Methods and apparatus for producing nonwoven fibrous webs

Patent metadata

Field	Value
Publication number	US-9422653-B2
Application number	US-201214368549-A
Country	US
Kind code	B2
Filing date	Dec 20, 2012
Priority date	Dec 30, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

Methods and apparatus including a chamber having a substantially open lower end positioned above a collector surface, at least one fiber inlet positioned above the lower end, a first multiplicity of rollers positioned within the chamber wherein each roller has a multiplicity of projections extending outwardly from a circumferential surface surrounding a center axis of rotation, a second multiplicity of rollers positioned within the chamber above the first multiplicity of rollers wherein each of the second multiplicity of rollers has a multiplicity of projections extending outwardly from a circumferential surface surrounding a center axis of rotation, the second multiplicity of rollers positioned so at least a portion of the projections extending outwardly from the circumferential surfaces of each of the second multiplicity of rollers vertically overlaps with at least a portion of the projections extending outwardly from the circumferential surface of at least one of the first multiplicity of rollers.

First claim

The invention claimed is:

1. An apparatus comprising:
a fiber opening chamber having an upper end and a substantially open lower end;
a fiber inlet for introducing a plurality of fibers into the fiber opening chamber;
a first plurality of rollers positioned within the fiber opening chamber, each of the first plurality of rollers having a center axis of rotation, a circumferential surface surrounding the center axis of rotation, and a plurality of projections extending outwardly from the circumferential surface; and
a forming chamber having an upper end and a lower end, wherein the upper end of the forming chamber is in flow communication with the upper end of the opening chamber, and the lower end of the forming chamber is substantially open and positioned above a collector having a collector surface.

2. The apparatus according to claim 1 , further comprising a stationary screen positioned within the forming chamber above the collector surface.

3. The apparatus of any one of claim 1 , further comprising a second plurality of rollers positioned within the opening chamber above the first plurality of rollers, each of the second plurality of rollers having a center axis of rotation, a circumferential surface surrounding the center axis of rotation, and a plurality of projections extending outwardly from the circumferential surface.

4. The apparatus of claim 3 , wherein each of the first plurality of rollers is aligned in a horizontal plane extending through the center axis of rotation of each of the first plurality of rollers, or each of the second plurality of rollers is aligned in a horizontal plane extending through the center axis of rotation of each of the second plurality of rollers, or both each of the first plurality of rollers is aligned in a horizontal plane extending through the center axis of rotation of each of the first plurality of rollers and each of the second plurality of rollers is aligned in a horizontal plane extending through the center axis of rotation of each of the second plurality of rollers.

5. The apparatus of claim 4 , wherein each of the second plurality of rollers rotates in a direction which opposite to a direction of rotation for each adjacent roller in the horizontal plane extending through each center axis of rotation of the second plurality of rollers.

6. The apparatus of claim 3 , wherein the center axis of rotation for one of each of the first plurality of rollers is vertically aligned with the center axis of rotation for a corresponding roller selected from the second plurality of rollers in a plane extending through the center axis of rotation for the one of the first plurality of rollers and the corresponding roller selected from the second plurality of rollers.

7. The apparatus of claim 6 , wherein each one of the first plurality of rollers rotates in a direction which is opposite to a direction of rotation for each adjacent roller in the horizontal plane extending through the center axis of rotation of each of the first plurality of rollers, and further wherein each of the first plurality of rollers rotates in a direction which is opposite to a direction of rotation for each corresponding roller selected from the second plurality of rollers, optionally wherein the fiber inlet is positioned to introduce the fibers into the lower end of the opening chamber above the first plurality of rollers.

8. The apparatus of claim 4 , wherein each of the second plurality of rollers rotates in a direction which is the same as a direction of rotation for each adjacent roller in the horizontal plane extending through each center axis of rotation of the second plurality of rollers.

9. The apparatus of claim 8 , wherein the center axis of rotation for one of each of the first plurality of rollers is vertically aligned with the center axis of rotation for a corresponding roller selected from the second plurality of rollers in a plane extending through the center axis of rotation for the one of the first plurality of rollers and the corresponding roller selected from the second plurality of rollers, wherein each one of the first plurality of rollers rotates in a direction which is opposite to a direction of rotation for each adjacent roller in the horizontal plane extending through the center axis of rotation of each of the first plurality of roller, optionally wherein the fiber inlet is positioned below the first plurality of rollers.

10. The apparatus according to claim 3 , wherein each projection has a length, and further wherein at least a portion of at least one projection of each of the first plurality of rollers lengthwise overlaps with at least a portion of at least one projection of one of the second plurality of rollers.

11. The apparatus according to claim 10 , wherein the lengthwise overlap corresponds to at least 90% of the length of at least one of the overlapping projections.

12. The apparatus according to claim 10 , wherein at least a portion of one projection of each of the second plurality of rollers lengthwise overlaps with at least a portion of one projection of an adjacent roller of the second plurality of rollers.

13. The apparatus according to claim 12 , wherein the lengthwise overlap corresponds to at least 90% of the length of at least one of the overlapping projections.

14. The apparatus according to claim 10 , wherein at least a portion of at least one projection of each of the first plurality of rollers lengthwise overlaps with at least a portion of at least one projection of an adjacent roller of the first plurality of rollers.

15. The apparatus according to claim 14 , wherein the lengthwise overlap corresponds to at least 90% of the length of at least one of the overlapping projections.

16. A method for making a nonwoven fibrous web, comprising:
providing an apparatus including:
a chamber having an upper end and a substantially open lower end positioned above a collector having a collector surface;
at least one fiber inlet positioned above the lower end of the chamber;
a first plurality of rollers positioned within the chamber, each of the first plurality of rollers having a center axis of rotation, a circumferential surface, and a plurality of projections extending outwardly from the circumferential surface;
a second plurality of rollers positioned within the chamber above the first plurality of rollers, each of the second plurality of rollers having a center axis of rotation, a circumferential surface, and a plurality of projections extending outwardly from the circumferential surface,

wherein the second plurality of rollers is positioned relative to the first plurality of rollers such that at least a portion of the plurality of projections extending outwardly from the circumferential surface of each of the second plurality of rollers vertically overlaps with at least a portion of the plurality of projections extending outwardly from the circumferential surface of at least one of the first plurality of rollers;
introducing a plurality of fibers into the upper end of the chamber;
dispersing the plurality of fibers as discrete, substantially non-agglomerated fibers in a gas phase;
introducing a plurality of particulates into the chamber;
mixing the plurality of discrete, substantially non-agglomerated fibers with the plurality of particulates within the chamber to form a mixture of the discrete, substantially non-agglomerated fibers and the particulates before collecting the mixture as a nonwoven fibrous web on the collector surface; and
securing at least a portion of the particulates to the nonwoven fibrous web.

17. The metho

Assignees

• 3M Innovative Properties Co

Inventors

• Wu Tien T
• Henderson John W
• Castro Gustavo H
• Hoffdahl Gerry A
• Vall David L

Classifications

• D04H1/4382

  Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather · CPC title

• D04H1/541

  Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres · CPC title

• D04H1/732 Primary

  by fluid current, e.g. air-lay · CPC title

• D04H1/413

  containing granules other than absorbent substances · CPC title

• D04H1/736

  characterised by the apparatus for arranging fibres (D04H1/728, D04H1/732 take precedence) · CPC title