US3769128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing semipermeable membrane elements
Assignee: Universal Water Corp
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Filing: 1971-05-05
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Granted: 1973-10-30
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Expires: 1991-05-05
Abstract
Abstract A membrane element for use in a reverse osmosis apparatus is produced by helically winding slightly wet or moist semipermeable membrane strip around the outside of a porous support structure. The contiguous turn edges of the semipermeable membrane strip are preferably overlapped and are sealed by interposition of autogenous bonding agent between overlapped surfaces or by application of pressure sensitive adhesive tape. A fabric layer, preferably double, may be wound under the membrane. The wound element may be heat treated to improve selectivity of the membrane and to set the bonding agent or adhesive.
Inventors
- 👤 S Manjikian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:25
CPC Classifications
B; B01; B01D; B01D63/00; B01D63/06; B01D63/062; B01D63/065; B01D69/00; B01D69/10; B01D69/107; B01D69/108
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
78 words
A method for producing a membrane element adapted for use in apparatus for treatment of a liquid by reverse osmosis comprising: a. winding a single layer of semipermeable membrane strip helically around a permeable core; b. sealing together the contiguous edges of said helically wound membrane strip; and, c. sealing the ends of said helically wound strip to surface of said permeable core by wrapping with pressure sensitive adhesive tape applied under tension in which the improvements comprise
Claim 2
Independent Claim
98 words
A method for producing a membrane element adapted for use in apparatus for treatment of a liquid by reverse osmosis comprising: a. winding a single layer of semipermeable membrane strip helically around a permeable core with contiguous edges over-lapping; b. sealing together the said overlapping contiguous edges of said helically wound semipermeable membrane strip by applying therebetween during winding a sealing agent capable of dissolving surfaces of said semipermeable membrane strip and forming an autogenous bond; and, c. sealing the ends of said helically wound membrane strip to surfaces of said permeable core in which the improvements comprise
Claim 3
Dependent Claim
18 words
A method according to claim 3 in which said sealing agent comprises a mixture of triacetin and 1-propanol.
References Cited (Backward Citations)
US2987472A
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US3042216A
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US3063888A
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US3213016A
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US3432585A
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US3494470A
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US3519560A
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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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |