US4189455A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of discontinuous fibrils
Assignee: Hercules LLC
•
Filing: 1972-08-01
•
Granted: 1980-02-19
•
Expires: 1992-08-01
Abstract
Abstract A continuous fibrillated structure, formed by the abrupt pressure release of a two-phase liquid mixture of polymer and solvent at elevated temperature and pressure so as to cause the instantaneous vaporization of the solvent, is shredded by a stream of fluid directed transversely against the continuous fibrillated structure at the moment of its formation.
Inventors
- 👤 Carlo Raganato
- 👤 Georges Voituron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:33
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/11
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
122 words
In a process for the manufacture of discontinuous fibrils by the abrupt pressure release of a liquid mixture of molten polymer and solvent which is at a temperature and pressure such as to be in the form of a system of two phases consisting of a continuous liquid phase which is poor in polymer and in which is dispersed a second liquid phase which is rich in polymer, the abrupt pressure release being adapted to bring about the instantaneous vaporization of the solvent and the solidification of said polymer to form a continuous fibrillated structure, the improvement which comprises shredding the continuous fibrillated structure so produced, at the moment of its formation, by directing a stream of fluid transversely against such structure.
Claim 2
Dependent Claim
122 words
In a process for the manufacture of discontinuous fibrils by the abrupt pressure release of a liquid mixture of molten polymer and solvent which is at a temperature and pressure such as to be in the form of a system of two phases consisting of a continuous liquid phase which is poor in polymer and in which is dispersed a second liquid phase which is rich in polymer, the abrupt pressure release being adapted to bring about the instantaneous vaporization of the solvent and the solidification of said polymer to form a continuous fibrillated structure, the improvement which comprises shredding the continuous fibrillated structure so produced, at the moment of its formation, by directing a stream of fluid transversely against such structure.
Claim 3
Dependent Claim
19 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is a gas.
Claim 4
Dependent Claim
12 words
A process as defined in claim 2 wherein said gas is nitrogen.
Claim 5
Dependent Claim
19 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is a vapor.
Claim 6
Dependent Claim
13 words
A process as defined in claim 4 wherein said vapor is water vapor.
Claim 7
Dependent Claim
17 words
A process as defined in claim 4 wherein said vapor is the vapor of an organic solvent.
Claim 8
Dependent Claim
19 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is a liquid.
Claim 9
Dependent Claim
12 words
A process as defined in claim 7 wherein said liquid is water.
Claim 10
Dependent Claim
14 words
A process as defined in claim 7 wherein said liquid is an organic solvent.
Claim 11
Dependent Claim
30 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is identical with the solvent used to make the two-phase mixture with the polymer.
Claim 12
Dependent Claim
30 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is the volatile constituent of the two-phase mixture vaporized by the abrupt pressure release.
Claim 13
Dependent Claim
25 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is driven at a speed higher than 1 m/sec.
Claim 14
Dependent Claim
31 words
A process as defined in claim 1 wherein said fluid used to shred the fibrillated structure is in the gaseous state and is driven at a speed higher than 50 m/sec.
Claim 15
Dependent Claim
37 words
A process as defined in claim 1 wherein the angle between th direction of movement of the fibrillated structure and the direction of the stream of fluid at the moment of impact is between 75° and 180°.
Claim 16
Dependent Claim
39 words
A process as defined in claim 1 wherein the fibrillated structure contracts after its moment of formation to tend to form a continuous roving and said stream of fluid is directed against the fibrillated structure before it so contracts.
Claim 17
Dependent Claim
39 words
A process as defined in claim 15 wherein the fibrillated structure expands at the moment of its formation and said stream of fluid is directed against the fibrillated structure at the zone where the latter reaches its maximum expansion.
Claim 18
Dependent Claim
46 words
A process as defined in claim 1 wherein there is a pipe through which said stream of fluid flows, the pipe having a wall and defining an orifice in the wall and the abrupt pressure release of the two-phase liquid mixture takes place through the orifice.
Claim 19
Dependent Claim
18 words
A process as defined in claim 17 wherein the pipe has a convergent zone and a restricted zone.
Claim 20
Dependent Claim
31 words
A process as defined in claim 18 wherein the orifice in which the abrupt pressure release of the two-phase liquid mixture takes place opens into the restricted zone in the pipe.
Claim 21
Dependent Claim
38 words
A process as defined in claim 17 wherein the orifice, in which the abrupt pressure release of the two-phase liquid mixture takes place, has an outlet which is set back in relation to the wall of the pipe.
Claim 22
Dependent Claim
26 words
A process as defined in claim 1 wherein the polymer is selected from the group consisting of polyolefins, polyamides, polyesters, polyurethanes, polycarbonates, vinyl and acrylic polymers.
Claim 23
Dependent Claim
19 words
A process as defined in claim 1 wherein the discontinuous fibrils have a length of 1 to 20 mm.
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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) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |