Method and apparatus for forming a fibrous media

• US 9,353,481 B2
• Filed: 08/27/2013
• Issued: 05/31/2016
• Est. Priority Date: 01/28/2009
• Status: Active Grant

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donldson Company Incorporated
• Inventors: Gupta, Hemant, Kahlbaugh, Brad E.
• Primary Examiner(s): KENNEDY, TIMOTHY J
• Application Number:
  US14/011,337
• Publication Number:
  US 20130340962A1
• Time in Patent Office: 1,008 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, 162/188, 162/216, 162/336, 162/343, 162/344, 162/348, 162/349, 162/350, 162/351, 162/352, 162/353, 162/354, 264/212
• US Class Current: 1/1
• 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 first fiber;

b) a second source configured to dispense a second fluid flow stream comprising a second fiber, wherein the first fluid stream comprises a first fiber and the second fluid stream comprises a second fiber, wherein the second fiber has different fiber characteristics than the first fiber;

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 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 first and second sources and designed to receive at least combined first and second fluid flow streams and form a nonwoven web by collecting first and second fibers from the combined first and second fluid flow streams;

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 one or more openings of the mixing partition onto the receiving region.

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

i) dispensing, from the apparatus, a first fluid stream from a first source and a second fluid stream from a second source, wherein the first fluid stream comprises a first fiber and the second fluid stream comprises a second fiber, wherein the second fiber has different fiber characteristics than the first fiber;

ii) providing a mixing partition downstream from the first and second sources, the mixing partition positioned between the first fluid stream and the second fluid stream, the mixing partition defining one or more openings in the mixing partition that permit fluid communication from at least one fluid stream to another, wherein a receiving region is positioned below at least a portion of the mixing partition so that portions of the second fluid stream pass through the openings of the mixing partition onto the first fluid stream and onto a receiving region;

iii) collecting first and second fibers on the receiving region situated downstream from the first and second sources, the receiving region configured to receive the combined first and second fluid streams and form a wet layer by collecting the first and second fibers from the combined fluid stream;

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

3. The method of claim 2 further comprising removing fluid from the wet layer.

4. The method of claim 2 wherein drying the wet layer further comprises applying heat to the wet layer.

5. The method of claim 2 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.

6. The method of claim 2 wherein the first fiber is a glass fiber and wherein the second fiber is a bicomponent fiber comprising a core and a shell.

7. The method of claim 2 wherein, in the apparatus, the mixing partition has a central axis in a downstream machine direction dividing the mixing partition into two halves, wherein one half is not identical to the other half.

8. The method of claim 2 wherein the one or more openings comprise one or more rectangular openings extending in a cross web direction of the mixing partition.

9. The method of claim 2 wherein the one or more 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.

10. The method of claim 9 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.

11. The method of claim 9 wherein a dimension of the mixing partition in a downstream machine direction is at least about 0.3 meter (11.8 inches) and at most about 1.5 meter (59 inches).

12. The method of claim 9 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.

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

14. The method of claim 2 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.

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

16. The method of claim 2 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.

17. The method of claim 2 wherein the fluid flow streams are liquid flow streams.

18. The method of claim 2 wherein the fluid flow streams are aqueous flow streams.

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

i) dispensing a first fluid stream from a first source, wherein the first fluid stream comprises a first fiber;

ii) dispensing a second fluid stream from a second source, wherein the second fluid stream comprises a second fiber;

iii) providing a mixing partition downstream from the first and second sources, the mixing partition positioned between the first fluid stream and the second fluid stream, the mixing partition defining one or more openings in the mixing partition that permit fluid communication from at least one fluid stream to another, wherein a receiving region is positioned below at least a portion of the mixing partition so that portions of the second fluid stream pass through the openings of the mixing partition onto the first fluid stream and onto the receiving region, wherein at least one of the openings extends across the entire mixing partition in the cross web direction;

iv) collecting first and second fibers on the receiving region situated downstream from the first and second sources, the receiving region configured to receive the combined first and second fluid streams and form a wet layer by collecting the first and second fibers from the combined fluid stream;

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

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

i) dispensing, from the apparatus, a first fluid stream from a first source and a second fluid stream from a second source, wherein the first fluid stream comprises a first fiber and the second fluid stream comprises a second fiber, wherein the second fiber has different fiber characteristics than the first fiber;

ii) providing a mixing partition downstream from the first and second sources, the mixing partition positioned between the first fluid stream and the second fluid stream, the mixing partition defining one or more openings in the mixing partition that permit fluid communication from at least one fluid stream to another, wherein the mixing partition has a proximal end closest to the sources and a distal end distant from the sources, wherein the at least one opening is located between a point above at least one drainage box and the distal end of the mixing partition;

iii) collecting first and second fibers on the receiving region situated downstream from the first and second sources, the receiving region configured to receive the combined first and second fluid streams and form a wet layer by collecting the first and second fibers from the combined fluid stream;

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