US4405536A
Expired / Lapsed
US
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Processes for severing hollow fiber membranes
Assignee: Permea Inc
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Filing: 1981-12-11
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Granted: 1983-09-20
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Expires: 2001-12-11
Abstract
Abstract Processes are disclosed for severing a plurality of hollow fiber membranes comprised of thermoplastic material which membranes are arranged in the form of a bundle and also sealing the bores of the membranes in an essentially fluid-tight manner. The severing and sealing of essentially all of the hollow fiber membranes in the bundle can readily be accomplished without any significant decrease in membrane performance or strength. The severing and sealing of the hollow fiber membranes is accomplished by passing a heated member through the bundle in a path transverse to the orientation of the hollow fiber membranes wherein the temperature of the heated member is above the melt temperature of the hollow fiber membranes. Advantageously, the hollow fiber membranes which are severed in accordance with this invention can have a significant void volume and may be anisotropic with a thin, dense skin.
Inventors
- 👤 Maurice L. Woodcock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:35
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/22; B01D63/00; B01D63/02; B01D63/021; B26; B26D; B26D3/00; B26D3/12; B29; B29C; B29C65/00; B29C65/02; B29C65/74; B29C65/743; B29C65/7433; B29C66/00; B29C66/50; B29C66/51; B29C66/52; B29C66/522; B29C66/5227; B29C66/90; B29C66/91; B29C66/914; B29C66/9141; B29C66/91421; B29C66/919; B29C66/9192; B29C66/91921; B29C66/91931; B29C66/91933; B01D2313/00; B01D2313/04; B29C65/18; B29C65/22; B29C65/221; B29C65/222; B29C65/223; B29C65/224; B29C66/70; B29C66/71; B29C66/9161; B29C66/91651; B29C66/91655; B29L; B29L2031/00; B29L2031/14; B29L2031/60; B29L2031/601
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
180 words
A process for simultaneously severing and sealing the bores of a plurality of thermoplastic hollow fiber membranes comprising passing a heated member through a bundle consisting of said plurality of hollow fiber membranes in a path transverse to the longitudinal orientation of the hollow fiber membranes, said heated member being at a temperature above the melt temperature of the thermoplastic hollow fiber membranes and being passed through said bundle at a rate less than 50 centimeters per minute, said rate being sufficient to effect severing and sealing the bores of the hollow fiber membranes in an essentially fluid-tight manner; and maintaining said bundle adjacent to the path of said heated member in substantially a desired cross-sectional configuration during the passing of the heated member through said bundle; wherein adjacent hollow fiber membranes adhere to one and another in a zone of thermoplastic material at least about 0.2 millimeters thick such that the hollow fiber membranes at the end of the bundle formed by the severing are substantially maintained in the same desired cross-sectional configuration in the absence of external support.
Claim 2
Dependent Claim
180 words
A process for simultaneously severing and sealing the bores of a plurality of thermoplastic hollow fiber membranes comprising passing a heated member through a bundle consisting of said plurality of hollow fiber membranes in a path transverse to the longitudinal orientation of the hollow fiber membranes, said heated member being at a temperature above the melt temperature of the thermoplastic hollow fiber membranes and being passed through said bundle at a rate less than 50 centimeters per minute, said rate being sufficient to effect severing and sealing the bores of the hollow fiber membranes in an essentially fluid-tight manner; and maintaining said bundle adjacent to the path of said heated member in substantially a desired cross-sectional configuration during the passing of the heated member through said bundle; wherein adjacent hollow fiber membranes adhere to one and another in a zone of thermoplastic material at least about 0.2 millimeters thick such that the hollow fiber membranes at the end of the bundle formed by the severing are substantially maintained in the same desired cross-sectional configuration in the absence of external support.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein heat is provided to the heated member during the severing and sealing.
Claim 4
Dependent Claim
27 words
The process of claim 2 wherein the heated member comprises an electrical resistance material and heat is generated by passing an electrical current through the heated member.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein the heated member is a wire.
Claim 6
Dependent Claim
30 words
The process of claim 1 or 3 wherein the temperature of the heated member is at least about 50° C. above the melt temperature of the thermoplastic hollow fiber membranes.
Claim 7
Dependent Claim
18 words
The process of claim 5 wherein the temperature of the heated member is about 700° to 950° C.
Claim 8
Dependent Claim
22 words
The process of claim 1 or 3 wherein the inside diameter of the thermoplastic fiber membrane is about 50 to 500 microns.
Claim 9
Dependent Claim
18 words
The process of claim 7 wherein the thermoplastic hollow fiber membranes have walls with a substantial void volume.
Claim 10
Dependent Claim
30 words
The process of claim 8 wherein the thermoplastic hollow fiber membranes are anisotropic with a thin, dense exterior skin and have a void volume of about 30 to 70 percent.
Claim 11
Dependent Claim
12 words
The process of claim 9 wherein the hollow fiber membrane comprises polysulfone.
Claim 12
Dependent Claim
17 words
The process of claim 10 wherein the temperature of the heated member is at least 700° C.
Claim 13
Dependent Claim
29 words
The process of claim 1 or 3 wherein the bundle at the path through which the heated member passes has a packing factor of about 50 to 65 percent.
Claim 14
Dependent Claim
17 words
The process of claim 1, 11 or 3 wherein the thickness is about 0.2 to 10 millimeters.
Claim 15
Dependent Claim
13 words
The process of claim 1 wherein said desired cross-sectional configuration is substantially circular.
Claim 16
Dependent Claim
18 words
The process of claim 14 wherein said bundle has a cross-sectional diameter of greater than about 0.02 meters.
Claim 17
Dependent Claim
15 words
The process of claim 15 wherein said cross-sectional diameter is greater than about 0.05 meters.
Claim 18
Dependent Claim
30 words
The process of claim 16 wherein said heated member comprises a wire of an electrical resistance material and heat is generated by passing an electrical current through said heated member.
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |