U.S. patent application number 15/634890 was filed with the patent office on 2017-10-12 for towel with quality wet scrubbing properties at relatively low basis weight and an apparatus and method for producing same.
The applicant listed for this patent is First Quality Tissue, LLC. Invention is credited to Taras Z. Andrukh, Chris B. Anklam, Shannon Gahan, Courtney E. Kessling, Byrd Tyler Miller, IV, Justin S. Pence, Karthik Ramaratnam, James E. Sealey.
Application Number | 20170291403 15/634890 |
Document ID | / |
Family ID | 56092526 |
Filed Date | 2017-10-12 |
United States Patent
Application |
20170291403 |
Kind Code |
A1 |
Miller, IV; Byrd Tyler ; et
al. |
October 12, 2017 |
TOWEL WITH QUALITY WET SCRUBBING PROPERTIES AT RELATIVELY LOW BASIS
WEIGHT AND AN APPARATUS AND METHOD FOR PRODUCING SAME
Abstract
A multi-ply absorbent product having a wet scrubbing resistance
greater than 120 revolutions and a basis weight of between 30 and
50 grams per square meter. A heated adhesive is applied between two
single plies/webs, the multiple plies are embossed according to
particular parameters, and the embossed webs are compressed with a
marrying roll. The adhesive is heated to a temperature of between
approximately 32 degrees C. to 66 degrees C. for application
between the multiple plies. For each ply, the embossed area
generally occupies between approximately 5 to 15% of the total
surface area of a surface of the ply, the depth of embossment of
the surface is generally between approximately 0.28 and 0.43
centimeters deep, and the embossment of the surface is generally
between approximately 0.04 to 0.08 square centimeters in size.
Inventors: |
Miller, IV; Byrd Tyler;
(Easley, SC) ; Pence; Justin S.; (Anderson,
SC) ; Ramaratnam; Karthik; (Anderson, SC) ;
Sealey; James E.; (Belton, SC) ; Kessling; Courtney
E.; (Howard, PA) ; Anklam; Chris B.;
(Anderson, SC) ; Gahan; Shannon; (Clemson, SC)
; Andrukh; Taras Z.; (Greenville, SC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
First Quality Tissue, LLC |
Great Neck |
NY |
US |
|
|
Family ID: |
56092526 |
Appl. No.: |
15/634890 |
Filed: |
June 27, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14561802 |
Dec 5, 2014 |
9719213 |
|
|
15634890 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D21H 19/10 20130101;
D21H 27/007 20130101; D21H 11/04 20130101; D21H 27/38 20130101;
B32B 38/06 20130101; B32B 37/0053 20130101; D21H 21/20 20130101;
D21H 27/002 20130101; B32B 37/1207 20130101; D21H 27/02 20130101;
D21H 11/12 20130101; D21H 23/56 20130101; D21H 27/30 20130101; D21H
27/005 20130101; D21H 27/32 20130101; D21H 27/36 20130101 |
International
Class: |
B32B 37/00 20060101
B32B037/00; D21H 19/10 20060101 D21H019/10; B32B 38/06 20060101
B32B038/06; D21H 27/00 20060101 D21H027/00; B32B 37/12 20060101
B32B037/12; D21H 21/20 20060101 D21H021/20; D21H 27/36 20060101
D21H027/36 |
Claims
1. An apparatus for laminating at least two plies together to form
a multi-ply absorbent product, the apparatus comprising: (a) a
plurality of embossing rolls that emboss the at least two plies
with a plurality of embossing rolls, the plurality of embossing
rolls having a nip formed therebetween; (b) an adhesive applicator
roll, located upstream of the nip between the plurality of
embossing rolls, that applies an adhesive to an interior side of at
least one of the embossed plies to adhere the at least two plies
together, wherein the interior side is a side of a ply that comes
into a face-to-face relationship with another ply for lamination;
(c) a marrying roll, located downstream of the nip between the
plurality of embossing rolls, that compresses the at least two
plies that have been embossed and to which a heated adhesive has
been applied so as to form a laminate of the at least two plies,
and (d) a heater for maintaining the adhesive at a temperature of
between approximately 32 degrees C. to 66 degrees C. during
application of the adhesive.
2. The apparatus of claim 1, wherein at least one of the embossing
rolls has a plurality of embossing knobs with crests thereon, and
wherein the adhesive applicator roll is positioned to apply the
heated adhesive to the absorbent product at the crests of the
embossing knobs on the at least one embossing roll.
3. The apparatus of claim 1, wherein the adhesive applicator roll
comprises an applicator for applying the adhesive comprising a
water soluble adhesive mixture comprised of (a) between
approximately 1% to 10% by weight of polyvinyl alcohol, polyvinyl
acetate, starch based resins or mixtures thereof, and (b) between
80% to 99% by weight of water.
4. The apparatus of claim 3, wherein the water soluble adhesive
mixture further comprises up to 10% by weight of a water soluble
cationic resin selected from the group consisting of
polyamide-epichlorohydrin resins, glyoxalated polyacrylamide
resins, polyethyleneimine resins, polyethylenimine resins, or
mixtures thereof;
5. The apparatus of claim 1, further comprising an insulated tank
in which the heater is located and in which the adhesive is heated
prior to application by the adhesive applicator roll.
6. The apparatus of claim 5, wherein the heater comprises heating
elements that are substantially uniformly distributed in the
interior heating surface of the insulated tank.
7. The apparatus of claim 6, wherein the insulated tank further
comprises an agitator that agitates the heated adhesive in the
insulated tank.
8. The apparatus of claim 1, wherein the plurality of embossing
rolls form an embossed area on each of the at least two plies,
wherein the embossed area occupies between approximately 5 to 15%
of the total surface area of a surface of the ply.
9. The apparatus of claim 1, wherein the plurality of embossing
rolls form an embossed area on each of the at least two plies,
wherein the embossed area has a surface, and wherein a depth of
embossment of the surface is between approximately 0.28 and 0.43
centimeters.
10. The apparatus of claim 1, wherein the plurality of embossing
rolls form an embossed area on each of the at least two plies,
wherein the embossed area has a surface, and wherein each
embossment of the surface is between approximately 0.04 and 0.08
square centimeters in size.
11. The apparatus of claim 1, wherein the multi-ply absorbent
product made with the apparatus is one of a paper towel, a
disposable towel or wipe, a bath or facial tissue, or a nonwoven
product.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of and claims priority to
U.S. patent application Ser. No. 14/561,802, entitled TOWEL WITH
QUALITY WET SCRUBBING PROPERTIES AT RELATIVELY LOW BASIS WEIGHT AND
AN APPARATUS AND METHOD FOR PRODUCING SAME and filed Dec. 5, 2014,
the contents of which are incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to absorbent products, such as
paper towels, disposable towels or wipes, bath or facial tissues,
or nonwoven products, having improved scrubbing properties at
relatively low basis weights compared to conventional absorbent
products.
BACKGROUND OF THE INVENTION
[0003] Across the globe there is great demand for disposable,
absorbent products used for household cleaning tasks. Disposable
towels and wipes meet this market demand. Disposable paper towels
and wipes that are made of cellulosic based fibers are also nearly
100% renewable and biodegradable thus catering to those whom are
eco-conscience. These disposable absorbent towels and wipes are
used for a multitude of tasks that require absorbency and strength.
These tasks include absorbing liquid spills, cleaning windows and
mirrors, scrubbing countertops and floors, scrubbing and drying
dishes, washing/cleaning bathroom sinks and toilets, and even
drying/cleaning hands and faces. A disposable towel or wipe that
can perform these demanding tasks and be produced at a price point
that provides a value proposition to the consumer is
advantageous.
[0004] To increase the strength of these absorbent products, more
than one layer of web (or ply) can be laminated together. It is
generally understood that a multi-ply absorbent product can also
have an absorbent capacity greater than the sum of the absorbent
capacities of the individual single plies. It is thought that this
difference is due to the inter-ply storage space created by the
addition of an extra ply. When producing a multi-ply absorbent
product, the plies are bonded together in a manner that will hold
up when subjected to the forces encountered when the product is
used by the consumer. Scrubbing tasks such as cleaning countertops,
dishes, and windows all impart forces upon the structure of the
absorbent product which can cause the structure to rupture and
tear. When the bonding between plies fails, the plies move against
each other imparting frictional forces at the ply interface. This
frictional force at the ply interface can induce failure (rupture
or tearing) of the structure thus reducing the overall
effectiveness of the product to perform scrubbing and cleaning
tasks.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a multi-ply
absorbent product, such as a paper towel, a disposable towel or
wipe, a bath or facial tissue, or a nonwoven product, that has a
relatively high scrubbing resistance to tear or rupture during use
of the product, as compared to conventional multi-ply absorbent
products.
[0006] Another object of the present invention is to provide a
method and apparatus for adhesively laminating single ply absorbent
products to produce a multi-ply absorbent product that has a
relatively high scrubbing resistance to tear or rupture during use,
as compared to conventional multi-ply absorbent products.
[0007] Another object of the present invention is to achieve a
multi-ply absorbent product that attains a high level of scrubbing
performance at a relatively low basis weight, as compared to
conventional multi-ply absorbent products.
[0008] To accomplish at least these objects, in some embodiments,
an absorbent product comprises a laminate of at least two
webs/plies of absorbent products that are embossed and adhered
together to achieve a wet scrubbing resistance greater than 120
revolutions and a basis weight of between 30 and 50 grams per
square meter of the laminate. In embodiments, one or more of the
plies may be formed from cellulosic-based fibers or synthetic
fibers, and may be formed with a wet-laid or an air-laid
technology. The multi-ply absorbent product may be one of a paper
towel, a disposable towel or wipe, a bath or facial tissue, or a
nonwoven product.
[0009] Also, in some embodiments, an absorbent product comprises a
laminate of at least two plies, wherein each of the at least two
plies is embossed and the at least two plies are adhered together.
At least one of the at least two plies comprises a first layer, a
second layer, and a third layer located between said first and
second layers, the absorbent product having a wet scrubbing
resistance greater than 120 revolutions and a basis weight of
between 30 and 50 grams per square meter.
[0010] In embodiments, a method for laminating the at least two
plies together comprises embossing the at least two plies and
applying a heated adhesive, such as a water soluble adhesive
mixture, to an interior side of at least one of the at least two
plies, wherein the interior side is a side of a ply that comes into
face-to-face relationship with another ply for lamination, and
marrying the at least two plies after the heated adhesive has been
applied. This method achieves an absorbent product that is a
laminate with a wet scrubbing resistance greater than 120
revolutions and a basis weight of between 30 and 50 grams per
square meter of the laminate. In embodiments, the step of embossing
is performed using embossing rolls having embossing knobs with
crests. In embodiments, the heated adhesive is applied with an
adhesive applicator roll to the absorbent product at the crests of
the embossing knobs. In embodiments, the adhesive is maintained at
a temperature of between approximately 32 degrees C. to 66 degrees
C. The adhesive may be maintained at the desired temperature in an
insulated tank that is heated and the adhesive may also be agitated
while in the insulated tank.
[0011] In embodiments of the present invention, the water soluble
adhesive mixture that is to be heated may comprise a mixture of (a)
between approximately 1% to 10% by weight of polyvinyl alcohol,
polyvinyl acetate, starch based resins or mixtures thereof, and (b)
between 80% to 99% by weight of water, and, in embodiments, the
mixture may further comprise (c) up to 10% by weight of a water
soluble cationic resin selected from the group consisting of
polyamide-epichlorohydrin resins, glyoxalated polyacrylamide
resins, polyethyleneimine resins, polyethylenimine resins, or
mixtures thereof.
[0012] Additionally, in some embodiments, each of the at least two
plies comprises an embossed area, wherein the embossed area
occupies between approximately 5 to 15% of the surface area,
wherein a depth of embossment is between approximately 0.28 and
0.43 centimeters deep, and wherein each embossment is between
approximately 0.04 to 0.08 square centimeters.
[0013] The present invention also discloses an apparatus for
producing the laminate. In some embodiments, the apparatus
comprises a plurality of embossing rolls, having a nip formed
therebetween, that emboss the at least two plies of absorbent
product. The apparatus further comprises an adhesive applicator
roll, located upstream of the nip between the plurality of
embossing rolls. The adhesive applicator roll applies an adhesive
to an interior side of at least one of the embossed plies to adhere
the at least two plies together, wherein the interior side is a
side of a ply that comes into a face-to-face relationship with
another ply for lamination. The apparatus further comprises a
marrying roll, located downstream of the nip between the plurality
of embossing rolls, that compresses the at least two plies of
absorbent product that have been embossed and to which a heated
adhesive has been applied so as to form a laminate of the at least
two plies. Additionally, the apparatus comprises a heater for
maintaining the adhesive at a temperature of between approximately
32 degrees C. to 66 degrees C. during application of the
adhesive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Exemplary embodiments of the present invention will be
described with references to the accompanying figures, wherein:
[0015] FIG. 1 is a schematic diagram of a three layer ply formed by
a Wet Laid process for use in an exemplary embodiment of the
present invention;
[0016] FIG. 2 is a block diagram of a system for manufacturing one
ply of a laminate according to an exemplary embodiment of the
present invention;
[0017] FIG. 3 is a block diagram of a system for manufacturing a
multi-ply absorbent product according to an exemplary embodiment of
the present invention;
[0018] FIG. 4 shows an embodiment of an absorbent product that has
an embossment pattern in accordance with an exemplary embodiment of
the present invention;
[0019] FIG. 5 is an exploded view of a towel sample mounted to an
abrading table in accordance with an embodiment of the present
invention;
[0020] FIG. 6 is a side view of an abrading table with a towel
sample attached thereto in accordance with an embodiment of the
present invention;
[0021] FIG. 7 is an exploded view of a specimen holder for abrasion
testing towel samples in accordance with an embodiment of the
present invention; and
[0022] FIG. 8 shows a top view of the textured polymer film of FIG.
7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] An absorbent product according to an exemplary embodiment of
the present invention includes two or more plies of absorbent
products/webs laminated together to achieve a wet scrubbing
resistance greater than 120 revolutions and a basis weight of
between 30 and 50 grams per square meter of the laminate. These
levels of wet scrubbing resistance and relatively low basis weight
are achieved by applying a heated, water soluble adhesive between
the two or more plies, embossing the plies, and then using a
marrying roll following the embossment. The present invention also
discloses an apparatus and method for producing the laminate.
[0024] The absorbent products or structures that are used for each
of the two or more webs/plies can be manufactured by any known or
later-discovered wet-laid, air-laid or spun-laid methods. In the
wet-laid method, water is used to form a web. In the air-laid
method, air is used to form a web.
[0025] Examples of some known wet-laid technologies that may be
used to form a cellulosic (or other natural or synthetic fiber
type) web include Through Air Drying (TAD), Uncreped Through Air
Drying (UCTAD), Conventional Wet Crepe (CWC), Conventional Dry
Crepe (CDC), Advanced Tissue Molding System (ATMOS), NTT, and
ETAD.
[0026] In Conventional Dry Crepe and Conventional Wet Crepe
methods, a nascent web is formed in a forming structure, the web is
transferred to a dewatering felt where it is pressed to remove
moisture, and the web is then adhered to a Yankee Dryer. The web is
then dried and creped from the Yankee Dryer and reeled. When creped
at a solids content of less than 90%, the process is referred to as
Conventional Wet Crepe. When creped at a solids content of greater
than 90%, the process is referred to as Conventional Dry Crepe.
[0027] The CWC and CDC methods are easy to operate at high speeds
and production rates. Energy consumption per ton is low since
nearly half of the water removed from the web is through drainage
and mechanical pressing. However, the sheet pressing also compacts
the web which lowers web thickness and resulting absorbency.
[0028] The Through Air Drying (TAD) and Uncreped Through Air Drying
(UCTAD) processes are wet-laid technologies that avoid compaction
of the web during drying and thereby produce absorbent products of
superior thickness and absorbency when compared to absorbent
products of similar basis weight and material inputs that are
produced using the CWC or the CDC process.
[0029] Other wet-laid processes, such as ATMOS, ETAD, and NTT, can
also be utilized to produce absorbent products. Each process/method
utilizes some pressing to dewater the web, or a portion of the web,
resulting in absorbent products with absorbent capacities that
correlate to the amount of pressing utilized when all other
variables are the same.
[0030] Absorbent products may alternatively be made using an
air-laid process. In this process, an air stream of cellulosic, or
other natural or synthetic fibers, is directed onto a moving belt.
The fibers collect together to form a web that can be thermally
bonded or spray bonded with resin and cured. Compared to the
wet-laid process, the web is thicker, softer, more absorbent,
stronger and has a textile-like surface and drape.
[0031] The spun-laid process is a variation of the air-laid
process. In the spun-laid process, plastic fibers (polyester or
polypropylene) are spun (melted, extruded, and blown) and then
directly spread into a web in one continuous process. This
technique has gained popularity as it can generate faster belt
speeds and reduce costs.
[0032] The materials used to produce the absorbent products can be
fibers in any ratio selected from cellulosic-based fibers, such as
wood pulps (softwood gymnosperms or hardwood angiosperms),
cannabis, cotton, regenerated or spun cellulose, jute, flax, ramie,
bagasse, kenaf, or other plant based cellulosic fiber sources.
Synthetic fibers, such as a polyolefin (e.g., polypropylene),
polyester, or polylactic acid can also be used. Each ply of a
multi-ply absorbent product of the present invention may comprise
cellulosic based fibers and/or synthetic fibers. Also, all the
plies may be made of the same type(s) of fibers or different fibers
may be used in some or all of the plies.
[0033] FIGS. 1 and 2 illustrate a single ply absorbent product and
a method for manufacturing the tissue product in which a TAD drying
method is used. The content of U.S. patent application Ser. No.
13/837,685, which describes such an absorbent, soft TAD tissue and
is assigned to applicant, is incorporated herein by reference.
[0034] FIG. 1 shows an example of a single ply, three layer tissue
generally designated by reference number 1 that has external
(exterior) layers 2 and 4 as well as an internal (interior), core
layer 3. In the figure, the three layers of the tissue from top to
bottom are labeled as air 4, core 3 and dry (or Yankee) 2. External
layer 2 is composed primarily of hardwood fibers 20 whereas
external layer 4 and core layer 3 are composed of a combination of
hardwood fibers 20 and softwood fibers 21. External layer 2 further
includes a dry strength additive 7. External layer 4 further
includes both a dry strength additive 7 and a temporary wet
strength additive 8.
[0035] Pulp mixes for exterior layers of the tissue are prepared
with a blend of primarily hardwood fibers. For example, the pulp
mix for at least one exterior layer is a blend containing about 70
percent or greater hardwood fibers relative to the total percentage
of fibers that make up the blend. As a further example, the pulp
mix for at least one exterior layer is a blend containing about
90-100 percent hardwood fibers relative to the total percentage of
fibers that make up the blend.
[0036] Pulp mixes for the interior layer of the tissue are prepared
with a blend of primarily softwood fibers. For example, the pulp
mix for the interior layer is a blend containing about 70 percent
or greater softwood fibers relative to the total percentage of
fibers that make up the blend. As a further example, the pulp mix
for the interior layer is a blend containing about 90-100 percent
softwood fibers relative to the total percentage of fibers that
make up the blend.
[0037] As known in the art, pulp mixes are subjected to a dilution
stage in which water is added to the mixes so as to form a slurry.
After the dilution stage but prior to reaching the headbox, each of
the pulp mixes are dewatered to obtain a thick stock of about 95%
water. In an exemplary embodiment of the invention, wet end
additives are introduced into the thick stock pulp mixes of at
least the interior layer.
[0038] In an exemplary embodiment, a dry strength additive is added
to the thick stock mix for at least one of the exterior layers. The
dry strength additive may be, for example, amphoteric starch, added
in a range of about 1 to 40 kg/ton. In another exemplary
embodiment, a wet strength additive is added to the thick stock mix
for at least one of the exterior layers. The wet strength additive
may be, for example, glyoxalated polyacrylamide, commonly known as
GPAM, added in a range of about 0.25 to 5 kg/ton. In a further
exemplary embodiment, both a dry strength additive, preferably
amphoteric starch and a wet strength additive, preferably GPAM are
added to one of the exterior layers. Without being bound by theory,
it is believed that the combination of both amphoteric starch and
GPAM in a single layer when added as wet end additives provides a
synergistic effect with regard to strength of the finished tissue.
Other exemplary temporary wet-strength agents include aldehyde
functionalized cationic starch, aldehyde functionalized
polyacrylamides, acrolein co-polymers and cis-hydroxyl
polysaccharide (guar gum and locust bean gum) used in combination
with any of the above mentioned compounds.
[0039] In addition to amphoteric starch, suitable dry strength
additives may include but are not limited to glyoxalated
polyacrylamide, cationic starch, carboxy methyl cellulose, guar
gum, locust bean gum, cationic polyacrylamide, polyvinyl alcohol,
anionic polyacrylamide or a combination thereof.
[0040] FIG. 2 is a block diagram of a system for manufacturing such
a three layer tissue, generally designated by reference number 100,
according to an exemplary embodiment of the present invention. The
system 100 includes a first exterior layer fan pump 102, a core
layer fan pump 104, a second exterior layer fan pump 106, a headbox
108, a forming section 110, a drying section 112 and a calender
section 114. The first and second exterior layer fan pumps 102, 106
deliver the pulp mixes of the first and second external layers 2, 4
to the headbox 108, and the core layer fan pump 104 delivers the
pulp mix of the core layer 3 to the headbox 108. As is known in the
art, the headbox delivers a wet web of pulp onto a forming wire
within the forming section 110. The wet web is then laid on the
forming wire with the core layer 3 disposed between the first and
second external layers 2, 4.
[0041] After formation in the forming section 110, the partially
dewatered web is transferred to the drying section 112. Within the
drying section 112, the tissue may be dried using conventional
through air drying processes. In an exemplary embodiment, the
tissue is dried to a humidity of about 7 to 20% using a through air
drier manufactured by Metso Corporation, of Helsinki, Finland. In
another exemplary embodiment, two or more through air drying stages
are used in series. However, it should be emphasized that this is
only one of various methods of manufacturing an absorbent tissue
product to be used in manufacturing the laminate of the present
invention.
[0042] In an exemplary embodiment, the tissue of the present
invention is patterned during the through air drying process. Such
patterning can be achieved through the use of a TAD fabric, such as
a G-weave (Prolux 003) or M-weave (Prolux 005) TAD fabric.
[0043] After the through air drying stage, the tissue of the
present invention may be further dried in a second phase using a
Yankee drying drum. In an exemplary embodiment, a creping adhesive
is applied to the drum prior to the tissue contacting the drum. A
creping blade is then used to remove the tissue from the Yankee
drying drum. The tissue may then be calendered in a subsequent
stage within the calendar section 114. According to an exemplary
embodiment, calendaring may be accomplished using a number of
calendar rolls (not shown) that deliver a calendering pressure in
the range of 0-100 pounds per linear inch (PLI). In general,
increased calendering pressure is associated with reduced caliper
and a smoother tissue surface.
[0044] According to an exemplary embodiment of the invention, a
ceramic coated creping blade is used to remove the tissue from the
Yankee drying drum. Ceramic coated creping blades result in reduced
adhesive build up and aid in achieving higher run speeds. Without
being bound by theory, it is believed that the ceramic coating of
the creping blades provides a less adhesive surface than metal
creping blades and is more resistant to edge wear that can lead to
localized spots of adhesive accumulation. The ceramic creping
blades allow for a greater amount of creping adhesive to be used
which in turn provides improved sheet integrity and faster run
speeds.
[0045] In addition to the use of wet end additives, the tissue of
the present invention may also be treated with topical or surface
deposited additives. Examples of surface deposited additives
include softeners for increasing fiber softness and skin lotions.
Examples of topical softeners include but are not limited to
quaternary ammonium compounds, including, but not limited to, the
dialkyldimethylammonium salts (e.g. ditallowdimethylammonium
chloride, ditallowdimethylammonium methyl sulfate, di(hydrogenated
tallow)dimethyl ammonium chloride, etc.). Another class of chemical
softening agents include the well-known organo-reactive
polydimethyl siloxane ingredients, including amino functional
polydimethyl siloxane. zinc stearate, aluminum stearate, sodium
stearate, calcium stearate, magnesium stearate, spermaceti, and
steryl oil.
[0046] To enhance the strength and absorbency of these towels and
wipes, multiple plies are laminated together using a heated
adhesive, as described below with respect to FIG. 3. The adhesive
mixture is water soluble and includes a mixture of one or more
adhesives, one or more water soluble cationic resins and water. The
one or more adhesives are present in an amount of 1% to 10% by
weight and may be polyvinyl alcohol, polyvinyl acetate, starch
based resins and/or mixtures thereof. A water soluble cationic
resin may be present in an amount of up to 10% by weight and may
include polyamide-epichlorohydrin resins, glyoxalated
polyacrylamide resins, polyethyleneimine resins, polyethylenimine
resins, and/or mixtures thereof. The remainder of the mixture is
composed of water.
[0047] FIG. 3 shows an apparatus for manufacturing a laminate of
two plies of an absorbent product that are joined to each other, in
a face-to-face relationship, in accordance with an exemplary
embodiment of the present invention to form an absorbent product,
such as a paper towel. As shown in the figure, two webs 200, 201 of
single ply tissue, which may be manufactured, for example,
according to a method described above, are fed to respective pairs
of mated pressure rolls 203, 205 and substantially axially parallel
embossing rolls 204, 206. A first web 200 is thus fed through a nip
202a formed by pressure roll 203 and embossing roll 204 (also known
as a pattern roll) and a second web 201 is likewise fed through a
nip 202b between pressure roll 205 and embossing roll 206. The
embossing rolls 204, 206, which rotate in the illustrated
directions, impress an embossment pattern onto the webs as they
pass through nip 202a and 202b. After being embossed, each ply may
have a plurality of embossments protruding outwardly from the plane
of the ply towards the adjacent ply. The adjacent ply likewise may
have opposing protuberances protruding towards the first ply. If a
three ply product is produced by adding a third pair of mated
pressure and embossing rolls, the central ply may have embossments
extending outwardly in both directions.
[0048] To perform the embossments at nips 202a and 202b, the
embossing rolls 204, 206 have embossing tips or embossing knobs
that extend radially outward from the rolls to make the
embossments. In the illustrated embodiment, embossing is performed
by nested embossing in which the crests of the embossing knobs on
one embossing roll intermesh with the embossing knobs on the
opposing embossing roll and a nip is formed between the embossing
rolls. As the web is fed through nips 202a and 202b, a pattern is
produced on the surface of the web by the interconnectivity of the
knobs on an embossing roll with the open spaces of the respective
pressure roll.
[0049] An adhesive applicator roll 212 is positioned upstream of
the nip 213 formed between the two embossing rolls and is aligned
in an axially parallel arrangement with one of the two embossing
rolls to form a nip therewith. The heated adhesive is fed from an
adhesive tank 207 via a conduit 210 to applicator roll 212. The
applicator roll 212 transfers heated adhesive to an interior side
of embossed ply 200 to adhere the at least two plies 200, 201
together, wherein the interior side is the side of ply 200 that
comes into a face-to-face relationship with ply 201 for lamination.
The adhesive is applied to the ply at the crests of the embossing
knobs 205 on embossing roll 204.
[0050] Notably, in the present invention, the adhesive is heated
and maintained at a desired temperature utilizing, in embodiments,
an adhesive tank 207, which is an insulated stainless steel tank
that may have heating elements 208 that are substantially uniformly
distributed throughout the interior heating surface. In this
manner, a large amount of surface area may be heated relatively
uniformly. Generally, an adjustable thermostat may be used to
control the temperature of the adhesive tank 207. It has been found
advantageous to maintain the temperature of the adhesive at between
approximately 32 degrees C. (90 degrees F.) to 66 degrees C. (150
degrees F.), and preferably to around 49 degrees C. (120 degrees
F.). In addition, in embodiments, the tank has an agitator 209 to
ensure proper mixing and heat transfer.
[0051] The webs are then fed through the nip 213 where the
embossing patterns on each embossing roll 204, 206 mesh with one
another.
[0052] In nested embossing, the crests of the embossing knobs
typically do not touch the perimeter of the opposing roll at the
nip formed therebetween. Therefore, after the application of the
embossments and the adhesive, a marrying roll 214 is used to apply
pressure for lamination. The marrying roll 214 forms a nip with the
same embossing roll 204 that forms the nip with the adhesive
applicator roll 212, downstream of the nip formed between the two
embossing rolls 204, 206. The marrying roll 214 is generally needed
because the crests of the nested embossing knobs 205 typically do
not touch the perimeter of the opposing roll 206 at the nip 213
formed therebetween.
[0053] The specific pattern that is embossed on the absorbent
products is significant for achieving the enhanced scrubbing
resistance of the present invention. In particular, it has been
found that the embossed area on any ply should cover between
approximately 5 to 15% of the surface area. Moreover, the size of
each embossment should be between approximately 0.04 to 0.08 square
centimeters. The depth of the embossment should be within the range
of between approximately 0.28 and 0.43 centimeters (0.110 and 0.170
inches) in depth.
[0054] FIG. 4 shows a sample pattern embossed on the absorbent
product according to an embodiment of the present invention. In the
illustrated pattern, the embossed area covers approximately 13% of
the surface, the embossment depth is approximately 0.34 centimeters
(0.135 inches) deep, and the embossment diameter is approximately
0.92 centimeters (0.115 inches) across.
[0055] The following discussion describes the tests that were used
to determine the basis weights and wet scrubbing measurements in
connection with the present invention.
Basis Weight
[0056] The basis weight for the present invention was measured in
grams/m.sup.2 using the following process. Using a dye and press,
six approximately 76.2 mm by 76.2 mm (approximately 3 inch.times.3
inch) square samples were cut from each two-ply product that was
tested with care taken to avoid including any web perforations in
the samples. The samples were placed in an oven at 105 degrees
Celsius for 5 minutes and were thereafter weighed on an analytical
balance to the fourth decimal point. The weight of the sample in
grams was then divided by (0.0762 m).sup.2 to determine the basis
weight in grams/m.sup.2.
Wet Scrubbing Test Method
[0057] A wet scrubbing test was used to measure the durability of a
wet towel. The test involved scrubbing a sample wet towel with an
abrasion tester and recording the number of revolutions of the
tester it takes to break the sample. Multiple samples of the same
product were tested and an average durability for that product was
determined. The measured durability was then compared with similar
durability measurements for other wet towel samples.
[0058] An abrasion tester was used for the wet scrubbing test. The
particular abrasion tester that was used was an M235 Martindale
Abrasion and Pilling Tester ("M235 tester") from SDL Atlas Textile
Testing Solutions. The M235 tester provides multiple abrading
tables on which the samples are abrasion tested and specimen
holders that abrade the towel samples to enable multiple towel
samples to be simultaneously tested. A motion plate is positioned
above the abrading tables and moves the specimen holders proximate
the abrasion tables to make the abrasions.
[0059] In preparation for the test, eight (8) towel samples,
approximately 140 mm (about 5.51 inches) in diameter, were cut.
Additionally, four (4) pieces, also approximately 140 mm
(approximately 5.51 inches) in diameter, were cut from an
approximately 82.+-.1 .mu.m thick non-textured polymer film. The
non-textured side of a Ziploc.RTM. Vacuum Sealer bag from Johnson
& Johnson was used as the non-textured polymer film. However,
any non-textured polymer film, such as high density polyethylene
(HDPE), low density polyethylene (LDPE), polypropylene (PP), or
polyester, to name a few, could be used. Additionally, four (4) 38
mm diameter circular pieces were cut from a textured polymer film
with protruding passages on the surface to provide roughness. The
textured polymer film that is used for this test is the textured
side of a Ziploc.RTM. Vacuum Sealer bag from Johnson & Johnson.
The textured film has a square-shaped pattern (FIG. 8). The
thickness of the protruding passages of the textured polymer film
that are used are approximately 213.+-.5 .mu.m and the thickness of
the film in the valley region of the textured film between the
protruding passages are approximately 131.+-.5 .mu.m. The samples
were cut using respective 140 mm diameter and 38 mm cutting dies
and a clicker press.
[0060] An example of an abrading table used in conjunction with the
M235 tester is shown in FIG. 5. FIG. 5 presents an exploded view of
the attachment of a towel sample to an abrading table 202. To
insert each sample to be tested in an abrading table, the motion
plate 204 of an abrading table was removed from the tester, a clamp
ring 214 was unscrewed, a piece of smooth polymer film 210 was
placed on the abrading table 202, and a towel sample 212 was then
placed on top of the smooth polymer film 210. A loading weight 215,
shown in FIG. 6, was temporarily placed on top of the sample 212 on
the abrading table 202 to hold everything in place while the clamp
ring 214 was reattached to abrading table 202 to hold the towel
sample 212 in place.
[0061] Referring to FIG. 7, for each abrading table 202 in the M235
tester, there is a corresponding specimen holder 206 to perform the
abrasion testing. The specimen holder 206 was assembled by
inserting a piece of the textured polymer film 216 within a
specimen holder insert 218 that is placed beneath and held in place
under a specimen holder body 220 with a specimen holder nut (not
shown). A spindle 222 was mounted to the top center of the specimen
holder body 206. A top view of the textured polymer film 216 of
FIG. 7 is shown in FIG. 8.
[0062] The M235 tester was then turned on and set for a cycle time
of 200 revolutions. 0.5 mL of water was placed on each towel
sample. After a 30 second wait, the scrubbing test was initiated,
thereby causing the specimen holder 206 to rotate 200 revolutions.
The number of revolutions that it took to break each sample on the
respective abrading table 202 (the "web scrubbing resistance" of
the sample) was recorded. The results for the samples of each
product were averaged and the products were then rated based on the
averages.
[0063] Table 1 lists the results of abrasion tests performed on the
indicated products, the dates on which the tests were performed,
and the number of revolutions that the respective product remained
intact before it broke. Table 1 also lists the basis weight of each
product that was calculated according to the basis weight test
described above.
TABLE-US-00001 TABLE 1 Paper Towel Wet Scrub and Basis Weight
Testing Wet Basis Scrub Weight Date Product Name Revolutions
g/m{circumflex over ( )}2 Mar. 20, 2014 Bounty Duratowel .RTM. 244
62 May 19, 2014 Bounty Duratowel .RTM. 82 62 Aug. 5, 2014 Bounty
Duratowel .RTM. 200 62 Jun. 1, 2014 Example # 1 130 39 Mar. 20,
2014 Viva Vantage .RTM. 13 61 May 19, 2014 Bounty Basic .RTM. 73
36-38 May 19, 2014 Wegmans .RTM. 26 44 May 19, 2014 Weis .TM. 8
42-43 May 19, 2014 Up & Up .RTM.-Target 22 43-45 May 30, 2014
Up & Up .RTM.-Target 29 43-45 Aug. 5, 2014 Up & Up
.RTM.-Target 68 43-45 May 19, 2014 Brawny .RTM. 7 46-50 Aug. 5,
2014 Brawny .RTM. 39 46-50 May 30, 2014 Great Value .TM. 23 42-44
May 30, 2014 Members Mark .RTM.-Walmart 33 43 May 30, 2014 Kirkland
Signature .RTM. Costco 34 40-41 Aug. 5, 2014 Kirkland Signature
.RTM. Costco 43 40-41 May 30, 2014 Safeway S .RTM. 17 44-45 Aug. 5,
2014 Sparkle .RTM. 36 44-46 May 19, 2014 Bounty .RTM. 60 47-50 May
19, 2014 Bounty .RTM. 42 47-50 May 30, 2014 Bounty .RTM. 62 47-50
Aug. 5, 2014 Bounty Extra Soft .RTM. 62 55-57
[0064] It is apparent from the test results that the present
invention achieves a laminate with superior web scrubbing
resistance of greater than 120 revolutions while maintaining a
relatively low basis weight, such as a basis weight approximately
at or below 50 g/m.sup.2 and preferably at a basis weight at or
above 30 g/m.sup.2.
[0065] Moreover, the multi-ply absorbent product of the present
invention is strong and has excellent absorptive properties.
Various additional tests can be performed to verify the superior
absorptive properties and strength of the laminate formed by the
present invention. They include ball burst testing, stretch &
MD, CD and wet CD tensile strength testing, caliper testing and
absorbency testing.
Ball Burst Testing
[0066] The Ball Burst of a 2-ply tissue web was determined using a
Tissue Softness Analyzer (TSA), available from emtec Electronic
GmbH of Leipzig, Germany using a ball burst head and holder. A
punch was used to cut out five 100 cm.sup.2 round samples from the
web. One of the samples was loaded into the TSA, with the embossed
surface facing down, over the holder and held into place using the
ring. The ball burst algorithm was selected from the list of
available softness testing algorithms displayed by the TSA. The
ball burst head was then pushed by the TSA through the sample until
the web ruptured and calculated the grams force required for the
rupture to occur. The test process was repeated for the remaining
samples and the results for all the samples were averaged.
Stretch & MD, CD, and Wet CD Tensile Strength Testing
[0067] An Instron 3343 tensile tester, manufactured by Instron of
Norwood, Mass., with a 100N load cell and 25.4 mm rubber coated jaw
faces was used for tensile strength measurement. Prior to
measurement, the Instron 3343 tensile tester was calibrated. After
calibration, 8 strips of 2-ply product, each 2.54 cm by 10.16 cm
(one inch by four inches), were provided as samples for each test.
When testing MD (Material Direction) tensile strength, the strips
are cut in the MD direction. When testing CD (Cross Direction)
tensile strength, the strips are cut in the CD direction. One of
the sample strips was placed in between the upper jaw faces and
clamp, and then between the lower jaw faces and clamp with a gap of
5.08 cm (2 inches) between the clamps. A test was run on the sample
strip to obtain tensile strength and stretch. The test procedure
was repeated until all the samples were tested. The values obtained
for the eight sample strips were averaged to determine the tensile
strength of the tissue. When testing CD wet tensile, the strips are
placed in an oven at 105 degrees Celsius for 5 minutes and
saturated with 75 microliters of deionized water immediately prior
to pulling the sample.
Caliper Testing
[0068] A Thwing-Albert ProGage 100 Thickness Tester, manufactured
by Thwing Albert of West Berlin, N.J. was used for the caliper
test. Eight 100 mm.times.100 mm square samples were cut from a
2-ply product. The samples were then tested individually and the
results were averaged to obtain a caliper result for the base
sheet.
Absorbency Testing
[0069] An absorbency test may also be run to determine absorption
characteristics of the product. One such test may be performed
using a Gravimetric Absorption Testing System (GATS) from M/K
Systems Inc. of Peabody, Mass. In this test, a sample is wet with a
liquid, generally water, and the testing equipment records the mass
of liquid that is absorbed as time progresses. This test may be run
with 100 cm.sup.2 samples.
[0070] The effectiveness of the lamination method of the present
invention to achieve previously unattainable levels of scrubbing
performance at particularly low basis weights is illustrated by the
following example.
EXAMPLE #1
[0071] A paper towel made on a wet-laid asset with a three layer
headbox was produced using the through air dried (TAD) method. The
paper towel was dried on a TAD fabric, Prolux 593, supplied by
Albany International of Rochester, N.H. The TAD fabric was a 13
shed design with 12.0 yarn/cm Mesh and Count, a 0.35 mm warp
monofilament, a 0.50 mm weft monofilament, a 1.29 mm caliper, with
a 670 cubic feet per minute (cfm) and a knuckle surface that is
sanded to impart 12% contact area with the yankee dryer. The air
layer 4, or outer layer, of the finished tissue was placed on the
TAD fabric, while the dry layer of the tissue was closest to the
surface of the Yankee dryer. The flow to each layer of the headbox
was maintained at about 33% of the total sheet.
[0072] The tissue was produced with approximately 20% eucalyptus,
15% Cannabis bast fiber, and 65% northern bleached softwood kraft
(NBSK) fibers. The Yankee layer fiber was approximately 50%
eucalyptus, 50% NBSK. Polyamine polyamide-epichlorohydrin resin at
10 kg/ton (dry basis) and 4 kg/ton (dry basis) of carboxymethyl
cellulose were added to each of the three layers to generate
permanent wet strength.
[0073] Using the method described above with reference to FIG. 3,
the towel was plied together as a laminate of the two tissues to
create a rolled 2-ply product with 142 sheets, a roll diameter of
142 mm, with sheets having a length of 15.24 cm (6.0 inches) and
width of 27.94 cm (11 inches). The 2-ply tissue product was found
to have approximately the following product attributes: a Basis
Weight of 39 g/m2, a Caliper of 0.850 mm, an MD tensile of 385 N/m,
a CD tensile of 365 N/m, a ball burst of 820 grams force, an MD
stretch of 18%, a CD stretch of 6%, a CD wet tensile of 105 N/m, an
absorbency of 750 gsm (grams per square meter) and a Wet Scrubbing
resistance of 130 revolutions.
[0074] Now that embodiments of the present invention have been
shown and described in detail, various modifications and
improvements thereon will become readily apparent to those skilled
in the art. Accordingly, the spirit and scope of the present
invention is to be construed broadly and not limited by the
foregoing specification.
* * * * *