U.S. patent application number 15/432012 was filed with the patent office on 2018-08-16 for paper towel.
The applicant listed for this patent is NIPPON PAPER INDUSTRIES CO.,LTD., NIPPON PAPER INDUSTRIES USA CO.,LTD.. Invention is credited to Robert Feller, Steve Johnson, Taichi Watanabe.
Application Number | 20180230654 15/432012 |
Document ID | / |
Family ID | 63106295 |
Filed Date | 2018-08-16 |
United States Patent
Application |
20180230654 |
Kind Code |
A1 |
Johnson; Steve ; et
al. |
August 16, 2018 |
PAPER TOWEL
Abstract
The present invention relates to a paper towel that can be
provided with dry crepes with no need for involving a large
equipment investment. The paper towel contains one or more of
chemical pulp, mechanical pulp, de-inked pulp, and recycled pulp,
being provided with crepes in an off-machine process by use of a
microcreper, such as a MICREX.RTM./Microcreper.TM. system, and
having a basis weight of 32.2 to 64.3 gsm, a density of 0.130 to
0.150 g/cm.sup.3, which is obtained by dividing the basis weight by
the caliper (.mu.m), and the number of crepes (cpi) of 12 to
30.
Inventors: |
Johnson; Steve; (Port
Angeles, WA) ; Feller; Robert; (Port Angeles, WA)
; Watanabe; Taichi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NIPPON PAPER INDUSTRIES USA CO.,LTD.
NIPPON PAPER INDUSTRIES CO.,LTD. |
Port Angeles
Tokyo |
WA |
US
JP |
|
|
Family ID: |
63106295 |
Appl. No.: |
15/432012 |
Filed: |
February 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D21H 11/14 20130101;
D21H 11/02 20130101; D21H 27/005 20130101; D21H 11/08 20130101;
D21H 25/005 20130101; D21H 27/002 20130101 |
International
Class: |
D21H 27/00 20060101
D21H027/00 |
Claims
1. A paper towel, comprising one or more of chemical pulp,
mechanical pulp, and recycled pulp, and provided with crepes
imparted by a microcreper in an off-machine process, the paper
towel having a basis weight of 32.2 to 64.3 gsm, a density, which
is the basis weight divided by the caliper (.mu.m), of 0.130 to
0.150 g/cm.sup.3, and the number of crepes (cpi) of 12 to 30.
2. The paper towel according to claim 1, having a longitudinal
stiffness of 170 to 240 mNm, and a water absorption of 250 to 420
sec/100 .mu.L.
3. The paper towel according to claim 1, wherein the off-machine
process for providing crepes is by use of a
MICREX.RTM./Microcreper.TM. system.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a paper towel, and more
particularly relates to a paper towel that can be provided with dry
crepes with no need for involving a large equipment investment. In
addition, the present invention relates to a rolled paper towel,
having a moderate stiffness, softness, and water absorbency, and
being suitable for "Away From home", in commercial and industrial
settings such as office and government buildings, hotels, schools,
airports, amusement parks, hospitals, highway rest stops--anywhere
restroom and kitchen facilities are not in a private home.
Description of the Related Art
[0002] In U.S. Pat. No. 7,449,085B2, there are disclosed absorptive
paper products, such as paper towels, having a combination of a
high absorbent capacity and a moderate to low rate of absorbency
for hand protection. More particularly, there is disclosed a
low-density paper product having one or more plies essentially
composed of hardwood kraft pulp, softwood kraft pulp, or blends
thereof, and having a discontinuous moisture retardant coating on
the surface thereof.
[0003] In Example 3 given in the 14th to 15th columns in the same
U.S. Pat. No. 7,449,085B2 patent document, there is disclosed a
paper towel that has a basis weight of 58.4 grams per square meter
(gsm) and a crepe ratio of 20%, being produced by use of an
MICREX.RTM./Microcreper system, which is manufactured by Micrex
Corporation. The density of the paper product (as measured by Bulk
values) is defined to be preferably 10 cubic centimeters or greater
per gram (under 0.10 g/cm.sup.3).
[0004] U.S. Pat. No. 7,449,085B2 also disclosed a nonwoven fabric
that is provided with crepes by use of an MICREX.RTM./Microcreper
system. The paper towels disclosed in U.S. Pat. No. 7,449,085B2 are
composed mainly of a virgin pulp, thereby being inevitably
expensive.
[0005] Citation of any document herein is not intended as an
admission that such document is pertinent prior art, or considered
material to the patentability of any claim of the present
application. Any statement as to content or a date of any document
is based on the information available to applicant at the time of
filing and does not constitute an admission as to the correctness
of such a statement.
SUMMARY OF THE INVENTION
[0006] In view of the problem of the paper towel in US74490985
being expensive, the present invention has been made to provide a
paper towel that is not only inexpensive but also has a high
productivity, containing inexpensive recycled pulp, especially
de-inked pulp, OCC (Old Corrugated Container) pulp, or the like,
and that can be adjusted for hue through appropriate adjustment of
the contents of chemical pulp, mechanical pulp, de-inked pulp, and
recycled pulp.
[0007] In addition, the present invention provides a paper towel
for which the original fabric for crepe processing can be
conveniently obtained with no need for involving a large equipment
investment, and thus the paper towel can be efficiently and
inexpensively manufactured, being provided with a moderate
stiffness, softness, and water absorbency.
[0008] As a result of an intensive study to solve the above
problem, the inventors of the present invention have conceived an
idea of using inexpensive de-inked pulp or recycled pulp, while
performing off-line crepe processing to provide an original fabric
with a moderate stiffness, softness, and water absorbency, and thus
have completed the present invention.
[0009] In other words, the present invention provides a paper towel
that contains one or more of chemical pulp, mechanical pulp,
de-inked pulp, and recycled pulp, being provided with crepes in an
off-machine process, such as by use of an
MICREX.RTM./Microcreper.TM. system, and having a basis weight of
32.2 to 64.3 gsm, a density of 0.130 to 0.150 g/cm.sup.3, which is
the basis weight divided by the caliper (.mu.m), and the number of
crepes (cpi; crepes per inch) of 12 to 30.
[0010] In one embodiment, the longitudinal stiffness is 170 to 240
mNm, and the water absorbency is 250 to 420 sec/100 .mu.L.
[0011] The present invention is as described above, and since it
provides an elongation for an original fabric in off-line crepe
processing, there is no need for involving a large equipment
investment, and thus a creped product can be conveniently obtained,
whereby the present invention offers the advantage that a paper
towel having a moderate stiffness, softness, and water absorbency
can be obtained efficiently at a low cost.
DETAILED DESCRIPTION OF THE INVENTION
[0012] A paper towel in accordance with the present invention
contains one or more of chemical pulp, mechanical pulp, de-inked
pulp, and recycled pulp, being provided with crepes, such as in an
off-machine process by use of an MICREX.RTM./Microcreper.TM.
system, and having a basis weight of 32.2 to 64.3 gsm, a density of
0.130 to 0.150 g/cm.sup.3, which is obtained by dividing the basis
weight by the caliper (.mu.m), and the number of crepes (cpi) of 12
to 30. In addition, the paper towel has a longitudinal stiffness of
170 to 240 mNm, and a water absorbency of 250 to 420 sec/100
.mu.L.
[0013] In this way, by containing inexpensive de-inked pulp or
recycled pulp, a paper towel that is inexpensive and has a high
productivity can be obtained. In addition, by appropriately
adjusting the contents of chemical pulp, mechanical pulp, and
recycled pulp, adjustment of the hue of the paper towel can be
achieved.
[0014] As the pulp for the paper towel, a well-known pulp can be
used, and specifically, as the chemical pulp, NBKP, NUKP, LBKP,
LUKP, NBSP, NUSP, LBSP, LUSP, and the like can be used. As the
mechanical pulp, GP, TMP, CTMP, and the like can be used. As the
recycled pulp, waste paper pulps, such as de-inked pulp, OCC (Old
Corrugated Container) pulp, and NCC (New Corrugated Container)
pulp, can be used.
[0015] By providing crepes to the paper towel in an off-machine
process by use of an MICREX.RTM./Microcreper.TM. system to give a
specific number of crepes (cpi), a paper towel having a moderate
softness and stiffness can be obtained. Further, there is no need
for a large equipment investment, and a compact facility can be
used for producing the present invention. In addition, the adhesive
to be applied to the dryer cylinder, the release agent, and the
doctor blade, which are used at the time of off-machine creping,
can be conveniently managed. In particular, the
MICREX.RTM./Microcreper.TM. system, which is manufactured by Micrex
Corporation, has a width of 1,067 to 3,150 mm and is compact (and
thus effective for implementing the present invention) is a
preferred off-machine process for producing crepes on a paper
towel.
[0016] The microcreping process employed is preferably the
microcreping process commercially available from the Micrex
Corporation, Walpole, Mass. 02081, referred to as
MICREX.RTM./Microcreper.TM., but is not limited thereto, as other
suitable microcreping process and system may be used. In the
microcreping process, using a microcreper such as the
MICREX.RTM./Microcreper.TM. system, a pressure plate applies a
predetermined amount of pressure extending across the path of a
continuously supplied planar sheet of paper. The sheet is carried
by a rotating drive roll on which the pressure is imparted through
the sheet and against the rotating drive roll. The rotating drive
roll has either a grooved surface or a flat (non-grooved) surface.
While the sheet is under applied pressure, it then further impinges
upon a flat retarding surface. The sheet is directed to the space
between the retarding surface and a creping blade positioned in the
path of the sheet. The creping blade is flat when the drive roll
surface is flat. The creping blade is combed when the drive roll
surface is grooved. The retarding surface in combination with the
applied pressure induces the sheet into a creped form, with a
resulting distortion of the planar aspect of the original
sheet.
[0017] By specifying the basis weight to be within the above range
of 32.2 to 64.3 gsm, a paper towel that is excellent in strength
and productivity can be obtained. In addition, by specifying the
density to be within the above range of 0.13 to 0.150 g/cm.sup.3, a
paper towel that has the properties of moderate softness and
stiffness can be obtained.
[0018] As stated above, the number of crepes (cpi) of the paper
towel in accordance with the present invention is specified to be
in the range of 12 to 30. By specifying the number of crepes (cpi)
to be within this range, a paper towel having a moderate softness
and stiffness can be obtained. In addition, by specifying the
number of crepes (cpi) to be 12 to 30, the surface area is
increased along with water absorption efficiency, and the dirt and
dust that are picked up between crepes thereby provides improved
dirt and dust removal performance when the paper towel of the
present invention is used for cleaning by wiping off. In addition,
the range of the number of crepes (cpi) being 12 to 30 also
provides a moderate stiff feel, so that the paper towel of the
present invention is suitable as a rolled paper towel for use in
lavatories and the like in public facilities, such as sports
grounds and movie houses.
[0019] The paper towel in accordance with the present invention has
a longitudinal stiffness of 170 to 240 mNm and a water absorbency
of 250 to 420 sec/100 .mu.L. In the case where the longitudinal
stiffness and the water absorbency are in these ranges, a paper
towel having a moderate stiffness and a moderate water absorbency
can be achieved.
[0020] The number of crepes (cpi), which is defined as the number
of irregularities per inch, is effective for use as an index of
touch feel and water absorbency. The number of crepes (cpi) is
preferably 12 or over, and it is particularly preferable to be in
the range of 20 to 25. If the number of crepes (cpi) is under 12,
the paper towel after processing is hard and inferior in touch
feel, with the speed of water absorption speed being slow,
resulting in a paper towel that is functionally insufficient. On
the other hand, if the number of crepes (cpi) is over 12, a soft
paper towel is provided that is both good in touch feel and water
absorption speed.
[0021] It is preferable that the longitudinal stiffness be 170 to
240 mNm. In the case where the longitudinal stiffness is in this
range, a moderate stiffness as a paper towel for use in lavatories
in public facilities, for example, can be obtained. In addition, it
is preferable that the water absorbency of a paper towel for use in
towel applications be under the range of 250 to 420 sec/100
.mu.L.
[0022] Although the off-line crepe processing allows various
elongations to be provided, it is most suitable to provide an
elongation of 5 to 10% as that in the direction of MD. In the case
where the elongation is in this range, there is no problem in small
roll processing and emboss processing. If the elongation is under
5%, such an insufficient elongation causes a hole to be produced in
the emboss processing, resulting in paper breakage, or pores to be
produced, thereby causing a problem with operation and quality. On
the other hand, if the elongation exceeds 10%, the tension at the
time of small roll processing with a converter after, for example,
the emboss processing of a creped paper is not stable, thereby
causing a problem, such as an unsatisfactory roll figure of the
small roll.
[0023] The paper towel in accordance with the present invention can
be produced with all types of paper making machines, including
well-known Fourdrinier machines, twin-wire paper machines (include
gap former, hybrid former), cylinder paper machines, and Yankee
paper machines. In addition, the paper towel in accordance with the
present invention is produced mainly by single-layer paper making;
however, it can also be produced by multiple layer paper making. In
addition, a wet strength agent or a rosin size agent, such as a
polyamide epichlorohydrin agent, can be added to the
above-mentioned pulp slurry as a raw material as needed for paper
making.
[0024] By selecting the pulp formulation, the hue can be adjusted
to what is desired by a particular customer. Examples of pulp
formulation are provided as follows: For brown 1, NUKP of 5%, RGP
of 25 to 35%, and OCC of 60 to 70%; for brown 2, NUKP of 5 to 10%,
RGP of 30 to 40%, and OCC of 50 to 65%; and for natural color, NBKP
of 5 to 10%, RGP of 30 to 60%, and DIP of 30 to 60%.
[0025] Having now generally described the invention, the same will
be more readily understood through reference to the following
example which is provided by way of illustration and is not
intended to be limiting of the present invention.
Example
[0026] Creped paper towels that were obtained by using an
MICREX.RTM./Microcreper.TM. system (having a width of 3,150 mm)
from the original fabric for crepe processing that was produced by
a twin-wire paper machine were evaluated. As a processing condition
for the MICREX.RTM./Microcreper.TM. system, by specifying a uniform
microcreping speed of 140 mm/min (450 fpm), and varying the
compaction ratio expressed as percentage (which is the difference
in paper drawing speed between the Microcreper and the winder that
is expressed as %), Examples 1 to 3 and Controls 1 to 3 were
prepared. Control 1 did not meet the specifications for density,
which is basis weight divided by caliper (.mu.m), longitudinal
stiffness, and crepe number of the present invention; Control 2 did
not meet the specification for the above-described density of the
present invention; and Control 3 did not meet the specifications
for the above-described density and crepe number of the present
invention.
Test and Evaluation Methods
[0027] The test and evaluation methods are presented in Table 1. As
can be seen from the results in Table 1 below, Examples 1 to 3,
which meet all the specifications of the paper towel of the present
invention, were evaluated to be good or excellent on all the points
of converting, softness, and water absorbency. Caliper is measured
by the thickness micrometer of B.C.Ames Inc. "Model number: 2W"
[0028] Having now fully described this invention, it will be
appreciated by those skilled in the art that the same can be
performed within a wide range of equivalent parameters,
concentrations, and conditions without departing from the spirit
and scope of the invention and without undue experimentation.
[0029] While this invention has been described in connection with
specific embodiments thereof, it will be understood that it is
capable of further modifications. This application is intended to
cover any variations, uses, or adaptations of the inventions
following, in general, the principles of the invention and
including such departures from the present disclosure as come
within known or customary practice within the art to which the
invention pertains and as may be applied to the essential features
hereinbefore set forth as follows in the scope of the appended
claims.
[0030] All references cited herein, including journal articles or
abstracts, published or corresponding U.S. or foreign patent
applications, issued U.S. or foreign patents, or any other
references, are entirely incorporated by reference herein,
including all data, tables, figures, and text presented in the
cited references. Additionally, the entire contents of the
references cited within the references cited herein are also
entirely incorporated by references.
[0031] Reference to known method steps, conventional methods steps,
known methods or conventional methods is not in any way an
admission that any aspect, description or embodiment of the present
invention is disclosed, taught or suggested in the relevant
art.
[0032] The foregoing description of the specific embodiments will
so fully reveal the general nature of the invention that others
can, by applying knowledge within the skill of the art (including
the contents of the references cited herein), readily modify and/or
adapt for various applications such specific embodiments, without
undue experimentation, without departing from the general concept
of the present invention. Therefore, such adaptations and
modifications are intended to be within the meaning and range of
equivalents of the disclosed embodiments, based on the teaching and
guidance presented herein. It is to be understood that the
phraseology or terminology herein is for the purpose of description
and not of limitation, such that the terminology or phraseology of
the present specification is to be interpreted by the skilled
artisan in light of the teachings and guidance presented herein, in
combination with the knowledge of one of ordinary skill in the
art.
TABLE-US-00001 TABLE 1 density (basis Evaluation of effect Basis
weight/ MD Water Number (sensory evaluation) Microcreper weight
Caliper caliper) stiffness absorbency of crepes Water condition gsm
.mu.m g/cm.sup.3 mN m sec/100 .mu.L cpi Converting Stiffness
absorbency Example 1 5.0 37.4 244 0.153 224 387 21 Good Excellent
Good Example 2 5.2 35.2 267 0.132 179 293 18 Good Good Excellent
Example 3 6.2 37.0 263 0.141 197 267 23 Good Excellent Excellent
Control 1 3.1 35.1 324 0.108 291 576 9 No good No good No good
Control 2 8.4 38.0 336 0.113 199 481 18 No good Good Good Control 3
3.7 33.9 378 0.090 204 912 10 No good No good No good Evaluation
ISO536: Measured ISO534: ISO2493- Water Original Ease of Touch
Water method 2012 by the 2011 2: absorption creping feeling
absorbency thickness 2011 time when and when water micrometer water
drop sharpness drop of of 100 .mu.L of crepes; of 100 .mu.L
B.C.Ames is dropped total is dropped Inc. evaluation "Model number:
2 W"
* * * * *