U.S. patent number RE42,968 [Application Number 13/048,002] was granted by the patent office on 2011-11-29 for fibrous structure product with high softness.
This patent grant is currently assigned to the Procter & Gamble Company. Invention is credited to Markus Wilhelm Altmann, Robert Stanley Ampulski, Osman Polat, Jeffrey Glen Sheehan.
United States Patent |
RE42,968 |
Sheehan , et al. |
November 29, 2011 |
Fibrous structure product with high softness
Abstract
A multiply fibrous structure product having two or more plies of
fibrous structure wherein the fibrous structure has a Compression
Slope from about 11 to about 30; a basis weight from about 26
lbs/3000 ft.sup.2 to about 50 lbs/3000 ft.sup.2; a Wet Caliper
greater than about 18 mils; and a Flex Modulus from about 0.1 to
about 0.8.
Inventors: |
Sheehan; Jeffrey Glen
(Cincinnati, OH), Altmann; Markus Wilhelm (Cincinnati,
OH), Polat; Osman (Montgomery, OH), Ampulski; Robert
Stanley (Fairfield, OH) |
Assignee: |
the Procter & Gamble
Company (Cincinnati, OH)
|
Family
ID: |
38668316 |
Appl.
No.: |
13/048,002 |
Filed: |
March 15, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60797244 |
May 3, 2006 |
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Reissue of: |
11799732 |
May 2, 2007 |
7744723 |
Jun 29, 2010 |
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Current U.S.
Class: |
162/123; 162/179;
162/158; 162/117; 162/111; 428/156; 428/172 |
Current CPC
Class: |
D21H
27/005 (20130101); Y10T 428/24612 (20150115); D21H
21/22 (20130101); D21H 11/12 (20130101); Y10T
428/249926 (20150401); Y10T 428/24479 (20150115) |
Current International
Class: |
D21H
27/00 (20060101); D04H 13/00 (20060101); B32B
5/00 (20060101) |
Field of
Search: |
;162/109,117,123-133,204-206,111-113,158,179
;428/153,156,172,340 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
617164 |
|
Aug 1997 |
|
EM |
|
631014 |
|
Oct 1997 |
|
EM |
|
806520 |
|
Nov 1997 |
|
EM |
|
568404 |
|
Dec 1997 |
|
EM |
|
938609 |
|
Mar 2003 |
|
EM |
|
0 342 646 |
|
Nov 1989 |
|
EP |
|
0 617 164 |
|
Aug 1997 |
|
EP |
|
0 631 014 |
|
Oct 1997 |
|
EP |
|
0 806 520 |
|
Nov 1997 |
|
EP |
|
0 568 404 |
|
Dec 1997 |
|
EP |
|
0 938 609 |
|
Mar 2003 |
|
EP |
|
1 212 473 |
|
Nov 1970 |
|
GB |
|
1212473 |
|
Aug 1975 |
|
GB |
|
1 533 045 |
|
Nov 1978 |
|
GB |
|
1533045 |
|
Nov 1978 |
|
GB |
|
2001370 |
|
Jan 1979 |
|
GB |
|
2006296 |
|
May 1979 |
|
GB |
|
2303647 |
|
Feb 1997 |
|
GB |
|
2304123 |
|
Mar 1997 |
|
GB |
|
05023262 |
|
Feb 1993 |
|
JP |
|
WO 9423128 |
|
Oct 1994 |
|
WO |
|
WO 9606223 |
|
Feb 1996 |
|
WO |
|
WO 9609435 |
|
Mar 1996 |
|
WO |
|
WO 9932722 |
|
Jul 1999 |
|
WO |
|
WO 00/47097 |
|
Aug 2000 |
|
WO |
|
WO 0047097 |
|
Aug 2000 |
|
WO |
|
WO 2005080677 |
|
Sep 2005 |
|
WO |
|
WO 2006133390 |
|
Dec 2006 |
|
WO |
|
WO 2007130540 |
|
Nov 2007 |
|
WO |
|
WO 2007130541 |
|
Nov 2007 |
|
WO |
|
WO 2007139851 |
|
Dec 2007 |
|
WO |
|
WO 2008050311 |
|
May 2008 |
|
WO |
|
Other References
International Search report dated Jan. 7, 2008. cited by examiner
.
U.S. Appl. No. 11/799,639, filed May 2, 2007, Sheehan, et al. cited
by examiner .
Horn, et al., "Fiber Morphology and New Crops", Timber Press, pp.
270-275 (1990). cited by examiner.
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Primary Examiner: Fortuna; Jose A
Attorney, Agent or Firm: Bullock; Roddy
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application
No. 60/797,244 filed on May 3, 2006.
Claims
What is claimed is:
1. A multiply fibrous structure product comprising: two or more
plies of fibrous structure wherein the fibrous structure has a
Compression Slope from .[.about 11.]. .Iadd.12 .Iaddend.to about
30; a basis weight from .[.about 26.]. .Iadd.28 .Iaddend.lbs/3000
ft.sup.2 to about 50 lbs/3000 ft.sup.2; a Wet Caliper of greater
than about 18 mils; and a Flex Modulus from about 0.1 to about
0.8.
2. The product of claim 1 wherein the Compression Slope is from
about 12 to about 25.
3. The product of claim 1 wherein the basis weight is from 27
lbs/3000 ft.sup.2 to about 40 lbs/3000 ft.sup.2.
4. The product of claim 3 wherein the basis weight is from 30
lbs/3000 ft.sup.2 and about 40 lbs/3000 ft.sup.2.
5. The product of claim 1 wherein the Flex Modulus is from about
0.2 to about 0.75.
6. The product of claim 5 wherein the Flex Modulus is from about
0.3 to about 0.7.
7. The product of claim 1 wherein at least one of the plies
comprises a plurality of domes formed during the papermaking
process wherein the ply comprises from about 10 to about 1000 domes
per square inch of the ply.
8. The product of claim 7 wherein the ply comprises from about 50
to about 300 domes per square inch of the ply.
9. The product of claim 7 wherein the fibrous substrate comprises
from about 8% to about 60% of eucalyptus fibers.
10. The product of claim 7 further comprising a sheet caliper of at
least about 29 mils.
11. The product of claim 10 wherein the sheet caliper is from about
30 mils to about 50 mils.
12. The product of claim 11 wherein the sheet caliper of from about
33 mils to about 45 mils.
13. The product of claim 7 wherein at least one of the plies is
selected from the group consisting of: creped or uncreped
through-air-dried fibrous structure plies, differential density
fibrous structure plies, wet laid fibrous structure plies, air laid
fibrous structure plies, conventional wet-pressed fibrous structure
plies and mixtures thereof.
14. The product of claim 13 wherein the ply comprises a creped
through-air dried paper.
15. The product of claim 1 wherein the Wet Caliper is from about 22
mils to about 35 mils.
16. The product of claim 15 wherein the Wet Caliper is from about
28 mils to about 30 mils.
17. The product of claim 1 wherein the fibrous structure product
further comprises a chemical softening agent at a level from about
0.05 lbs/ton to about 6 lbs/ton, of furnish.
18. The product of claim 17 wherein the chemical softening agent is
selected from the group consisting of quaternary ammonium
compounds, organo-reactive polydimethyl siloxane compounds, and
mixtures thereof.
19. The product of claim 18 wherein the chemical softening compound
is selected from the group consisting of dialkyldimethylamnmonium
salts, ditallowdimethylammonium chloride, ditallowdimethylammonium
methyl sulfate, di(hydrogenated tallow)dimethyl ammonium chloride,
mono or diester variations of the dialkyldimethylammonium, and
mixtures thereof.
20. The product of claim 1 wherein at least one of the plies has a
plurality of embossments.
21. The product of claim 1 wherein only one of the plies has a
plurality of embossments.
22. The product of claim 1 wherein the product is two ply wherein
both plies comprise a plurality of embossments.
23. A fibrous structure product comprising: one ply of fibrous
structure wherein the fibrous structure has a Compression Slope
from about 11 to about 30; a basis weight from about 28 lbs/3000
ft.sup.2 to about 50 lbs/3000 ft.sup.2; a Wet Caliper from about 18
mils to about 40 mils; and a Flex Modulus from about 0.1 to about
0.8.
24. The product of claim 23 wherein the Compression Slope is from
about 12 to about 25.
25. The product of claim 23 wherein the basis weight is from 27
lbs/3000 ft.sup.2 to about 40 lbs/3000 ft.sup.2.
26. The product of claim 25 wherein the basis weight is from 30
lbs/3000 ft.sup.2 and about 40 lbs/3000 ft.sup.2.
27. The product of claim 23 wherein the Flex Modulus is from about
0.2 to about 0.75.
28. The product of claim 27 wherein the Flex Modulus is from about
0.3 to about 0.7.
29. The product of claim 23 comprising a plurality of domes formed
during the papermaking process wherein the ply comprises from about
10 to about 1000 domes per square inch of the ply.
30. The product of claim 29 wherein the ply comprises from about 50
to about 300 domes per square inch of the ply.
31. The product of claim 23 wherein the fibrous substrate comprises
from about 8% to about 60% of eucalyptus fibers.
32. The product of claim 23 wherein the Wet Caliper is from about
22 mils to about 3 mils.
33. The product of claim 32 wherein the Wet Caliper is from about
28 mils to about 30 mils.
34. The product of claim 23 further comprising a sheet caliper of
at least about 29 mils.
35. The product of claim 34 wherein the sheet caliper is from about
30 mils to about 50 mils.
36. The product of claim 35 wherein the sheet caliper of from about
33 mils to about 45 mils.
37. The product of claim 23 wherein the fibrous structure product
further comprises a chemical softening agent at a level from about
0.05 lbs/ton to about 6 lbs/ton, of furnish.
38. The product of claim 23 wherein the ply is selected from the
group consisting of: creped or uncreped through-air-dried fibrous
structure ply, differential density fibrous structure ply, wet laid
fibrous structure ply, air laid fibrous structure ply, or
conventional wet-pressed fibrous structure ply.
39. The product of claim 38 wherein the ply comprises a creped
through-air dried paper.
40. The product of claim 23 comprising a plurality of embossments.
Description
FIELD OF THE INVENTION
The present invention relates to fibrous structure products, more
specifically multi-ply fibrous structure products having multiple
enhanced attributes and methods of making the same.
BACKGROUND OF THE INVENTION
Cellulosic fibrous structures are a staple of everyday life.
Cellulosic fibrous structures are used as consumer products for
paper towels, toilet tissue, facial tissue, napkins, and the like.
The large demand for such paper products has created a demand for
improved versions of the products and the methods of their
manufacture.
Consumers prefer cellulosic fibrous structure products having
multiple attributes. These attributes include softness, absorbency,
strength, flexibility, and bulk. Consumers may especially prefer
fibrous structure products having improved softness. Softness is
the pleasing tactile sensation consumers perceive when they handle
the product in their hands and while using the paper for its
intended purpose. Consumers also desire products that will be
useful for a broad variety of cleaning tasks including any type of
surface from the cleaning of floors, countertops, drying dishes to
the cleaning of faces, hands, arms, etc. Softness is generally a
function of the compressibility of the paper, the flexibility of
the paper, and the surface smoothness. These attributes may
communicate to the consumer that the product will be versatile and
that the product will be useful for a variety of cleaning tasks and
surfaces.
Usually, however, the improvement of one attribute, may compromise
the quality of another attribute. For example, increasing the
softness of the fibrous structure product may decrease the
absorbency, strength, and/or bulk of the product. Therefore,
providing a product with improved softness and therefore an
improved impression of product versatility without sacrificing the
strength, bulk, and/or absorbency of the product is difficult.
Hence, the present invention unexpectedly provides an aesthetically
pleasing soft and flexible tissue/towel product while also
providing strength, bulk, and/or absorbency. The present invention
provides a fibrous structure that exhibits a particular Flex
Modulus, basis weight, and Compression Slope relationship, as
described herein, which unexpectedly provides a product with
enhanced softness without sacrificing strength, bulk, and/or
absorbency attributes.
SUMMARY OF THE INVENTION
The present invention relates to a fibrous structure product
comprising: two or more plies of fibrous structure wherein the
fibrous structure has a Compression Slope from about 11 to about
30; a basis weight from about 26 lbs/3000 ft.sup.2 to about 50
lbs/3000 ft.sup.2; a Wet Caliper of greater than about 18 mils; and
a Flex Modulus from about 0.1 to about 0.8.
The present invention further relates to a fibrous structure
product comprising: one ply of fibrous structure wherein the
fibrous structure has a Compression Slope from about 11 to about
30; a basis weight from about 28 lbs/3000 ft.sup.2 to about 50
lbs/3000 ft.sup.2; a Wet Caliper greater than about 18 mils; and a
Flex Modulus from about 0.1 to about 0.8.
BRIEF DESCRIPTION OF THE DRAWINGS
Without intending to limit the invention, embodiments are described
in more detail below:
FIG. 1 is a fragmentary plan view of a multi-ply fibrous structure
product displaying an embodiment of the present invention having
domes formed during the paper making process, in a regular
arrangement, and an embossment pattern on the first ply made
according to the present invention.
FIG. 2 is a cross sectional view of a portion of the multi-py
fibrous structure product shown in FIG. 1 as taken along line
2-2.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
As used herein, "paper product" refers to any formed, fibrous
structure products, traditionally, but not necessarily, comprising
cellulose fibers. In one embodiment, the paper products of the
present invention include tissue-towel paper products.
A "tissue-towel paper product" refers to products comprising paper
tissue or paper towel technology in general, including, but not
limited to, conventional felt-pressed or conventional wet-pressed
tissue paper, pattern densified tissue paper, starch substrates,
and high bulk, uncompacted tissue paper. Non-limiting examples of
tissue-towel paper products include toweling, facial tissue, bath
tissue, table napkins, and the like.
"Ply" or "Plies", as used herein, means an individual fibrous
structure or sheet of fibrous structure, optionally to be disposed
in a substantially contiguous, face-to-face relationship with other
plies, forming a multi-ply fibrous structure. It is also
contemplated that a single fibrous structure can effectively form
two "plies" or multiple "plies", for example, by being folded on
itself. In one embodiment, the ply has an end use as a tissue-towel
paper product. A ply may comprise one or more wet-laid layers,
air-laid layers, and/or combinations thereof. If more than one
layer is used, it is not necessary for each layer to be made from
the same fibrous structure. Further, the fibers may or may not be
homogenous within a layer. The actual makeup of a tissue paper ply
is generally determined by the desired benefits of the final
tissue-towel paper product, as would be known to one of skill in
the art. The fibrous structure may comprise one or more plies of
non-woven materials in addition to the wet-laid and/or air-laid
plies.
The term "fibrous structure", as used herein, means an arrangement
of fibers produced in any papermaking machine known in the art to
create a ply of paper. "Fiber" means an elongate particulate having
an apparent length greatly exceeding its apparent width. More
specifically, and as used herein, fiber refers to such fibers
suitable for a papermaking process.
"Basis Weight", as used herein, is the weight per unit area of a
sample reported in lbs/3000 ft.sup.2 or g/m.sup.2.
"Machine Direction" or "MD", as used herein, means the direction
parallel to the flow of the fibrous structure through the
papermaking machine and/or product manufacturing equipment.
"Cross Machine Direction" or "CD", as used herein, means the
direction perpendicular to the machine direction in the same plane
of the fibrous structure and/or fibrous structure product
comprising the fibrous structure.
"Sheet Caliper" or "Caliper", as used herein, means the macroscopic
thickness of a product sample under load.
"Densified", as used herein, means a portion of a fibrous structure
product that is characterized by having a relatively high-bulk
field of relatively low fiber density and an array of densified
zones of relatively high fiber density. The high-bulk field is
alternatively characterized as a field of pillow regions. The
densified zones are alternatively referred to as knuckle regions.
The densified zones may be discretely spaced within the high-bulk
field or may be interconnected, either fully or partially, within
the high-bulk field. One embodiment of a method of making a pattern
densified fibrous structure and devices used therein are described
in U.S. Pat. Nos. 4,529,480 and 4,528,239.
"Non-densified", as used herein, means a portion of a fibrous
structure product that exhibits a lesser density than another
portion of the fibrous structure product.
"Bulk Density", as used herein, means the apparent density of an
entire fibrous structure product rather than a discrete area
thereof.
"Laminating" refers to the process of firmly uniting super-imposed
layers of paper with or without adhesive, to form a multi-ply
sheet.
"Non-naturally occurring fiber" as used herein means that the fiber
is not found in nature in that form. In other words, some chemical
processing of materials needs to occur in order to obtain the
non-naturally occurring fiber. For example, a wood pulp fiber is a
naturally occurring fiber, however, if the wood pulp fiber is
chemically processed, such as via a lyocell-type process, a
solution of cellulose is formed. The solution of cellulose may then
be spun into a fiber. Accordingly, this spun fiber would be
considered to be a non-naturally occurring fiber since it is not
directly obtainable from nature in its present form.
"Naturally occurring fiber" as used herein means that a fiber
and/or a material is found in nature in its present form. An
example of a naturally occurring fiber is a wood pulp fiber.
Fibrous Structure Product
In one embodiment the fibrous structure product has a Compression
Slope of from about 11 to about 30; in another embodiment from
about 12 to about 25, and in yet another embodiment from about 13
to about 25 or about 13 to about 23.
In one embodiment, the fibrous structure product has a basis weight
of greater than about 26 lbs/3000 ft.sup.2, in another embodiment
from about 26 lbs/3000 ft.sup.2 to about 50 lbs/3000 ft.sup.2. In
another embodiment the basis weight is about 27 lbs/3000 ft.sup.2
to about 40 lbs/3000 ft.sup.2; in another embodiment the basis
weight is about 30 lbs/3000 ft.sup.2 and about 40 lbs/3000 ft.sup.2
and in another embodiment the basis weight is about 32 lbs/3000
ft.sup.2 and about 37 lbs/3000 ft.sup.2.
In one embodiment the fibrous structure product has a Wet Caliper
of greater than about 18 mils or greater than about 25 mils; in
another embodiment from about 18, 22, 27, 28 mils to about 30, 32,
35, 40 mils, or any combination of these ranges.
In one embodiment the fibrous structure product has a Flex Modulus
from about 0.1 to about 0.8; in another embodiment from about 0.2
to about 0.75; and in another embodiment from about 0.3 to about
0.7.
In still yet another embodiment, the fibrous structure product
exhibits a sheet caliper or loaded caliper of at least about 29
mils, in another embodiment from about 30 mils to about 50 mils,
and/or from about 33 mils to about 45 mils.
In one embodiment the fibrous structure has a High Load Caliper of
from about 17 mils to about 45 mils; in another embodiment from
about 18 mils to about 30 mils; in another embodiment from about 19
mils to about 28 mils, and in another embodiment from about 20 mils
to about 25 mils.
In one embodiment the fibrous structure product exhibits a wet
burst strength of greater than about 270 grams, in another
embodiment from about 290 g, 300 g, 315 g to about 360 g, 380 g,
400 g, or any combination of these ranges. A nonlimiting example of
an embossed multi-ply fibrous structure product 100 in accordance
with the present invention is shown in FIG. 1. As shown in FIG. 1 a
fragmentary plan view of a ply of multi-ply fibrous structure 100
comprising two plies of fibrous structure wherein at least one of
the plies of the paper product has a plurality of domes 101 formed
by a resin coated woven belt during the papermaking process and
ordered in a regular arrangement. The domes may also be ordered in
a random arrangement. The exemplary multi-ply fibrous structure 100
further comprises a non geometric foreground pattern 103 of
embossments 102 on the first ply (may also be on the second ply)
according to the present invention. The embossments 102 form a
latticework, defining a plurality of unembossed cells 104; wherein
each cell comprises a plurality of domes 101 formed during the
papermaking process.
The multi-ply fibrous structure product 100 in accordance with
cross section 2-2 of FIG. 1 is shown in FIG. 2. As shown in FIG. 2,
the multi-ply fibrous structure product 100 comprises a first ply
201 and a second ply 202 that are bonded together by an adhesive
203 along the adjacent inside first-ply surface 207 and inside
second-ply surface 209 at first-ply bond sites 206. The multi-ply
fibrous structure product 100 further comprises embossments 102.
The cells 104 are not adhered to the adjacent ply. The cells 104
exhibit an embossment height, a, of from about 300 .mu.m to about
1500 .mu.m. The embossment height a extends in the Z-direction
which is perpendicular to the plan formed in the machine direction
and the cross machine direction of the multi-ply fibrous structure
product 100. In one embodiment of the present invention, the
multi-ply fibrous structure product 100 comprises an embossment
height a from about 300, 600, or 700 .mu.m to about 1,500 .mu.m,
and in another embodiment from about 800 .mu.m or to about 1,000
.mu.m as measured by the GFM MikroCAD optical profiler instrument
described according to U.S. Application Nos. 2006/0005916A1,
2006/0013998A1. The bond sites 206 may be densified or
non-densified
In one embodiment, because of the deformation caused by the
embossments 102 of the first ply 201, the extensibility of the
second ply 202 as compared to the first ply 201 constrains the
first ply from being elongated substantially in the cross machine
direction plane of the paper product. Suitable means of embossing
include those disclosed in U.S. Pat. Nos. 3,323,983, 5,468,323,
5,693,406, 5,972,466, 6,030,690 and 6,086,715.
As exemplified in FIGS. 1 and 2, the embossments on the present
invention multi-ply fibrous structure product 100 may be arranged
to form a non geometric foreground pattern 103 or, in some
embodiments, a curved latticework. The curved latticework of
embossments can form an outline of a foreground pattern of
unembossed cells in the latticework. The lines that substantially
describe each segment of the outline of the foreground pattern of
embossments that form the latticework can be, but are not limited
to, curved, wavy, snaking, S-waves, and sinusoidal. The latticework
may form regular or irregular patterns. In one embodiment of the
present invention, the embossments may be arranged to form one or
more non-geometric foreground patterns of unembossed cells wherein
no two cells are defined by the same embossments.
The present invention is equally applicable to all types of
consumer paper products such as paper towels, toilet tissue, facial
tissue, napkins, and the like.
The present invention contemplates the use of a variety of paper
making fibers, such as, natural fibers, synthetic fibers, as well
as any other suitable fibers, starches, and combinations thereof.
Paper making fibers useful in the present invention include
cellulosic fibers commonly known as wood pulp fibers. Applicable
wood pulps include chemical pulps, such as Kraft, sulfite and
sulfate pulps, as well as mechanical pulps including, groundwood,
thermomechanical pulp, chemically modified, and the like. Chemical
pulps may be used in tissue towel embodiments since they are known
to those of skill in the art to impart a superior tactical sense of
softness to tissue sheets made therefrom. Pulps derived from
deciduous trees (hardwood) and/or coniferous trees (softwood) can
be utilized herein. Such hardwood and softwood fibers can be
blended or deposited in layers to provide a stratified web.
Exemplary layering embodiments and processes of layering are
disclosed in U.S. Pat. Nos. 3,994,771 and 4,300,981. Additionally,
fibers derived from wood pulp such as cotton linters, bagesse, and
the like, can be used. Additionally, fibers derived from recycled
paper, which may contain any of all of the categories as well as
other non-fibrous materials such as fillers and adhesives used to
manufacture the original paper product may be used in the present
web. In addition, fibers and/or filaments made from polymers,
specifically hydroxyl polymers, may be used in the present
invention. Non-limiting examples of suitable hydroxyl polymers
include polyvinyl alcohol, starch, starch derivatives, chitosan,
chitosan derivatives, cellulose derivatives, gums, arabinans,
galactans, and combinations thereof. Additionally, other synthetic
fibers such as rayon, polyethylene, and polypropylene fibers can be
used within the scope of the present invention. Further, such
fibers may be latex bonded.
In one embodiment the paper is produced by forming a predominantly
aqueous slurry comprising about 95% to about 99.9% water. In one
embodiment the non-aqueous component of the slurry used to make the
fibrous structure comprises from about 5% to about 80% of
eucalpyptus fibers by weight. In another embodiment the non-aqueous
components comprises from about 8% to about 60% of eucalpyptus
fibers by weight, and in yet another embodiment from about 12% to
about 40% of eucalpyptus fibers by weight of the non-aqueous
component of the slurry. The aqueous slurry can be pumped to the
headbox of the papermaking process.
In one embodiment the present invention may comprise a co-formed
fibrous structure. A co-formed fibrous structure comprises a
mixture of at least two different materials wherein at least one of
the materials comprises a non-naturally occurring fiber, such as a
polypropylene fiber, and at least one other material, different
from the first material, comprising a solid additive, such as
another fiber and/or a particulate. In one example, a co-formed
fibrous structure comprises solid additives, such as naturally
occurring fibers, such as wood pulp fibers, and non-naturally
occurring fibers, such as polypropylene fibers.
Synthetic fibers useful herein include any material, such as, but
not limited to polymers, such as those selected from the group
consisting of polyesters, polypropylenes, polyethylenes,
polyethers, polyamides, polyhydroxyalkanoates, polysaccharides, and
combinations thereof. More specifically, the material of the
polymer segment may be selected from the group consisting of
poly(ethylene terephthalate), poly(butylene terephthalate),
poly(1,4-cyclohexylenedimethylene terephthalate), isophthalic acid
copolymers (e.g., terephthalate cyclohexylene-dimethylene
isophthalate copolymer), ethylene glycol copolymers (e.g., ethylene
terephthalate cyclohexylene-dimethylene copolymer),
polycaprolactone, poly(hydroxylether ester), poly(hydroxylether
amide), polyesteramide, poly(lactic acid), polyhydroxybutyrate, and
combinations thereof.
Further, the synthetic fibers can be a single component (i.e.,
single synthetic material or a mixture to make up the entire
fiber), bi-component (i.e., the fiber is divided into regions, the
regions including two or more different synthetic materials or
mixtures thereof and may include co-extruded fibers) and
combinations thereof. It is also possible to use bicomponent
fibers, or simply bicomponent or sheath polymers. Nonlimiting
examples of suitable bicomponent fibers are fibers made of
copolymers of polyester (polyethylene terephthalate)/polyester
(polyethylene terephthalate) otherwise known as "CoPET/PET" fibers,
which are commercially available from Fiber Innovation Technology,
Inc., Johnson City, Tenn.
These bicomponent fibers can be used as a component fiber of the
structure, and/or they may be present to act as a binder for the
other fibers present. Any or all of the synthetic fibers may be
treated before, during, or after the process of the present
invention to change any desired properties of the fibers. For
example, in certain embodiments, it may be desirable to treat the
synthetic fibers before or during the papermaking process to make
them more hydrophilic, more wettable, etc.
These multicomponent and/or synthetic fibers are further described
in U.S. Pat. Nos. 6,746,766, issued on Jun. 8, 2004; 6,946,506,
issued Sep. 20, 2005; 6,890,872, issued May 10, 2005; US
Publication No. 2003/0077444A1, published on Apr. 24, 2003; US
Publication No. 2003/0168912A1, published on Nov. 14, 2002; US
Publication No. 2003/0092343A1, published on May 15, 2003; US
Publication No. 2002/0168518A1, published on Nov. 14, 2002; US
Publication No. 2005/0079785A1, published on Apr. 14, 2005; US
Publication No. 2005/0026529A1, published on Feb.3, 2005; US
Publication No. 2004/0154768A1, published on Aug. 12, 2004; US
Publication No. 2004/0154767, published on Aug. 12, 2004; US
Publication No. 2004/0154769A1, published on Aug. 12, 2004; US
Publication No. 2004/0157524A1, published on Aug. 12, 2004; US
Publication No. 2005/0201965A1, published on Sep. 15, 2005.
The fibrous structure may comprise any tissue-towel paper product
known in the industry. Embodiment of these substrates may be made
according U.S. Pat. Nos. 4,191,609 issued Mar. 4, 1980 to Trokhan;
4,300,981 issued to Carstens on Nov. 17, 1981; 4,191,609 issued to
Trokhan on Mar. 4, 1980; 4,514,345 issued to Johnson et al. on Apr.
30, 1985; 4,528,239 issued to Trokhan on Jul. 9, 1985; 4,529,480
issued to Trokhan on Jul. 16, 1985; 4,637,859 issued to Trokhan on
Jan. 20, 1987; 5,245,025 issued to Trokhan et al. on Sep. 14, 1993;
5,275,700 issued to Trokhan on Jan. 4, 1994; 5,328,565 issued to
Rasch et al. on Jul. 12, 1994; 5,334,289 issued to Trokhan et al.
on Aug. 2, 1994; 5,364,504 issued to Smurkowski et al. on Nov. 15,
1995; 5,527,428 issued to Trokhan et al. on Jun. 18, 1996;
5,556,509 issued to Trokhan et al. on Sep. 17, 1996; 5,628,876
issued to Ayers et al. on May 13, 1997; 5,629,052 issued to Trokhan
et al. on May 13, 1997; 5,637,194 issued to Ampulski et al. on Jun.
10, 1997; 5,411,636 issued to Hermans et al. on May 2, 1995; EP
677612 published in the name of Wendt et al. on Oct. 18, 1995, and
U.S. Patent Application 2004/0192136A1 published in the name of
Gusky et al. on Sep. 30, 2004.
The tissue-towel substrates may be manufactured via a wet-laid
making process where the resulting web is through-air-dried or
conventionally dried. Optionally, the substrate may be
foreshortened by creping or by wet microcontraction. Creping and/or
wet microcontraction are disclosed in commonly assigned U.S. Pat.
Nos. 6,048,938 issued to Neal et al. on Apr. 11, 2000; 5,942,085
issued to Neal et al. on Aug. 24, 1999; 5,865,950 issued to Vinson
et al. on Feb. 2, 1999; 4,440,597 issued to Wells et al. on Apr. 3,
1984; 4,191,756 issued to Sawdai on May 4, 1980; and 6,187,138
issued to Neal et al. on Feb. 13, 2001.
Conventionally pressed tissue paper and methods for making such
paper are known in the art, for example U.S. Pat. No. 6,547,928
issued to Barnholtz et al. on Apr. 15, 2003. One suitable tissue
paper is pattern densified tissue paper which is characterized by
having a relatively high-bulk field of relatively low fiber density
and an array of densified zones of relatively high fiber density.
The high-bulk field is alternatively characterized as a field of
pillow regions. The densified zones are alternatively referred to
as knuckle regions. The densified zones may be discretely spaced
within the high-bulk field or may be interconnected, either fully
or partially, within the high-bulk field. Processes for making
pattern densified tissue webs are disclosed in U.S. Pat. No.
3,301,746, issued to Sanford, et al. on Jan. 31, 1967; U.S. Pat.
No. 3,974,025, issued to Ayers on Aug. 10, 1976; U.S. Pat. No.
4,191,609, issued to on Mar. 4, 1980; and U.S. Pat. No. 4,637,859,
issued to on Jan. 20, 1987; U.S. Pat. No. 3,301,746, issued to
Sanford, et al. on Jan. 31, 1967; U.S. Pat. No. 3,821,068, issued
to Salvucci, Jr. et al. on May 21, 1974; U.S. Pat. No. 3,974,025,
issued to Ayers on Aug. 10, 1976; U.S. Pat. No. 3,573,164, issued
to Friedberg, et al. on Mar. 30, 1971; U.S. Pat. No. 3,473,576,
issued to Amneus on Oct. 21, 1969; U.S. Pat. No. 4,239,065, issued
to Trokhan on Dec. 16, 1980; and U.S. Pat. No. 4,528,239, issued to
Trokhan on Jul. 9, 1985.
Uncompacted, non pattern-densified tissue paper structures are also
contemplated within the scope of the present invention and are
described in U.S. Pat. No. 3,812,000 issued to Joseph L. Salvucci,
Jr. et al. on May 21, 1974; and U.S. Pat. No. 4,208,459, issued to
Henry E. Becker, et al. on Jun. 17, 1980. Uncreped tissue paper as
defined in the art are also contemplated. The techniques to produce
uncreped tissue in this manner are taught in the prior art. For
example, Wendt, et al. in European Patent Application 0 677 612A2,
published Oct. 18, 1995; Hyland, et al. in European Patent
Application 0 617 164 Al, published Sep. 28, 1994; and Farrington,
et al. in U.S. Pat. No. 5,656,132 issued Aug. 12, 1997.
Uncreped tissue paper, in one embodiment, refers to tissue paper
which is non-compressively dried, by through air drying. Resultant
through air dried webs are pattern densified such that zones of
relatively high density are dispersed within a high bulk field,
including pattern densified tissue wherein zones of relatively high
density are continuous and the high bulk field is discrete. The
techniques to produce uncreped tissue in this manner are taught in
the prior art. For example, Wendt, et. al. in European Patent
Application 0 677 612A2, published Oct. 18, 1995; Hyland, et. al.
in European Patent Application 0 617 164 A1, published Sep. 28,
1994; and Farrington, et. al. in U.S. Pat. No. 5,656,132 published
Aug. 12, 1997.
Other materials are also intended to be within the scope of the
present invention as long as they do not interfere or counteract
any advantage presented by the instant invention.
The substrate which comprises the fibrous structure of the present
invention may be cellulosic, non-cellulosic, or a combination of
both. The substrate may be conventionally dried using one or more
press felts or through-air dried. If the substrate which comprises
the paper according to the present invention is conventionally
dried, it may be conventionally dried using a felt which applies a
pattern to the paper as taught by commonly assigned U.S. Pat. No.
5,556,509 issued Sep. 17, 1996 to Trokhan et al. and PCT
Application WO 96/00812 published Jan. 11, 1996 in the name of
Trokhan et al. The substrate which comprises the paper according to
the present invention may also be through air dried. A suitable
through air dried substrate may be made according to commonly
assigned U.S. Pat. No. 4,191,609.
Plurality of Domes
In one embodiment at least one ply of fibrous structure comprises a
plurality of domes formed during the papermaking process wherein
the ply comprises from about 10 to about 1000 (i.e.; about 1.55 to
about 155 domes per square centimeter) domes per square inch of the
ply. In another embodiment the ply comprises from about 25 to about
500 domes per square inch of the ply or product; in another
embodiment the ply comprises from about 50 to about 300 and in
another embodiment the ply comprises from about 120 to about 200 or
from about 130 to about 160 domes per square inch of the ply.
In one embodiment, the fibrous structure is through air dried on a
belt having a patterned framework. The belt according to the
present invention may be made according to any of commonly assigned
U.S. Pat. No. 4,637,859 issued Jan. 20, 1987 to Trokhan; U.S. Pat.
No. 4,514,345 issued Apr. 30, 1985 to Johnson et al.; U.S. Pat. No.
5,328,565 issued Jul. 12, 1994 to Rasch et al.; and U.S. Pat. No.
5,334,289 issued Aug. 2, 1994 to Trokhan et al. The belts that
result from the belt making techniques disclosed in the referenced
patents provide advantages over conventional belts in the art and
are herein referred to as resin coated woven belts.
In one embodiment, the patterned framework of the belt imprints a
pattern comprising an essentially continuous network onto the paper
and further has deflection conduits dispersed within the pattern.
The deflection conduits extend between opposed first and second
surfaces of the framework. The deflection conduits allow domes to
form in the paper.
In one embodiment, the fibrous substrate is a through air dried
paper made according to the foregoing patents and has a plurality
of domes formed during the papermaking process which are dispersed
throughout an essentially continuous network region. The domes
extend generally perpendicular to the paper and increase its
caliper. The domes generally correspond in geometry, and during
papermaking in position, to the deflection conduits of the belt
described above. There are an infinite variety of possible
geometries, shapes, and arrangements for the deflection conduits
and the domes formed in the paper therefrom. These shapes include
those disclosed in commonly assigned U.S. Pat. No. 5,275,700 issued
on Jan. 4, 1994 to Trokan. Examples of these shapes include, but
are not limited to those described as a bow-tie pattern or
snowflake pattern. Further examples of these shapes include, but
are not limited to, circles, ovals, diamonds, triangles, hexagons,
and various quadrilaterals.
The domes that form the essentially continuous network of domes
protrude outwardly from the plane of the paper due to molding into
the deflection conduits during the papermaking process. By molding
into the deflection conduits during the papermaking process, the
regions of the paper comprising the domes are deflected in the
Z-direction.
If the fibrous structure has domes, or other prominent features in
the topography, the domes, or other prominent feature, may be
arranged in a variety of different configurations. These
configurations include, but are not limited to: regular
arrangements, random arrangements, multiple regular arrangements,
and combinations thereof.
The fibrous structure product according to the present invention
having domes may be made according to commonly assigned U.S. Pat.
No. 4,528,239 issued Jul. 9, 1985 to Trokhan; U.S. Pat. No.
4,529,480 issued Jul. 16, 1985 to Trokhan; U.S. Pat. No. 5,275,700
issued Jan. 4, 1994 to Trokhan; U.S. Pat. No. 5,364,504 issued Nov.
15, 1985 to Smurkoski et al.; U.S. Pat. No. 5,527,428 issued Jun.
18, 1996 to Trokhan et al.; U.S. Pat. No. 5,609,725 issued Mar. 11,
1997 to Van Phan; U.S. Pat. No. 5,679,222 issued Oct. 21, 1997 to
Rasch et al.; U.S. Pat. No. 5,709,775 issued Jan. 20, 1995 to
Trokhan et al.; U.S. Pat. No. 5,795,440 issued Aug. 18, 1998 to
Ampulski et al.; U.S. Pat. No. 5,900,122 issued May 4, 1999 to
Huston; U.S. Pat. No. 5,906,710 issued May 25, 1999 to Trokhan;
U.S. Pat. No. 5,935,381 issued Aug. 10, 1999 to Trokhan et al.; and
U.S. Pat. No. 5,938,893 issued Aug. 17, 1999 to Trokhan et al.
In one embodiment the fibrous structure is made using the
papermaking belt as disclosed in U.S. Pat. No. 5,334,289, issued on
Aug. 2, 1994, Paul Trokhan and Glenn Boutilier.
In one embodiment the plies of the multi-ply fibrous structure may
be the same substrate respectively or the plies may comprise
different substrates combined to create desired consumer benefits.
In one embodiment the fibrous structures comprise two plies of
tissue substrate. In another embodiment the fibrous structure
comprises a first ply, a second ply, and at least one inner
ply.
In one embodiment of the present invention, the fibrous structure
product has a plurality of embossments. In one embodiment the
embossment pattern is applied only to the first ply, and therefore,
each of the two plies serve different objectives and are visually
distinguishable. For instance, the embossment pattern on the first
ply provides, among other things, improved aesthetics regarding
thickness and quilted appearance, while the second ply, being
unembossed, is devised to enhance functional qualities such as
absorbency, thickness and strength. In another embodiment the
fibrous structure product is a two ply product wherein both plies
comprise a plurality of embossments.
Suitable means of embossing include those disclosed in U.S. Pat.
Nos. 3,323,983 issued to Palmer on Sep. 8, 1964; 5,468,323 issued
to McNeil on Nov. 21, 1995; 5,693,406 issued to Wegele et al. on
Dec. 2, 1997; 5,972,466 issued to Trokhan on Oct. 26, 1999;
6,030,690 issued to McNeil et al. on Feb. 29, 2000; and 6,086,715
issued to McNeil on July 11.
Suitable means of laminating the plies include but are not limited
to those methods disclosed in commonly assigned U.S. Pat. Nos.
6,113,723 issued to McNeil et al. on Sep. 5, 2000; 6,086,715 issued
to McNeil on Jul. 11, 2000; 5,972,466 issued to Trokhan on Oct. 26,
1999; 5,858,554 issued to Neal et al. on Jan. 12, 1999; 5,693,406
issued to Wegele et al. on Dec. 2, 1997; 5,468,323 issued to McNeil
on Nov. 21, 1995; 5,294,475 issued to McNeil on Mar. 15, 1994.
The fibrous structure product may be in roll form. When in roll
form, the fibrous structure product may be wound about a core or
may be wound without a core.
Optional Ingredients
The multi-ply fibrous structure product herein may optionally
comprise one or more ingredients that may be added to the aqueous
papermaking furnish or the embryonic web. These optional
ingredients may be added to impart other desirable characteristics
to the product or improve the papermaking process so long as they
are compatible with the other components of the fibrous structure
product and do not significantly and adversely effect the
functional qualities of the present invention. The listing of
optional chemical ingredients is intended to be merely exemplary in
nature, and are not meant to limit the scope of the invention.
Other materials may be included as well so long as they do not
interfere or counteract the advantages of the present
invention.
A cationic charge biasing species may be added to the papermaking
process to control the zeta potential of the aqueous papermaking
furnish as it is delivered to the papermaking process. These
materials are used because most of the solids in nature have
negative surface charges, including the surfaces of cellulosic
fibers and fines and most inorganic fillers. In one embodiment the
cationic charge biasing species is alum. In addition charge biasing
may be accomplished by use of relatively low molecular weight
cationic synthetic polymer, in one embodiment having a molecular
weight of no more than about 500,000 and in another embodiment no
more than about 200,000, or even about 100,000. The charge
densities of such low molecular weight cationic synthetic polymers
are relatively high. These charge densities range from about 4 to
about 8 equivalents of cationic nitrogen per kilogram of polymer.
An exemplary material is Cypro 514.RTM., a product of Cytec, Inc.
of Stamford, Conn.
High surface area, high anionic charge microparticles for the
purposes of improving formation, drainage, strength, and retention
may also be included herein. See, for example, U.S. Pat. No.
5,221,435, issued to Smith on Jun. 22, 1993.
If permanent wet strength is desired, cationic wet strength resins
may be optionally added to the papermaking furnish or to the
embryonic web. From about 2 to about 50 lbs./ton of dry paper
fibers of the cationic wet strength resin may be used, in another
embodiment from about 5 to about 30 lbs./ton, and in another
embodiment from about 10 to about 25 lbs./ton.
The cationic wet strength resins useful in this invention include
without limitation cationic water soluble resins. These resins
impart wet strength to paper sheets and are well known to the paper
making art. These resins may impart either temporary or permanent
wet strength to the sheet. Such resins include the following
Hercules products. KYMENE.RTM. resins obtainable from Hercules
Inc., Wilmington, Del. may be used, including KYMENE.RTM. 736 which
is a polyethylene-imine (PEI) wet strength polymer. It is believed
that the PEI imparts wet strength by ionic bonding with the pulps
carboxyl sites. KYMENE.RTM. 557LX is polyamide epichlorohydrin
(PAE) wet strength polymer. It is believed that the PAE contains
cationic sites that lead to resin retention by forming an ionic
bond with the carboxyl sites on the pulp. The polymer contains
3-azetidinium groups which react to form covalent bonds with the
pulps' carboxyl sites as well as with the polymer backbone. The
product must undergo curing in the form of heat or undergo natural
aging for the reaction of the azentidinium group. KYMENE.RTM. 450
is a base activated epoxide polyamide epichlorohydrin polymer. It
is theorized that like 557LX the resin attaches itself ionically to
the pulps' carboxyl sites. The epoxide group is much more reactive
than the azentidinium group. The epoxide group reacts with both the
hydroxyl and carboxyl sites on the pulp, thereby giving higher wet
strengths. The epoxide group can also crosslink to the polymer
backbone. KYMENE.RTM. 2064 is also a base activated epoxide
polyamide epichlorohydrin polymer. It is theorized that KYMENE.RTM.
2064 imparts its wet strength by the same mechanism as KYMENE.RTM.
450. KYMENE.RTM. 2064 differs in that the polymer backbond contains
more epoxide functional groups than does KYMENE.RTM. 450. Both
KYMENE.RTM. 450 and KYMENE.RTM. 2064 require curing in the form of
heat or natural aging to fully react all the epoxide groups,
however, due to the reactiveness of the epoxide group, the majority
of the groups (80-90%) react and impart wet strength off the paper
machine. Mixtures of the foregoing may be used. Other suitable
types of such resins include urea-formaldehyde resins, melamine
formaldehyde resins, polyamide-epichlorohydrin resins,
polyethyleneimine resins, polyacrylamide resins, dialdehyde
starches, and mixtures thereof. Other suitable types of such resins
are described in U.S. Pat. No. 3,700,623, issued Oct. 24, 1972;
U.S. Pat. No. 3,772,076, issued Nov. 13, 1973; U.S. Pat. No.
4,557,801, issued Dec. 10, 1985 and U.S. Pat. No. 4,391,878, issued
Jul. 5, 1983.
In one embodiment, the cationic wet strength resin may be added at
any point in the processes, where it will come in contact with the
paper fibers prior to forming the wet web.
If enhanced absorbency is needed, surfactants may be used to treat
the paper webs of the present invention. The level of surfactant,
if used, in one embodiment, from about 0.01% to about 2.0% by
weight, based on the dry fiber weight of the tissue web. In one
embodiment the surfactants have alkyl chains with eight or more
carbon atoms. Exemplary anionic surfactants include linear alkyl
sulfonates and alkylbenzene sulfonates. Exemplary nonionic
surfactants include alkylglycosides including alkylglycoside esters
such as Crodesta SL40.RTM. which is available from Croda, Inc. (New
York. N.Y.); alkylglycoside ethers as described in U.S. Pat. No.
4,011,389, issued to Langdon, et al. on Mar. 8, 1977; and
alkylpolyethoxylated esters such as Pegosperse 200 ML available
from Glyco Chemicals, Inc. (Greenwich, Conn.) and IGEPAL
RC-520.RTM. available from Rhone Poulenc Corporation (Cranbury,
N.J.). Alternatively, cationic softener active ingredients with a
high degree of unsaturated (mono and/or poly) and/or branched chain
alkyl groups can greatly enhance absorbency.
In addition, chemical softening agents may be used. In one
embodiment the chemical softening agents comprise quaternary
ammonium compounds including, but not limited to, the well-known
dialkyldimethylammonium salts (e.g., ditallowedimethylammonium
chloride, ditallowedimethylammonium methyl sulfate ("DTDMAMS"),
di(hydrogenated tallow)dimethyl ammonium chloride, etc.). In
another embodiment variants of these softening agents include mono
or diester variations of the before mentioned
dialkyldimethylammonium salts and ester quaternaries made from the
reaction of fatty acid and either methyl diethanol amine and/or
triethanol amine, followed by quaternization with methyl chloride
or dimethyl sulfate.
Another class of papermaking-added chemical softening agents
comprises organo-reactive polydimethyl siloxane ingredients,
including the amino functional polydimethyl siloxane. The fibrous
structure product of the present invention may further comprise a
diorganopolysiloxane-based polymer. These
diorganopolysiloxane-based polymers useful in the present invention
span a large range of viscosities; from about 10 to about
10,000,000 centistokes (cSt)at 25.degree. C. Some
diorganopolysiloxane-based polymers useful in this invention
exhibit viscosities greater than 10,000,000 centistokes (cSt) at
25.degree. C. and therefore are characterized by manufacturer
specific penetration testing. Examples of this characterization are
GE silicone materials SE 30 and SE 63 with penetration
specifications of 500-1500 and 250-600 (tenths of a millimeter)
respectively.
Among the diorganopolysiloxane polymers of the present invention
are diorganopolysiloxane polymers comprising repeating units, where
said units correspond to the formula (R.sub.2SiO).sub.n, where R is
a monovalent radical containing from 1 to 6 carbon atoms, in one
embodiment selected from the group consisting of methyl, ethyl,
propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, hexyl, vinyl,
allyl, cyclohexyl, amino alkyl, phenyl, fluoroalkyl and mixtures
thereof. The diorganopoylsiloxane polymers which may be employed in
the present invention may contain one or more of these radicals as
substituents on the siloxane polymer backbone. The
diorganopolysiloxane polymers may be terminated by triorganosilyl
groups of the formula (R'.sub.3Si) where R' is a monovalent radical
selected from the group consisting of radicals containing from 1-6
carbon atoms, hydroxyl groups, alkoxyl groups, and mixtures
thereof. In one embodiment the silicone polymer is a higher
viscosity polymers, e.g., poly(dimethylsiloxane), herein referred
to as PDMS or silicone gum, having a viscosity of at least 100,000
cSt.
Silicone gums, optionally useful herein, corresponds to the
formula:
##STR00001## where R is a methyl group.
Fluid diorganopolysiloxane polymers that are commercially
available, include SE 30 silicone gum and SF96 silicone fluid
available from the General Electric Company. Similar materials can
also be obtained from Dow Corning and from Wacker Silicones.
An additional fluid diorganosiloxane-based polymer optionally for
use in the present invention is a dimethicone copolyol. The
dimethicone copolyol can be further characterized as polyalkylene
oxide modified polydimethysiloxanes, such as manufactured by the
Witco Corporation under the trade name Silwet. Similar materials
can be obtained from Dow Corning, Wacker Silicones and Goldschmidt
Chemical Corporation as well as other silicone manufacturers.
Silicones useful herein are further disclosed in U.S. Pat. Nos.
5,059,282; 5,164,046; 5,246,545; 5,246,546; 5,552,345; 69238,682;
5,716,692.
The chemical softening agents are generally useful at a level of
from about 0.05 lbs/ton to about 300 lbs/ton, in another embodiment
from about 0.2 lbs/ton to about 60 lbs/ton, and in another
embodiment from about 0.4 lbs/ton to about 6 lbs/ton. In addition
antibacterial agents, coloring agents such as print elements,
perfumes, dyes, and mixtures thereof, may be included in the
fibrous structure product of the present invention.
EXAMPLES
Example 1
One fibrous structure useful in achieving the fibrous structure
paper products of the present invention is a through-air-dried
(TAD), differential density structure formed by the following
process. (Examples of TAD structures are generally described in
U.S. Pat. No. 4,528,239.)
A Fourdrinier, through-air-dried papermaking machine is used. A
slurry of papermaking fibers is pumped to the head-box at a
consistency of about 0.15%. The slurry consists of about 70%
Northern Softwood Kraft fibers, about 30% unrefined Eucalyptus
fibers, a cationic polyamine-epichlorohydrin wet burst strength
resin at a concentration of about 25 lbs per ton of dry fiber, and
carboxymethyl cellulose at a concentration of about 5 lbs per ton
of dry fiber, as well as DTD-MAMS at a concentration of about 6 lbs
per ton of dry fiber.
Dewatering occurs through the Fourdrinier wire and is assisted by
vacuum boxes. The embryonic wet web is transferred from the
Fourdrinier wire at a fiber consistency of about 20% at the point
of transfer, to a TAD carrier fabric. The wire speed is about 620
feet per minute. The carrier fabric speed is about 600 feet per
minute. Since the wire speed is faster than the carrier fabric, wet
shortening of the web occurs at the transfer point. Thus, the wet
web foreshortening is about 3%. The sheet side of the carrier
fabric consists of a continuous, patterned network of photopolymer
resin, the pattern containing about 150 deflection conduits or
domes per square inch. The deflection conduits or domes are
arranged in a regular configuration, and the polymer network covers
about 25% of the surface area of the carrier fabric. The polymer
resin is supported by and attached to a woven support member. The
photopolymer network rises about 18 mils above the support
member.
The consistency of the web is about 60% after the action of the TAD
dryers operating about a 400.degree. F., before transfer onto the
Yankee dryer. An aqueous solution of creping adhesive is applied to
the Yankee surface by spray applicators before the location of the
sheet transfer. The fiber consistency is increased to an estimated
95.5% before creping the web with a doctor blade. The doctor blade
has a bevel angle of about 25 degrees and is positioned with
respect to the Yankee dryer to provide an impact angle of about 81
degrees. The Yankee dryer is operated at about 360.degree. F., and
Yankee hoods are operated at about 350.degree. F.
The dry, creped web is passed between two calendar rolls and rolled
on a reel operated at 560 feet per minute so that there is about 7%
foreshortening of the web by crepe.
The paper described above is then subjected to a knob-to-rubber
impression embossing process as follows. An emboss roll is engraved
with a nonrandom pattern of protrusions. The emboss roll is
mounted, along with a backside impression roll, in an apparatus
with their respective axes being generally parallel to one another.
The emboss roll comprises embossing protrusions which are
frustaconical in shape. The backside impression roll is made of
Valcoat.TM. material from Valley Roller Company, Mansfield, Tex.
The paper web is passed through the nip to create an embossed
ply.
The resulting paper has a Wet Burst strength of 300 g, Basis Weight
of about 34 lbs/3000 ft..sup.2 to about 36 lbs/3000 ft..sup.2,
Compression slope of about 14, a Wet Caliper of about 31 mils, and
a Flex Modulus of about 0.6, and an embossment height of from about
600 to about 950 .mu.m.
Example 2
One fibrous structure useful in achieving the fibrous structure
paper products of the present invention is a through-air-dried
(TAD), differential density structure formed by the following
process. (Examples of TAD structures are generally described in
U.S. Pat. No. 4,528,239.)
A Fourdrinier, through-air-dried papermaking machine is used. A
slurry of papermaking fibers is pumped to the head-box at a
consistency of about 0.15%. The slurry consists of about 70%
Northern Softwood Kraft fibers, about 20% unrefined Eucalyptus
fibers, and about 10% of bicomponent fibers of copolymers of
polyester (polyethylene terephthalate)/polyester (polyethylene
terephthalate) such as "CoPET/PET" fibers, which are commercially
available from Fiber Innovation Technology, Inc., Johnson City,
Tenn. The slurry further comprises a cationic
polyamine-epichlorohydrin wet burst strength resin at a
concentration of about 25 lbs per ton of dry fiber, and
carboxymethyl cellulose at a concentration of about 5 lbs per ton
of dry fiber, as well as DTDMAMS at a concentration of about 6 lbs
per ton of dry fiber.
Dewatering occurs through the Fourdrinier wire and is assisted by
vacuum boxes. The embryonic wet web is transferred from the
Fourdrinier wire at a fiber consistency of about 24% at the point
of transfer, to a TAD carrier fabric. The wire speed is about 620
feet per minute. The carrier fabric speed is about 600 feet per
minute. Since the wire speed is faster than the carrier fabric, wet
shortening of the web occurs at the transfer point. Thus, the wet
web foreshortening is about 3%. The sheet side of the carrier
fabric consists of a continuous, patterned network of photopolymer
resin, the pattern containing about 150 deflection conduits or
domes per square inch. The deflection conduits or domes are
arranged in a regular configuration, and the polymer network covers
about 25% of the surface area of the carrier fabric. The polymer
resin is supported by and attached to a woven support member. The
photopolymer network rises about 18 mils above the support
member.
The consistency of the web is about 72% after the action of the TAD
dryers operating about a 350.degree. F., before transfer onto the
Yankee dryer. An aqueous solution of creping adhesive is applied to
the Yankee surface by spray applicators before location of sheet
transfer. The fiber consistency is increased to an estimated 97%
before creping the web with a doctor blade. The doctor blade has a
bevel angle of about 25 degrees and is positioned with respect to
the Yankee dryer to provide an impact angle of about 81 degrees.
The Yankee dryer is operated at about 500.degree. F., and Yankee
hoods are operated at about 380.degree. F.
The dry, creped web is passed between two calendar rolls and rolled
on a reel operated at 560 feet per minute so that there is about 7%
foreshortening of the web by crepe.
The paper described above is then subjected to a knob-to-rubber
impression embossing process as follows. An emboss roll is engraved
with a nonrandom pattern of protrusions. The emboss roll is
mounted, along with a backside impression roll, in an apparatus
with their respective axes being generally parallel to one another.
The emboss roll comprises embossing protrusions which are
frustaconical in shape. The backside impression roll is made of
Valcoat.TM. material from Valley Roller Company, Mansfield, Tex.
The paper web is passed through the nip to create an embossed
ply.
The resulting paper has a Wet Burst strength of 310 g, Basis Weight
of about 35 lbs/3000 ft.sup.2, Compression Slope of about 20, a Wet
Caliper of about 29 mils, Flex Modulus of about 0.5, and an
embossment height of from about 600 to about 950 .mu.m.
Test Methods
The following describe the test methods utilized herein to
determine the values consistent with those presented herein. All
measurements for the test methods are made at 23+/-1.degree. C. and
50% +/-2% relative humidity, unless otherwise specified.
Flex Modulus
The Flex Modulus is a measurement of the bending stiffness of the
fibrous structure product herein. The following procedure can be
used to determine the bending stiffness of paper product. The
Kawabata Evaluation System-2, Pure Bending Tester (i.e.; KES-FB2,
manufactured by a Division of Instrumentation, Kato Tekko Company,
Ltd. of Kyoto, Japan) may be used for this purpose.
Samples of the paper product to be tested are cut to approximately
20.times.20 cm in the machine and cross machine direction. The
sample width is measured to 0.01 inches (0.025 cm). The outer ply
(i.e.; the ply that is facing outwardly on a roll of the paper
sample) and inner ply as presented on the roll are identified and
marked.
The sample is placed in the jaws of the KES-FB2 Auto A such that
the sample is first bent with the outer ply undergoing compression
and the inner ply undergoing tension. In the orientation of the
KES-FB2 the outer ply is right facing and the inner ply is left
facing. The distance between the front moving jaw and the rear
stationary jaw is 1 cm. The sample is secured in the instrument in
the following manner. First the front moving chuck and the rear
stationary chuck are opened to accept the sample. The sample is
inserted midway between the top and bottom of the jaws such that
the machine direction of the sample is parallel to the jaws (i.e.;
vertical in the KES-FB2 holder).
The rear stationary chuck is then closed by uniformly tightening
the upper and lower thumb screws until the sample is snug, but not
overly tight. The jaws on the front stationary chuck are then
closed in a similar fashion. The sample is adjusted for squareness
in the chuck, then the front jaws are tightened to insure the
sample is held securely. The distance (d) between the front chuck
and the rear chuck is 1 cm.
The output of the instrument is load cell voltage (Vy) and
curvature voltage (Vx). The load cell voltage is converted to a
bending moment normalized for sample width (M) in the following
manner:
Moment (M, gf*cm/cm)=(Vy*Sy*d)/W
where Vy is the load cell voltage; Sy is the instrument sensitivity
in gf*cm/V; d is the distance between the chucks; and W is the
sample width in centimeters.
The sensitivity switch of the instrument is set at 5.times.1. Using
this setting the instrument is calibrated using two 50 gram
weights. Each weight is suspended from a thread. The thread is
wrapped around the bar on the bottom end of the rear stationary
chuck and hooked to a pin extending from the front and back of the
center of the shaft. One weight thread is wrapped around the front
and hooked to the back pin. The other weight thread is wrapped
around the back of the shaft and hooked to the front pin. Two
pulleys are secured to the instrument on the right and left side.
The top of the pulleys are horizontal to the center pin. Both
weights are then hung over the pulleys (one on the left and one on
the right) at the same time. The full scale voltage is set at 10 V.
The radius of the center shaft is 0.5 cm. Thus the resultant full
scale sensitivity (Sy) for the Moment axis is 100 gf*0.5 cm/10V (5
gf*cm/V).
The output for the Curvature axis is calibrated by starting the
measurement motor and manually stopping the moving chuck when the
indicator dial reaches the stop. The output voltage (Vx) is
adjusted to 0.5 volts. The resultant sensitivity (Sx) for the
curvature axis is 2/(volts*cm). The curvature (K) is obtained in
the following manner:
Curvature (K, cm.sup.-1)=Sx*Vx
where Sx is the sensitivity of the curvature axis; and Vx is the
output voltage.
For determination of the bending stiffness the moving chuck is
cycled from a curvature of 0 cm.sup.-1 to +2.5 cm.sup.-1 to -2.5
cm.sup.-1 to 0 cm.sup.-1 at a rate of 0.5 cm.sup.-1/sec. Each
sample is cycled once. The output voltage of the instrument is
recorded in a digital format using a personal computer. At the
start of the test there is no tension on the sample. As the test
begins the load cell begins to experience a load as the sample is
bent. The initial rotation is clockwise when viewed from the top
down on the instrument.
The load continues to increase until the bending curvature reaches
approximately +2.5 cm.sup.-1 (this is the Forward Bend (FB)). At
approximately +2.5 cm.sup.-1 the direction of rotation was
reversed. During the return the load cell reading decreases. This
is the Forward Bend Return (FR). As the rotating chuck passes 0,
curvature begins in the opposite direction. The Backward Bend (BB)
and Backward Bend Return (BR) is obtained.
The data was analyzed in the following manner. A linear regression
line is obtained between approximately 0.2 and 0.7 cm.sup.-1 for
the Forward Bend (FB). The slope of the line is reported as the
Bending Stiffness (B) or Flex Modulus, in units of gf*cm.sup.2 /cm.
The method is repeated with the sample oriented such that the cross
direction is parallel to the jaws. Three or more separate samples
are run. The reported values are the averages of the BFB on the MD
and CD samples. This method is also described in U.S. Pat. No.
6,602,577B1.
Sheet Caliper or Loaded Caliper Test Method
Samples are conditioned at 23+/-1.degree. C. and 50%+/-2% relative
humidity for two hours prior to testing.
Sheet Caliper or Loaded Caliper of a sample of fibrous structure
product is determined by cutting a sample of the fibrous structure
product such that it is larger in size than a load foot loading
surface where the load foot loading surface has a circular surface
area of about 3.14 in 2. The sample is confined between a
horizontal flat surface and the load foot loading surface. The load
foot loading surface applies a confining pressure to the sample of
14.7 g/cm.sup.2 (about 0.21 psi). The caliper is the resulting gap
between the flat surface and the load foot loading surface. Such
measurements can be obtained on a VIR Electronic Thickness Tester
Model II available from Thwing-Albert Instrument Company,
Philadelphia, Pa. The caliper measurement is repeated and recorded
at least five (5) times so that an average caliper can be
calculated. The result is reported in mils.
Wet Caliper Test Method
Samples are conditioned at 23+/-1.degree. C. and 50% relative
humidity for two hours prior to testing.
Wet Caliper of a sample of fibrous structure product is determined
by cutting a sample of the fibrous structure product such that it
is larger in size than a load foot loading surface where the load
foot loading surface has a circular surface area of about 3.14
in.sup.2. Each sample is wetted by submerging the sample in a
distilled water bath for 30 seconds. The caliper of the wet sample
is measured within 30 seconds of removing the sample from the bath.
The sample is then confined between a horizontal flat surface and
the load foot loading surface. The load foot loading surface
applies a confining pressure to the sample of 14.7 g/cm.sup.2
(about 0.21 psi). The caliper is the resulting gap between the flat
surface and the load foot loading surface. Such measurements can be
obtained on a VIR Electronic Thickness Tester Model II available
from Thwing-Albert Instrument Company, Philadelphia, Pa. The
caliper measurement is repeated and recorded at least five (5)
times so that an average caliper can be calculated. The result is
reported in mils.
High Load Caliper and Compression Slope
Caliper versus load data are obtained using a Thwing-Albert Model
EJA Materials Tester, equipped with a 2000 g load cell and
compression fixture. The compression fixture consisted of the
following; load cell adaptor plate, 2000 gram overload protected
load cell, load cell adaptor/foot mount 1.128 inch diameter presser
foot, #89-14 anvil, 89-157 leveling plate, anvil mount, and a grip
pin, all available from Thwing-Albert Instrument Company,
Philadelphia, Pa. The compression foot is one square inch in area.
The instrument is run under the control of Thwing-Albert Motion
Analysis Presentation Software (MAP V1,1,6,9). A single sheet of a
conditioned sample is cut to a diameter of approximately two
inches. Samples are conditioned for a minimum of 2 hours at
23+/-1.degree. C. and 50.+-.2% relative humidity. Testing is
carried out under the same temperature and humidity conditions. The
sample must be less than 2.5-inch diameter (the diameter of the
anvil) to prevent interference of the fixture with the sample. Care
should be taken to avoid damage to the center portion of the
sample, which will be under test. Scissors or other cutting tools
may be used. For the test, the sample is centered on the
compression table under the compression foot. The compression and
relaxation data are obtained using a crosshead speed of 0.1
inches/minute. The deflection of the load cell is obtained by
running the test without a sample being present. This is generally
known as the Steel-to-Steel data. The Steel-to-Steel data are
obtained at a crosshead speed of 0.005 in/min. Crosshead position
and load cell data are recorded between the load cell range of 5
grams and 1500 grams for both the compression and relaxation
portions of the test. Since the foot area is one square inch this
corresponded to a range of 5 grams/sq in to 1500 grams/sq in. The
maximum pressure exerted on the sample is 1500 g/sq in. At 1500
g/sq in the crosshead reverses its travel direction. Crosshead
position values are collected at 31 selected load values during the
test. These correspond to pressure values of 10, 25, 50, 75, 100,
125, 150, 200, 300, 400, 500, 600, 750, 1000, 1250, 1500, 1250,
1000, 750, 500, 400, 300, 250, 200, 150, 125, 100, 75, 50, 25, 10
g/sq. in. for the compression and the relaxation direction. During
the compression portion of the test, crosshead position values are
collected by the MAP software, by defining fifteen traps (Trap1 to
Trap 15) at load settings of 10, 25, 50, 75, 100, 125, 150, 200,
300, 400, 500, 600, 750, 1000, 1250. During the return portion of
the test, crosshead position values are collected by the MAP
software, by defining fifteen return traps (Return Trap1 to Return
Trap 15) at load settings of 1250, 1000, 750, 500, 400, 300, 250,
200, 150, 125, 100, 75, 50, 25, 10. The thirty-first trap is the
trap at max load (1500 g). Again values are obtained for both the
Steel-to-Steel and the sample. Steel-to-Steel values are obtained
for each batch of testing. If multiple days are involved in the
testing, the values are checked daily. The Steel-to-Steel values
and the sample values are an average of four replicates (1500
g).
Caliper values are obtained by subtracting the average
Steel-to-Steel crosshead trap values from the sample crosshead trap
value at each trap point. For example, the values from two, three,
or four individual replicates on each sample are averaged and is
used to obtain plots of the Caliper versus Load and Caliper versus
Log(10) Load.
The Compression Slope is defined as the absolute value of the
initial slope of the caliper versus Log(10)Load. The value is
calculated by taking four data pairs from the compression direction
of the curve that is, the caliper at 500, 600, 750, 1,000 or 750,
1,000, 1250, 1500, g/sq in at the start of the test. The pressure
is converted to the Log(10) of the pressure. A least square
regression is then obtained using the four pairs of caliper
(y-axis) and Log(10) pressure (x-axis). The absolute value of the
slope of the regression line is the Compression Slope. The units of
the Compression Slope are mils/(log(10) g/sq in). For simplicity
the Compression Slope is reported here without units. High Load
Caliper is the average caliper at 1,500 g/sq. inch.
Wet Burst Strength Test Method
"Wet Burst Strength" as used herein is a measure of the ability of
a fibrous structure and/or a fibrous structure product
incorporating a fibrous structure to absorb energy, when wet and
subjected to deformation normal to the plane of the fibrous
structure and/or fibrous structure product.
Wet burst strength may be measured using a Thwing-Albert Burst
Tester Cat. No. 177 equipped with a 2000 g load cell commercially
available from Thwing-Albert Instrument Company, Philadelphia,
Pa.
Wet burst strength is measured by taking two (2) multi-ply fibrous
structure product samples. Using scissors, cut the samples in half
in the MD so that they are approximately 228 mm in the machine
direction and approximately 114 mm in the cross machine direction,
each two (2) plies thick (you now have 4 samples). First, condition
the samples for two (2) hours at a temperature of 73.degree.
F..+-.2.degree. F. (about 23.degree. C..+-.1.degree. C.) and a
relative humidity of 50%.+-.2%. Next age the samples by stacking
the samples together with a small paper clip and "fan" the other
end of the stack of samples by a clamp in a 105.degree. C.
(.+-.1.degree. C.) forced draft oven for 5 minutes (.+-.10
seconds). After the heating period, remove the sample stack from
the oven and cool for a minimum of three (3) minutes before
testing. Take one sample strip, holding the sample by the narrow
cross machine direction edges, dipping the center of the sample
into a pan filled with about 25 mm of distilled water. Leave the
sample in the water four (4) (.+-.0.5) seconds. Remove and drain
for three (3) (.+-.0.5) seconds holding the sample so the water
runs off in the cross machine direction. Proceed with the test
immediately after the drain step. Place the wet sample on the lower
ring of a sample holding device of the Burst Tester with the outer
surface of the sample facing up so that the wet part of the sample
completely covers the open surface of the sample holding ring. If
wrinkles are present, discard the samples and repeat with a new
sample. After the sample is properly in place on the lower sample
holding ring, turn the switch that lowers the upper ring on the
Burst Tester. The sample to be tested is now securely gripped in
the sample holding unit. Start the burst test immediately at this
point by pressing the start button on the Burst Tester. A plunger
will begin to rise toward the wet surface of the sample. At the
point when the sample tears or ruptures, report the maximum
reading. The plunger will automatically reverse and return to its
original starting position. Repeat this procedure on three (3) more
samples for a total of four (4) tests, i.e., four (4) replicates.
Report the results as an average of the four (4) replicates, to the
nearest g.
All measurements referred to herein are made at 23+/-1.degree. C.
and 50% relative humidity, unless otherwise specified.
All documents cited in the Detailed Description of the Invention
are, in relevant part, incorporated herein by reference; the
citation of any document is not to be construed as an admission
that it is prior art with respect to the present invention. To the
extent that any meaning or definition of a term in this written
document conflicts with any meaning or definition of the term in a
document incorporated by reference, the meaning or definition
assigned to the term in this written document shall govern.
The dimensions and values disclosed herein are not to be understood
as being strictly limited to the exact numerical values recited.
Instead, unless otherwise specified, each such dimension is
intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm".
While particular embodiments of the present invention have been
illustrated and described, it would be obvious to those skilled in
the art that various other changes and modifications can be made
without departing from the spirit and scope of the invention. It is
therefore intended to cover in the appended claims all such changes
and modifications that are within the scope of this invention.
* * * * *