U.S. patent application number 16/846322 was filed with the patent office on 2020-07-30 for lightweight paper board.
The applicant listed for this patent is FLEX R&D, INC.. Invention is credited to PRAKASH MALLYA.
Application Number | 20200240080 16/846322 |
Document ID | 20200240080 / US20200240080 |
Family ID | 1000004752419 |
Filed Date | 2020-07-30 |
Patent Application | download [pdf] |
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United States Patent
Application |
20200240080 |
Kind Code |
A1 |
MALLYA; PRAKASH |
July 30, 2020 |
Lightweight Paper Board
Abstract
A fibrous material, method for making the same, and articles
comprising the same are shown and described. The fibrous material
is a low density material that exhibits high strength properties.
In embodiments, the fibrous material has a density of 0.15
g/cm.sup.3 or less and a tensile strength of 10 N/inch or greater.
The fibrous material may be in the form of a paperboard and is
suitable for use in a variety of applications including as a
packaging material.
Inventors: |
MALLYA; PRAKASH; (SIERRA
MADRE, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FLEX R&D, INC. |
Berkeley Hills |
CA |
US |
|
|
Family ID: |
1000004752419 |
Appl. No.: |
16/846322 |
Filed: |
April 11, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16481820 |
Oct 7, 2019 |
10640925 |
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PCT/US18/17930 |
Feb 13, 2018 |
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16846322 |
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62459119 |
Feb 15, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D21H 11/10 20130101;
D21F 11/002 20130101; D21H 27/10 20130101; D21H 27/30 20130101;
D21H 21/24 20130101; D21H 17/55 20130101 |
International
Class: |
D21F 11/00 20060101
D21F011/00; D21H 27/30 20060101 D21H027/30; D21H 27/10 20060101
D21H027/10; D21H 21/24 20060101 D21H021/24; D21H 17/55 20060101
D21H017/55; D21H 11/10 20060101 D21H011/10 |
Claims
1. A composition forming a foamed structure, comprising: (a) a
fibrous material selected from a group including a cellulosic
fiber, or a combination of the cellulosic fiber and a synthetic
fiber; (b) a fibrillated cellulose selected from a group including
a microfibrillated cellulose, a nanofibrillated cellulose, or a
combination thereof, a concentration of the fibrillated cellulose
being up to about 10 wt %; (c) a cross-linker, said cross-linker
being a polyaminoamide epichlorohydrin, the concentration of the
cross-linker being up to about 2.5 wt %; (d) a surfactant; (e)
water; wherein: the foamed structure that contains the fibrillated
cellulose at the concentration in (b) above and does not contain
the cross-linker has an average dry tensile strength less than the
average dry tensile strength of the foamed structure that contains
both the fibrillated cellulose at the concentration in (b) above
and the cross-linker at the concentration in (c) above; the foamed
structure that contains the cross-linker at the concentration in
(c) above and does not contain the fibrillated cellulose has the
average dry tensile strength less than the average dry tensile
strength of the foamed structure that contains both the fibrillated
cellulose at the concentration in (b) above and the cross-linker at
the concentration in (c) above; and the cross-linker forms bridges
between the cellulosic fiber and the microfibrillated cellulose, or
between the cellulosic fiber and the nanofibrillated cellulose, or
between the microfibrillated cellulose and the nanofibrillated
cellulose.
2. The composition of claim 1, wherein the microfibrillated
cellulose or the nanofibrillated cellulose or the combination of
the microfibrillated cellulose and the nanofibrillated cellulose is
present in an amount greater than 3.5 wt % based on the dry weight
of the fibrous material.
3. The composition of claim 1, wherein the foamed structure has a
density less than about 0.15 g/cc.
4. The composition of claim 1, wherein the microfibrillated
cellulose or the nanofibrillated cellulose or the combination of
the microfibrillated cellulose and the nanofibrillated cellulose is
present in an amount of from about 3.5 wt % to about 10 wt % based
on the dry weight of the fibrous material.
5. The composition of claim 1, wherein the microfibrillated
cellulose or the nanofibrillated cellulose or the combination of
the microfibrillated cellulose and the nanofibrillated cellulose is
present in an amount of from about 4 wt % to about 9 wt % based on
the weight of dry fibrous material.
6. The composition of claim 1, wherein the microfibrillated
cellulose or the nanofibrillated cellulose or the combination of
the microfibrillated cellulose and the nanofibrillated cellulose is
present in an amount of from about 5 wt % to about 7.5 wt % based
on the weight of dry fibrous material.
7. The composition of claim 1, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
8. The composition of claim 1, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 0.75 wt % to
about 2 wt %, based on the dry weight of the fibrous material.
9. The composition of claim 1, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 1 wt % to
about 1.5 wt %, based on the dry weight of the fibrous
material.
10. The composition of claim 1, wherein the fibrillated cellulose
is present in an amount of from about 3.5 wt % to about 10 wt %
based on the dry weight of the fibrous material, and the
polyaminoamide epichlorohydrin is present in an amount of from
about 0.5 wt % to about 2.5 wt %, based on the dry weight of the
fibrous material.
11. The composition of claim 10, wherein the composition is formed
from a slurry comprising from about 30% by volume to about 60% by
volume of a gas entrained therein.
12. The composition of claim 11, wherein the gas is chosen from a
group including air, nitrogen, oxygen, argon, carbon dioxide, or
combination thereof.
13. A foamed paperboard formed from the composition of claim
12.
14. The foamed paperboard of claim 13, wherein the foamed
paperboard has the average dry tensile strength of 10 N/inch or
greater.
15. An article comprising the foamed paperboard material of claim
14.
16. The article of claim 15 in the form of a container comprising
three or more walls defining an opening between the walls, wherein
at least one of the walls comprises the foamed paperboard
material.
17. The article of claim 16, wherein the at least one of the walls
comprising the foamed paperboard material is a multilayer
structure, and at least one of the layers is formed from the foamed
paperboard material.
18. The article of claim 16, wherein the at least one of the walls
comprising the foamed paperboard material is a multilayer structure
comprising (i) the foamed paperboard, and (ii) at least a second
paperboard having a tensile strength of greater than 10 N/inch.
19. The article of article of claim 17, wherein the multilayer
structure comprises (i) the foamed paperboard disposed between (ii)
a first paperboard material having tensile strength greater than 10
N/inch and a second paperboard material having a tensile strength
of greater than 10 N/inch.
20. The article of claim 17, wherein the multilayer structure
comprises (i) a first foamed paperboard having tensile strength of
greater than 10 N/inch having an upper surface and a lower surface,
(ii) an upper layer disposed on the upper surface of the first
foamed paperboard, and (iii) a lower layer disposed on the lower
surface of the first foamed paperboard, wherein the upper and lower
layers are formed from a second and a third low foamed
paperboard.
21. The article of claim 17, wherein the multilayer structure
comprises (i) a first foamed paperboard having tensile strength of
greater than 10 N/inch having an upper surface and a lower surface,
(ii) an upper layer disposed on the upper surface of the first
foamed paperboard, and (iii) a lower layer disposed on the lower
surface of the first foamed paperboard, wherein the upper and lower
layers are formed from films selected from a group including a
cellulose based film, a synthetic material film, a metallized film,
wherein the upper and the lower layers comprise one or more
properties selected from a group including barrier to gas, barrier
to water, insulation and heat reflection.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 16/481,820 filed Jul. 29, 2019 which is a 371
of international Application PCT/US18/17930 filed Feb. 13, 2018 and
claims priority to and the benefit of U.S. Provisional Patent
Application No. 62/459,119 filed on Feb. 15, 2017, the entire
disclosure of which is incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to a composition and method
for making a lightweight fibrous web, a paperboard formed from such
a fibrous web and an article comprising the paperboard material. In
particular, the present invention relates to a fibrous web that has
a low density and good mechanical properties and can be used to
form a paperboard product as may be used in a packaging
material.
BACKGROUND
[0003] The paper and paperboard industry is a $39 billion/year
industry in the United States. Dating back to the 1800s, paper has
been made by a process of taking wood or other fibers in water to
form a slurry and filtering and drying these slurries on a
continuous press. These slurries have a low solids content of the
range of 0.5 to 2% and require large amounts of energy to make the
finished product. Such paperboards made on a conventional paper
machine, such as a Fourdrinier, have densities of 0.3 g/cc or
higher depending on further processing such as calendaring. Such
paperboards are widely used for all kinds of packaging applications
by various industries.
[0004] Over the years, attempts have been made to make lower
density papers. U.S. Pat. No. 3,716,449 describes a process for
making non-woven webs using a foamed fiber dispersion. The examples
describe making filter papers, which are generally known to be weak
in strength. U.S. Pat. Nos. 3.871,952 and 4,994,843 focus on
improving the process of manufacturing such non-woven products.
U.S. Pat. No. 4,443,297 describes a method for making non-woven
fibrous webs using a foamable liquid that is deposited onto the
web.
[0005] An article published in the journal Cellulose (A. Madani, S.
Zeinoddini, S. Varahmi, H. Turnbull, A. B. Phillion, J. A. Olson
and D. M. Martinez, Feb. 18, 2014) describes a method for making
ultra-lightweight paper foams. This article describes a method for
making paper with ultra-low density (as low as 0.01 g/cc). The
mechanical properties described in the paper, however, are very
poor.
[0006] Although foam forming has been known and has been practiced
for some time, the key challenge that has stopped it becoming
mainstream is that the mechanical properties of the resulting foam
papers are too weak when the density is lowered.
[0007] U.S. Publication No. 2015/0114581 describes a method for
making foamed paper using microfibrillated cellulose (MFC). The
'581 publication describes using 5 to 40 wt % MFC along with 60 to
95 wt % pulp having a fiber length greater than the MFC and
achieving densities as low as 0.143 g/cc (bulk density of 7 cc/g).
The '581 publication describes that, with foamed paper, the
structure becomes bulkier (more porous and low density), which
leads to smaller tensile strength values. Although the mechanical
properties of the foamed paper containing MFC is described as being
improved relative to foamed papers containing no MFC, the relative
drop in mechanical properties of the foamed paper compared to the
products without foam is very significant. In particular, there is
a greater than 50% loss in mechanical property when the density is
lowered from 0.5 g/cc to 0.25 g/cc (400 j/m.sup.2 at a bulk density
of 2 cc/g or density of 0.5 g/cc compared to less than 200
j/m.sup.2 at a bulk density of 4 cc/g or density of 0.25 g/cc).
[0008] Strengthening additives have been used on the wet end of
making paperboard. Such agents include water-soluble polyimines,
anionic and cationic polyacrylamides, and cationic starches.
Despite this, foamed papers or paperboard with lower density and
pulp usage and mechanical properties equivalent to that of normal
paper are generally not available.
SUMMARY
[0009] The following presents a summary of this disclosure to
provide a basic understanding of some aspects. This summary is
intended to neither identify key or critical elements nor define
any limitations of embodiments or claims. Furthermore, this summary
may provide a simplified overview of some aspects that may be
described in greater detail in other portions of this
disclosure.
[0010] Provided is a composition for making a fibrous web, a
fibrous web made from such material, a paperboard formed from the
fibrous web, and an article formed from such a material. The
fibrous web has a low density and good mechanical properties. In
embodiments, the fibrous web and paperboard formed therefrom
exhibit a high tensile strength.
[0011] In one embodiment, the fibrous web has a density of about
0.15 g/cc or less.
[0012] In one embodiment, the fibrous web has a tensile strength of
about 10 N/inch or higher.
[0013] It has been found that a combination of polyaminoamide
epichlorohydrin (PAE) resin and a fibrillated cellulose provide a
fibrous web with a low density and excellent mechanical properties.
In one embodiment, a fibrous web with PAE at levels of about 0.5 to
about 2 wt % based on dry paper pulp, along with very low levels of
NFC and/or MFC (3.5 to 10 wt % based on dry paper pulp) provides a
paperboard foam having a density of less than 0.15 g/cc, even as
low as 0.02 g/cc, and a tensile strength that matches or exceeds
that of unfoamed paper with a density of 0.37 g/cc. While not being
bound to any particular theory, the PAE amine is believed to form a
crosslinked network with NFC or MFC and the paper fibers.
[0014] In one aspect, provided is a composition comprising: (a) a
fibrous material; (b) a fibrillated cellulose chosen from
microfibrillated cellulose, nanofibrillated cellulose, or a
combination thereof; (c) polyaminoamide epichlorohydrin; (d) a
surfactant; and (e) water.
[0015] In one embodiment, the fibrillated cellulose is present in
an amount of from about 3.5 wt % to about 10 wt % based on the dry
weight of the fibrous material.
[0016] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 4 wt % to about 9 wt % based on
the weight of dry fibrous material.
[0017] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 5 wt % to about 7.5 wt % based
on the weight of dry fibrous material.
[0018] In one embodiment, provided is a composition according to
any previous embodiment, wherein the polyaminoamide epichlorohydrin
is present in an amount of from about 0.5 wt % to about 2.5 wt %,
based on the dry weight of the fibrous material.
[0019] In one embodiment, provided is a composition according to
any previous embodiment, wherein the polyaminoamide epichlorohydrin
is present in an amount of from about 0.75 wt % to about 2 wt %,
based on the dry weight of the fibrous material.
[0020] In one embodiment, provided is a composition according to
any previous embodiment, wherein the polyaminoamide epichlorohydrin
is present in an amount of from about 1 wt % to about 1.5 wt %,
based on the dry weight of the fibrous material.
[0021] In one embodiment, provided is a composition according to
any previous embodiment, wherein the fibrillated cellulose is
present in an amount of from about 3.5 wt % to about 10 wt % based
on the dry weight of the fibrous material, and the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
[0022] In one embodiment, provided is a composition according to
any previous embodiment, wherein the composition is in the form of
a slurry and comprises from about 30% by volume to about 60% by
volume of a gas entrained therein. In one embodiment, the gas is
chosen from air, nitrogen, oxygen, argon, or carbon dioxide.
[0023] In another aspect, provided is a method for forming a
fibrous paperboard web comprising: (i) providing a composition
comprising: (a) a fibrous material; (b) fibrillated cellulose
chosen from microfibrillated cellulose, nanofibrilliated cellulose,
or a combination thereof: (c) epichlorohydrin: (d) a surfactant;
and (e) water;
(ii) mixing the composition in the presence of a gas to form a
foamed composition: (iii) supplying the foamed composition onto a
forming fabric: and (iv) dewatering the foamed composition to form
a dry fibrous paperboard product.
[0024] In one embodiment, the fibrillated cellulose is present in
an amount of from about 3.5 wt % to about 10 wt % based on the dry
weight of the fibrous material.
[0025] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 4 wt % to about 9 wt % based on
the weight of dry fibrous material.
[0026] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 5 wt % to about 7.5 wt % based
on the weight of dry fibrous material.
[0027] In one embodiment, provided is a method according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 0.5 wt % to about 2.5 wt %,
based on the dry weight of the fibrous material.
[0028] In one embodiment, provided is a method according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 0.75 wt % to about 2 wt %, based
on the dry weight of the fibrous material.
[0029] In one embodiment, provided is a method according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 1 wt % to about 1.5 wt %, based
on the dry weight of the fibrous material.
[0030] In one embodiment, provided is a method according to any
previous embodiment, wherein the fibrillated cellulose is present
in an amount of from about 3.5 wt % to about 10 wt % based on the
dry weight of the fibrous material, and the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
[0031] In one embodiment, provided is a method according to any
previous embodiment, wherein the composition is in the form of a
slurry and comprises from about 30% by volume to about 60% by
volume of a gas entrained therein. In one embodiment, the gas is
chosen from air, nitrogen, oxygen, argon, or carbon dioxide.
[0032] In still another aspect, provided is a foamed paperboard
comprising (a) a fibrous material; (b) a fibrillated cellulose
chosen from microfibrillated cellulose, nanofibrillated cellulose,
or a combination thereof; (c) polyaminoamide epichlorohydrin; and
(d) a surfactant.
[0033] In one embodiment, the fibrillated cellulose is present in
an amount of from about 3.5 wt % to about 10 wt % based on the dry
weight of the fibrous material.
[0034] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 4 wt % to about 9 wt % based on
the weight of dry fibrous material.
[0035] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 5 wt % to about 7.5 wt % based
on the weight of dry fibrous material.
[0036] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
[0037] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 0.75 wt % to
about 2 wt %, based on the dry weight of the fibrous material.
[0038] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the polyaminoamide
epichlorohydrin is present in an amount of from about 1 wt % to
about 1.5 wt %, based on the dry weight of the fibrous
material.
[0039] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the fibrillated cellulose is
present in an amount of from about 3.5 wt % to about 10 wt % based
on the dry weight of the fibrous material, and the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
[0040] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the paperboard comprises from
about 30% by volume to about 60% by volume of a gas entrained
therein. In one embodiment, the gas is chosen from air, nitrogen,
oxygen, argon, or carbon dioxide.
[0041] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the paperboard has a density of
about 0.15 g/cm.sup.3 or less.
[0042] In one embodiment, provided is a foamed paperboard according
to any previous embodiment, wherein the paperboard as a tensile
strength of 10 N/inch or greater.
[0043] In still another aspect, provided is an article comprising a
foamed paperboard material, the foamed paperboard material
comprising (a) a fibrous material; (b) a fibrillated cellulose
chosen from microfibrillated cellulose, nanofibrillated cellulose,
or a combination thereof; (c) polyaminoamide epichlorohydrin; and
(d) a surfactant.
[0044] In one embodiment, the fibrillated cellulose is present in
an amount of from about 3.5 wt % to about 10 wt % based on the dry
weight of the fibrous material.
[0045] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 4 wt % to about 9 wt % based on
the weight of dry fibrous material.
[0046] In one embodiment, wherein the fibrillated cellulose is
present in an amount of from about 5 wt % to about 7.5 wt % based
on the weight of dry fibrous material.
[0047] In one embodiment, provided is an article according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 0.5 wt % to about 2.5 wt %,
based on the dry weight of the fibrous material.
[0048] In one embodiment, provided is an article according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 0.75 wt % to about 2 wt %, based
on the dry weight of the fibrous material.
[0049] In one embodiment, provided an article according to any
previous embodiment, wherein the polyaminoamide epichlorohydrin is
present in an amount of from about 1 wt % to about 1.5 wt %, based
on the dry weight of the fibrous material.
[0050] In one embodiment, provided is an article according to any
previous embodiment, wherein the fibrillated cellulose is present
in an amount of from about 3.5 wt % to about 10 wt % based on the
dry weight of the fibrous material, and the polyaminoamide
epichlorohydrin is present in an amount of from about 0.5 wt % to
about 2.5 wt %, based on the dry weight of the fibrous
material.
[0051] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard comprises from about
30% by volume to about 60% by volume of a gas entrained therein. In
one embodiment, the gas is chosen from air, nitrogen, oxygen,
argon, or carbon dioxide.
[0052] In one embodiment, provided is an article according to any
previous embodiment in the form of a container comprising three or
more walls defining an opening between the walls, wherein at least
one of the walls comprises the foamed paperboard material.
[0053] In one embodiment, the at least one of the walls comprising
the foamed paperboard material is a multilayer structure, and at
least one of the layers is formed from the foamed paperboard
material.
[0054] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard has a density of about
0.15 g/cm.sup.3 or less.
[0055] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard as a tensile strength
of 10 N/inch or greater.
[0056] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard has a tensile strength
of 10 N/inch to about 40 N/inch.
[0057] In still yet a further aspect, provided is an article
comprising a paperboard, the paperboard comprising a low density
foamed paperboard having a density of 0.15 g/cm.sup.3 or less and a
tensile strength of 10 N/inch or greater.
[0058] In one embodiment, the paperboard has a tensile strength of
10 N/inch to about 40 N/inch.
[0059] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard is a multilayered
structure comprising a plurality of paperboard layers.
[0060] In one embodiment, wherein two or more of the plurality of
paperboard layers are formed from the low density paperboard.
[0061] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard is a multilayer
structure comprising (i) the low density foamed paperboard, and
(ii) a second paperboard having a density of greater than 0.15
N/inch.
[0062] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard is a multilayer
structure comprising (i) the low density foamed paperboard disposed
between (ii) a first paperboard material having density of greater
than 0.15 N/inch and a second paperboard material having a density
of greater than 0.15 N/inch.
[0063] In one embodiment, provided is an article according to any
previous embodiment, wherein the paperboard is a multilayer
structure comprising (i) a foamed paperboard having density of
greater than 0.15 N/inch having an upper surface and a lower
surface, (ii) an upper layer disposed on the upper surface of the
layer (i), and (iii) a lower layer disposed on the lower surface of
the layer (i), wherein the upper and lower layers are independently
formed from the low density paperboard.
[0064] In one embodiment, provided is an article according to any
previous embodiment, wherein the article is in the form of a
container comprising three or more walls defining an interior
region, at least one of the three or more walls comprising the
paperboard material.
[0065] The following description and the drawings disclose various
illustrative aspects. Some improvements and novel aspects may be
expressly identified, while others may be apparent from the
description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0066] The accompanying drawings illustrate various systems,
apparatuses, devices and related methods, in which like reference
characters refer to like parts throughout, and in which:
[0067] FIG. 1 is a cross section of a fibrous web/paperboard in
accordance with an aspect of the invention;
[0068] FIG. 2 is a cross section of a fibrous web/paperboard in
accordance with another aspect of the invention;
[0069] FIG. 3 is a cross section of a fibrous web/paperboard in
accordance with still another aspect of the invention;
[0070] FIG. 4 is a cross section of a fibrous web/paperboard in
accordance with yet a further aspect of the invention;
[0071] FIG. 5 is a graph showing the relationship of the density
and tensile strength for the paperboards formed in Examples
1-11;
[0072] FIG. 6 is a graph showing the relationship of the density
and tensile strength in paperboards using conventional strength
additives;
[0073] FIG. 7 is a graph comparing the insulating properties of
boxes formed from different paperboards.
DETAILED DESCRIPTION
[0074] Reference will now be made to exemplary embodiments,
examples of which are illustrated in the accompanying drawings. It
is to be understood that other embodiments may be utilized and
structural and functional changes may be made. Moreover, features
of the various embodiments may be combined or altered. As such, the
following description is presented by way of illustration only and
should not limit in any way the various alternatives and
modifications that may be made to the illustrated embodiments. In
this disclosure, numerous specific details provide a thorough
understanding of the subject disclosure. It should be understood
that aspects of this disclosure may be practiced with other
embodiments not necessarily including all aspects described herein,
etc.
[0075] As used herein, the words "example" and "exemplary" means an
instance, or illustration. The words "example" or "exemplary" do
not indicate a key or preferred aspect or embodiment. The word "or"
is intended to be inclusive rather than exclusive, unless context
suggests otherwise. As an example, the phrase "A employs B or C."
includes any inclusive permutation (e.g., A employs B; A employs C;
or A employs both B and C). As another matter, the articles "a" and
"an" are generally intended to mean "one or more" unless context
suggest otherwise.
[0076] Provided is a composition for making a fibrous material,
e.g., a fibrous web, that can be used as a paperboard product or
can form a layer in a paperboard product. The present fibrous
material and web formed therefrom exhibits a low density while
maintaining excellent mechanical properties (e.g., tensile
strength).
[0077] The fibrous web is formed from a fibrous composition
comprising fibers, PAE, a fibrillated cellulose material, and a
surfactant. It has been found that the combination of PAE with
fibrillated cellulose, when foamed, provides a fibrous web that
exhibits both low density and excellent mechanical properties.
[0078] The fibers can be selected from any suitable fiber as may be
desired for a particular purpose or intended application. Suitable
fibers may be chosen from but are not limited to, natural pulp
fibers, recycled pulp fibers, or synthetic fibers. Examples of
suitable natural and/or recycled fibers include, but are not
limited to, thermomechanical pulp fibers, chemithermomechanical
pulp fibers, kraft pulp fibers, sulphite pulp fibers, soda pulp
fibers, dissolving pulp fibers, fluff pulp fibers, NBSK pulp
fibers, SBSK pulp fibers, recycled pulp fibers, deinked pulp
fibers, organosolv pulp fibers, bleached pulp fibers or a mixture
of two or more thereof. Optionally, the natural/recycled fibers may
be used in combination with synthetic polymer fibers, such as
thermoplastic polymer fibers.
[0079] Examples of synthetic fibers that can be used in the
composition and fibrous web include polyester fibers, aramid
fibers, acrylonitrile fibers, polylactide fibers, aromatic polymide
fibers, polyamide fibers, polyurethane fibers, polyethylene fibers,
polypropylene fibers, and combinations of two or more thereof.
[0080] The fibrous material composition further comprises
polyamineamide epichlorohydrin (PAE). The composition comprises
from about 0.5 to 2.5 wt % based on the weight of the dry fibers;
from about 0.75 to 2 wt % based on the dry weight of the fibers; or
about 1 to 1.5 wt % based on the dry weight of the fibers.
[0081] The composition further comprises a fibrillated cellulose
material. The fibrillated cellulose may be chosen from
microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC),
or a combination thereof. These fibrils are made by mechanically or
chemically breaking down cellulose fibers to the nano and micro
dimensions. Due to the high surface area and large number of
hydrogen bonds, these form gels in water at low concentrations and
also tend to have high hydrophilicity limiting their use in
papermaking. The size and/or diameter of the MFC or NFC is not
particularly limited and may be selected as desired for a
particular use or intended application. In one embodiment, the
microfibrils of MFC typically have a fibers length of about 1 m to
10 .mu.m and a fibers diameter of about 3 nm to about 2 .mu.m. In
embodiments, the MFC may have a fiber diameter of from about 3 nm
to about 200 nm. NFC is nanoscale cellulose microfibrils
defibrillated from cellulosic materials. The NFC microfibrils have
dimensions of about 100 nm to about 900 nm in length, and about 3
nm to about 2 .mu.m. In one embodiment the NFC has a diameter of
from about 3 nm to about 200 nm. In one embodiment, the NFC has a
diameter of from about 500 nm to about 0.5 .mu.m. The fibrillated
cellulose is present in an amount of from about 3.5 to 10 wt %
based on the weight of the dried fibers; from about 4 to about 9 wt
% based on the weight of the dried fibers; or from about 5 to about
7.5 wt % based on the weight of the dry fibers.
[0082] It has been found that the combination of the PAE along with
the fibrillated cellulose, when foamed, provides a foamed fibrous
web having low density and excellent mechanical properties.
[0083] The composition comprises a surfactant. The surfactant may
be chosen from a suitable surfactant as may be used in forming a
fibrous web. Examples of surfactants include, but are not limited
to, anionic surfactants, cationic surfactants, amphoteric
surfactants, nonionic surfactants, or a combination of two or more
thereof. Examples of suitable surfactants include, but are not
limited to, ammonium lauryl ether sulfate (Polystep B11, Stepan
Company), sodium C14-C16 olefin sulfonate (Bioterg AS-40, Stepan
Company), sodium dodecyl sulfate, sodium dodecyl sulfonate,
sulfosuccinates, ethoxylated nonyl and octyl phenol sulfonates,
alkylated diphenyl oxide disulfonates, block copolymer surfactants
such as Pluronics and Tetronics, etc.
[0084] The composition may include other additives as may be
desirable for a fibrous web material. Such additives include, but
are not limited to, pigments, thickeners, strengthening additives,
covalent bonding additives, nanoparticles, fillers, etc.
[0085] Additives such as associative or alkali-swellable thickeners
can be used to provide stability to the foam through rheology
control and also provide sites for hydrogen or ionic bonding with
the functional groups on the paper fiber. These additives also
provide thickness control during paperboard manufacture. Examples
of such thickeners include salts of poly(meth)acrylic acid or
hydrophobically modified alkali-swellable emulsions, or
hydrophobically modified ethoxylate urethanes.
[0086] Strengthening additives that can form bridges between the
paper fibers can be used either alone or in combinations. These
bridges can be based on (i) hydrogen bonds. (ii) ionic and hydrogen
bonds, (iii) a combination of hydrogen and covalent bonds, and/or,
(iv) a combination of ionic, hydrogen, and covalent bonds.
[0087] Examples of hydrogen bonding additives include, but are not
limited to, (i) poly(meth)acrylic acid homopolymers and copolymers
with monomers such as hydroxyethyl acrylate, acetoacetoxyethyl
methacrylate, urea pyridimino methacrylate, (ii) starches, (iii)
cellulosics such as hydroxyethyl cellulose, and/or carboxymethyl
cellulose, (iv) polyvinyl alcohols, (v) high molecular weight water
soluble or dispersible polymers with hydrogen bonding groups, (vi)
emulsion copolymers partially neutralized to form an expanded
core-shell network, and/or (vii) nanocrystalline cellulose. These
are capable of forming hydrogen bonds with hydroxyl groups on
cellulosic fibers providing the mechanical strength to the
paper.
[0088] Additives capable of ionic bonding with the hydroxyl groups
on the paper fiber include multivalent ionic species such as: (i)
ammonium zirconium carbonate, or (ii) polymers which are
cationically charged such as cationic starch, quaternary
dimethylaminoethyl methacrylate, amphoteric cationic
polyacrylamides. By regulating the pH of the water slurry, the
zirconium ions can be made to form strong linkages with the
hydroxyl groups of the cellulose fibers leading to improved
mechanical properties.
[0089] Covalent bonding additives, that can react with the hydroxyl
groups on the paper fiber and within the polymer network to
improved mechanical strength include: (i) urea formaldehyde resins
and melamine formaldehyde resins, (ii) epoxy resins, (iii) Kemira
PAE resin, (iv) Hercobond.TM. dry strength additives such as
anionic, amphoteric, cationic polyacrylamides, and/or (v) modified
polyamines, etc.
[0090] Other nanoparticles, emulsion particles, dendritic, graft,
or copolymers containing multi-hydrogen bonding monomers can also
be incorporated alone or in combinations to further regulate the
mechanical properties.
[0091] The composition is used to form a foamed fibrous web. Light
weighting is achieved through foaming of the fibrous composition
using a surfactant in a high shear mixer in the presence of a large
volume of air so that 30 to 60% more by volume of a gas is
entrained in the slurry. An example of a suitable mixer is an Arrow
variable speed electric stirrer with pitched turbine blades running
at 2000 rpm. The gas can be chosen from air, oxygen, nitrogen,
argon, helium, carbon dioxide, etc. In addition to air or other
gases, additives such as hollow polymer particles (e.g.,
Expancel.RTM. WE) can also be used. These hollow particles lead to
a closed foam cell structure in addition to the open foam structure
obtained using air alone.
[0092] The foamed composition is supplied to a forming sheet (e.g.,
a forming fabric), dewatered, and dried to form a board. Dewatering
may be accomplished by applying a vacuum to the wet foamed sheet.
Additionally, the sheet/web may be heated for a period of time at a
temperature of from about 90.degree. C. to about 110.degree. C.
[0093] The present fibrous web material, e.g., paperboard material,
may be used in any application as suitable for such materials. The
fibrous web material may be used as a single layer material or it
may be combined with other materials as desired to form a
multilayered structure. A multilayered structure can, in one
embodiment, comprise a plurality of low density/high strength
paperboards in accordance with aspects and embodiments of the
invention. Alternatively, a multilayered structure may include
other paperboard materials, e.g., other low density paperboards
(but that might not exhibit the same strength properties as those
of the present invention) and/or higher density paperboards (e.g.,
paperboards with a density greater than 0.15 g/cc).
[0094] In FIG. 1, a fibrous web 100 is provided having an upper
surface 102 and a lower surface 104. As is discussed further
herein, the surface of the web may be treated in a converting
process to provide certain properties to the web including, for
example, mechanical properties such as strength, reinforcement,
sealing, fluid barrier properties, etc.
[0095] The fibrous web may also be combined with other fibrous
web/board structures to provide a multi-layered paperboard. In FIG.
2, a two layer fibrous web 200) is provided with a first fibrous
web 210 with an upper surface 212 and a second fibrous web 220 with
a lower surface 222, where at least one of the fibrous webs 210 or
220 is a fibrous web in accordance with the present invention. The
other fibrous web can be provided by another suitable material,
e.g., a high density fibrous web material or another low density
fibrous web material.
[0096] FIG. 3 shows a three layer fibrous web 300. In the
embodiment of FIG. 3, the fibrous web 300 includes a low density
fibrous web 320 in accordance with the present technology disposed
between a fibrous web 310 having an upper surface 312 and a fibrous
web 330 having a lower surface 332. The fibrous webs 310 and 330
may individually be a low density fibrous web in accordance with
the present technology, other types of low density fibrous webs
(e.g., low density webs that do not exhibit tensile strengths
greater than 10 N/inch), a high density fibrous web, or a
combination thereof.
[0097] FIG. 4 shows a three layer fibrous web 400. In the
embodiment of FIG. 4, the fibrous web 400 includes a fibrous web
420 disposed between a fibrous web 410 having an upper surface 412
and a fibrous web 430 having a lower surface 432, where the fibrous
webs 410 and 430 are formed from a fibrous web in accordance with
the present technology. The fibrous webs 320 may be a low density
fibrous web in accordance with the present technology, other types
of low density fibrous webs (e.g., low density webs that do not
exhibit tensile strengths greater than 10 N/inch), or a high
density fibrous web, or a combination thereof.
[0098] It will be appreciated that the multi-layered structures of
FIGS. 3 and 4 are merely illustrative examples of possible
arrangements of a multi-layered web that includes at least one
layer formed from a low density fibrous web in accordance with the
present technology, and that other embodiments with different
arrangements, additional layers, etc., are within the scope of the
present technology. The multi-layered board constructions may be
formed by laminating the various board materials together or by
successive layers being formed during the paper making process.
[0099] The foamed paperboard, or a construction comprising a foamed
paperboard in accordance with the present technology, may be
further treated as desired for a particular application or intended
use. The foamed paperboard can be subjected to a converting step
such as coating, printing, or lamination, or combinations thereof,
either on one side or both sides of the paperboard construction.
Converting may impart reinforcement or additional mechanical
properties to the construction.
[0100] Converting steps to improve mechanical properties of foamed
paperboard can involve coating, printing, extrusion coating, or
laminating. Coating can be conventional water-based coating or
extrusion coating either on one side of the paperboard or on both
sides. There are a number of coatings that can be used to add
strength to the paper. These can be starch based, PVA based,
Acrylic, styrene acrylic, SBR coating, etc. The coatings can be
applied via processes such as size press, blade coating, spray
coating, knife over roll coating, etc. Various conventionally known
printing techniques can be used either on one side or on both sides
to further enhance strength properties along with aesthetics. Such
a paperboard can be laminated on one or both sides with metal foil
or film or metallized film to enhance strength and/or become a
radiant barrier to enhance insulating characteristics. Other
additives such as phase change materials can be used to add
insulating properties to containers made with such a paperboard.
Examples of phase change materials are waxes that have high latent
heats of fusion such as Sasolwax R4250 in a binder coated on the
paperboard or encapsulated phase change materials from Microtek
Laboratories.
[0101] For extrusion coating on the paperboard, examples of
suitable materials include, but are not limited to, polyethylene
polymers (Exxon, Mobil, Dow, and Lyondel-Basell) with a melt index
ranging from 10-12, ultra-low density polyethylene (less than 0.915
g/cm.sup.3), low density polyethylene (0.915-0.93 g/cm.sup.3),
linear low density polyethylene (0.92-0.93 g/cm), medium density
polyethylene (0.94-0.95 gcm.sup.3), high density polyethylene (0.96
g/cm.sup.3), and ethylene vinyl acetate.
[0102] Other functional films (nylon, poly-vinylidenechloride,
etc.) can also be extrusion laminated to the surface of the
paperboard using low viscosity PE having melt indices of 20 or
greater, or other functional materials such as EVA polymer
(ethylene vinyl acetate), EAA polymer (ethylene acrylic
acid--DuPont Amplify), or EMA polymer ethylene methyl
acrylate--Dupont Nucrel).
[0103] For some applications, adhesive lamination to laminate the
paperboard to a metal foil can be used. Instead of metal foil,
another embodiment can also use very thin metallized film such as
0.5 mil metallized polyester for example.
[0104] Specialty inks based on polyurethanes, epoxies, etc., can be
printed in patterns or continuously to further add strength to the
paper. These can be conventional inks or these inks further
modified to enhance strength properties. Companies such as Siegwerk
USA supply such inks for printing applications.
[0105] In the case of converted paperboard material for primary
food packaging, an embodiment of the invention uses the converting
process (and material) as a way to build mechanical strength,
stiffness, or other properties into the product. For example, in
the case of poly-coated board, an embodiment of the invention can
increase the thickness of the coating layer or use a higher density
polyethylene to build stiffness into the paperboard.
[0106] In the case of secondary packaging, where few barrier
properties are needed from the package, an embodiment of the
invention can look to the image receptive outer layer (coating) to
build the strength or stiffness.
[0107] The paperboard may be used to form an article as desired.
Examples of suitable products that may be formed from or
incorporate the present paperboard material include, but are not
limited to, containers, e.g., packaging material, cups, plates,
trays, clam-shells, card-stock for printed media (like marketing
flyers), etc. In one embodiment, the article is a container
comprising three or more adjacent walls defining an interior space.
One ore more of the walls may comprise the paperboard material of
the present technology. The walls may include a single layer wall
formed from the paperboard, or a multi-layer wall (e.g., a
multi-layer structure as described in FIGS. 2-4). In one
embodiment, the paperboard may be used to form boxes, e.g.,
corrugated boxes as may be used in shipping materials. An
embodiment of the invention provides thermal insulation properties
to such articles such that food stays warm or the outer surface
stays cool as in the case of paper cups where currently a separate
corrugated paperboard is used.
[0108] In embodiments, the present paperboard material or a
paperboard material incorporating the present paperboard may be
employed to form a packaging material. The present paperboard
products may be used to form primary packaging and/or secondary
packaging materials. Primary packaging is in direct contact with
the product and provides three distinct functions: (i) provides a
print surface for branding and information. (ii) protects the
product from the environment (for example moisture and/or oxygen),
and/or (iii) assists with usage such as in microwaveable food
products where the package absorbs the microwave energy to help
with the cooking process. Examples of primary paperboard packaging
include milk and juice cartons, ice cream tubs, and microwaveable
food trays. In most of these cases the base paperboard is
subsequently converted through a coating (like polyethylene) or a
lamination (with aluminum foil) process. Typical converted
paperboard products are: (a) paperboard/polyethylene (milk or ice
cream packaging); (b) paperboard/polyethylene/foil/polyethylene
(UHT--Ultra-Heat Treated--milk, juice, paste); and (c)
paperboard/adhesive/metallized-polyethylene terephthalate
(microwavable food trays).
[0109] For secondary packaging, any package that currently uses
paperboard or a plastic can be envisioned to be replaced by this
light weight paperboard product Examples include, but are not
limited to: (i) boxes for holding all manner of packaged foods such
as cereal foods, packaged frozen foods, (ii) packaged pet foods,
(iii) boxes used for packaging consumer items such as shampoo,
beauty products that are sold in department stores, drug stores or
any consumer goods store, and (iv) cartons for holding beverages
such as 12 packs of soda, 6 packs of beer.
[0110] Aspects and embodiments of the invention are further
understood and described with reference to the following
examples:
EXAMPLES
[0111] The MFC and NFC used in the present study were obtained from
the University of British Columbia (laboratory of Prof. Olson). The
micro fibrillated cellulose had been mechanically refined using
NBSK pulp from Canfor, at energies from 500 KWH/ton and ending at
2000 KWH/ton. This MFC had fiber length of about 0.3 mm and fiber
diameter slightly larger than 1 micron. The NFC had fiber length of
well below 0.3 mm and diameter of 0.5 micron.
[0112] Examples 1-11 relate to a series of trials on paperboards
formed from various compositions. The compositions and data for
Examples 1 through 11 are shown in Table 1. Generally, the
procedure for producing the paperboards of Examples 1-11 follow the
procedure discussed in Example 1, with the difference being the
specific compositions used for the respective examples.
Example 1 (Comparative)
[0113] 60 grams of Northern bleached softwood kraft (NBSK) pulp
from CANFOR, with an average fiber length of 2.5 mm was dispersed
in 3000 grams of water using an Arrow variable speed mixer
(equipped with 3'' pitched turbine blades) at 2000 rpm for 1 hour.
About 375 grams of this aqueous slurry was cast on a cotton cloth
enclosed in a 6'' diameter Buchner funnel, allowed to drain, and
very light vacuum applied when the flow of water almost stopped.
Vacuum (0.9 bar) was applied for about 20 seconds and then the disc
was transferred to a forced air oven maintained at 105.degree. C.
and dried for 1 hour. Thickness of the disc was measured over
multiple regions and the average recorded. The disc was weighed and
the volume of the disc calculated using the diameter and thickness
from which the density of the dry foamed paperboard (0.37 g/cc) is
calculated. The tensile strength (TS) was measured using Labthink
XLB(B) Auto Tensile Tester (Labthink Instruments Co. Ltd.) with a
half inch width sample and using a separation speed of 300 mm/min.
An average of about 10 specimens was used for calculating the
average and was evaluated to be 10.14 N/inch.
Example 2.0 through 2.2 (Comparative)
[0114] An amount of NBSK pulp as shown in Table 1 was dispersed in
water and after 1 hour of mixing. Polystep B-11 (60%) surfactant
was added. Mixing was continued and after fixed intervals, samples
were withdrawn and discs were prepared, dried, and measured for
density and TS. The data shows a steady drop in TS as the density
is lowered.
Example 3.0 through 3.5 (Comparative)
[0115] An amount of NBSK pulp as shown in Table 1 was dispersed in
water and after 1 hour of mixing, Fennostrength 4063 (Kemira
Chemicals) was added to the pulp prior to adding Polystep B-11
surfactant. Now the pulp was foamed with good mixing. The amounts
of FS 4063 added, density and TS are shown in Table 1. FS 4063
increases the TS of the paperboard initially but after foaming,
even at high levels of FS 4063 (2%), the TS drops below the TS of
the unfoamed paper (10 N/inch).
Example 4.0 through 4.5 (Comparative)
[0116] Example 2 was carried out with MFC added to the pulp prior
to adding Polystep B11 surfactant. The amounts of MFC added and
properties of the resulting foamed paper are shown in Table 1. MFC
improves the TS of the unfoamed paper but after foaming, TS starts
to drop and at density of below 0.1 g/cc, it shows no substantial
improvement over NBSK paper with no strength additives.
Example 5 through 5.2 (Comparative)
[0117] Example 2 was repeated with NFC added to the pulp. At
densities of below 0.12 g/cc, NFC shows no improvement over NBSK
paper with no strength additives.
Example 6 through 6.8
[0118] Examples 6-11 illustrate examples in accordance with aspects
and embodiments of the invention. Example 6 was carried out with
combination of NFC and Fennostrength 4063. A combination of 6% NFC
and 2% 4063 was found to give dramatic improvement in TS at a
density of 0.115. At less than one third the density of unfoamed
NBSK paper, the TS was nearly 3 times higher. At a density of 0.02
g/cc (5% density of unfoamed NBSK), the TS was equal.
[0119] A combination of NFC and Fennostrength 716 (Kemira
Chemicals) (Examples 6.5 and 6.6) and NFC and Fennobond 3300
(Kemira Chemicals) (Examples 6.7 and 6.8) was also investigated. No
synergy was seen between these additives and NFC, with no
enhancement in TS.
Example 7 through 7.6
[0120] Example 6 was repeated with a combination of MFC and
Fennostrength 4063. The results are again very similar to those
seen above with NFC and unexpected. There is a strong synergy
between fibrillated cellulose (MFC and NFC) and the polyamide--EPI
resin (4063) responsible for the strength development between the
fibers even in the presence of a lot of air.
Example 8, 8.1, 9.0, 9.1, 10, 11
[0121] The synergy between MFC and 4063 was investigated with two
other paper pulp fibers--recycled fibers (made up in the lab from
various sources) and chemi-thermomechanical pulp (CTMP from QRP
West Fraser, Canada). Similar enhancement in TS at low density was
seen with both of these pulp types as seen with NBSK.
[0122] Data for the trials of Examples 1-11 are shown in Table 1.
FIG. 5 shows the relationship between paperboard foam density and
tensile strength for paperboards with and without several strength
additives. The plot shows a steady drop in tensile strength as the
density is lowered even with strengthening additives such as MFC,
NFC and polyaminoeamide epicholorhydrin (PAE). The solid flat line
drawn at 10 Newtons/inch in FIG. 1 corresponds to the tensile
strength of NBSK pulp paperboard made in the lab without foaming
and without any additives. At density below 0.15 g/cc, the tensile
strength of paperboard starts to drop dramatically even with
significant amounts of strength additives such as PAE (0.5 to 2 wt
% based on dry pulp), NFC and MFC (even as much as 10 wt %/based on
dry pulp) when used separately. It is also highly fortuitous that
such a low level of NFC or MFC combined with PAE provides superior
strength since (i) it is nearly 3 times as expensive as paper pulp,
and (ii) high levels of MFC or NFC lead to undesirable side effects
such as high water retention and higher energy for drying. TS
TABLE-US-00001 TABLE 1 Weight of Tensile Pulp, Water, Additive,
Surfactant, paperboard Density, strength, Bulk, Grammage, Example
wt., grams liters % on pulp % on pulp disc, grams g/cc N/in cc/g
grams/sq m 1.0 NBSK, 60 3 0 0 9.74 0.370 10.14 2.7 534 2.0 NBSK, 40
2 0 Polystep B- 7.473 0.133 6.22 7.5 410 11, 0.45 2.1 NBSK, 60 3 0
Bioterg AS 6.016 0.097 4.57 10.3 330 40, 0.4 2.2 NBSK, 40 2 0
Polystep B- 5.8 0.024 2.17 42.6 318 11, 0.45 3.0 NBSK, 60 3 FS
4063, 0.5 0 10.114 0.282 23.92 3.5 555 3.1 NBSK, 60 3 FS 4063, 0.5
Bioterg AS 9.281 0.210 10.74 4.8 509 40, 0.4 3.2 NBSK, 40 2 FS
4063, 1 Bioterg AS 6.875 0.192 12 5.2 377 40, 0.2 3.3 NBSK, 40 2 FS
4063, 1 Bioterg AS 5.543 0.122 9.5 8.2 304 40, 0.2 3.4 NBSK, 80 4
FS 4063, 2 Bioterg AS 9.822 0.233 12.7 4.3 539 40, 0.1 3.5 NBSK, 80
4 FS 4063, 2 Bioterg AS 9.134 0.168 9.3 6.0 501 40, 0.1 4.0 NBSK,
60 3 MFC, 3.4 0 10.935 0.370 36.1 2.7 600 4.1 NBSK, 60 3 MFC, 3.4
Bioterg AS 10.1 0.157 16.5 6.4 554 40, 0.4 4.2 NBSK, 80 4 MFC, 6.0
Polystep B 7.86 0.072 9.25 13.9 431 11, 0.45 4.3 NBSK, 80 4 MFC,
6.0 Poly step B 6.9 0.038 6.53 26.7 378 11, 0.45 4.4 NBSK, 80 4
MFC, 1 Polystep B 9.158 0.074 5.32 13.5 502 11, 0.45 4.5 NBSK, 80 4
MFC, 1 Polystep B 6.05 0.032 2.61 31.3 332 11, 0.45 5.0 NBSK, 80 4
NFC, 6 Polystep B 9.523 0.172 13.7 5.8 522 11, 0.45 5.1 NBSK, 80 4
NFC, 6 Polystep B 8.5 0.122 6.54 8.2 466 11, 0.45 5.2 NBSK, 80 4
NFC, 6 Polystep B 6.042 0.040 3.19 25.0 331 11, 0.60 6.0 NBSK, 80 4
NFC, 6 + Polystep B 9.11 0.115 32.47 8.7 500 4063, 2 11, 0.563 6.1
NBSK, 80 4 NFC, 6 + Polystep B 7.331 0.044 21.5 23.0 402 4063, 2
11, 1.013 6.2 NBSK, 80 4 NFC, 6 + Polystep B 5.58 0.021 10.02 48.8
306 4063, 2 11, 1.576 6.3 NBSK, 40 2 NFC, 6 + Polystep B 7.485
0.098 17.82 10.3 411 4063, 1 11, 0.90 6.4 NBSK, 40 2 NFC, 6 +
Polystep B 4.61 0.021 3.63 47.6 253 4063, 1 11, 2.7 6.5 NBSK, 40 2
NFC, 6 + FS Polystep B 8.302 0.200 29.6 5.0 455 716, 2 11, 2.25 6.6
NBSK, 40 2 NFC, 6 + FS Polystep B 4.553 0.025 3.94 40.8 250 716, 2
11, 3.6 6.7 NBSK, 40 2 NFC, 6 + FB Polystep B 7.757 0.065 7.53 15.5
425 3300, 2 11, 3.7 6.8 NBSK, 40 2 NFC, 6 + FB Polystep B 5.16
0.025 4.46 40.0 283 3300, 2 11, 3.8 7.0 NBSK, 80 4 MFC, 3.5 +
Bioterg AS 8.396 0.063 10.7 15.9 461 4063, 2 40, 1.2 7.1 NBSK, 80 4
MFC, 6 + Bioterg AS 10.173 0.173 30.29 5.8 558 4063, 2 40, 0.675
7.2 NBSK, 80 4 MFC, 6 + Bioterg AS 9.04 0.124 20.7 8.1 496 4063, 2
40, 1.125 7.3 NBSK, 80 4 MFC, 3.5 + Bioterg AS 9.29 0.131 14.89 7.6
510 4063, 0.5 40, 045 7.4 NBSK, 80 4 MFC, 3.5 + Bioterg AS 6.753
0.047 5.92 21.3 370 4063, 0.5 40, 0.788 7.5 NBSK, 80 4 MFC, 6 +
Bioterg AS 9.75 0.132 21.75 7.6 535 4063, 0.5 40, 0.45 7.6 NBSK, 80
4 MFC, 6 + Bioterg AS 6.473 0.039 4.78 25.6 355 4063, 0.5 40, 0.788
8.0 Recycled 2 0 Polystep 4.14 0.081 8.28 12.3 227 pulp, 40 B11,
0.675 8.1 Recycled 2 0 Polystep 3.284 0.046 4.18 22.0 180 pulp, 40
B11, 0.675 9.0 Recycled 2 MFC, 6 + FS Polystep B 5.118 0.104 29.75
9.6 281 pulp, 40 4063, 2 11, 1.575 9.1 Recycled 2 MFC, 6 + FS
Polystep B 3.973 0.049 9.06 20.4 218 pulp, 40 4063, 2 11, 2.025
10.0 CTMP, 40 0 Polystep B 4.411 0.061 8 16.4 242 11, 0.45 11.0
CTMP, 40 2 MFC, 6 + FS Poly step B 4.15 0.047 16.1 21.5 228 4063, 2
11, 0.45
Example 12 through 18
[0123] Example 2 was repeated with Fennobond 3300 (Kemira),
Cationic polyacrylamide, Cationic starch, Polyacrylic acid,
Cellulose nano crystal, Acrysol ASE 95NP, and Expancel beads along
with Fennostrength 716. The results are shown in Table 2.
TABLE-US-00002 TABLE 2 Weight of Tensile Pulp, Water, Additive,
Surfactant, paperboard Density, strength, Bulk, Grammage, Example
wt., grams liters % on pulp % on pulp disc, grams g/cc N/in cc/g
grams/sq m 12.0 100 5 FB 3300, Bioterg AS 6.047 0.095 4.7 10.5 746
1 40, 0.4 12.1 60 3 FB 3300, Bioterg AS 9.377 0.094 7.2 10.6 514 3
40, 0.4 13 80 4 CPAM, 3 Polystep B 8.673 0.263 6.86 3.8 476 11, 0.4
13.1 80 4 CPAM, 3 Polystep B 7.483 0.049 4.83 20.4 410 11, 0.563 14
80 4 Cationic Polystep B 7.645 0.062 2.22 16.1 419 Starch, 11, 0.3
Redibond 5330, 2.5 14.1 80 4 Cationic Polystep B 5.837 0.038 1.84
26.3 320 Starch, 11, 0.3 Redibond 5330, 2.5 15 60 3 PAA Bioterg AS
10.03 0.278 26.5 3.6 550 (Polysciences, 40, 0.4 MW = 345K), 0.83
15.1 60 3 PAA Bioterg AS 9.08 0.144 7.21 6.9 498 (Polysciences, 40,
0.4 MW = 345K), 0.83 16 60 3 CNC Bioterg AS 9.387 0.094 6.52 10.6
515 (Alberta 40, 0.4 Innovates), 3 16.1 60 3 CNC Bioterg AS 9.075
0.06 4.47 16.7 498 (Alberta 40, 0.4 Innovates), 3 17 80 4 Acrysol
Bioterg AS 9.88 0.245 30 4.1 542 ASE 40, 0.3 95NP, 1, FS 716, 0.4
17.1 80 4 Acrysol Bioterg AS 9.279 0.142 8.75 7.0 509 ASE 40, 0.3
95NP, 1, FS 716, 0.4 18 60 3 Expancel Bioterg AS 13.811 0.319 12.12
3.1 758 551WE 40, 0.4 40, 4.8, FS 716, 0.86 18.1 60 3 Expancel
Bioterg AS 8.092 0.169 6.83 5.9 444 551WE 40, 0.4 40, 4.8, FS 716,
0.86
[0124] FIG. 6 shows TS vs density relationship with other
conventionally known strength additives. The additives used
included well known agents used to increase mechanical properties
of conventional paper, such as cationic polyacrylamide, cationic
starch, cellulose nano crystal, and glyoxylated polyacrylamide
(GPAM). It is seen that with all these additives the TS drops
steadily with lowering of density.
Example 19
[0125] A paperboard was made as per example 2 and had a TS of
2N/inch and a density of 0.044 g/cc. The thickness of the sheet was
0.516 cm. This sheet was laminated to a pressure-sensitive adhesive
transfer tape and the TS of this laminate was 20.4 N/inch. A three
mil metallized mylar film was laminated to the adhesive and the TS
was measured to be over 50N/inch.
Example 20
[0126] A paperboard was made as per example 2 with a density of
0.044 g/cc and a thickness of 0.516 cm. A box was made using this
sheet having dimensions of 3.times.2.times.1'' and glued together
with Elmer's glue. A temperature data logger (HOBO UX 100-001 by
Onset) was introduced into the box, the box was sealed with Elmer's
glue, and maintained at RT for 10 minutes followed by introducing
into an oven maintained at 60.degree. C. After 30 minutes, the box
was taken out and the temperature profile experienced by the HOBO
in the box was plotted. The temperature in the box at the end of 30
minutes was 47.2.degree. C.
[0127] Another box was made of the same dimensions using this
paperboard and HOBO and 4 grams of phase change materials were
introduced in the box--2 grams of Microteck MPCM 43D and 2 grams of
Microtek MPCM 32 and subjected to the same temperature profile as
the earlier box. The temperature in the box was 43.2.degree. C.
[0128] Another box was made using paperboard made without foaming
and having a density of 0.174 g/cc and a sheet thickness of 0.465
cm and subjected to the same profile as above. The temperature in
the box was 53.2.degree. C.
[0129] This shows that the foamed paperboard shows significant
insulating properties--a 6.degree. C. drop in interior temperature
when subjected to an exterior temperature of 60.degree. C. and a
10.degree. C. drop with foam and phase change material. The data is
shown in FIG. 1.
[0130] What has been described above includes examples of the
present specification. It is, of course, not possible to describe
every conceivable combination of components or methodologies for
purposes of describing the present specification, but one of
ordinary skill in the art may recognize that many further
combinations and permutations of the present specification are
possible. Accordingly, the present specification is intended to
embrace all such alterations, modifications and variations that
fall within the spirit and scope of the appended claims.
Furthermore, to the extent that the term "includes" is used in
either the detailed description or the claims, such term is
intended to be inclusive in a manner similar to the term
"comprising" as "comprising" is interpreted when employed as a
transitional word in a claim.
[0131] The foregoing description identifies various, non-limiting
embodiments of a fibrous composition, a fibrous web, and paperboard
formed from such materials. Modifications may occur to those
skilled in the art and to those who may make and use the invention.
The disclosed embodiments are merely for illustrative purposes and
not intended to limit the scope of the invention or the subject
matter set forth in the claims.
* * * * *