Method and Apparatus for Forming a Fibrous Media

• US 20100187712A1
• Filed: 01/27/2010
• Published: 07/29/2010
• Est. Priority Date: 01/28/2009
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Kahlbaugh, Brad E., Gupta, Hemant
• Granted Patent: US 8,267,681 B2
• Time in Patent Office: Days
• US Class Current: 264/86
• CPC Class Codes: D04H 1/42 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: D04H 1/4218 Glass fibres
• CPC Class Codes: D04H 1/435 Polyesters
• CPC Class Codes: D04H 1/43828 sheath-core
• CPC Class Codes: D04H 1/43832 side-by-side
• CPC Class Codes: D04H 1/43835 Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• CPC Class Codes: D04H 1/43838 Ultrafine fibres, e.g. microfibres
• CPC Class Codes: D21F 11/04 paper or board consisting on two or more layers
• CPC Class Codes: D21F 11/14 Making cellulose wadding, filter or blotting paper
• CPC Class Codes: D21F 9/006 paper or board consisting of two or more layers
• CPC Class Codes: D21H 13/24 Polyesters
• CPC Class Codes: D21H 13/40 vitreous, e.g. mineral wool, glass fibres
• CPC Class Codes: D21H 27/08 Filter paper self-supporting filtering material B01D39/14; making on paper-making machines D21F11/14

Abstract

Embodiments for methods and apparatuses for forming a nonwoven web are described herein. In one embodiment, an apparatus includes one or more sources configured to dispense a first fluid flow stream comprising a fiber and a second fluid flow stream also comprising a fiber. The apparatus also includes a mixing partition downstream from the one or more sources, where the mixing partition is positioned between the first and second flow streams from the one or more sources. The mixing partition defines one or more openings that permit fluid communication between the two flow streams. The apparatus also includes a receiving region situated downstream from the one or more sources and designed to receive at least a combined flow stream and form a nonwoven web by collecting fiber from the combined flow stream.

Claims

1. An apparatus for making a nonwoven web, the apparatus comprising:

a) one or more sources configured to dispense a first fluid flow stream comprising a fiber and a second fluid flow stream also comprising a fiber;

b) a mixing partition downstream from the one or more sources, the mixing partition positioned between the first and second flow streams from the one or more sources, the mixing partition defining one or more openings in the mixing partition that permit fluid communication between the two flow streams; and

c) a receiving region situated downstream from the one or more sources and designed to receive at least a combined flow stream and form a nonwoven web by collecting fiber from the combined flow stream.

2. The apparatus of claim 1 wherein the mixing partition is inclined relative to a horizontal plane.

3. The apparatus of claim 1 wherein the mixing partition defining two or more openings.

4. The apparatus of claim 3 wherein the two or more openings comprise two or more rectangular openings extending in a cross web direction of the mixing partition.

5. The apparatus of claim 4 wherein the one or more rectangular openings extend fully across the mixing partition in a cross web direction.

6. The apparatus of claim 1 wherein the openings comprise two or more slots extending from a first cross web edge of the mixing partition to a second cross web edge of the mixing partition.

7. The apparatus of claim 6 wherein the two or more slots each comprise a different width, a different length, a different orientation with respect to the flow stream, different spacing from an end of the mixing portion, or a combination of one or more such aspect thereof.

8. The apparatus of claim 6 wherein a dimension of the mixing partition in the machine direction is at least about 0.3 meter (11.8 inches) and at most about 1.5 meter (59 inches).

9. The apparatus of claim 6 wherein the mixing partition further comprises at least three slots and at most eight slots, each slot individually having a width of at least 1 cm and at most 20 cm.

10. The apparatus of claim 9 wherein the slots are rectangular and are defined by a plurality of removable rectangular pieces.

11. The apparatus of claim 6 wherein the mixing partition comprises five rectangular openings defined by five or more removable rectangular members, wherein the widths of the members each are about 1.5 cm to 15 cm (0.6 inch to 5.9 inches) and the widths of the openings each are about 0.5 cm to 10 cm (0.2 inch to 3.9 inches).

12. The apparatus of claim 1 wherein the one or more openings comprise one or more slots extending in a machine direction of the mixing partition.

13. The apparatus of claim 1 wherein the one or more openings comprise a plurality of discrete circular openings.

14. The apparatus of claim 1 wherein the mixing partition defines at least a first opening having first dimensions and at least a second opening having second, different dimensions.

15. The apparatus of claim 1 wherein the one or more openings of the mixing partition occupy at least 5% and at most 70% of the total area of the mixing partition.

16. The apparatus of claim 1 wherein the one or more openings of the mixing partition occupy at least 10% and at most 30% of the total area of the mixing partition.

17. The apparatus of claim 3 wherein the mixing partition has a central axis in the machine direction dividing the mixing partition into two halves, wherein one half is not identical to the other half.

18. The apparatus of claim 17 wherein one half has no openings and the other half defines the plurality of openings.

19. The apparatus of claim 17 wherein the mixing partition has a first outer edge and a second outer edge, wherein the first and second outer edges are parallel to the machine direction, wherein the mixing partition defines a first opening that varies in machine-direction-width so that the machine-direction-width closest to the first outer edge is smaller than the machine-direction width closest to the second outer edge.

20. The apparatus of claim 1 wherein the mixing partition comprises a first edge portion without openings and a second edge portion without openings, where the first and second edge portions each extend from a downstream cross-web edge to an upstream cross-web edge, wherein the mixing partition further comprises a central portion between the first and second edge portions and wherein the openings are defined in the central portion.

21. The apparatus of claim 1 wherein the receiving region further comprises a device for removing liquid from the flow streams.

22. The apparatus of claim 21 wherein the device for removing fluid comprises one or more gravity drainage devices, one or more vacuum devices, one or more table rolls, vacuum foils, vacuum rolls, or a combination thereof.

23. The apparatus of claim 1 further comprising a drying section proximal and downstream to the receiving region, the drying section comprising a drying can section, one or more IR heaters, one or more UV heaters, a through-air dryer, a transfer wire, a conveyor, or a combination thereof.

24. The apparatus of claim 1 comprising two sources, wherein a first source produces the first flow stream and a second source produces the second flow stream.

25. The apparatus of claim 1 wherein the first flow stream comprises a first fiber type and the second flow stream comprises a second fiber type, each fiber type having at least one different fiber characteristics from the other.

26. The apparatus of claim 1 wherein the one or more sources are selected from the group consisting of a headbox and a nozzle.

27. The apparatus of claim 1 wherein the mixing partition comprises an offset portion adjacent to an upstream edge of the mixing partition, wherein there are no openings in the offset portion.

28. The apparatus of claim 1 wherein the fluid flow stream is a liquid flow stream.

29. The apparatus of claim 1 wherein the fluid flow stream is an aqueous flow stream

30. An apparatus for making a nonwoven web, the apparatus comprising:

a) a first source configured to dispense a first fluid flow stream comprising a fiber;

b) a second source configured to dispense a second fluid flow stream also comprising a fiber;

c) a mixing partition downstream from the first and second sources, the mixing partition positioned between the first and second flow streams, the mixing partition defining two or more openings in the mixing partition that permit fluid communication and mixing between the first and second flow streams; and

d) a receiving region situated downstream from the first and second sources and designed to receive at least a combined flow stream and form a nonwoven web by collecting the combined flow stream.

31. The apparatus of claim 30 wherein the one or more openings comprise one or more rectangular openings extending in a cross web direction of the mixing partition.

32. The apparatus of claim 31 wherein the two or more slots each comprise a different width, a different length, a different orientation with respect to the flow stream, different spacing from an end of the mixing portion, or a combination of one or more such aspect thereof.

33. The apparatus of claim 30 wherein the openings comprise two or more slots extending from a first cross web edge of the mixing partition to a second cross web edge of the mixing partition.

34. An apparatus for making a nonwoven web, the apparatus comprising:

a) a source designed to dispense a first liquid flow stream including a fiber;

b) a mixing partition downstream from the source, the mixing partition comprising one or more openings in the mixing partition; and

c) a receiving region situated downstream from the source and designed to receive the flow stream and form a nonwoven web by collecting fiber from the flow stream.

35. The apparatus of claim 34 wherein at least one opening of the mixing partition is configured to allow passage of only a first portion of the first flow stream, wherein a remainder of the first flow stream flows on the mixing partition downstream of the first opening.

36. The apparatus of claim 34 wherein the first fluid flow stream comprises a mix of at least two fiber types, each fiber type having at least one different fiber characteristics from the other.

37. A method of making a nonwoven web using an apparatus, comprising:

i) dispensing a first fluid stream from a first source, wherein the fluid stream comprises fiber, the apparatus comprising a mixing partition downstream from the first source, the mixing partition positioned between two flow paths from the first source, the flow paths separated by the mixing partition, the mixing partition defining one or more openings in the mixing partition that permit fluid communication from at least one flow path to another;

ii) collecting fiber on a receiving region situated proximal and downstream to the source, the receiving region designed to receive the flow stream dispensed from the source and form a wet layer by collecting the fiber;

iii) drying the wet layer to form the nonwoven web.

38. The method of claim 37 further comprising removing fluid from the wet layer.

39. The method of claim 37 further comprising applying heat to the wet layer.

40. The method of claim 37 wherein at least one of the flow streams comprises a water-based slurry of one or more fibers having a fiber concentration of less than about 20 grams of fiber per liter of the water-based slurry.

41. The method of claim 37 wherein the mixing partition permits two-way fluid communication between the two flow paths.

42. The method of claim 37 further comprising:

dispensing a second fluid stream from a second source, wherein the fluid stream comprises fibers, wherein portions of the first fluid stream flow through the mixing partition onto the second fluid stream on the receiving region.

43. The method of claim 42 wherein the first fluid stream comprises at least a first fiber and the second fluid stream comprises at least a second fiber, the second fiber having different fiber characteristics than the first fiber.

44. The method of claim 43 wherein the first fiber is a glass fiber and wherein the second fiber is a bicomponent fiber comprising a core and a shell.

45. The method of claim 37 wherein the mixing partition has a central axis in the machine direction dividing the mixing partition into two halves, wherein one half is not identical to the other half.

46. The method of claim 45 wherein one half has no openings and the other half defines the plurality of openings.

47. The method of claim 37 wherein the openings comprise two or more slots extending from a first cross web edge of the mixing partition to a second cross web edge of the mixing partition.

48. The method of claim 37 wherein the one or more openings comprise one or more rectangular openings extending in a cross web direction of the mixing partition.

49. A method of making a nonwoven web comprising:

i) providing a furnish from a source, the furnish comprising at least a first fiber;

ii) dispensing a stream of the furnish from an apparatus for making a nonwoven web, the apparatus comprising a mixing partition downstream from a source of the stream, the mixing partition comprising at least one opening in the mixing partition configured to allow passage of at least a portion of the stream;

iii) collecting fiber passing through the at least one opening on a receiving region situated downstream from the source;

iv) collecting a remainder of fiber on the receiving region at a downstream portion of the mixing partition; and

iv) drying the wet layer to form the nonwoven web.