US4347206A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of extruding polypropylene yarn
Assignee: KLING-TECS Inc A CORP OF NJ
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Filing: 1981-01-27
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Granted: 1982-08-31
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Expires: 2001-01-27
Abstract
Abstract A method of extruding polypropylene filaments in which the polypropylene is extruded at a temperature below 375° F., such as in the range 335° F. to 365° F., particularly about 350° F., into a quiescent hot zone having a temperature sufficiently high to retard cooling of the extruded polypropylene filaments. The filaments are then passed through and cooled in a quench zone across which cooling air is blown. The polypropylene has a narrow molecular weight distribution with a swell value less than 2.5, and its melt flow may be greater than 30. The yarn is drawn-down in the hot zone and the filaments may be drawn-down to an undrawn denier of less than 15 with substantial elimination of resonance.
Inventors
- 👤 John S. Roberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:55
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/02; D01F6/04; D01F6/06; D01D; D01D5/00; D01D5/08; D01D5/084
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
140 words
A method of producing a multi-filament polypropylene yarn, comprising: heating polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5 to a temperature at which it is molten; extruding the molten polypropylene at a temperature less than 350° F. into a plurality of filaments; passing the filaments through a first zone having a temperature sufficiently high to retard cooling of the filaments therein; drawing-down the filaments to their undrawn denier in said first zone; then passing the filaments through a second zone; and directing cooling gas over the filaments in said second zone to cool them; the combination of the swell value of the polypropylene, the temperature of extrusion, and the temperature of said first zone interacting to substantially eliminate the occurrence of resonance in the filaments as they are drawn-down in said first zone.
Claim 2
Independent Claim
140 words
A method of producing a multi-filament polypropylene yarn, comprising: heating polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5 to a temperature at which it is molten; extruding the molten polypropylene at a temperature less than 350° F. into a plurality of filaments; passing the filaments through a first zone having a temperature sufficiently high to retard cooling of the filaments therein; drawing-down the filaments to their undrawn denier in said first zone; then passing the filaments through a second zone; and directing cooling gas over the filaments in said second zone to cool them; the combination of the swell value of the polypropylene, the temperature of extrusion, and the temperature of said first zone interacting to substantially eliminate the occurrence of resonance in the filaments as they are drawn-down in said first zone.
Claim 3
Independent Claim
71 words
A method of extruding a polypropylene filament, comprising: extruding at a temperature less than 375° F. molten polypropylene having a swell value of less than 2.5 into a filament; passing the filament through a hot zone to retard cooling of the filament; drawing-down the filament to determine its undrawn denier while it is in said hot zone; and thereafter passing the filament through a quenching zone to substantially cool the filament.
Claim 4
Independent Claim
71 words
A method of extruding a polypropylene filament, comprising: extruding at a temperature less than 375° F. molten polypropylene having a swell value of less than 2.5 into a filament; passing the filament through a hot zone to retard cooling of the filament; drawing-down the filament to determine its undrawn denier while it is in said hot zone; and thereafter passing the filament through a quenching zone to substantially cool the filament.
Claim 5
Independent Claim
131 words
A method of producing a polypropylene filament, comprising: extruding at a temperature less than 375° F. molten polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5 and a melt flow greater than 30 into a filament; passing the filament through a hot zone to retard cooling of the extruded filament; elongating the filament by a predetermined ratio while in said hot zone to determine its undrawn denier; and then passing the elongated filament through a quenching zone to cool the filament; the characteristics of the polypropylene, the temperature of extrusion, the temperature and length of said hot zone, and the ratio by which said filament is elongated interacting to retain said elongating in said hot zone and reduce the occurrence of resonance in the filament.
Claim 6
Independent Claim
131 words
A method of producing a polypropylene filament, comprising: extruding at a temperature less than 375° F. molten polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5 and a melt flow greater than 30 into a filament; passing the filament through a hot zone to retard cooling of the extruded filament; elongating the filament by a predetermined ratio while in said hot zone to determine its undrawn denier; and then passing the elongated filament through a quenching zone to cool the filament; the characteristics of the polypropylene, the temperature of extrusion, the temperature and length of said hot zone, and the ratio by which said filament is elongated interacting to retain said elongating in said hot zone and reduce the occurrence of resonance in the filament.
Claim 7
Dependent Claim
15 words
The method recited in claim 3 in which said swell value is less than 2.
Claim 8
Dependent Claim
15 words
The method recited in claim 4 in which said melt flow is greater than 35.
Claim 9
Dependent Claim
15 words
The method recited in claim 5 in which said melt flow is greater than 40.
Claim 10
Dependent Claim
16 words
The method recited in claim 5 or 6 wherein said swell value is less than 1.5.
Claim 11
Dependent Claim
22 words
The method recited in claim 3 wherein cooling air is directed over the filament in said quenching zone to cool the filament.
Claim 12
Dependent Claim
26 words
The method recited in claim 8 wherein said hot zone is relatively short in relation to the length of said quenching zone and contains quiescent air.
Claim 13
Independent Claim
114 words
A method of producing drawn multifilament polypropylene yarn, comprising: extruding a plurality of filaments from molten polypropylene at a temperature in the range 335° F. to 365° F.; said molten polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5; passing said filaments through a hot zone having a temperature below that at which the filaments are extruded but sufficiently high to retard cooling of the filaments; elongating said filaments in said hot zone to determine the undrawn denier of said filaments before the latter leave said hot zone; then cooling said elongated filaments; and subsequently drawing said filaments at a draw ratio of at least 3 to 1.
Claim 14
Independent Claim
114 words
A method of producing drawn multifilament polypropylene yarn, comprising: extruding a plurality of filaments from molten polypropylene at a temperature in the range 335° F. to 365° F.; said molten polypropylene having a narrow molecular weight distribution with a swell value of less than 2.5; passing said filaments through a hot zone having a temperature below that at which the filaments are extruded but sufficiently high to retard cooling of the filaments; elongating said filaments in said hot zone to determine the undrawn denier of said filaments before the latter leave said hot zone; then cooling said elongated filaments; and subsequently drawing said filaments at a draw ratio of at least 3 to 1.
Claim 15
Dependent Claim
42 words
The method recited in claim 10 wherein said molten polypropylene has a melt flow greater than 35, said swell value is less than 1.7, the extrusion temperature is less than 365° F., and said draw ratio is at least 3.7 to 1.
Claim 16
Dependent Claim
31 words
The method recited in claim 11 wherein said hot zone contains quiescent air, and cooling air is directed transversely over the elongated filaments in a quench zone to effect said cooling.
Claim 17
Dependent Claim
18 words
The method recited in claim 12 in which said undrawn denier is less than 15 denier per filament.
Claim 18
Dependent Claim
18 words
The method recited in claim 13 in which said undrawn denier is less than 10 denier per filament.
Claim 19
Independent Claim
86 words
A method of producing a multi-filament polypropylene yarn, comprising: heating polypropylene having a swell value in the range 1.2 to 1.7 to a temperature in the range 350° F. to 360° F. at which it is molten; extruding the molten polypropylene into a plurality of filaments; passing the filaments through a first zone having a temperature sufficiently high to prevent substantially cooling the filaments therein; then passing the filaments through a second zone; and directing gas over the filaments in said second zone to cool them.
Claim 20
Independent Claim
86 words
A method of producing a multi-filament polypropylene yarn, comprising: heating polypropylene having a swell value in the range 1.2 to 1.7 to a temperature in the range 350° F. to 360° F. at which it is molten; extruding the molten polypropylene into a plurality of filaments; passing the filaments through a first zone having a temperature sufficiently high to prevent substantially cooling the filaments therein; then passing the filaments through a second zone; and directing gas over the filaments in said second zone to cool them.
Claim 21
Dependent Claim
20 words
The method recited in claim 15 in which said polypropylene has a melt flow in the range 35 to 45.
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) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |