Claims
- 1. A filter comprising:
- (a) layer of particulate removal medium having a thickness of between about 0.1 and about 5.0 mm.;
- (b) layer of organic vapor adsorbing medium comprising porous activated carbon beads affixed to a substrate, wherein the porous activated carbon beads have an average diameter of between about 0.3 and about 1 mm., and said porous activated carbon beads being impregnated with between about 2 and about 5% by weight chemical for adsorbing acid gas; and
- (c) scrim layers covering said layer of particulate removal medium and layer of organic vapor adsorbing medium, and wherein said filter has sealed edges,
- wherein said filter has a figure of merit greater than about 10 wherein the figure of merit is calculated based upon a fractional efficiency determined for particles having a size of 0.3 .mu.m in an air flow having a velocity of 10.5 ft./min. and for Frazier permeability at 0.5 inches H.sub.2 O.
- 2. A filter according to claim 1, wherein the thickness of the layer of particulate removal medium is between about 0.15 and about 1.0 mm.
- 3. A filter according to claim 1, wherein the thickness of the layer of particulate removal medium is between about 0.20 and about 0.25 mm.
- 4. A filter according to claim 1, wherein the particulate removal medium comprises an electrostatic medium.
- 5. A filter according to claim 4, wherein the electrostatic medium comprises a mixed fiber medium comprising polypropylene and acrylic.
- 6. A filter according to claim 1, wherein the particulate removal layer comprises polytetrafluoroethylene.
- 7. A filter according to claim 1, wherein the porous activated carbon beads comprise pores having an average size of less than 20 angstrom.
- 8. A filter according to claim 1, wherein the chemical is selected from the group consisting of sodium carbonate, calcium carbonate, and potassium carbonate.
- 9. A filter according to claim 1, wherein the filter is a recirculation filter for use in a disk drive.
- 10. A filter according to claim 1, wherein said figure of merit of said filter is greater than about 60.
- 11. A filter according to claim 1, wherein said figure of merit of said filter is between about 150 and about 200.
- 12. A method for preparing a filter for use in removing particulates and organic vapors from an air stream provided inside of a disk drive, said method including steps of:
- (a) providing a filter comprising:
- (i) layer of particulate removal medium having a thickness of between about 0.1 and about 5.0 mm.;
- (ii) layer of organic vapor adsorbing medium comprising porous activated carbon beads affixed to a substrate, wherein the porous activated carbon beads have an average diameter of between about 0.3 and about 1 mm., and said porous activated carbon beads being impregnated with between about 2 and about 5% by weight chemical for adsorbing acid gas; and
- (iii) scrim layers covering said layer of particulate removal medium and layer of organic vapor adsorbing medium, and wherein said filter has sealed edges,
- (b) placing said filter inside a disk drive.
- 13. A method for preparing a filter according to claim 12, wherein the thickness of the layer of particulate removal medium is between about 0.15 and about 1.0 mm.
- 14. A method for preparing a filter according to claim 12, wherein the thickness of the layer of particulate removal medium is between about 0.20 and about 0.25 mm.
- 15. A method for preparing a filter according to claim 12, wherein the particulate removal medium comprises an electrostatic medium.
- 16. A method for preparing a filter according to claim 15, wherein the electrostatic medium comprises a mixed fiber medium comprising polypropylene and acrylic.
- 17. A method for preparing a filter according to claim 12, wherein the particulate removal layer comprises polytetrafluoroethylene.
- 18. A method for preparing a filter according to claim 12, wherein the porous activated carbon beads comprise pores having an average size of less than 20 angstrom.
- 19. A method for preparing a filter according to claim 12, wherein the chemical is selected from the group consisting of sodium carbonate, calcium carbonate and potassium carbonate.
- 20. A method for preparing a filter according to claim 12, wherein the filter has a figure of merit greater than about 60.
- 21. A method for preparing a filter according to claim 12, wherein said filter has a figure of merit between about 150 and about 200.
Parent Case Info
This is a Continuation of application Ser. No. 08/492,725, filed Jun. 20, 1995, now abandoned, which application is incorporated herein by reference.
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Continuations (1)
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Number |
Date |
Country |
Parent |
492725 |
Jun 1995 |
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