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Granted: 1996-06-18
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Expires: 2013-05-12
Abstract
Abstract A method of preparing paper for filter bags, the method of the type comprising a step during which a non-woven paper is prepared comprising two superposed layers, namely a layer based on synthetic fibers and a layer of cellulose fibers, by a technique which is known per se, wherein the method includes a subsequent step of subjecting the non-woven paper to a calendering operation between a support structure and a heated cylinder having projections. The present invention also provides apparatus for implementing the method and products obtained in this manner.
Inventors
- 👤 Abel Dambreville
- 👤 Roger Le Fol
- 👤 Philippe Deleplanque
- 👤 Yves Le Brech
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:20
CPC Classifications
D; D21; D21H; D21H27/00; D21H27/08; B; B31; B31F; B31F1/00; B31F1/07; D21H13/00; D21H13/10; D21H13/12; D21H25/00; D21H25/005; D21H27/30; D21H27/38; B31F2201/00; B31F2201/07; B31F2201/0707; B31F2201/0715; B31F2201/0723; B31F2201/0738; B31F2201/0756; B31F2201/0758; B31F2201/0761; B31F2201/0771; B31F2201/0776; B31F2201/0784; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/24496
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
Non-woven paper for filter bags designed for infusion purposes comprising: a first layer of synthetic fibers having a constant thickness throughout the total area of said non-woven paper except where each of a plurality of repetitive calendered symbols is located, wherein the synthetic fibers are melted and compressed to a thickness about the thickness of said first layer by calendering to form said calendered symbols having a width in a range of 0.1 mm to 5.0 mm, so that the appearance of said repetitive calendered symbols differs from the appearance of other parts of said first layer and form an apparent repetitive texture, and said calendered symbols have a total=area which is less than one-fifth of the total area of said non-woven paper; and a second layer of cellulose fibers having a constant thickness throughout said non-woven paper.
Claim 2
Dependent Claim
138 words
Non-woven paper for filter bags designed for infusion purposes comprising: a first layer of synthetic fibers having a constant thickness throughout the total area of said non-woven paper except where each of a plurality of repetitive calendered symbols is located, wherein the synthetic fibers are melted and compressed to a thickness about the thickness of said first layer by calendering to form said calendered symbols having a width in a range of 0.1 mm to 5.0 mm, so that the appearance of said repetitive calendered symbols differs from the appearance of other parts of said first layer and form an apparent repetitive texture, and said calendered symbols have a total=area which is less than one-fifth of the total area of said non-woven paper; and a second layer of cellulose fibers having a constant thickness throughout said non-woven paper.
Claim 3
Dependent Claim
16 words
Paper according to claim 1, wherein said calendered symbols have a width of about 1 mm.
Claim 4
Dependent Claim
23 words
Paper according to claim 1, wherein said first layer of synthetic fibers has a thickness which is between 10 μm and 15 μm.
Claim 5
Dependent Claim
23 words
Paper according to claim 1, wherein said second layer of cellulose fibers has a thickness which is between 25 μm and 40 μm.
Claim 6
Dependent Claim
15 words
Paper according to claim 1, wherein said synthetic fibers comprise polyethylene, polyvinyl chloride and polypropylene.
Claim 7
Dependent Claim
145 words
Non-woven paper for filter bags designed for infusion purposes comprising: a first layer of synthetic fibers having a constant thickness between 10 μm and 15 μm throughout the total area of said non-woven paper except where each of a plurality of repetitive calendered symbols is located, wherein the synthetic fibers are melted and compressed to a thickness about the thickness of said first layer by calendering to form said calendered symbols having a width in a range of 0.1 mm to 5.0 mm, so that the appearance of said repetitive calendered symbols differs from the appearance of other parts of said first layer and form an apparent repetitive texture, and said calendered symbols have a total area which is less than one-fifth of the total area of said non-woven paper; and a second layer of cellulose fibers having a constant thickness throughout said non-woven paper.
Claim 8
Dependent Claim
145 words
Non-woven paper for filter bags designed for infusion purposes comprising: a first layer of synthetic fibers having a constant thickness between 10 μm and 15 μm throughout the total area of said non-woven paper except where each of a plurality of repetitive calendered symbols is located, wherein the synthetic fibers are melted and compressed to a thickness about the thickness of said first layer by calendering to form said calendered symbols having a width in a range of 0.1 mm to 5.0 mm, so that the appearance of said repetitive calendered symbols differs from the appearance of other parts of said first layer and form an apparent repetitive texture, and said calendered symbols have a total area which is less than one-fifth of the total area of said non-woven paper; and a second layer of cellulose fibers having a constant thickness throughout said non-woven paper.
Claim 9
Dependent Claim
16 words
Paper according to claim 6, wherein said calendered symbols have a width of about 1 mm.
Claim 10
Dependent Claim
23 words
Paper according to claim 6, wherein said second layer of cellulose fibers has a thickness which is between 25 μm and 40 μm.
Claim 11
Dependent Claim
15 words
Paper according to claim 6, wherein said synthetic fibers comprise polyethylene, polyvinyl chloride and polypropylene.
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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) | 1999-06-18 | 1999-12-18 | 2000-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-18 | 2003-12-18 | 2004-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-18 | 2007-12-18 | 2008-06-18 | $7700.00 | Window Closed / Lapsed |