Patent US4855179A successfully refreshed from Google Patents.
US4855179A
Expired / Lapsed
US
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Production of nonwoven fibrous articles
Assignee: CAMELOT S A Inc
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Filing: 1987-07-29
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Granted: 1989-08-08
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Expires: 2007-07-29
Abstract
Abstract Superabsorbent articles in the form of soft, nonwoven fibrous webs are produced from aqueous fiber-forming polymer solutions by forming the polymer into water soluble filaments, contacting the filaments with a primary air stream having a velocity effective to attenuate and to partially dry the filaments, contacting the attenuated filaments with a secondary air stream having a velocity effective to fragment the filaments into fibers and to transport the fibers to a web-forming zone while also further attenuating and drying the fibers, collecting the fibers in reticulated web-form in the web-forming zone and curing the web to a water insoluble state. The temperature and air stream velocities are controlled with respect to ambient humidity and water content of the fiber during the fiber and web formation such that the fibers are collected without sticking. Collection is preferably on a wire belt followed by transport through a curing oven to compacting rolls and web take-up.
Inventors
- 👤 Larry G. Bourland
- 👤 Robert J. DiLullo
- 👤 Kimberly E. Ritrievi
- 👤 Jon R. Valbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:01
CPC Classifications
D; D04; D04H; D04H3/00; D04H3/02; A; A61; A61L; A61L15/00; A61L15/16; A61L15/42; A61L15/60; D01; D01D; D01D5/00; D01D5/04; D01D5/12; D01D5/14; D04H1/00; D04H1/70; D04H1/72; Y; Y10; Y10T; Y10T442/00; Y10T442/60; Y10T442/69
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
163 words
A process for producing a nonwoven fibrous web from an aqueous solution of a polymer composition which is water insoluble and superabsorbent upon curing, which comprises: (a) forming the polymer solution into water soluble filaments, (b) contacting the filaments with a primary air stream having a velocity effective to partially attenuate and to partially dry the filaments, (c) contacting the filaments in a fiber-forming zone with a secondary air stream having a velocity effective to further attenuate and to fragment the filaments into fibers, to further dry the fibers and to transport the fibers to a web-forming zone, (d) collecting the fibers in reticulated web-form in the web-forming zone, and (e) curing the web in a curing zone; wherein the temperature and air stream velocities are controlled with respect to ambient humidity and water content of the fiber during fiber and web formation such that during collection the fibers remain substantially non-sticking and cure in the curing step to a soft, integral web.
Claim 2
Dependent Claim
163 words
A process for producing a nonwoven fibrous web from an aqueous solution of a polymer composition which is water insoluble and superabsorbent upon curing, which comprises: (a) forming the polymer solution into water soluble filaments, (b) contacting the filaments with a primary air stream having a velocity effective to partially attenuate and to partially dry the filaments, (c) contacting the filaments in a fiber-forming zone with a secondary air stream having a velocity effective to further attenuate and to fragment the filaments into fibers, to further dry the fibers and to transport the fibers to a web-forming zone, (d) collecting the fibers in reticulated web-form in the web-forming zone, and (e) curing the web in a curing zone; wherein the temperature and air stream velocities are controlled with respect to ambient humidity and water content of the fiber during fiber and web formation such that during collection the fibers remain substantially non-sticking and cure in the curing step to a soft, integral web.
Claim 3
Dependent Claim
32 words
The process of claim 1 wherein the fibers formed from the polymer solution are collected on a forming wire and the forming wire carrying the fibers moves continuously through the curing zone.
Claim 4
Dependent Claim
11 words
The process of claim 1 including (f) compacting the cured web.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein the compacting includes embossing the web.
Claim 6
Dependent Claim
36 words
The process of claim 1 wherein the temperature and air stream velocities are controlled in the fiber-forming and web-forming zones whereby the moisture content of the fibers prior to curing is less than 20% by weight.
Claim 7
Dependent Claim
20 words
The process of claim 1 wherein the primary air stream entrains and transports the filaments to the fiber forming zone.
Claim 8
Dependent Claim
31 words
The process of claim 1 wherein the velocity of the primary air is at least about 500 fpm and the velocity of the secondary air is at least about 3000 fpm.
Claim 9
Dependent Claim
59 words
The process of claim 1 wherein the polymer solution comprises about 25 to 60% polymer solids and the polymer composition comprises a blend of (1) a copolymer of at least one alpha, beta-unsaturated carboxylic monomer and at least one monomer copolymerizable therewith and (2) a crosslinking agent wherein the crosslinking functionality is selected from hydroxyl or heterocyclic carbonate groups.
Claim 10
Dependent Claim
25 words
The process of claim 8 wherein the copolymer comprises about 20-80 weight % pendant carboxylic acid groups and about 80-20 weight % pendant carboxylate groups.
Claim 11
Dependent Claim
45 words
The process of claim 8 wherein the copolymer is a copolymer of maleic anhydride and styrene, isobutylene, or a mixture of styrene and isobutylene, and the crosslinking agent is propylene carbonate, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, glycerol, pentaerythritol, mesoerythritol or any mixture thereof.
Claim 12
Dependent Claim
110 words
The process of claim 1 wherein the polymer solution comprises about 25 to 60% polymer solids, the polymer composition comprises a blend of (1) a copolymer of at least one alpha, beta-unsaturated carboxylic monomer and at least one monomer copolymerizable therewith, and (2) a crosslinking agent, wherein the crosslinking functionality is selected from hydroxyl or heterocyclic carbonate groups, and the process conditions are as follows: primary air velocity: about 500 to 8000 fpm; secondary air velocity: at least about 3000 fpm; secondary air temperature: about 25° to 140° C. temperature of curing zone: about 150° to 275° C. residence time of web in curing zone: about 0.5 to 35 minutes.
Claim 13
Dependent Claim
115 words
The process of claim 1 wherein the polymer solution comprises about 35 to 55% polymer solids, the polymer composition comprises a blend of (1) a partially neutralized copolymer of maleic anhydride and styrene, isobutylene, or a mixture of styrene and isobutylene, and (2) a crosslinking amount of propylene carbonate, ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, glycerol, pentaerythritol, meso-erythritol or any mixture thereof, and the process conditions are as follows: primary air velocity: about 500 to 8000 fpm; secondary air velocity: at least about 3000 fpm; secondary air temperature: about 25° to 140° C. temperature of curing zone: about 150° to 275° C. residence time of web in curing zone: about 0.5 to 35 minutes.
Claim 14
Dependent Claim
10 words
The nonwoven web produced by the process of claim 1.
Claim 15
Dependent Claim
10 words
The nonwoven web produced by the process of claim 8.
Claim 16
Dependent Claim
10 words
The nonwoven web produced by the process of claim 10.
Claim 17
Dependent Claim
10 words
The nonwoven web produced by the process of claim 12.
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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) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |