Patent US4923608A successfully refreshed from Google Patents.
US4923608A
Expired / Lapsed
US
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Micro/ultrafiltration membranes with a fixed pore size formed through irradiation with pulsed lasers and process for manufacturing the same
Assignee: Akzo NV
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Filing: 1988-12-16
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Granted: 1990-05-08
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Expires: 2008-12-16
Abstract
Abstract Flat membranes from foils of organic polymers, glass or ceramic materials have pores tapering in funnel-shaped fashion, with a fixed pore size and a pore size distribution of less than 10% and an arrangement of the pores in a pattern of adjacent rows, wherein the average pore diameters range from 0.05 to 10 μm and the pore patterns are evenly arranged in a regularly bounded area and, between the individual pores, have remaining webs with varying heights in the plane parallel to the increase in thickness of the foil material. It is manufactured through erosion of the pores by use of one or more intensity-modulated laser beams and continuous transport of the foil past the laser or lasers, with a pulse duration ranging from 1 to 1000 ns.
Inventors
- 👤 Thomas Flottmann
- 👤 Joachim Tretzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:10
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/0032; B01D67/0025; B01D69/00; B01D69/02; B01D71/00; B01D71/02; B01D71/0213; B23; B23K; B23K26/00; B23K26/36; B23K26/38; B23K26/382; B23K26/40; C; C03; C03B; C03B21/00; C03B21/06; C03B33/00; C03B33/08; C03B33/082; C04; C04B; C04B38/00; C04B38/0051; B23K2103/00; B23K2103/30; B23K2103/50; B23K2103/52; C04B2111/00; C04B2111/00474; C04B2111/00793; C04B2111/00801; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/496; Y10T29/49604
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
A flat membrane comprising a foil of organic polymers, glass or ceramic materials, with pores formed by at least one pulsed laser tapering in funnel-shaped fashion, and having a fixed pore size and a pore size distribution of less than 10% and an arrangement of the pores in a pattern of adjacent rows sufficient to provide a clear separation limit, wherein average diameters of said pores range from 0.05 to 10 μm and the pore patterns are evenly arranged in a regularly bounded area and have, between the individual pores, remaining ribs with varying heights in a direction of a thickness of the foil material sufficient to permit underwashing of retained parts of a filtered medium.
Claim 2
Dependent Claim
116 words
A flat membrane comprising a foil of organic polymers, glass or ceramic materials, with pores formed by at least one pulsed laser tapering in funnel-shaped fashion, and having a fixed pore size and a pore size distribution of less than 10% and an arrangement of the pores in a pattern of adjacent rows sufficient to provide a clear separation limit, wherein average diameters of said pores range from 0.05 to 10 μm and the pore patterns are evenly arranged in a regularly bounded area and have, between the individual pores, remaining ribs with varying heights in a direction of a thickness of the foil material sufficient to permit underwashing of retained parts of a filtered medium.
Claim 3
Dependent Claim
17 words
A flat membrane as set forth in claim 1, wherein the regularly bounded area is a square.
Claim 4
Dependent Claim
17 words
A flat membrane as set forth in claim 1, wherein the regularly bounded area is a rectangle.
Claim 5
Dependent Claim
17 words
A flat membrane as set forth in claim 1, wherein the regularly bounded area is a circle.
Claim 6
Dependent Claim
21 words
A flat membrane as set forth in claim 1, wherein the ribs are arranged with varying heights parallel in one direction.
Claim 7
Dependent Claim
23 words
A flat membrane as set forth in claim 1, wherein the ribs which are disposed perpendicularly to each other have alternately varying heights.
Claim 8
Dependent Claim
20 words
A flat membrane as set forth in claim 1, wherein the flat membrane is installed on a coarse-pored support material.
Claim 9
Dependent Claim
96 words
A process for manufacturing a flat membrane from a foil of organic polymers, glass or ceramic materials, comprising eroding pores in said membrane with at least one pulsed laser and continuously transporting the foil past said at least one laser, wherein a uniformly spatially intensity-modulated laser beam bounded by a regular area is pulsed onto the foil with a pulse duration ranging from 1 to 100 nanoseconds said membrane being sufficient to provided a clear separation limit, said pores being separated by ribs which are capable of providing underwashing of retained parts of a filtered medium.
Claim 10
Dependent Claim
96 words
A process for manufacturing a flat membrane from a foil of organic polymers, glass or ceramic materials, comprising eroding pores in said membrane with at least one pulsed laser and continuously transporting the foil past said at least one laser, wherein a uniformly spatially intensity-modulated laser beam bounded by a regular area is pulsed onto the foil with a pulse duration ranging from 1 to 100 nanoseconds said membrane being sufficient to provided a clear separation limit, said pores being separated by ribs which are capable of providing underwashing of retained parts of a filtered medium.
Claim 11
Dependent Claim
20 words
A method as set forth in claim 8, wherein the uniform spatial intensity modulation is generated by crossed interference lines.
Claim 12
Dependent Claim
24 words
A method as set forth in claim 8, wherein the uniform spatial intensity modulation is generated by optical image formation of a shadow mask.
Claim 13
Dependent Claim
23 words
A method as set forth in claim 8, wherein the foil is mounted onto a coarse-pored support system prior to radiation with lasers.
Claim 14
Dependent Claim
33 words
A method as set forth in claim 8, wherein said foil further comprises a thin metal foil and the metal foil is provided with coarse-pored openings prior to or after said eroding step.
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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) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |