Patent US4562022A successfully refreshed from Google Patents.
US4562022A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Producing foamed fibers
Assignee: Honeywell International Inc
•
Filing: 1983-04-29
•
Granted: 1985-12-31
•
Expires: 2003-04-29
Abstract
Abstract A molten polymer containing a blowing agent and, usually, a nucleating agent, is spun into fibers with screen packs or equivalent structures upstream of the spinning apertures. The use of screen packs enables the production of fibers with finer bubbles, which are therefore susceptable to greater melt-drawdown and postdrawing and can have better tensile properties. Foamed polyamide fibers are produced with average bubble diameters one-twentieth or less, compared to the effective fiber diameter.
Inventors
- 👤 Hsin L. Li
- 👤 Hendrikus J. Oswald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:39
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/58; D01F6/60; D01D; D01D5/00; D01D5/24; D01D5/247; D01F1/00; D01F1/02; D01F1/08; Y; Y10; Y10S; Y10S264/00; Y10S264/05
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
112 words
A method of forming foam fibers which comprises the steps: (a) forming at elevated temperature and under super atmospheric pressure a melt of a polymer of fiber forming molecular weight in which is admixed a blowing agent; (b) extruding said melt through a spinerette having at least one aperture with said melt passing through a distributor plate and at least one additional member comprising a plurality of small channels upstream of said at least one spinerette aperture; (c) quenching said melt downstream of said at least one spinerette aperture under conditions at which a plurality of predominately closed-cell bubbles form in said melt; and (d) drawing said melt as it is quenched.
Claim 2
Independent Claim
112 words
A method of forming foam fibers which comprises the steps: (a) forming at elevated temperature and under super atmospheric pressure a melt of a polymer of fiber forming molecular weight in which is admixed a blowing agent; (b) extruding said melt through a spinerette having at least one aperture with said melt passing through a distributor plate and at least one additional member comprising a plurality of small channels upstream of said at least one spinerette aperture; (c) quenching said melt downstream of said at least one spinerette aperture under conditions at which a plurality of predominately closed-cell bubbles form in said melt; and (d) drawing said melt as it is quenched.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein said polymer is a polyamide.
Claim 4
Dependent Claim
10 words
The method of claim 1 wherein said compound is azodicarbonamide.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein said compound is present in an amount between about 0.1% and about 2%, by weight of polymer.
Claim 6
Dependent Claim
11 words
The method of claim 4 wherein said polymer is a polyamide.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein said plurality of small channels are located adjacent to and upstream of the spinnerette.
Claim 8
Dependent Claim
34 words
The method of claim 6 wherein said plurality of small channels are formed by a plurality of screens, with the finest screen having a mesh size between about 50 mesh/cm and about 300 mesh/cm.
Claim 9
Dependent Claim
34 words
The method of claim 1 wherein said plurality of small channels are formed by a plurality of screens, with the finest screen having a mesh size between about 50 mesh/cm and about 300 mesh/cm.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein said plurality of small channels are formed by a porous metal piece.
Claim 11
Dependent Claim
29 words
The method of claim 1 wherein the melt is drawn while quenching sufficiently to lower the effective diameter of the fiber to between about 0.01 and about 1.0 millimeters.
Claim 12
Dependent Claim
17 words
A method of claim 1 wherein the drawing occurs at a ratio of at least about 2:1.
Claim 13
Independent Claim
125 words
A method of forming foam fibers which comprises the steps: (a) forming at elevated temperature and under super atmospheric pressure a melt of a polymer of fiber-forming molecular weight in which is admixed a blowing agent; (b) extruding said melt through a spinerette having at least one aperture with said melt passing through a plurality of small channels in the form of a plurality of screens, with the finest screen having a mesh size between about 50 mesh/cm and about 300 mesh/cm, upstream of said at least one spinerette aperture: (c) quenching said melt downstream of said at least one spinerette aperture under conditions at which a plurality of predominately closed-cell bubbles form in said melt; and (d) drawing said melt as it is quenched.
Claim 14
Independent Claim
125 words
A method of forming foam fibers which comprises the steps: (a) forming at elevated temperature and under super atmospheric pressure a melt of a polymer of fiber-forming molecular weight in which is admixed a blowing agent; (b) extruding said melt through a spinerette having at least one aperture with said melt passing through a plurality of small channels in the form of a plurality of screens, with the finest screen having a mesh size between about 50 mesh/cm and about 300 mesh/cm, upstream of said at least one spinerette aperture: (c) quenching said melt downstream of said at least one spinerette aperture under conditions at which a plurality of predominately closed-cell bubbles form in said melt; and (d) drawing said melt as it is quenched.
Claim 15
Dependent Claim
17 words
The method of claim 12 wherein the drawing occurs at a ratio of at least about 2:1.
Claim 16
Dependent Claim
45 words
The method of claim 12 wherein the step of drawing produces a formed fiber having an effective diameter of between about 0.01 and about 1.0 mm and a plurality of predominantly closed-cell bubbles of diameter less than one-twentieth the effective diameter of the polyamide fiber.
References Cited (Backward Citations)
US3028627A
Cited
US3006028A
Cited
US3295161A
Cited
GB1221488A
Cited
GB1296710A
Cited
GB1318964A
Cited
GB1316465A
Cited
US3847524A
Cited
DE2148588A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |