U.S. patent application number 15/302230 was filed with the patent office on 2017-02-02 for flushable hydroentangled moist wipe or hygiene tissue.
The applicant listed for this patent is SCA Hygiene Products AB. Invention is credited to Hannu AHONIEMI, Lars FINGAL, Anna NIHLSTRAND, Anders STR LIN.
Application Number | 20170027392 15/302230 |
Document ID | / |
Family ID | 54288162 |
Filed Date | 2017-02-02 |
United States Patent
Application |
20170027392 |
Kind Code |
A1 |
STR LIN; Anders ; et
al. |
February 2, 2017 |
FLUSHABLE HYDROENTANGLED MOIST WIPE OR HYGIENE TISSUE
Abstract
A flushable wipe or hygiene tissue includes a hydraulically
entangled nonwoven material impregnated with a wetting composition,
wherein the nonwoven material includes cellulose pulp fibers and/or
manmade staple fibers. The nonwoven material includes
disintegration elements having a projected surface area between 2
and 50 mm.sup.2 and an aspect ratio (L/D) between 1 and 10. The
disintegration elements may be selected from the following group:
botanical elements, paper containing a wet-strength agent, nonwoven
material, and film material, and will result in a material that is
more readily disintegratable when flushed in a sewer.
Inventors: |
STR LIN; Anders; (Torslanda,
SE) ; AHONIEMI; Hannu; (Goteborg, SE) ;
FINGAL; Lars; (Goteborg, SE) ; NIHLSTRAND; Anna;
(Goteborg, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCA Hygiene Products AB |
Gateborg |
|
SE |
|
|
Family ID: |
54288162 |
Appl. No.: |
15/302230 |
Filed: |
April 8, 2014 |
PCT Filed: |
April 8, 2014 |
PCT NO: |
PCT/SE2014/050433 |
371 Date: |
October 6, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D21H 21/20 20130101;
D04H 1/492 20130101; D04H 1/425 20130101; D04H 1/732 20130101; A47K
7/03 20130101; D21H 21/52 20130101; D04H 1/413 20130101; A61F
13/15211 20130101 |
International
Class: |
A47K 7/03 20060101
A47K007/03; D21H 21/20 20060101 D21H021/20; D04H 1/732 20060101
D04H001/732; D04H 1/425 20060101 D04H001/425; D04H 1/492 20060101
D04H001/492; D21H 21/52 20060101 D21H021/52; D04H 1/413 20060101
D04H001/413 |
Claims
1. A flushable wipe or hygiene tissue comprising a hydraulically
entangled nonwoven material impregnated with a wetting composition,
said nonwoven material comprising cellulose pulp fibers and/or
manmade staple fibers and disintegration elements having a
projected surface area between 2 and 50 mm.sup.2 and an aspect
ratio (L/D) between 1 and 10.
2. The flushable wipe or hygiene tissue according to claim 1,
wherein the amount of the disintegration elements in the flushable
wipe or hygiene tissue is between 0.5 and 2.5 weight % as
calculated on the dry weight of the wipe or hygiene tissue.
3. The flushable wipe or hygiene tissue according to claim 1,
wherein said disintegration elements are of a material having a
disintegration time as measured by French Standard NF Q 34-020 that
differs from the nonwoven material.
4. The flushable wipe or hygiene tissue according to claim 3,
wherein said disintegration elements are of a material having a
slower disintegration time as measured by French Standard NT Q
34-020 than the nonwoven material.
5. The flushable wipe or hygiene tissue according to claim 1,
wherein said disintegration elements are of a material selected
from the group consisting of: botanical elements, paper containing
a wet-strength agent, nonwoven material, and film material
6. The flushable wipe or hygiene tissue according to claim 1,
wherein said aspect ratio of said disintegration elements is
between 1 and 7.
7. The flushable wipe or hygiene tissue according to claim 1, said
disintegration elements have a thickness between 50 .mu.m and the
thickness of the nonwoven material.
8. The flushable wipe or hygiene tissue according to claim 1,
wherein said disintegration elements are embedded by fibers in the
nonwoven material.
9. The flushable wipe or hygiene tissue according to claim 1,
wherein said disintegration elements have a different colour or
tint than the rest of the nonwoven material.
10. The flushable wipe or hygiene tissue according to claim 1,
wherein said disintegrating elements have a decorative and/or
informative shape.
Description
CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This application is a .sctn.371 National Stage application
of PCT International Application No. PCT/SE2014/050433 filed Apr.
8, 2014, which is incorporated herein in its entirety.
TECHNICAL FIELD
[0002] The present disclosure refers to a flushable hydroentangled
wipe or hygiene tissue impregnated with a wetting composition,
wherein the nonwoven material includes cellulose pulp fibers and/or
manmade staple fibers.
BACKGROUND
[0003] Pre-moistened wipes or hygiene tissue, are commonly used for
cleansing different parts of the human body. Examples of specific
uses are baby care, hand wiping, feminine care and toilet paper or
a complement to toilet paper.
[0004] Since a long period of time often elapses from the time of
manufacture of pre-moistened wipes until the time of use, they must
have a sufficient structural integrity for their intended wiping
function during such period. Adding a wet strength agent to the
wipe will provide such wet integrity. However, especially when used
as toilet paper, there is a strong desire that the wipe or tissue
can be flushed in the sewer without causing problems with blocked
pipes and filters. Wipes or tissue having a high wet strength will
not disintegrate or break up into small fibre clumps when flushed
in conventional household toilet systems, which may cause plugging
of the drainage system.
[0005] Previously moist flushable pre-moistened wipes and toilet
papers which were on the market were flushable due to their small
size. They could move along the drainage and sewage pipes, but were
not readily dispersible and could therefore cause problems with
blocked pipes and filters. Nowadays disintegratable materials are
available for use in flushable wipes and hygiene tissue.
[0006] U.S. Pat. No. 4,755,421 discloses a hydroentangled
disintegratable nonwoven fabric used as a flushable wet wipe. The
fabric comprises a mixture of pulp fibers and staple length
regenerated cellulose fibers. No binder is added.
[0007] US 2004/0013859 discloses a hydroentangled nonwoven web used
as a wet wipe that is disintegrated with mild agitation in water.
The nonwoven web comprises natural cellulose fibers and high
crystallinity cellulose fibers, preferably lyocell fibers. A binder
is also added, for example in the form of binder fibers. The
nonwoven web is said to have high wet tensile strength but
disintegrates or disperses with mild agitation in water, making it
flushable in a sewer.
[0008] WO 2013/015735 discloses a hydroentangled moist wipe that is
flushable. The wipe material comprises pulp fibers and poly(lactic
acid) fibers having a length between 8 and 20 mm. The wipe is free
from added binders and wet-strength agents.
[0009] JP 2008073357 discloses a hydroentangled wipe material that
has water dissolving properties. The wipe material comprises
hydrophilic fibers and fibers having a modified cross-section.
[0010] JP 2012057289 discloses a flat hollow rayon fiber with
creases formed in the outer surface. These flat rayon fibers may be
used in different kinds of products, wherein water-dispersible
sheets are mentioned as one example.
[0011] There is however still a need for a moist wipe or hygiene
tissue which has sufficient structural integrity for its intended
wiping function but which is readily disintegratable when flushed
in a sewer.
SUMMARY
[0012] It is desired to provide a moist wipe or hygiene tissue
having sufficient wet strength for its intended use but which is
disintegrated when flushed in a sewer. One such moist wipe or
hygiene tissue includes a hydraulically entangled nonwoven material
impregnated with a wetting composition, said nonwoven material
containing cellulose pulp fibers and/or manmade staple fibers,
wherein the nonwoven material also includes disintegration elements
having a projected surface area between 2 and 50 mm.sup.2 and an
aspect ratio between 1 and 10.
[0013] These disintegrating elements will create spots in the
nonwoven material, that weaken the material resulting in a material
that disintegrates or disperses in water under mild agitation, such
as present in a standard sewer.
[0014] The flushable wipe or hygiene tissue may include between 0.5
and 2.5 weight % of said disintegration elements as calculated on
the dry weight of the wipe or hygiene tissue.
[0015] Said disintegration elements may be of a material having a
disintegration time as measured by French Standard NF Q 34-020 that
differs from the nonwoven material.
[0016] Said disintegration elements may be of a material having a
slower disintegration time as measured by French Standard NF Q
34-020 than the nonwoven material.
[0017] The disintegration elements may be of a material selected
from the following group: botanical elements, paper containing a
wet-strength agent, nonwoven material, film material.
[0018] The disintegration elements may have an aspect ratio between
1 and 7.
[0019] The thickness of the disintegration elements may be between
50 .mu.m and the thickness of the nonwoven material, for example
below 1 mm.
[0020] The disintegration elements may be embedded by fibers in the
nonwoven material.
[0021] The disintegration elements may have a different colour or
tint than the rest of the nonwoven material.
[0022] The disintegrating elements may have a decorative and/or
informative shape, such as symbols, characters, logotypes and the
like.
BRIEF DESCRIPTION OF THE FIGURES
[0023] FIG. 1 is a schematic sketch of a hydroentangled material
including disintegration elements according to an embodiment of the
invention.
[0024] FIG. 2 a-h are schematic sketches of disintegration elements
having different shapes and illustrate how the aspect ratio is
measured.
DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS
[0025] A premoistened wipe or hygiene tissue according to
embodiments of the invention includes a hydroentangled nonwoven
material impregnated with a wetting composition. The wetting
composition may contain a major proportion of water and other
ingredients depending on the intended use. Wetting compositions
useful in moist wipes and hygiene tissue are well-known in the
art.
[0026] Hydroentangling or spunlacing is a technique for forming a
nonwoven web introduced during the 1970'ies, see e g CA patent no.
841 938. The method involves forming a fibre web, which is either
drylaid or wetlaid, after which the fibres are entangled by means
of very fine water jets under high pressure. Several rows of water
jets are directed against the fibre web, which is supported by a
movable foraminous support or a perforated drum. In this process,
the fibres entangle with one another providing sufficient bonding
strength to the fibrous web without the use of chemical bonding
agents. The entangled fibrous web is then dried. The fibres that
are used in the material can be natural fibres, especially
cellulosic pulp fibres, manmade staple fibres, and mixtures of pulp
fibres and staple fibres. Hydroentangled materials can be produced
with high quality at a reasonable cost and they possess a high
absorption capacity.
[0027] The wipe or hygiene tissue according to embodiments of the
invention may include a mixture of cellulosic pulp fibers and
manmade fibers, and, in particular embodiments, biodegradable
manmade fibers such as regenerated cellulose fibres, e.g. viscose,
rayon and lyocell, and/or poly(lactic acid) fibers. The length of
these manmade fibres may be in the range of 4 to 20 mm. Other
natural fibres than pulp fibres may also be included in the fibrous
web, such as cotton fibres, sisal, hemp, ramie, flax etc. These
natural fibres usually have a length of more than 4 mm.
[0028] Cellulose pulp fibres can be selected from any type of pulp
and blends thereof. In particular embodiments, the pulp is
characterized by being entirely natural cellulosic fibres and can
include wood fibres as well as cotton. Preferred pulp fibres are
softwood papermaking pulp, although hardwood pulp and non-wood
pulp, such as hemp and sisal may be used. The length of pulp fibres
may vary from less than 1 mm for hardwood pulp and recycled pulp,
to up to 6 mm for certain types of softwood pulp. Pulp fibres are
advantageous to use since they are inexpensive, readily available
and absorbent.
[0029] A suitable amount of cellulose pulp fibers in the nonwoven
material forming the moist wipe or hygiene tissue may be between 0
and 95% by weight cellulose pulp fibers, between 50 and 95% by
weight cellulose pulp fibers, or between 70 and 95% by weight
cellulose pulp fibers. A suitable amount of manmade fibers in the
nonwoven material forming the moist wipe or hygiene tissue may be
between 5 and 100% by weight manmade fibers, between 5 and 50% by
weight manmade fibers, or between 5 and 30% by weight manmade
fibers. The wipe or hygiene tissue may have a basis weight in the
range 30 to 100 gsm, or 40 to 80 gsm, based on the dry weight of
the material.
[0030] The fibers forming the nonwoven material may be wetlaid,
wherein a slurry including the fibres is wetlaid on a moving
forming fabric by a headbox as in a conventional papermaking
equipment. A special variant of wetlaying or wetforming is
foamforming, wherein the fibres are dispersed in a foamed liquid
containing water and a surfactant. Alternatively the fibers may be
drylaid on a moving forming fabric to form a drylaid fibrous web
which is subsequently hydroentangled.
[0031] In addition to the fibers the nonwoven material 1 includes
disintegration elements 2 in the form of flakes having a projected
surface area between 2 mm.sup.2 and 50 mm.sup.2 and an aspect ratio
L/D between 1 and 10, or between 1 and 7. The projected surface
area may be measured by image analysis.
[0032] The aspect ratio is defined as the ratio of the length L to
the width D of the disintegration element 2. The length L is
defined as the longest straight line that can be drawn/found in the
element. The width D is defined as the longest straight line that
can be found/drawn in said element perpendicular to the line L. No
parts of the lines L and D should cross the edge of the element,
i.e. the full length of the lines L and D must be inside the
element. In cases where two or more lines with the same length can
be found (L1=L2= . . . Lx), the length L which generates the
longest line D, i.e. resulting in the lowest L/D ratio, should be
used.
[0033] FIG. 2 a-h illustrate how the aspect ratio L/D is measured
for disintegration elements having varying shapes.
[0034] The disintegration elements 2 are mixed with the fibers, for
example in the slurry used in wetlaying.
[0035] The disintegration elements 2 in the form of flakes having
the above mentioned proportions are different from fibers and will
not easily entangle with the fibers during hydroentangling. They
will rather form spots in the nonwoven material that will weaken
the material, for example in the cross direction, CD, thus making
it more readily disintegratable when flushed in a sewer.
[0036] The disintegration elements 2 may be contained in the
nonwoven material 1 in an amount between 0.5% by weight and 2.5% by
weight as calculated on the dry weight of the nonwoven material,
i.e. excluding the wetting composition. The disintegration elements
2 can be distributed throughout the area of the nonwoven material
1.
[0037] The disintegrating elements 2 may be of a material selected
from: botanical elements, wet-strong paper, i.e. paper containing a
wet-strength agent, nonwoven material, film material. In particular
embodiments, the disintegrating elements 2 are of a biodegradable
material. They should further be of a material that has a
disintegration time as measured by French Standard NF Q 34-020 that
differs from the nonwoven material as such, for example a slower
disintegration time, such as at least 10% longer disintegration
time than the nonwoven material. This will ensure that they will
maintain their effect of weakening the nonwoven material until this
has been disintegrated. The thickness of the disintegration
elements should be at least 50 .mu.m and not more than the
thickness of the nonwoven material, for example less than 1 mm.
[0038] Examples of botanical elements suited for use as
disintegrating elements are petals, e g from marigold, lavender or
similar flowers. Such botanical elements may have a colour or tint
different from the nonwoven material as such. They may also have a
fragrance and/or a skin care effect.
[0039] The disintegrating elements 2 may be formed of cut pieces of
a sheet material, e g wet-strong paper, nonwoven or film material.
These pieces may have a colour or tint different from the rest of
the nonwoven material. They may also have a decorative and/or
informative shape such as symbols, characters, logotypes and the
like.
Description of Test Method
[0040] The test method for measuring disintegration time is French
Standard NF Q 34-20 Aug. 1998. In addition to measuring the
disintegration time, the weight of the remaining lump of fibers (if
any) in the test vessel is also measured. The test was performed in
the following manner: [0041] Put the dried sample in a climate room
23.degree. C., 50% humidity for minimum 4 hours; [0042] Weigh the
sample before start; [0043] Stop the timer when the sample is
disintegrated into pieces smaller than 1 cm.sup.2 and record the
disintegration time; [0044] Alt. 1: Start stirring again and let
stir until 10 minutes have passed (including the initial
disintegration time); [0045] Alt. 2: Omit the additional step of
stirring 10 minutes; [0046] Pick up the remaining lump with a pair
of tweezers; [0047] Put the lump in a 900 ml beaker filled with
water up to 300 ml, wait 5 sec.; [0048] Pick up the lump with
tweezers and let excess water drip off, wait 5 sec.; [0049] Put the
lump in a second 900 ml beaker filled with water up to 300 ml, wait
5 sec.; [0050] Pick up the lump with tweezers and let excess water
drip off, wait 5 sec.; [0051] Put the lump on a tissue paper to
drain excess water; [0052] Put the lump in a climate chamber for 2
h 80.degree. C. to dry; [0053] Put the dried lump in a climate room
23.degree. C., 50% humidity, for minimum 4 h; [0054] Weigh the
lump; [0055] Calculate the remaining weight of the dried lump as a
percentage of the initial dry sample weight (dry weight of
remaining lump/dry weight of sample).times.100(%).
Examples
[0056] Trials have been made on hydroentangled nonwoven materials
containing disintegration elements in the form of marigold petals
and a reference sample containing no disintegration elements. The
samples had the following composition.
[0057] Reference: 80 wt % cellulose pulp+10 wt % lyocell fibers 12
mm+10 wt % PLA:poly(lactic acid) fibers 12 mm. The basis weight was
60 gsm and the material was hydroentangled with 3 manifolds/jet
strips on each sides of the web with 60 bars with entanglement
nozzles hole diameter 115 .mu.m with a pitch of 0.8 mm between
holes. The sample size and number of folds was adapted to Samples
1-4 referred to below.
[0058] Sample 1: 79 wt % cellulose pulp+10 wt % lyocell fibers 12
mm+10 wt % PLA:poly(lactic acid) fibers 12 mm+1 wt % marigold
petals. The basis weight was 60 gsm and the material was
hydroentangled with 3 manifolds/jet strips on each side of the web
with 60 bars with entanglement nozzles. Sample size was 10.times.25
cm, folded twice in longitudinal direction.
[0059] Sample 2: 79 wt % cellulose pulp+10 wt % lyocell fibers 12
mm+10 wt % PLA:poly(lactic acid) fibers 12 mm+1 wt % marigold
petals. The basis weight was 60 gsm and the material was
hydroentangled with 3 manifolds/jet strips on each side of the web
with 60 bars with entanglement nozzles. Sample size was 10.times.25
cm, folded once in longitudinal direction.
[0060] Sample 3: a) 79 wt % cellulose pulp+10 wt % lyocell fibers
12 mm+10 wt % PLA:poly(lactic acid) fibers 12 mm+1 wt % marigold
petals; b) 77 wt % cellulose pulp+10 wt % lyocell fibers 12 mm+10
wt % PLA:poly(lactic acid) fibers 12 mm+3 wt % marigold petals. The
basis weight was 60 gsm and the materials were hydroentangled with
3 manifolds/jet strips on each side of the web with 60 bars with
entanglement nozzles. Sample size was 10.times.10 cm with no
fold.
[0061] Sample 4: 77 wt % cellulose pulp+10 wt % lyocell fibers 12
mm+10 wt % PLA:poly(lactic acid) fibers 12 mm+3 wt % marigold
petals. The basis weight was 60 gsm and the material was
hydroentangled with 3 manifolds/jet strips on each side of the web
with 60 bars with entanglement nozzles. Sample size was 10.times.25
cm folded once in longitudinal direction.
[0062] Wet strength in water in CD according to SS-EN ISO
12625-5:2005 was measured for the different samples as well as
disintegration time and weight of remaining lump were measured. The
following results were obtained.
[0063] Sample 1
TABLE-US-00001 CD wet tensile Basis weight.sup.2 Disintegration
Lump strength.sup.1 (N/m) (g/m2) time.sup.3 (sec) (wt-%) Reference
24.5 62.0 163 Small, not measured 1% 24.4 63.4 139 Small, not
Marigold measured Difference -0.2% -14.7% (Ref-1%): .sup.1Average
of 10 samples .sup.2Average of 15 samples .sup.3Average of 8
samples
[0064] Sample 2
TABLE-US-00002 Lump at Basis 10 min CD wet tensile weight.sup.2
Disintegration (Alt. 1) strength.sup.1 (N/m) (g/m2) time.sup.2
(sec) (wt-%) Reference 24.5 61.4 156 9.8 1% Marigold 24.4 63.8 124
4.8 Difference (Ref- -0.2% -20.5% 1% Marigold): .sup.1Average of 10
samples .sup.2Average of 9 samples
[0065] Sample 3
TABLE-US-00003 CD wet Lump at tensile Basis disintegration
strength.sup.1 weight.sup.1 Disintegration time.sup.1 (Alt. 2)
(N/m) (g/m2) time.sup.1 (sec) (wt-%) Reference -- 64.1 107 9.5 1%
Marigold -- 64.1 80 4.1 3% Marigold -- 64.2 119 19.9 Difference
(Ref- -24.8% 1% Marigold): Difference (Ref- +12.0% 3% Marigold):
.sup.1Average of 5 samples
[0066] Sample 4
TABLE-US-00004 Basis Lump CD wet tensile weight Disintegration at
10 min strength.sup.1 (N/m) (g/m2) time (sec) (Alt. 1) (wt-%)
Reference 35.3 64.6.sup.2 151.sup.2 2.1.sup.2 3% Marigold 26.9
63.9.sup.3 146.sup.3 3.9.sup.3 Difference -23.9% -2.8% (Ref-3%):
.sup.1Average of 5 samples .sup.2Average of 4 samples .sup.3Average
of 9 samples
[0067] It is interesting to note that a 1% admixture of marigold
petals resulted in a significantly lower disintegration time as
well as lump than for the reference, while the CD wet strength was
maintained. A 3% admixture of marigold petals, however, resulted in
an increased disintegration time and lump and a decrease in CD wet
strength.
* * * * *