U.S. patent application number 14/234676 was filed with the patent office on 2014-07-10 for flushable moist wipe or hygiene tissue and a method for making it.
This patent application is currently assigned to SCA HYGIENE PRODUCTS AB. The applicant listed for this patent is SCA HYGIENE PRODUCTS AB. Invention is credited to Lars Fingal, Anders Stralin, Kaveh Tondkar.
Application Number | 20140189970 14/234676 |
Document ID | / |
Family ID | 47601363 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140189970 |
Kind Code |
A1 |
Fingal; Lars ; et
al. |
July 10, 2014 |
FLUSHABLE MOIST WIPE OR HYGIENE TISSUE AND A METHOD FOR MAKING
IT
Abstract
A flushable moist wipe or hygiene tissue including a
hydraulically entangled nonwoven material impregnated with a
wetting composition is provided. The nonwoven material contains at
least 70%, by fibre weight, pulp fibres and at least 5%, by fibre
weight, poly(lactic acid) fibres having a length between 8 and 20
mm and a fineness between 0.5 and 3 dtex. The poly(lactic acid)
fibres are non-melted, and the moist wipe or hygiene tissue is free
from added binders and wet-strength agents.
Inventors: |
Fingal; Lars; (Goteborg,
SE) ; Tondkar; Kaveh; (Hisings Backa, SE) ;
Stralin; Anders; (Torslanda, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SCA HYGIENE PRODUCTS AB |
Goteborg |
|
SE |
|
|
Assignee: |
SCA HYGIENE PRODUCTS AB
Goteborg
SE
|
Family ID: |
47601363 |
Appl. No.: |
14/234676 |
Filed: |
July 12, 2012 |
PCT Filed: |
July 12, 2012 |
PCT NO: |
PCT/SE2012/050832 |
371 Date: |
February 7, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61511580 |
Jul 26, 2011 |
|
|
|
Current U.S.
Class: |
15/104.93 ;
162/135 |
Current CPC
Class: |
D21H 27/002 20130101;
D21H 13/22 20130101; D21H 13/24 20130101; D04H 1/435 20130101; D04H
1/425 20130101; A47L 13/17 20130101; D04H 1/26 20130101; D04H 1/492
20130101; D21H 21/22 20130101 |
Class at
Publication: |
15/104.93 ;
162/135 |
International
Class: |
A47L 13/17 20060101
A47L013/17; D21H 13/24 20060101 D21H013/24 |
Claims
1. A flushable moist wipe or hygiene tissue comprising a
hydraulically entangled nonwoven material impregnated with a
wetting composition, said nonwoven material containing at least
70%, by fibre weight, pulp fibres, wherein said moist wipe or
hygiene tissue comprises at least 5%, by fibre weight, poly(lactic
acid) fibres having a length between 8 and 20 mm and a fineness
between 0.5 and 3 dtex, said poly(lactic acid) fibres are
non-melted, and wherein the moist wipe or hygiene tissue is free
from added binders and wet-strength agents.
2. A moist wipe or hygiene tissue as claimed in claim 1, wherein
said moist wipe or hygiene tissue comprises up to 10%, by fibre
weight, regenerated cellulose staple fibres and/or natural fibers
having a fibre length of at least 4 mm.
3. A moist wipe or hygiene tissue as claimed in claim 1 wherein the
poly(lactic acid) fibres have a length between 12 and 18 mm.
4. A moist wipe or hygiene tissue as claimed in claim 1, wherein
the poly(lactic acid) fibres have a fineness between 1 and 2
dtex.
5. A moist wipe or hygiene tissue as claimed in claim 1, wherein
the poly(lactic acid) fibres are monocomponent fibres having a
melting point of at least 140.degree. C.
6. A moist wipe or hygiene tissue as claimed in claim 1, wherein
said moist wipe or hygiene tissue has a basis weight between 40 and
100 g/m.sup.2.
7. A moist wipe or hygiene tissue as claimed in claim 1, wherein
said moist wipe or hygiene tissue is a moist toilet paper.
8. A moist wipe or hygiene tissue as claimed in claim 1, wherein
said moist wipe or hygiene tissue has a wet strength in cross
direction between 25 and 200 N/m.
9. A moist wipe or hygiene tissue as claimed in claim 1, wherein
the poly(lactic acid) fibres form an open interlaid structure
mechanically bonded to the pulp fibers and the optional regenerated
cellulose staple fibers and/or natural fibres.
10. A moist wipe or hygiene tissue as claimed in claim 1, wherein
the poly(lactic acid) fibres have a modulus according to ASTM
method D2256/D3822 of between 20 and 50 g/denier.
11. A method of making a moist wipe or hygiene tissue comprising
the steps of: foam-forming a fibre mixture of at least 70%, by
fibre weight, pulp fibres and at least 5%, by fibre weight,
poly(lactic acid) fibres having a length between 8 and 20 mm and a
fineness between 0.5 and 3 dtex, hydroentangling said mixture to
form a hydroentangled nonwoven web, drying said web, wherein said
web is free from added binders and wet-strength agent, and wherein
the poly(lactic acid) fibres are non-melted, and impregnating the
web with a wetting composition.
12. The method as claimed in claim 11, wherein the fibre mixture
comprises up to 10%, by fibre weight, manmade staple fibres other
than poly(lactic acid) fibres.
13. The method as claimed in claim 11, wherein the poly(lactic
acid) fibres have a length between 12 and 18 mm.
14. The method as claimed in claim 11, wherein the poly(lactic
acid) fibres have a fineness between 1.5 and 2 dtex.
15. The method as claimed in claim 11, wherein that the poly(lactic
acid) fibres are monocomponent fibres having a melting point of at
least 140.degree. C.
Description
CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This application is a .sctn.371 National Stage Application
of PCT International Application No. PCT/SE2012/050832 filed on
Jul. 12, 2012, which claims priority to U.S. Provisional
Application No. 61/511,580 filed on Jul. 26, 2011, both of which
are incorporated herein in their entirety.
TECHNICAL FIELD
[0002] The present disclosure refers to a moist wipe or hygiene
tissue including a hydraulically entangled nonwoven material
impregnated with a wetting composition. It is especially related to
moist toilet paper and other wipes or hygiene tissue intended to be
flushable in a sewer. It further refers to a method for making the
flushable moist wipe or hygiene tissue.
TECHNICAL 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] Most moist flushable pre-moistened toilet papers which are
on the market today are flushable due to their small size. They can
move along the drainage and sewage pipes, but are not readily
dispersible and may therefore cause problems with blocked pipes and
filters.
[0006] It is previously known, for example through U.S. Pat. No.
3,554,788 to use an adhesive having a water-soluble component as a
bonding agent in a water dispersible nonwoven material. The
material is told to have a good dry strength but readily disperses
in water and is flushable. This nonwoven material is packaged in
dry condition and would not retain sufficient structural integrity
for any longer period of time as is required for wet wipes.
[0007] A wet wipe made of a hydroentangled three ply sandwich
structure comprising outer layers of synthetic fibres and a middle
layer of cellulosic fibres is known through U.S. Pat. No.
6,110,848.
[0008] EP 1 320 458 B1 discloses a wet wipe capable of
disintegrating under mild agitation in water and comprising at
least 50% by weight cellulose fibres, at least 5% by weight manmade
high crystallinity cellulose fibres and at least 0.5% by weight
binder fibres. The fibres are hydroentangled and the binder fibres
create a network that after activation and fusing lightly bonds the
pulp fibres and high crystallinity cellulose fibres together.
[0009] U.S. Pat. No. 5,935,880 discloses a dispersible wet wipe
comprising a hydroentangled fibrous web containing pulp fibres,
optionally synthetic fibres and a binder composition, said binder
composition comprises a divalent ion inhibitor, which facilitates
the disintegration process.
[0010] EP 0 303 528 Al discloses a hydroentangled disintegratable
nonwoven fibrous web used as a wet wipe. It comprises at least 70
weight % pulp fibres and at least 5 weight % staple length
regenerated cellulose fibres.
[0011] U.S. Pat. No. 6,670,521 discloses a flushable wet wipe
comprising a fibrous web having mechanically weakened regions. The
fibrous web comprises at least 50 weight % cellulose fibres and may
further contain poly(lactic acid) fibres. The web contains a wet
strength agent.
[0012] There is 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
[0013] It is desired to provide a moist wipe or hygiene tissue
intended to be flushable in a sewer. In a first aspect, there is
disclosed a moist wipe or hygiene tissue including a hydraulically
entangled nonwoven material impregnated with a wetting composition.
The nonwoven material contains at least 70%, by fibre weight, pulp
fibres, wherein said moist wipe or hygiene tissue includes at least
5%, by fibre weight, poly(lactic acid) fibres having a length
between 8 and 20 mm and a fineness between 0.5 and 3 dtex. The
poly(lactic acid) fibres are non-melted, and the moist wipe or
hygiene tissue is free from added binders and wet-strength
agents.
[0014] The moist wipe or hygiene tissue may comprise up to 10%, by
fibre weight, regenerated cellulose staple fibres and/or natural
fibers having a fibre length of at least 4 mm.
[0015] The poly(lactic acid) fibres may have a length between 12
and 18 mm.
[0016] The poly(lactic acid) fibres may have a fineness between 1
and 2 dtex.
[0017] The poly(lactic acid) fibres may be monocomponent fibres
having a melting point of at least 140.degree. C.
[0018] The moist wipe or hygiene tissue may have a basis weight
between 40 and 100 g/m.sup.2, wherein the basis weight is
calculated on the nonwoven material without the wetting
composition.
[0019] The moist wipe or hygiene tissue may be a moist toilet
paper.
[0020] The moist wipe or hygiene tissue may have a wet strength in
cross direction between 25 and 200 N/M, or between 40 and 200
N/m.
[0021] The poly(lactic acid) fibres may form an open interlaid
structure mechanically bonded to the pulp fibers and the optional
regenerated cellulose staple fibers and/or natural fibres.
[0022] The poly(lactic acid) fibres may have a modulus according to
ASTM method D2256/D3822 of between 20 and 50 g/denier, or between
30 and 40 g/denier.
[0023] In a second aspect, there is disclosed a method of making a
moist wipe or hygiene tissue comprising the steps of: foam-forming
a fibre mixture of at least 70%, by fibre weight, pulp fibres and
at least 5%, by fibre weight, poly(lactic acid) fibres having a
length between 8 and 20 mm and a fineness between 0.5 and 3 dtex,
hydroentangling said mixture to form a hydroentangled nonwoven web,
and drying said web. The web is free from added binders and
wet-strength agent, and the poly(lactic acid) fibres are
non-melted, and impregnating the web with a wetting
composition.
BRIEF DESCRIPTION OF THE FIGURES
[0024] FIG. 1 is a microscope picture of a hydroentangled nonwoven
web according to an embodiment of the invention.
[0025] FIG. 2 illustrates flushability tests performed with four
hydroentangled moist wipe materials as described below.
DETAILED DESCRIPTION OF EMBODIMENTS
[0026] A premoistened wipe or hygiene tissue 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.
[0027] 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. Spunlace materials can be produced with
high quality at a reasonable cost and they possess a high
absorption capacity.
[0028] The fibres used in the moist wipe or hygiene tissue are at
least 70%, by fibre weight, pulp fibres and at least 5%, by fibre
weight, poly(lactic acid), PLA, fibres having a length between 8
and 20 mm and a fineness between 0.5 and 3 dtex. The PLA fibres may
have a modulus between 20 and 50 g/denier, or between 30 and 40
g/denier, according to ASTM method D2256/D3822.
[0029] Optionally other manmade staple fibres may be included. In
certain embodiments, manmade staple fibres are biodegradable, such
as regenerated cellulose fibres, e.g. viscose, rayon and lyocell.
The nonwoven web may contain up to 10% by fibre weight of such
manmade staple fibres, other than PLA fibres. 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.
[0030] 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. In particular embodiments,
the 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.
[0031] PLA is a hydrophobic polymer prepared from renewable
agricultural raw materials. Fibres made of PLA are thus also
hydrophobic and are considered to be non absorbent. As only minor
amount of water is absorbed no major plasticizing (softening)
effect is obtained and the wet flexural modulus of the PLA fibre is
essentially the same as the dry flexural modulus and the PLA fibres
are relatively stiff also in water.
[0032] For cellulosic based fibers like wood pulp, cotton, viscose,
rayon or lyocell water is absorbed by the fibres. The wet flexural
modulus thus collapse and the fibers become very flexible in water.
Because of the low wet flexural modulus, these types of fibers have
a tendency to entangle and bind with each other in the pulper if
fiber length is too long. For pulp fibres this is not a problem due
to its relatively short fibre lengths in the range of 0.5-2 mm.
Pulp fibres can thus be used at high concentrations in the fibre
mixtures.
[0033] Man-made regenerated cellulose fibers like viscose, rayon or
lyocell are used at longer lengths in order to increase strength in
the hydroentangled material. The longer the fibres are, and the
higher the concentration is, the better reinforcing effect is
obtained. Because of the low wet flexural modulus, these fibers are
very effective in creating strength by hydroentanglement bonding.
However, it is experienced that with too much regenerated cellulose
fibers entanglement already occur in the pulper and poor runability
and formation of the material is obtained. Shorter regenerated
cellulose fibres are easier to process. For that reason it is
important to balance the regenerated cellulose fibre length and
fibre concentration considering the formation and desired
strength.
[0034] When a wet web is able to be formed with pulp fibres and PLA
fibres of relatively long length it is believed that a relatively
open network of interlaid PLA fibres is formed. The pulp fibres
will fill the space between and around the PLA fibres. Without any
hydroentanglement, the wet strength of this material is poor. By
the hydroentanglement, the pulp is interwined with the long PLA
fibres and especially the interwinings at PLA fibre crossings
creates strength in the material. By knitting the material together
at the PLA fibre crossings a fibre network is obtained with a
structural integrity allowing the material to be used in
pre-moistened applications. The strength obtained in the material
is created due to mechanical bondings/interlockings between pulp
and the long PLA fibres. At entanglement of materials with a high
pulp dosing, the entanglement energy must however be on a
relatively low level so that the pulp is not flushed away from the
web. For materials produced for applications such as moist wipes
intended to be flushable in a sewer, the entanglement energy must
also be balanced and kept on a relatively low level to secure a
good disintegration. For that reason it is not believed that any
major entanglement between PLA fibres occurs at low
hydroentanglement energy levels. The hydroentanglement is also
believed to compress certain areas in the structure and here the
short, fine and mobile pulp fibres may work as a wedge. This is
also believed to contribute to the strength of the material.
[0035] FIG. 1 is showing an image obtained with a Scanning Electron
Microscope (SEM) of a hydroentangled material made with PLA and
pulp fibres. The reinforcing network structure created by the PLA
fibers is shown as well as the shorter and mobile cellulosic pulp
fibers that have entangled and filled up the spaces between the PLA
fibers. This image supports the theory described above.
[0036] By also using regenerated cellulose fibres together with PLA
fibres and pulp fibres it has unexpectedly been shown that it might
be easier to balance and control the structural integrity and
strength required for a material to be used as a moist wipe,
intended to be flushable in a sewer. Longer regenerated cellulose
fibres will take part in the interlaid fibre network together with
the PLA fibres, however differently. As for the PLA-pulp composite
material, the pulp fibres will fill the space between and around
the PLA and regenerated cellulose fibres. At hydroentanglement, the
pulp fibres will create strength as described above for the PLA and
pulp composite. By the low wet flexural modulus of the regenerated
cellulose fibres, it is believed that they will entangle to a
higher degree than the PLA fibres at the low hydroentanglement
energy levels. The regenerated cellulose fibres may thus also
entangle with each other and with PLA fibres to create
strength.
[0037] By combining PLA fibres, regenerated cellulose fibres and
pulp it is thus possible to balance the strength that the product
become flushable i.e. disintegrates in a sewer. At the same time,
the wet tensile strength is high enough that the product does not
break at dispensing and during the wet wipe use. Surprisingly,
sufficient wet strength is thus obtained for the hydroentangled
composite material without any thermal bonds between PLA staple
fibres or without use of any chemical binders.
[0038] The PLA fibers may, according to one embodiment, have a
length between 12 and 18 mm.
[0039] The PLA fibres are non-melted so that the reinforcing
network may be broken when the web is flushed in a sewer, for
example. This will make the web to disintegrate.
[0040] The mechanical strength of a hydroentangled staple
fibre-pulp composite material is a function of staple fibre
concentration, staple fibre length, staple fibre coarseness, staple
fibre flexural modulus, input of hydroentanglement energy as well
as a function of the formation, including how the fibres are
aligned in the structure. The material strength in the machine
direction is always higher compared to the cross directional
strength because of the alignment of the fibers in the direction of
manufacture, due to the hydrodynamic shear as the sheet is formed,
as well as because of the stress exerted on the material at web
transfer through hydroentanglement and drying to the rewinder. In a
simple fibre network approach it is usually considered that the
number of fiber crossings can be described by simple probability
distributions.
[0041] In an attempt to characterize the network structure created
by the PLA fibres a theoretical value of number of crossover points
between the PLA fibres can be calculated as described below.
[0042] For a web having a basis weight of 60 g/m.sup.2 and a
concentration of PLA fibres of 5 weight % the amount of PLA fibres
will be 3 g/m.sup.2. For PLA fibres having a fineness of 1.5 dtex
(1.5 g/10 000 m) the total fibre length PLA fibres will be 20 000 m
for 1 m.sup.2 web. Half total fibre length is 10 000 m/m.sup.2. The
distance between fibres in mm is calculated by dividing 1000 (mm)
with half the total fibre length, which in the above example will
be 0.1 mm. By dividing the actual fibre length with this distance a
theoretical value of number of crossover points can be obtained.
The number of crossover points shows a linear relationship with the
actual fibre length and with the concentration of PLA fibres and is
illustrated in Table 1 below.
TABLE-US-00001 TABLE 1 Theoretical number of crossover points as a
function of fibre length and fibre concentration for 1.5 dtex PLA
fibres Fibre conc. (wt %) Fibre length (mm) 5 10 15 25 8 80 160 240
400 12 120 240 360 600 18 180 360 540 900
[0043] The PLA fibres may have a melting temperature of at least
140.degree. C. so that they will withstand normal drying processes
without softening or melting. In particular embodiments, the PLA
fibres are monocomponent fibres. The moist wipe or hygiene tissue
should be free from added binders and wet strength agents. Addition
of binders and wet strength agents will deteriorate the
flushability of the wipe since it makes it more difficult to break
up and disperse in a sewer. Even small amount of wet strength
agents may have big effects on the flushability.
[0044] PLA fibres are wettable and biodegradable, which is an
advantage for their use in a moist wipe or hygiene tissue intended
to be disposed after use.
[0045] The PLA fibres, pulp fibres and optional other fibres are
mixed and formed into a fibrous web. The fibrous web can be foam
formed, which is a variant of a wet-laying process. A surfactant is
added to a dispersion of the fibres in a liquid, normally water.
The foamed fibre dispersion is deposited on a foraminous support
member where it is dewatered to form a continuous web-like
material. The fibre dispersion may be diluted to any consistency
that is typically used in conventional papermaking process. A very
even fibre distribution is achieved in a foam forming process and
it is also possible to use longer fibres than in a conventional
wet-laying process.
[0046] The formed fibrous web is then subjected to
hydroentanglement from several rows of manifolds, from which water
jets at a high pressure are directed towards a fibrous web, while
this is supported by the foraminous support member. The fibrous web
is drained over suction boxes. Thereby, the water jets accomplish
an entanglement of the fibrous web, i.e. an intertwining of the
fibres. Appropriate pressures in the entanglement manifolds are
adapted to the fibrous material, grammage of the fibrous web, etc.
In particular embodiments, the entangling energy is relatively low
to ensure that the fibres in the web are not too strongly
entangled, but that the web will be disintegratable as desired. The
water from the entanglement manifolds is removed via the suction
boxes and is pumped to a water purification plant, and is then
re-circulated to the entangling stations.
[0047] For a further description of the hydroentanglement or, as it
is also called, spunlacing technology, reference is made e.g. to CA
patent No. 841 938.
[0048] Hydroentangling may occur in one or several steps and from
one side of the web or from both sides thereof. The web may be
transferred to another foraminous support between two subsequent
hydroentangling steps.
[0049] The entangled material is dewatered and brought to a drying
station for drying before the finished material is reeled up and
converted. Drying can be performed by blowing hot air through the
fibrous web, by IR dryers or other non-compacting drying
technique.
[0050] The entangled web is converted into wipes or hygiene tissue
of appropriate dimensions.
[0051] The wet strength in the cross-machine direction should be
between 25 and 200 N/m, or between 40 and 200 N/m. The wet strength
in machine direction is usually higher. The wet strength is
measured with water according to the test method SS-EN
ISO12625-5:2005.
[0052] In certain embodiments, the basis weight of the wipe or
hygiene tissue is between 40 and 100 g/m.sup.2 as calculated on the
dry weight of the fibrous material, excluding the wetting
composition.
[0053] The relatively low strength at least in cross-machine
direction may be accomplished by controlling the hydroentangling
process, for example the pressure in the entanglement manifolds
and/or the web speed through the process. Thus by lowering the
pressure in the entanglement manifolds and/or increasing the speed
through the process, the strength properties of the hydroentangled
web will usually be lowered, especially the strength in the
cross-machine direction. The strength in the machine direction will
always be higher due to the fibre orientation and not effected by
the hydroentangling process to the same extent as the cross-machine
direction strength. It is also known that the fibre orientation in
machine direction can be effected during the formation of the fibre
web by controlling the speed of the jet of the fibre dispersion
from the inlet box relative to the speed of the forming wire.
[0054] The wipe or hygiene tissue may be creped, embossed or
otherwise textured to enhance softness of the product. Normally,
working the web to enhance softness tends to reduce the wet
strength of the web.
[0055] The wipe or hygiene tissue is impregnated with a wetting
composition containing ingredients depending on the intended use of
the product. A major proportion of the wetting composition is
normally water. Other ingredients may include cleansing agents,
skin care agents, bactericides, fungicides, emollients, perfumes,
preservatives etc. depending on the intended use.
[0056] The ingredients in the wetting composition will also
influence the wet strength as well as the disintegration of the
moist wipe. Most likely ingredients such as cleansing agents and
emollients will decrease the wet strength and favour the
disintegration of the product.
[0057] One use of the wipe or hygiene tissue is as a moist toilet
paper. As an example a suitable wetting composition in a moist
toilet paper may be aqueous based and may contain ingredients like
propylene glycol, phenoxy ethanol, coco-glycocide, polyaminopropyl
biguanide, dehydroacetic acid, perfume, cocoamidopropyl betaine,
chamomilla recutita, bisabolol, citric acid, amylcinnamal,
citonellol, hexylcinnamaldehyd, butylphenylmethylpropional and the
like.
[0058] The moist wipe or hygiene tissue is either individually
packed in a sealed package that can be torn open by the user, or a
dispenser containing a large number of wipes or tissue that may be
dispensed through a dispenser opening in the dispenser.
EXAMPLE
[0059] Embodiments of the invention are further illustrated by the
enclosed test results. PLA fibres at a length of 12.7 and 18 mm
were supplied by Fibre Innovation Technology (Johnson City, Tenn.,
US). Lyocell fibres i.e. regenerated cellulose fibres at a length
of 12 mm were supplied by Lenzing. Pulp fibres were supplied by
International Paper.
[0060] The pulp and staple fibre compositions were wet laid onto a
forming wire with a Fourdrinier headbox. Hydroentanglement was made
with multiple hydroentanglement heads using an entangling energy in
the range between 60 and 150 kWh/ton. After hydroentanglement the
material was dried by through air drying technology. For material
4, 0.3 weight-% wet strength agent was added to the material after
the entanglement by spraying.
[0061] For materials 1-3, no chemical binder was used, a sufficient
CD wet strength was obtained and materials were disintegrated with
the tipping tube method. For material 4 were 0.3% wet strength
agent was added to the material no disintegration was obtained by
the tipping tube method.
[0062] The following test methods were used: Basis weight:
SS-EN-ISO 12625-6:2005; Dry strength: SS-EN-ISO 12625-4:2005; Wet
strength: SS-EN ISO12625-5:2005 (measured in water).
TABLE-US-00002 TABLE 2 Material composition Material 1 2 3 4 18 mm
PLA (%) 18 18 -- -- 12.7 mm PLA (%) -- -- 10 10 12 mm Lyocell (%)
-- -- 10 10 Pulp (%) 82 82 80 79.7 Wet strength agent (%) 0 0 0
0.3
TABLE-US-00003 TABLE 3 Test results Material 1 2 3 4 Basis weight
(g/m.sup.2) 68.2 66.5 73.4 73.7 Thickness (.mu.m) 631 618 572 577
Tensile strength wet MD (N/m) 173 247 305 330 Tensile strength wet
CD (N/m) 52 48 160 134
[0063] The disintegration of the material in the form of a sheet
18.5.times.12 cm is illustrated in the form of photos taken after
480 rotations in a tipping tube according to EDANA flushability
test and is shown in FIG. 2, wherein photo 1) represents material
1, photo 2) represents material 2 etc.
* * * * *