US3686386A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multifilament extrusion method and apparatus
Assignee: Beloit Corp
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Filing: 1970-09-24
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Granted: 1972-08-22
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Expires: 1990-09-24
Abstract
Abstract Apparatus for producing a multifilament strand wherein the strand is extruded downwardly in heat exchange relationship with a gas is improved according to the present invention by providing the gas as an upwardly flowing annular gas flow surrounding the downwardly flowing filaments. The gas is conducted upwardly parallel to the filaments and thus does not impinge laterally upon the filaments. The extruded filaments entrap ambient air which tends to remain entrained in the downwardly moving strand. The upwardly flowing annular gas stream tends to pull this entrained gas out of the downwardly moving filament thus effectively cooling the filament without causing adjacent strands to impinge upon one another. In this manner, the capacity of the apparatus is increased substantially. Fibers such as polypropylene can be melt spun according to the present invention by passing the molten extruded fibers downwardly inside an annular upwardly flowing heat exchange gas stream. As mentioned, this tends to remove entrained air from the downwardly moving filaments thus effectively rapidly cooling the filaments without causing them to impinge upon one another.
Inventors
- 👤 Ronnie A Arav
- 👤 Gianpietro Trentini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:33
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/08; D01D5/088; D01D5/092
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
14 words
A method according to claim 1 wherein said heat exchange gas comprises ambient air.
Claim 2
Dependent Claim
14 words
A method according to claim 1 wherein said heat exchange gas comprises cooled air.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein said fiber-forming material compriSes a synthetic resin.
Claim 4
Dependent Claim
13 words
A method according to claim 4 wherein said resin comprises an olefin polymer.
Claim 5
Dependent Claim
13 words
A method according to claim 5 wherein said olefin comprises ethylene or propylene.
Claim 6
Dependent Claim
308 words
Apparatus for producing a multifilament strand comprising: extrusion means for exturding a multifilament strand comprising a plurality of downwardly directed extrusion orifices for extruding a multifilament strand in a substantially vertical downwards direction; a heat exchanger comprising a tube disposed below said extrusion orifice and disposed substantially vertically with its longitudinal axis in alignment with said extruded strand, said tube having its upper open end spaced downwardly of said extrusion orifice and having an opening in the lower end thereof within said tube for passing the extruded strand therethrough; means for introducing a heat exchange gas into the lower portion of said tube for passage upwardly therethrough in counter-current heat exchange relationship with said strand; first baffle means located in a lower portion of said tube forming with said tube an annular chamber for guiding said heat exchange gas in an annular flow pattern flowing upwardly in said tube surrounding said strand, said first baffle means isolating said strand from said gas for a first distance adjacent the lower end of said tube and permitting said gas to flow upwardly in said annular pattern surrounding and in contact with said strand a second distance upwards of the first baffle means; and second baffle means comprising a tube positioned within said heat exchanger tube forming therewith an annular chamber for isolating said strand from said gas for a second distance adjacent the upper end of said tube, said second baffle means being spaced upwardly of said first baffle means and located at the upper portion of said tube for conveying said heat exchange gas in an annular flow pattern away from the upper portion of said tube, the uppermost portion of said second baffle means being spaced downwardly of said extrusion orifice defining a gap therebetween for admitting ambient air to enter said heat exchanger tube with said strand.
Claim 7
Dependent Claim
10 words
Apparatus according to claim 7 wherein said tube is cylindrical.
Claim 8
Dependent Claim
71 words
Apparatus according to claim 8 wherein the lower end of said tube is closed and wherein said first baffle means comprises a further cylindrical tube open at both ends located concentrically with respect to said heat exchanger tube and extending through an aperture in the lower end thereof to provide a passageway for said strand, said tubes forming an annular conduit therebetween for forming said annular heat exchange gas flow pattern.
Claim 9
Dependent Claim
67 words
Apparatus according to claim 8 wherein said second baffle means comprises a further cylindrical tube open at both ends and located concentrically with respect to said heat exchanger tube to provide a passageway within said tube for said strand, said tubes forming an annular conduit therebetween for conveying said heat exchange gas in an annular flow pattern away from the upper portion of said heat exchanger tube.
Claim 10
Dependent Claim
52 words
Apparatus according to claim 10 wherein said second baffle tube comprises a first cylindrical portion located concentrically within said heat exchanger tube and a second portion conically diverging outwardly above the upper end of said heat exchanger tube for conveying said heat exchange gas upwardly and outwardly away from said extrusion orifice.
Claim 11
Dependent Claim
22 words
Apparatus according to claim 7 further including means for cooling said heat exchange gas prior to introduction to said heat exchanger tube.
References Cited (Backward Citations)
US2252684A
Cited
US3611485A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |