Note: Descriptions are shown in the official language in which they were submitted.
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FOLDING AND STACKING CONFIGURATION FOR WET WIPES
Field of the Invention
The present invention relates to stacks of wet wipes which are
provided with an improved interfolding and interleaving configuration, such
that each wipe can be readily separated from the wet wipe stack by the
consumer.
Background of the Invention
Wet wipes are typically premoistened, disposable towelettes which
may be utilised in a variety of applications both domestic and industrial and
perform a variety of functions. Wet wipes are typically used to wipe surfaces
both animate and inanimate, and may provide numerous benefits such as
cleaning, cleansing, disinfecting, and skin care benefits.
One particular application is the use of wet wipes for wiping parts of
the human body particularly when wash water is not available, for example
when traveling. Wipes are commonly used for human cleansing and wiping
such as anal, perineal cleansing and genital cleansing and face and hand
cleansing for example as intimate hygiene wipes such as feminine wet
wipes. Wet wipes may also be used for application of substances to the
body including removing and applying of make-up, skin conditioners and
medications. Another application of wipes is during diaper changes and also
for the treatment of adult and baby dermatitis partly caused by the use of
diapers and incontinence devices. In addition wet wipes are also applicable
for wiping and or cleaning other surfaces or for the application of
compositions to surfaces, for example kitchen and bathroom surfaces,
eyeglasses, shoes and surfaces which require cleaning in industry for
example surfaces of machinery or automobiles. Wet wipes also include
articles used for the cleaning or grooming of pets.
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Wet wipes are commonly constructed of combinations of synthetic and
natural fibres, such as polyolefin fibres, viscose fibres and cotton fibres,
which are generally moistened with an aqueous composition which contains
amongst others surfactants, preservatives, oils and scents. The wet wipes
are then typically provided in a folded stacked configuration within a
covered container such as a tub-like container having a lid. Alternatively,
the wipes may be provided in tub containers having a dispensing aperture.
In both cases this allows easy transportation and storage of the wipes.
However, a problem with the current stacking of folded wet wipes is
the lack of easy, single wipe dispensation from the wet wipe stack. This
problem is particularly acute in circumstances of use such as when a
consumer is holding a baby during a diaper change. Under such conditions
the consumer needs to be able to pick up and separate the wipe from the
stack using only one hand. This is not achieved satisfactorily with current
products.
The problem of the Lack of satisfactory wet wipe dispensation from the
stack and container is due to a number of reasons. Firstly, wet wipes are
typically folded and either placed one on top of the other or interleaved with
an adjacent wipe. However, the exact location of the leading edge of the
upper most wipe of the current stack is not easily identifiable, either
visually
or tacitly. This is because the substrate material of the wipe is typically
homogeneous and thus the leading edge of the wipe, particularly when
folded, cannot be distinguished from the wipe substrate material on which it
rests. In addition, the leading edge portion of the wipe also has a tendency
to adhere to the underlying wipe substrate material on which it rests. Hence
even tactile identification of the edge by running or dragging of the fingers
across the wipe surface does not immediately result in the identification of
the location of the edge.
Secondly, once the leading edge has been located, it is difficult for the
consumer to grasp hold of sufficient substrate material and maintain grasp
thereof, in order to separate a single wipe from the stack upon which it
rests. The consumer often is only able to grasp a small portion of the
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leading edge such that a tight grip thereof is not established and hence the
wipe easily slips from the fingers of the consumer.
These problems associated with wet wipe dispensation have been
recognised in the art. For example US 5 540 332 addresses dispensability
of wet wipes and a method of producing these wipes. The improved
dispensability is achieved by providing at least a portion of one of the end
edges of the wipe with a repeating non-linear pattern such as a sine wave
configuration. However, the problem of single wet wipe dispensation is
neither addressed or overcome by the use of a non linear leading edge.
Another proposed solution to the dispensing problem is described in
US 4 778 048, which discloses a product comprising a stack of wet wipes
tilted on edge within a container for improved access, dispensing and equal
liquid distribution. In a preferred embodiment, the edge of each wipe has a
Gurley Stiffness greater than the stiffness of the main body of the wipe.
However, the provision of such a stiff edge is in itself undesirable
characteristics of a wet wipe. Wet wipes, particularly those intended for use
on sensitive areas of the skin such as baby wipes require a certain degree
of softness. The edge of the wipe which is stiffened is no longer suitable for
use as is indeed recognised in the patent itself, and hence the wipes have a
reduced substrate surface suitable for use. Also care needs to be taken to
reduce or avoid contact of this edge portion with the skin as it may cause
irritation. Moreover, the stiffness of the edge again does not solve the
problem of single wipe dispensation. In addition, the provision of such a non
linear edge on a nonwoven substrate using current manufacturing
techniques would also result in the fraying of the edges of the substrate
which is also highly undesirable.
Alternatively, it has also been proposed to provide specifically
designed dispensing containers having dispensing orifices in order to aid in
the identification of the leading edge by the consumer. These containers are
designed such that during the removal action of the upper most wipe from
the container, the adjacent wipe is elevated from the stack such that it
partially protrudes through the orifice once the upper most wipe has been
removed. In this manner the uppermost wipe is positioned for easy grasp by
the consumer. However, a disadvantage with such devices is that too much
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substrate material of the adjacent wipe is exposed through the orifice.
Accordingly, the wipe becomes dry and unsuitable for use and has to be
discarded. EP 747 313 proposes a means to address this problem and
discloses a multiple folded paper, such as wetted tissue paper, for
continuous disposal through a container orifice. In this manner a maximum
of a quarter of the length of the adjacent wipe is exposed through the
dispensing orifice. However, such paper tissue products cannot be utilised
for all wet wipe applications, such as baby wipes as the wetted tissue paper
is not satisfactory in terms of softness or strength. In particular, such
wetted
tissues suffer from a tendency to tear during use and hence are not
suitable for use as wet wipes.
Another key contributory factor to the problem of single wet wipe
dispensation from the wet wipe stack which is not addressed by any of the
foregoing prior art, is the tendency of the wipe substrate material to adhere
to itself. In particular, this is due to the compression of the wipe stacks
during manufacture and storage, the actual weight of the stack of wipes
themselves, and the existence of attractive forces in-between the substrate
material and the lotion of the wipes. As a result, when the wipes are folded
to form a stack, the substrate material tends to adhere to itself and the
substrate material of adjacent wipes. Consequently, once the consumer has
raised the wipe from the stack, the wipe tends to maintain its folded
configuration. Moreover, the wipe typically remains at least partially
adhered to the adjacent wipe on which it was resting. Hence, in addition
during the action of wipe removal from the stack, the adjacent wipe is also
at least partially separated from the stack. As a result the consumer is
required not only to unfold the wipe before commencing with the desired
application of the wipe but also, to separated it from the adjacent wipe in
the
stack and returned this wipe to the stack in the container. This is obviously
particularly inconvenient to consumers utilising baby wipes during diaper
changes.
The problem of substrate wipe adhesion has been recognised in the
prior art. Attempts at resolving this problem have typically resided in the
provision of interleaved wipes as for example described in JP 08 089 439 .
Indeed interleaving is also known in the prior art related to dry tissue
products such as disclosed in US 2 772 021 and US 3 330 553. However
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due to complex interactions that exist between substrate material and lotion
in the wet wipe product, it is known that the folding configurations generally
utilized in such dry tissue products cannot be reapplied to wet wipes.
Furthermore, many of the proposed interleaving configurations have
associated problems therewith. In particular, when as a result of interleaving
the degree of overlap of substrate material between adjacent wipes is large,
then the problem of substrate adhesion is merely exacerbated such that the
wipes are effectively always released in pairs, or although the wipe is
dispensed singly, a large proportion of an adjacent wipe may still be
exposed through the dispensing orifice after the removal of the upper wipe,
such that the wipe becomes dry. On the other hand, if the overlap between
adjacent wipes is minimised such that single wipe dispensation is
guaranteed, there is no recognisable separation of the adjacent wipe from
the stack and the problem of leading edge identification reappears.
Furthermore, in addition to the unsatisfactory dispensation of the
wipes, other problems related to the proposed prior art interleaving
configurations may also arise. For example, as a result of the interleaving
configurations the substrate material may be unevenly distributed in the
container, which leads to a number of undesirable effects such as uneven
lotion distribution throughout the stack of wipes and within the individual
wipes themselves resulting in concentration of the lotion at specific areas
within the stack. Moreover, many of the interleaving configurations also
result in the formation of ridges and grooves in the substrate material, which
both tends to reduce the strength and softness of the wipe in addition to
being aesthetically undesirable .
It is therefore desirable to provide a wet wipe substrate which is
suitable for multiple applications such as baby wipes, which are strong, soft
and absorbent. It is further desirable to provide a stacking configuration for
such wet wipes which faciliates easy, single wipe dispensation from the
wipe stack,
The present invention addresses these problems by providing a stack
of wet wipes which have an improved folding and interleaving
configuration.
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Summary of the Invention
The present invention hence relates to a wet wipe for wiping parts of
the human body such as baby wipes and other surfaces. In particular, the
present invention relates to a stacking configuration for wet wipes so as to
facilitate ease of dispensation and separation of a single wipe from the
stack of wet wipes, especially for applications utilising a container and
dispensing orifice.
Accordingly, the wet wipe stacking configuration comprises a first
assembly of wipes and a second assembly of wipes, each of the wipes
comprising a substrate and a liquid composition. Each of said wipes extends
lengthwise from a first leading end edge to a second trailing end edge and
has at feast two folds thereby providing, a leading edge panel, a central
panel and a trailing edge panel.
According to the present invention, said first assembly of wipes is
interleaved said second assembly of wipes, such that at least a portion of
said central panel and at least a portion of said trailing edge panel of each
of said first assembly of wipes are interleaved between at least a portion of
said leading edge panel and at least a portion of said central panel of one
wipe of said second assembly of wipes. Similarly, at least a portion of said
central panel and at least a portion of said trailing edge panel of each of
said second assembly of wipes are interleaved between at least a portion of
said leading edge panel and at least a portion of said central panel of one
wipe of said first assembly of wipes. In addition the wipes are interleaved
such that the length of said leading edge panel or said trailing edge panel of
each of said first assembly of wipes is no more than 50% of the length of the
corresponding central panel, and such that the length of said leading edge
panel or said trailing edge panel of each of said second assembly of wipes
is no more than 50% of the length of the corresponding central panel.
Brief Description of the Figures
Figure 1: Depicts a perspective view of a z-folded wet wipe.
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Figure 2: is a cross sectional schematic illustration of a stack of
folded and interleaved wet wipes in a dispensing
container.
Figure 3a: Is a cross sectional illustration taken along line x-x in
' figure 1 showing a wipe having a leading edge panel 2,
a central panel 4 and a trailing edge panel 3 and folded
in a Z fold configuration.
Figure 3b: !s a cross sectional illustration of a folded Wipe having a
lip 36 on the leading edge panel.
Figures 4a,
4b, 4c & 4d: Cross sectional illustration of 4 embodiments of folding
and interleaving configurations for wet wipes according to
the present invention.
Detailed Description of the Invention
According to the present invention the wet wipe comprises a substrate
which is coated or impregnated with a liquid composition. The substrate
may be woven or nonwoven, foam, sponge, battings, balls, puffs or films,
most preferably a nonwoven and may be composed or natural or synthetic
fibres or mixtures thereof. Preferably, the fibre compositions are a mixed of
hydrophilic fibre material such as viscose, cotton, or flax and a hydrophobic
fibre material such as polyethylene tetraphthalate (PET) or polypropylene
(PP) in a ratio of 20%-80% hydrophilic and 80%-20% hydrophobic material
by weight. Two particularly preferred compositions are 50% viscose
50%PP and 50% viscose / 50 % PET. The substrate preferably has a basis
weight of at least 20 gm-2 and preferably less than 150gm-2, and most
preferably the base weight is in the range of 20 gm-2 to 70 gm-2, more
preferably from 50 gm-2 to 65 gm-2. The substrate may have any caliper.
Typically, when the substrate is made by a hydroentangling process, the
. average substrate caliper is less than 0.8 mm. More preferably the average
caliper of the substrate is from 0.1 mm to 0.4 mm. The substrate caliper is
measured according to standard EDANA non woven industry methodology,
reference method # 30.4-89. The bulk density of the substrate is preferably
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not more than 1.0 g/cm3, preferably not more than 0.9 g/cm3, most
preferably not more than 0.7 g/cm3 .
In addition to the fibers used to make the substrates, the substrate
can have other components or materials added thereto as known in the art.
The types of additives desirable will be dependent upon the particular end
use of the substrate contemplated. For example, in wet wipe products such
as moist toilet paper, paper towels, facial tissues, baby wipes and other
similar air laid products, high wet strength is a desirable attribute. Thus,
it is
often desirable particularly for cellulose based substrates to add chemical
substances known in the art as wet strength resins. A general dissertation
on the types of wet strength resins utilized in the paper art can be found in
TAPPI monograph series No. 29, Wet Strength in Paper and Paperboard,
Technical Association of the Pulp and Paper industry (New York, 1985). In
addition to wet strength additives, it can also be desirable to include
certain
dry strength and lint control additives known in the art such as starch
binders. Furthermore, the substrate may also comprise agents to improve
the optical characteristics of the substrate material such as opacifying
agents, for example titanium dioxide.
According to the present invention the substrate may be produced by
any methods known in the art. For example nonwoven substrates can be
formed by dry forming techniques such as air-laying or wet laying such as
on a paper making machine. Other nonwoven manufacturing techniques
such as melt blown, spun bonded, needle punched and spun laced
methods may also be used. A preferred method is hydroentangling.
According to the present invention a stacking configuration for wet
wipes is provided, which results in the improved ease of dispensation and
separation of a single wipe from the wet wipe stack and easily recognition
of the location of the leading edge of each subsequent wipe.
The present invention will now be described with reference to the
figures. Figure 1 provides a perspective view of a single folded wet wipe 1.
Figure 2 is a cross sectional illustration of a stack of folded interleaved
wipes 23 according to the present invention housed in a container 20. The
container 20 includes a tub portion 21 and a iid 22, pivotably joined to the
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tube portion, by for example a hinge mechanism and a dispensing orifice 24.
In an alternative embodiment, the wipes can also be stacked and then
packaged in a moisture impervious wrapper, such as a foil or laminated
polymeric film wrapper, to provide a refill package for use in refilling such
a
container.
According to the present invention the stacking configuration
comprises a first and a second assembly of wipes which are interleaved with
one another. Referring to figures 1-3, each folded wipe 1 in each assembly
extends lengthwise from a first, leading end edge 2, to a second, trailing end
edge 3. The folded webs also have side edges 4 and 5 which extend
lengthwise from the first leading end edge 2 to the second trailing end edge
3. Each folded wipe 1 has at least two folds thereby providing three panels.
As used herein a panel is a portion of a wipe extending between two folds,
or between a fold and an edge end.
The first panel fold 6 is generally parallel to the leading edge 2, and
generally perpendicular to the side edges 4, 5. The first panel fold 6 is
spaced Lengthwise from the leading edge 2 to provide a leading edge panel
9 extending between the first panel fold 6 and the leading edge 2. The
second panel fold 7 is generally parallel to, and spaced lengthwise from, the
first panel fold 6, thereby providing a central panel 8 joined to the leading
edge panel 9, at the first panel fold 6, and extending between the first panel
fold 6 and the second panel fold 7. The trailing edge panel 10 is joined to
the central panel 8 at the second panel fold 7, and extends between the
second panel fold 7 and the trailing edge 3. According to the present
invention the wipes are folded at the first and second panel folds 6 and 7, to
provide the corresponding leading edge panel, central panel, and trailing
edge panels 9, 8 and 10. The wipes can thus be folded into a number of
configurations prior to interleaving. This is clearly demonstrated with
reference to the respective surfaces of each of the panels as indicated in
figure 3.
In figure 3, each wipe has a first upper surface leading edge panel 30,
a second lower surface leading edge panel 31, a first upper surtace trailing
edge panel 32, a second lower surtace trailing edge panel 33, a first upper
surface centrai panel 34 and a second lower surface central panel 35. The
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leading edge panel and the trailing edge panel may thus be provided by the
first panel fold and the second panel fold respectively such that the panel
rests on the upper facing surface of the central panel or the lower facing
surface of the central panel. As exemplified in Figure 1 and 3a, the leading
edge panel 9 is adjacent to and overlies a portion of the upper facing
surtace of the central panel 8 and the trailing edge panel is adjacent to and
underlies a portion of the lower facing surface of the central panel 8 thereby
providing a so called reversed Z folded wipe. Alternatively, the wipes may
be folded so as to provided a Z fold configuration. In yet another alternative
both the leading edge panel and the trailing edge panel of each wipe maybe
folded such that they are both adjacent and overlie a portion of the upper
surface of the central panel. Preferably the wipes of the first and second
assemblies are folded so as to provide mirror images of one another, for
example whereby the first assembly of wipes are folded in a Z fold and the
wipes of the second assembly are folded in a reversed Z fold.
Furthermore, in addition to the leading edge panel, central panel and
trailing edge panel described herein above, each wipe may also have
further additional panels. In particular, the leading edge panel and or the
trailing edge panel may also be provided with an additional fold so as to
provide a leading edge panel lip or a trailing edge panel lip as illustrated
in
Figure 3b. Such a lip is formed by providing the leading edge panel or the
trailing edge panel with a panel lip fold which is adjacent to and spaced from
the leading or trailing edge of the folded substrate to provide a lip
extending
between the panel lip fold and the end edge. The panel lip fold may be
folded onto the lower surface of the leading edge panel such that the
leading end edge is below the leading edge end panel. This configuration is
particularly beneficial in facilitating grasping of the edge. Alternatively,
the
leading edge panel may be folded such that the leading end edge rests on
the upper surface of the leading edge panel. The lip may also be positioned
on the upper or lower surface of the trailing edge panel. The lip typically
extends from the leading or trailing edge from between 4 cm to 0.1 cm,
preferably from 2 cm to 0.25cm to the leading edge panel lip fold or the
trailing edge panel lip fold.
According to the present invention, the overall dimensions of the
substrate material and the panels thereof is dependent on the intended
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application of the wipe and can be selected accordingly. Preferably the ratio
of the lengths of the leading edge panel to central panel to trailing edge
panel is from 1:2:1 to 1:5:1 and most preferably the ratio is 1:3:1. More
preferably the ratio of the lengths of the panels of the wipes of the first
and
second assembly of wipes are identical and most preferably the leading and
trailing edge panels are both approximately one quarter the total length of
the wipe. In one non limiting, illustrative example wherein the wipe may be
utilised as a baby wipe, each folded wipe 1 can have an unfolded length of
from 10 cm to 30 crn as measured lengthwise from the leading end edge 2
to the trailing end edge 3. For each folded wipe 1, the spacing between the
first panel fold 6 and the second panel fold 7 can be from 2 cm to 7 cm,
while the lengths of the leading edge panel 9 and trailing edge panel 10 can
be from 2 cm to 7 cm. In a preferred embodiment the spacing between the
first panel fold 6 and the leading end edge 2 is more preferably from 3 cm to
6 cm, and even more preferably between about 3 cm and 5 cm. The spacing
between the first panel fold 6 and the second panel fold is more preferably
from 3 cm to 12 cm, and even more preferably between about 10 cm and 12
cm. The spacing between the second panel fold 7 and the trailing edge is
more preferably from 3 cm to 6 cm, and even more preferably between
about 3 cm and 5 cm.
According to the present invention and with reference to the
embodiments illustrated in figure 4a, 4b, 4c and 4d, an essential feature of
the stacking configuration is that each of the first assembly of folded wipes
40 are interleaved with each of the second assembly of folded wipes 41.
For example wipe x of the first assembly of wipes is folded in a
reversed Z fold and interleaved between a Z folded wipe x of the second
assembly of wipes. Similarly wipe x of the second assembly of wipes is
interleaved between wipe y of the first assembly of wipes and, wipe y of the
first assembly of wipes is interleaved with wipe y of the second assembly of
wipes and so on. In this manner, commencing with the first assembly wipe x,
at least a portion of said central panel 42x and at least a portion of said
trailing edge panel 43x of each of said first assembly of wipes 40 are
interleaved with wipe x of the second assembly of wipes between at least a
portion of said leading edge panel 51 x and at least a portion of said central
pane! 52x of each of said second assembly of wipes 50. Similarly, at least a
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portion of said central panel 52x and at least a portion of said trailing edge
panel 53x of each of said second assembly of wipes 50, are interleaved
between at least a portion of said leading edge panel 41 y and at least a
portion of said central panel 42y of each of said first assembly of wipes 40.
According to the present invention another essential feature of the
stacking configuration is related to the relative lengths of the panels of
each
of the wipes of the first and second assemblies. Accordingly, it has been
found that the length of the leading edge panel or the trailing edge panel of
each wipe for example wipes x of said first assembly of wipes, is no more
than 50% of the length of the corresponding central panel. Similarly, the
length of the leading edge panel or said trailing edge panel of each wipe of
said second assembly of wipes, is no more than 50% the length of the
corresponding central panel. Hence, the leading and trailing edge panels of
each of the first and second assemblies of wipes may be of any length
provided that the sum of the length of the leading edge panel and the length
of the trailing edge panel of any wipe is not greater than the length of the
corresponding central panel of the wipe. Preferably however, the lengths of
the panels of all of the wipes in each assembly and more preferably the
corresponding panels in both first and second assemblies are of
substantially identical dimensions.
Wet wipes stacked as described herein above result in superior
dispensation than wipes stacked according to the prior art. Whilst not
wishing to be bound by theory it has been found that the improved
dispensing is related to the combination of the specific interleaved folding
configuration between the first and second assemblies of wipes and the
specific area of overlap between the panels of the wipes.
By the utilisation of the herein above described interleaving
configuration the removal of the uppermost wipe, for example wipe x of the
first assembly; from the interleaved stack will cause the agitation of the
leading edge panel of the adjacent wipe x of the second assembly from the
stack. This thereby facilitates the identification of the location of the
leading
edge of the adjacent wipe to the consumer. Furthermore, it has been found
that the area of overlap between the leading edge panel of the adjacent
wipe (i.e. wipe x of the second assembly of wipes) and the central panel or
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trailing edge panel of the uppermost wipe, (i.e. wipe x of the first assembly
of wipes) ensures that the required amount of length of the substrate
material of the wipe x of the second assembly is raised and separated from
the stack. The area of overlap between the central panel of the adjacent
wipe (x of the second assembly) and the trailing edge panel or the central
panel of the uppermost wipe (x of first assembly) appear to be of lesser
importance. Hence, the positioning of the first and second panel folds and
the relative lengths of the leading and trailing edge panels to the central
panel is of critical importance. However, the improved dispensation provided
by the present invention may also involve other effects and interactions in
addition to or instead of the hypothesis given, and hence no reliance should
be placed thereon.
Further in addition to the dispensing improvement, the interleaving
configuration of the present invention particularly the embodiment illustrated
in figure 4a, also ensures that the majority of the substrate material of each
wipe in the stack is positioned in the horizontal plane. This reduces the
tendency of the stack to produce ridges or grooves of substrate material.
Moreover, the stacking configuration also reduces the tendency of the liquid
composition to become unevenly distributed throughout the stack.
The further details of the invention will now be described with
reference in turn to each of the embodiments 4a, 4b, 4c and 4d.
Figure 4a, depicts a most preferred stacking configuration of the
present invention. The configuration comprises a first assembly of wipes 40
folded in a Z configuration interleaved with a second assembly of wipes
folded in a reversed Z fold configuration. Thereby, a portion of the central
panel 42x (42y) of each wipe of the first assembly 40 is in contact with a
portion of the leading edge panel 51 x (52x) of each wipe of the second
assembly 50, such that substantially all of one of the surfaces of the leading
edge panel 51x (51 y) of each of the wipes of the second assembly 50 is in
contact with a portion of the central panel 42x (42y) of each of the wipes of
the first assembly 40. In this embodiment the leading edge panel 41x (41 y)
and the trailing edge panel 43x (43y) of each of said first assembly of wipes
40 are both no more than 50% the length of said corresponding central
panel 42x (42y) and are substantially equal in length. Correspondingly, the
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leading edge panel 51x (51 y} and the trailing edge panel 53x (53y) of each
of said second assembly 50 of said wipes are both not more than 50% the
length of said corresponding central panel 52x (52y) and are substantially
equal in length. Furthermore, the lengths of the leading edge panel 41 x
(41 y), the trailing edge panel 43x (43y) and the central panel 42x (42y) of
the each of the wipes of the first assembly 40 are substantially equal in
length to the lengths of the corresponding leading edge panel 51 x (51 y),
trailing edge panel 53x (53y) and central panel 52x (52y) of the second
assembly of wipes 50. In particular, in the embodiment depicted in 4a the
leading edge of each of said first assembly of wipes and each of said
second assembly of wipes is approximately a quarter of the total length of
each of said wipes.
The embodiment depicted in Figure 4b, is identical to that of 4a in
terms of length of the respective panels. However in this embodiment, the
wipes of both the first and second assemblies are folded such that the
leading edge panel and the trailing edge panel of the wipes is adjacent to
the upper surface of the central panel of the corresponding wipe prior to
interleaving. Hence, after interfolding according to the present invention a
portion of the central panel 42x (42y) of each wipe of the first assembly 40
is
in contact with a portion of the central panel 52x (52y) of each of the wipes
of the second assembly 50 and a portion of the trailing edge panel 53x (53y)
of the wipes of the second assembly being in contact with the leading edge
panel 41y of the wipes of the first assembly 40. Similarly, a portion of the
trailing edge panel 53x of each wipe of the second assembly is in contact
with a portion of the leading edge panel 41 y of each wipe of the first
assembly and a portion of the central panel 52x of each wipe of the second
assembly is in contact with a portion of the central panel 42y of each wipe of
the first assembly of wipes.
The embodiments according to figure 4c and 4d depict a stacking
configuration wherein the wipes of the first assembly 40, are folded in a Z
configuration and are interleaved with a second assembly of wipes 50
folded in a reversed Z fold. However in these embodiments the lengths of
the leading and trailing edge panel of the wipes of each of the respective
assemblies are not equal. In the embodiment depicted in 4c, the length of
the trailing edge panel of the wipes of both the first and second assemblies
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is over 50% the length of the central panel and is in fact about 60% the
length of the central panel of each of the wipes of both the first and second
assemblies. Consequently, the length of the leading edge panel of each of
the wipes of both first and second assemblies is less than 50% the length of
the central panel and is about 30%. In the embodiment depicted in 4d, the
length of the leading edge panel of each of the wipes of both the first and
second assemblies is over 50% and is about 60% of the length of the
central panel of each of the wipes of both the first and second assemblies.
Correspondingly, the length of the trailing edge panel of each of the wipes is
less than 50%, and is about 30% of the length of the central panel.
In a particularly preferred embodiment according to the present
invention, as depicted for example in figure 4a, the second panel fold 44x of
each of the wipes of the first assembly should not be in direct contact with
the first panel fold 54x of each of the adjacent wipes of the second assembly
of wipes. Similarly, the second panel fold 55x of each of the wipes of the
second assembly should not be contact with the first panel fold 44y of the
adjacent wipes of the first assembly. Preferably, there should be a distance
between the fold lines of at least 1 mm, preferably from between 1 mm to
5mm, and most preferably from between 1 mm and 3mm. This is because it
is believed that contact between two adjacent folds of two adjacent wipes (x
of the first and second assemblies) hinders the ability of the uppermost wipe
to be separated from the adjacent wipe and cause too much of the substrate
material of the adjacent wipe to be separated from the stack.
In another preferred embodiment of the present invention it is also
preferable to provide the leading edge or panel with a visual and or tactile
indicator. Such indicators further assist in the location of the leading edge
itself by the consumer. Visual indicators may be provided for example in the
form of a thin coloured strip or band printed on the surface of the leading
edge panel in the vicinity of the edge itself.
A particularly preferred means for providing an edge indicator is by
the use of a non linear edge such as a repeating sine wave or a repeating
zig-zag pattern. Such non linear patterns may extend partially along the
length of the edge in a continuous or intermittent manner or more preferably
extend substantially along the entire length of the edge of the wipe. The
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provision of such an edge provides both a visual and tactile edge location
indicator. Such mechanisms further promote ease of dispensation of the
wipes.
According to the present invention, the substrate material is typically
impregnated or coated with a liquid composition. An advantage of the
present invention is that the stacking configuration allows a variety of
composition to be used with the substrate material without significant impact
on the dispensing mechanism. This is not only useful in allowing the nature
of the composition to be varied, but also allows the loading of the
composition throughout the stack to be varied in order to combat the
composition settling at the base of the stack. According to the present
invention the term liquid composition refers to any composition which is in a
liquid form when the wipe is in contact with the surface. Typically, the
composition may be aqueous, alcohol based or an emulsion, either a water-
in-oil or an oil-in-water or a multiple emulsion, preferably the emulsion is a
oil-in-water emulsion. The emulsion may also comprise a lipid phase which
can be broken by the application of minimal pressure for example by wiping
the skin. Typically, the composition will comprise from 2% to 50% by weight
of said composition of actives and from 50% to 98% water, preferably de-
ionised or distilled. Of the active component, preferably 2% to 20% are
present in the oil phase and the remainder are present in the aqueous
phase.
According to the present invention the wet wipes are provided with an
emulsion composition comprising a oil phase in the range of 1 % to 20%,
preferably 2% to 10%, by weight of the composition. Advantageously, the oil
based phase is derived from natural resources such as from vegetable or
animal oils or may be synthetic or any mixtures thereof. Suitable vegetable
and animal oils for use herein include waxes such as beeswax, lanolin,
candelilla, and oils such as glycerine esters and glycerine ethers, fatty acid
alcohols, fatty acid esters and fatty acid ethers such as caprylic and capric
triglycerides and octylpalmitate. Suitable mineral oils include petroleum
based oils such as paraffin and petroleum jelly. Synthetic oils for use herein
include ethylenic polymers for example polyethylene wax or silicone based
oils. Suitable silicon oils include polydimethylsiloxanes, volatile cyclo-
methicones, dimethiconols, siloxysilicates and amino- and phenyl
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derivatives of siloxanes and mixtures thereof. Examples include
dimethicone (Dow Corning 200 Fluids), cyclomethicone and dimethiconol
(Dow Corning 1401 Fluid), cetyf dimethicone (Dow Corning 2502 Fluid),
dimethicone and trimethylsiloxysilicate (Dow Corning 593 Fluid),
cyclomethicone (Dow Corning 244, 245, 344 or 345 Fluid), phenyl
trimethicone (Dow Corning 556 Fiuid), or combinations thereof.
The oil-in-water emulsions typically require emulsifying agents. The
emulsifying agents which may be used in the present invention are
preferably capable of primary emulsification of oil-in-water emulsions. The
emulsifying agent is present in the range of 0.02% to 5.0%, preferably
0.02% to 3.0%, by weight of the composition.
In a preferred embodiment the emulsifying agent is a polymeric type of
emulsifying agent such as a copolymer of C10-C30 alkyl acrylates and one
or more monomers of acrylic acid, methylacrylic acid or one of their simple
esters cross linked with an allyl ether of sucrose or an allyl ether of
pentaerythritol. The emulsifying agents which are thus useful in the present
invention include Ceteareth-12, Ceteareth-20 or Pemulen TR1 and TR2
which are available from B.F. Goodrich company of the USA. However,
other known emulsifying agents such as ethoxylated fatty alcohols,
glycerine esters of fatty acids, soaps, sugar derived agents are also suitable
for use herein. Other useful emulsifying agents include those disclosed in
detail in EP-A-328 355.
According to the present invention the composition may comprise a
stability agent or preservative. Stability agents suitable for use herein
include phenoxyethanol preferably present in the range of from 0.1 to 1.0%,
sodium benzoate, potassium sorbate, methylparaben, propylparaben,
ethylparaben, butylparaben, sodium benzoate, potassium sorbate,
benzalkonium chloride, and disodium salt ethylenediamine tetraacetic acid
(hereinafter referred to as EDTA) or other EDTA salts (sequestrenes).
Sequestrene is a series of complexing agents and metal complexes general
of ethylenediamine-tetraacetic acid and salts. The total quantity of stability
agents should be in the range of 0.1 % to 4.0% by weight of the composition.
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The composition of the present invention may further comprise from
0.02% to 5.0% by weight of said composition of an emollient or moisturiser.
Preferably the emollient is water soluble and includes polyhydric alcohols,
such as propylene glycol, glycerin, and also water soluble lanolin
derivatives.
Further optional ingredients which may be used in the present
invention include, anti fungal agents, antibacterial agents, skin protectants,
oil soluble cleansing agents, water soluble surfactants or detergents,
preferably nonionic or amphoteric, pH adjusters, perfumes, fragrances and
the like.
In order for the emulsion to provide the wet wipe with good cleaning
performance the delivered viscosity should be less than 500 mPas,
preferably in the range of 300 to more than 100 mPas and most preferably
in the range of 180 to 120 mPas.
In preparing wet wipe products according to the present invention, the
composition is applied to at least one surface of the substrate material. The
composition can be applied at any time during the manufacture of the wet
wipe. Preferably the composition can be applied to the substrate after the
substrate has been dried. Any variety of application methods that evenly
distribute lubricious materials having a molten or liquid consistency can be
used. Suitable methods include spraying, printing, (e. g. flexographic
printing), coating (e. g. gravure coating or flood coating) extrusion whereby
the composition is forced through tubes in contact with the substrate whilst
the substrate passes across the tube or combinations of these application
techniques. For example spraying the composition on a rotating surface
such as calender roll that then transfers the composition to the surface of
the substrate. The composition can be applied either to one surface of the
substrate or both surfaces, preferably both surfaces. The preferred
application method is extrusion coating.
The composition can also be applied non uniformly to the surfaces of
the substrate. By non uniform it is meant that for example the amount,
pattern of distribution of the composition can vary over the surface of the
substrate. For example some of the surface of the substrate can have
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greater or lesser amounts of composition, including portions of the surface
that do not have any composition on it. The composition is typically applied
in an amount of from about 0.5 g to 10 g per gram of substrate, preferably
from 1.0 g to 5 g per gram of substrate, most preferably from 2 g to 4 g per
gram of dry substrate.
Preferably, the composition can be applied to the substrate at any
point after it has been dried. For example the composition can be applied to
the substrate prior to calendering or after calendering and prior to being
wound up onto a parent roll. Typically, the application will be carried out on
a substrate unwound from a roll having a width equal to a substantial
number of wipes it is intended to produce. The substrate with the
composition applied thereto is then subsequently severed to produce
individual wipes.
