Method and apparatus for forming a fibrous media

• US 8,267,681 B2
• Filed: 01/27/2010
• Issued: 09/18/2012
• Est. Priority Date: 01/28/2009
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Gupta, Hemant, Kahlbaugh, Brad E.
• Primary Examiner(s): Sole, Joseph Del
• Assistant Examiner(s): KENNEDY, TIMOTHY J
• Application Number:
  US12/694,935
• Publication Number:
  US 20100187712A1
• Time in Patent Office: 965 Days
• Field of Search: 425/80.1, 425/81.1, 425/83.1, 425/223, 425/224, 425/130, 162/129, 162/130, 162/131, 162/141, 162/149, 162/216, 162/336, 162/343, 162/344, 162/348, 162/349, 162/350, 162/351, 162/352, 162/353, 162/354
• US Class Current: 425/130
• 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) 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, wherein the first flow stream has a different composition than the second flow stream;

b) 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 between the two flow streams; and

c) 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 fiber from the combined flow stream;

wherein the receiving region is positioned below at least a portion of the mixing partition so that portions of the second fluid flow stream pass through the openings of the mixing partition onto the receiving region.

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 three 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 3 wherein the mixing partition has an axis in the machine direction dividing the mixing partition into a first side and a second side, wherein the first side has no openings and the second side 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 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.

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

26. 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.

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

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

33. The apparatus of claim 6 wherein the mixing partition defines at least a first slot, second slot and third slot, each slot extending from a first cross web edge of the mixing partition to a second cross web edge of the mixing partition, wherein the second opening is downstream from the first opening, and wherein the third opening is downstream from the first opening.

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

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

b) a second source configured to dispense a second fluid flow stream comprising a second type of fiber, wherein the first flow stream has a different composition than the second flow stream;

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, wherein at least one of the openings extends across the entire mixing partition in the cross web direction; 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;

wherein the receiving region is positioned below at least a portion of the mixing partition so that portions of the second fluid flow stream pass through the openings of the mixing partition onto the receiving region.

30. The apparatus of claim 29 wherein the one or more openings comprise one or more rectangular openings extending in a cross web direction of the mixing partition.

31. The apparatus of claim 30 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.

32. The apparatus of claim 29 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. The apparatus of claim 29 wherein the mixing partition defines at least a first slot, second slot and third slot, each slot extending from a first cross web edge of the mixing partition to a second cross web edge of the mixing partition, wherein the second opening is downstream from the first opening, and wherein the third opening is downstream from the first opening.