MONOLITHIC FILTER BODY AND FABRICATION TECHNIQUE

• US 20030168396A1
• Filed: 05/29/2003
• Published: 09/11/2003
• Est. Priority Date: 12/08/1999
• Status: Abandoned Application

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Jacobson, James D.
• Application Number:
  US10/250,020
• Publication Number:
  US 20030168396A1
• Time in Patent Office: Days
• US Class Current: 210/321.75
• CPC Class Codes: B01D 2323/24 Use of template or surface directing agents [SDA]
• CPC Class Codes: B01D 2323/30 Cross-linking
• CPC Class Codes: B01D 2323/345 UV-treatment
• CPC Class Codes: B01D 2325/02 Details relating to pores or porosity of the membranes
• CPC Class Codes: B01D 2325/24 Mechanical properties, e.g. strength
• CPC Class Codes: B01D 63/16 Rotary, reciprocated or vibrated modules
• CPC Class Codes: B01D 67/002 from melts
• CPC Class Codes: B01D 67/0039 Inorganic membrane manufacture
• CPC Class Codes: B01D 67/0044 by chemical reaction
• CPC Class Codes: B01D 67/0058 by selective elimination of components, e.g. by leaching
• CPC Class Codes: B01D 67/0062 by micromachining techniques, e.g. using masking and etching steps, photolithography
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/10 Supported membranes; Membrane supports
• CPC Class Codes: B01D 71/64 Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: B01D 71/70 Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only
• CPC Class Codes: B01D 71/701 Polydimethylsiloxane
• CPC Class Codes: B23K 26/384 of specially shaped holes
• CPC Class Codes: B26F 1/31 by radiation by laser beam B23K26/00
• CPC Class Codes: B29C 33/38 characterised by the material or the manufacturing process B29C33/44 takes precedence
• CPC Class Codes: B29C 33/424 Moulding surfaces provided with means for marking or patterning for injection moulding B29C45/372
• CPC Class Codes: G03F 7/0015 : Production of aperture devices, microporous systems or stamps

Abstract

A filter having a monolithic filter body having pores, cavities, and cavity side walls disposed between and formed integrally with first and second spaced apart faces of the filter body and providing structural support therefor. A method of fabrication thereof involving molding using mold halves, and a flowable, curable material to form the monolithic filter body. A method of fabricating such mold halves.

Claims

1. a method of fabricating a monolithic filter body having first and second spaced apart faces extending generally transverse to a direction of flow, at least one cavity extending from the second face toward the first face and having a cavity depth, cavity side walls providing structural support for the monolithic filter body, and a plurality of pores extending from the first face to the at least one cavity, the method comprising:

mating a first mold half with a second mold half to form a mold configured for forming the monolithic filter body including said at least one cavity, said cavity side walls, and said pores;

curing a flowable, curable material in the mold to form the monolithic filter body; and

removing the monolithic filter body from the mold.

2. The method of claim 1 wherein the filter body has a porosity between about 15% and about 65%.

3. The method of claim 1 wherein the pores have an aspect ratio between about 2 and about 40.

4. The method of claim 1 wherein the pores have an aspect ratio of less than about 10.

5. The method of claim 1 wherein the pores have an aspect ratio of less than about 5.

6. The method of claim 2 wherein the pores have an aspect ratio between about 2 and about 40.

7. The method of claim 2 wherein the pores have an aspect ratio of less than about 10.

8. The method of claim 2 wherein the pores have an aspect ratio of less than about 5.

9. The method of claim 1 wherein the flowable, curable material comprises an elastomer.

10. The method of claim 1 wherein the flowable, curable material comprises PDMS elastomer.

11. The method of claim 10 wherein the filter body has a porosity between about 15% and about 65%.

12. The method of claim 10 wherein the pores have an aspect ratio between about 2 and about 40.

13. The method of claim 10 wherein the pores have an aspect ratio of less than about 10.

14. The method of claim 10 wherein the pores have an aspect ratio of less than about 5.

15. The method of claim 1 wherein the filter body has a porosity between about 15% and about 65%, wherein the pores have an aspect ratio of less than about 10, and wherein the pores have a cross-sectional area of between about 0.008 Î

¼

m2 and about 175 Î

¼

m2.

16. The method of claim 9 wherein the filter body has a porosity between about 15% and about 65%, wherein the pores have an aspect ratio of less than about 10, and wherein the pores have a cross-sectional area of between about 0.008 Î

¼

m2 and about 175 Î

¼

m2.

17. The method of claim 10 wherein the filter body has a porosity between about 15% and about 65%, wherein the pores have an aspect ratio of less than about 10, and wherein the pores have a cross-sectional area of between about 0.008 Î

¼

m2 and about 175 Î

¼

m2.

18. The method of claim 1 wherein the flowable, curable material comprises a material selected from among rubber, plastic, and silicone materials.

19. The method of claim 1 wherein the first mold half is configured for forming said at least one cavity and said cavity side walls, and the second mold half is configured for forming said pores.

20. The method of claim 1 wherein the first mold half is configured for forming said at least one cavity, said cavity side walls, and said pores.

21. The method of claim 1 comprising:

forming the first mold half prior to mating the first and second mold halves by a) forming a pattern of etch-resistant material on a first-mold-half mold substrate;

b) etching material from the first-mold-half mold substrate as defined by said pattern to provide a form corresponding to said at least one filter cavity; and

c) stripping the etch-resistant material from the first-mold-half mold substrate to form the first mold half.

22. The method of claim 1 comprising:

forming the second mold half prior to mating the first and second mold halves by a) forming a pattern of etch-resistant material on a second-mold-half mold substrate;

b) etching material from the second-mold-half mold substrate as defined by said pattern to provide a form corresponding to said pores; and

c) stripping the etch-resistant material from the second-mold-half mold substrate to form the second mold half.

23. The method of claim 21 comprising:

forming the second mold half prior to mating the first and second mold halves by a) forming a pattern of etch-resistant material on a second-mold-half mold substrate;

b) etching material from the second-mold-half mold substrate as defined by said pattern to provide a form corresponding to said pores; and

c) stripping the etch-resistant material from the second-mold-half mold substrate to form the second mold half.

24. A method of fabricating a mold half of a mold for molding a monolithic filter body having first and second spaced apart faces extending generally transverse to a direction of flow, at least one cavity extending from the second face toward the first face and having a cavity depth, cavity side walls providing structural support for the monolithic filter body, and a plurality of pores extending from the first face to the at least one cavity, the method comprising:

forming a pattern of etch-resistant material on a mold-half mold substrate;

etching material from the mold-half mold substrate as defined by said pattern to provide a form corresponding to features selected from among said pores and said at least one cavity; and

stripping the etch-resistant material from the first-mold half mold substrate to form the mold half.

25. A method of fabricating a mold half of a mold for molding a monolithic filter body having first and second spaced apart faces extending generally transverse to a direction of flow, at least one cavity extending from the second face toward the first face and having a cavity depth, cavity side walls providing structural support for the monolithic filter body, and a plurality of pores extending from the first face to the at least one cavity, the method comprising:

forming a first pattern of etch-resistant material on a mold-half mold substrate;

etching material from the mold-half mold substrate as defined by said first pattern to provide a form corresponding to said pores;

stripping the first pattern of etch-resistant material from the mold-half mold substrate;

forming a second pattern of etch-resistant material on the mold-half substrate;

etching material from the mold-half mold substrate as defined by said second pattern to provide a form corresponding to said at least one cavity;

stripping the second pattern of etch-resistant material from the mold-half mold substrate to yield the mold half.

26. A filter comprising:

a monolithic filter body having first and second spaced apart faces extending generally transverse to a direction of flow;

at least one cavity extending from the second face toward the first face and having a cavity depth;

cavity side walls formed integrally with the first and second spaced apart faces and providing structural support for the monolithic filter body; and

a plurality of pores extending from the first face to the at least one cavity.

27. The filter of claim 26 wherein the filter body has a porosity between about 15% and about 65%.

28. The filter of claim 26 wherein the pores have an aspect ratio between about 2 and about 40.

29. The filter of claim 26 wherein the pores have an aspect ratio of less than about 10.

30. The filter of claim 26 wherein the pores have an aspect ratio of less than about 5.

31. The filter of claim 27 wherein the, pores have an aspect ratio between about 2 and about 40.

32. The filter of claim 27 wherein the pores have an aspect ratio of less than about 10.

33. The filter of claim 27 wherein the pores have an aspect ratio of less than about 5.

34. The filter of claim 26 wherein the flowable, curable material comprises an elastomer.

35. The filter of claim 26 wherein the flowable, curable material comprises PDMS elastomer.

36. The filter of claim 35 wherein the filter body has a porosity between about 15% and about 65%.

37. The filter of claim 35 wherein the pores have an aspect ratio between about 2 and about 40.

38. The filter of claim 35 wherein the pores have an aspect ratio of less than about 10.

39. The filter of claim 35 wherein the pores have an aspect ratio of less than about 5.

40. The filter of claim 26 wherein the filter body has a porosity between about 15% and about 65%, wherein the pores have an aspect ratio of less than about 10, and wherein the pores have a cross-sectional area of between about 0.008 Î

¼

m2 and about 175 Î

¼

m2.

41. The filter of claim 26 wherein the flowable, curable material comprises a material selected from among rubber, plastic, and silicone materials.

42. The filter of claim 26 wherein the first mold half is configured for forming said at least one cavity and said cavity side walls, and the second mold half is configured for forming said pores.

43. The filter of claim 26 wherein the first mold half is configured for forming said at least one cavity, said cavity side walls, and said pores.

44. The filter of claim 26 wherein the filter body is seamless.