US3947537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery separator manufacturing process
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1973-07-20
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Granted: 1976-03-30
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Expires: 1993-07-20
Abstract
Abstract Battery separators are produced from nonwoven mats of thermoplastic fibers by wetting the fibers with a surfactant-water mixture to modify the surface properties of the fibers in the nonwoven mat, vaporizing the water while depositing the surfactant on the fibers, heating the nonwoven mat prior to compressing and then compressing to increase the fiber-to-fiber bonding as well as to form the desired structure. During compressing, ribs may be formed by using appropriate embossed rolls or press plate patterns. After the compressing step, slitting, cooling and cutting steps are carried out to produce a battery separator of the desired dimensions.
Inventors
- 👤 Robert R. Buntin
- 👤 Walter A. Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:30
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56; H; H01; H01M; H01M50/00; H01M50/40; H01M50/489; H01M50/491; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A method for producing a battery acid wettable nonwoven battery separator from nonwoven mats of polypropylene thermoplastic fibers, which mats before treatment are not wettable by at least a 35% sulfuric acid battery acid, which method comprises: wetting a nonwoven mat of said thermoplastic fibers with a surfactant-water solution at a temperature of 60° to 170° F., wherein said surfactant is cationic or nonionic and is present as a 0.2 to about 1.0 wt. % solution in said water by contacting only one side of said mat and permitting said solution to spread through said mat; vaporizing the water from the surfactantwater solution within said mat in a hot air countercurrent oven whereby said surfactant is evenly deposited in an amount of 0.3 to 1.0% by weight based on fibers of said nonwoven mat which is now essentially dry; then heating said nonwoven mat to a temperature in excess of the softening point of said thermoplastic fibers but insufficient to melt, shrink or degrade said fibers; and subsequently compressing said heated nonwoven mat to a void fraction of at least 0.4.
Claim 2
Independent Claim
181 words
A method for producing a battery acid wettable nonwoven battery separator from nonwoven mats of polypropylene thermoplastic fibers, which mats before treatment are not wettable by at least a 35% sulfuric acid battery acid, which method comprises: wetting a nonwoven mat of said thermoplastic fibers with a surfactant-water solution at a temperature of 60° to 170° F., wherein said surfactant is cationic or nonionic and is present as a 0.2 to about 1.0 wt. % solution in said water by contacting only one side of said mat and permitting said solution to spread through said mat; vaporizing the water from the surfactantwater solution within said mat in a hot air countercurrent oven whereby said surfactant is evenly deposited in an amount of 0.3 to 1.0% by weight based on fibers of said nonwoven mat which is now essentially dry; then heating said nonwoven mat to a temperature in excess of the softening point of said thermoplastic fibers but insufficient to melt, shrink or degrade said fibers; and subsequently compressing said heated nonwoven mat to a void fraction of at least 0.4.
Claim 3
Dependent Claim
26 words
A method according to claim 1 wherein said nonwoven mat is passed through a mechanical wringer before the vaporizing of the water from the surfactant-water mixture.
Claim 4
Dependent Claim
12 words
A method according to claim 1 wherein said compressing includes forming ribs.
Claim 5
Dependent Claim
42 words
A method according to claim 1 wherein said nonwoven mat is comprised of polypropylene fibers and is heaed to a temperature of 255° to 300° F and compressed by male and female members heated within the range of 270° to 300° F.
Claim 6
Dependent Claim
15 words
A method according to claim 4 wherein said fibers are from 1-10 microns in diameter.
References Cited (Backward Citations)
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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) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |