Enhanced co-formed meltblown fibrous web

Patent metadata

Field	Value
Publication number	US-10889922-B2
Application number	US-201615197878-A
Country	US
Kind code	B2
Filing date	Jun 30, 2016
Priority date	Jun 30, 2015
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

An enhanced, co-formed fibrous web structure is disclosed. The web structure may have a co-formed core layer sandwiched between two scrim layers. The core layer may be formed of a blend of cellulose pulp fibers and melt spun filaments. The scrim layers may be formed of melt spun filaments. Filaments of one or both of the scrim layers, and optionally the core layer, may also be meltblown filaments. The core layer may include consolidated masses of cellulose pulp fibers to, for example, enhance texture and cleaning efficacy of a wet wipe made from the structure. The material forming the consolidated masses may be selected and/or processed so as to cause the masses to have reduced visual discernibility relative the surrounding areas of the structure, when the fibrous web structure is wetted. A method for forming the structure, including formation and inclusion of the consolidated masses, is also disclosed.

First claim

What is claimed is:

1. A method for manufacturing a fibrous web structure, comprising the steps of:
melt spinning first polymer filaments and laying down the first polymer filaments on a moving belt without cellulose pulp fibers, thereby forming a first scrim layer of polymer filaments on the belt;
defibrating first cellulose pulp dry lap sheets in a first defibrating apparatus, to produce first cellulose pulp fibers;
incompletely defibrating second cellulose pulp dry lap sheets in the first defibrating apparatus or a second defibrating apparatus, to produce incompletely defibrated consolidated masses of second cellulose pulp fibers;
entraining the first cellulose pulp fibers and the consolidated masses in an air stream;
directing the first cellulose pulp fibers and the consolidated masses into a fiber spreader;
melt spinning second polymer filaments, blending the second polymer filaments with the first cellulose pulp fibers and the consolidated masses in co-forming equipment comprising a co-form box, and directing the blend of second polymer filaments, first cellulose pulp fibers and consolidated masses at the belt and the first scrim layer, to form a core layer overlying the first scrim layer, wherein the first scrim layer is disposed on a first side of the core layer;
downstream of the core layer forming step, melt spinning third polymer filaments and directing the third polymer filaments at the belt and the core layer, thereby forming a second scrim layer overlying the core layer, wherein the second scrim layer is disposed on a second side of the core layer, wherein one or both of the first melt spun polymer filaments and third melt spun polymer filaments are mist quenched following spinning and prior to formation of the respective scrim layer(s);
conveying the first scrim layer, overlying core layer, and overlying second scrim layer into the nip between a pair of calendar rollers, at least one of the rollers having thereon a pattern of bonding protrusions, the rollers having a source of heating energy supplied at the nip;
compressing the layers in the nip and beneath the bonding protrusions to form a pattern of thermal bonds bonding the scrim layers to and thereby complete the fibrous web structure; and
dividing the fibrous nonwoven structure into sheets, gathering the sheets into a supply of wipes, and wetting the wipes with a liquid composition to form a supply of wet wipes.

2. The method of claim 1 wherein the core layer forming step is repeated in successive configurations of co-forming equipment, and wherein the successive configurations increase the basis weight of the core layer.

3. The method of claim 1 wherein the one or more of the first, second or third melt spun polymer filaments comprise meltblown filaments.

4. The method of claim 3 wherein one or both of the first and second scrim layers comprise meltblown polymer filaments.

5. The method of claim 1 wherein the second cellulose pulp fibers comprise hardwood pulp fibers.

6. The method of claim 1 wherein the bonding protrusions have a bonding area percentage of from 2% to 12%.

7. The method of claim 1 comprising the step of folding and/or stacking the sheets to form a stack supply of wipes having a rectangular cuboid form.

8. A method for manufacturing a fibrous web structure, comprising the steps of:
defibrating first cellulose pulp dry lap sheets in a first defibrating apparatus, to produce first cellulose pulp fibers;
incompletely defibrating second cellulose pulp dry lap sheets in the first defibrating apparatus or a second defibrating apparatus, to produce incompletely defibrated consolidated masses of second cellulose pulp fibers;
entraining the first cellulose pulp fibers and the consolidated masses in a single air stream;
melt spinning first polymer filaments, blending the first polymer filaments with the first cellulose pulp fibers and the consolidated masses in co-forming equipment comprising a co-form box, and directing the blend of first polymer filaments, first cellulose pulp fibers and consolidated masses at a first moving belt, to form a core layer;
melt spinning second polymer filaments and directing the second polymer filaments toward the moving belt carrying the core layer, and directly forming a first scrim layer of melt spun second polymer filaments directly over the core layer, on one a first side of the core layer;

releasing the core layer and the overlying first scrim layer from the moving belt, passing the core layer and the first scrim layer to a second moving belt such that the first scrim layer is in facing contact with the second moving belt;
melt spinning third polymer filaments, directing the third polymer filaments toward the second moving belt that is carrying the core layer and the first scrim layer, and forming a second scrim layer of third polymer filaments directly over the core layer, on the second side of the core layer;
bringing a second scrim layer comprising third melt spun polymer filaments into facing contact with the core layer on the other side of the core layer;
conveying the first scrim layer, core layer, and second scrim layer together into the nip between a pair of calender rollers, at least one of the calender rollers having thereon a pattern of bonding protrusions, with a source of heat energy supplied at the nip;
compressing the layers in the nip and beneath the bonding protrusions to form a pattern of thermal bonds bonding the scrim layers to, and thereby complete, the fibrous web structure; and

dividing the fibrous nonwoven structure into sheets, gathering the sheets into a supply of wipes, and wetting the wipes with a liquid composition to form a supply of wet wipes.

9. The method of claim 8 wherein the core layer, the first scrim layer and the second scrim layer are formed in a single pass.

10. The method of claim 8 wherein the core layer forming step is repeated in successive configurations of co-forming equipment, and wherein the successive configurations increase the basis weight of the core layer.

11. The method of claim 8 wherein the one or more of the first, second or third melt spun polymer filaments comprise meltblown filaments.

12. The method of claim 11 wherein one or both of the first and second scrim layers comprise meltblown polymer filaments.

13. The method of claim 8 wherein one or both of the second melt spun polymer filaments and third melt spun polymer filaments are mist quenched following spinning and prior to formation of the respective scrim layer(s).

14. The method of claim 8 wherein the second cellulose pulp fibers comprise hardwood pulp fibers.

15. The method of claim 8 wherein the bonding protrusions have a bonding area percentage of from 2% to 12%.

16. The method of claim 8 comprising the step of folding and/or stacking the sheets to form a stack supply of wipes having a rectangular cuboid form.

Assignees

• Procter & Gamble

Inventors

• Castillo Mario
• Barnholtz Steven Lee
• Burt Adam James
• Morison Pamela Marie

Classifications

• B32B5/022 Primary

  Non-woven fabric · CPC title

• D21H1/00

  Paper; Cardboard (fibreboard D21J) · CPC title

• D04H1/56

  in association with fibre formation, e.g. immediately following extrusion of staple fibres · CPC title

• B32B2432/00

  Cleaning articles, e.g. mops or wipes · CPC title

• B32B2307/726

  Permeability to liquids, absorption · CPC title