Field of the Invention
Background of the Invention
The present invention relates to a dispensing system for wet wipes
comprising a container and a stack of wet wipes therein which deliver an
improved pop-up dispensing of an individual wipe from the wet wipe stack.
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
travelling. Wipes are also commonly used for human cleansing and wiping in
general such as anal, perineal 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.
Wet wipes are commonly provided as a structure of a combination 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 wipes
are then typically packaged in a container in order to facilitate easy transport and
There are two basic types of containers for such wet wipes namely, multi
wipe containers and single wipe packages. In typical multi wipe containers, a
flexible or rigid moisture impervious container is utilised, the wipes being folded
and stacked in such an arrangement therein, so that a single wipe is exposed to
and removed by a consumer at one time. These containers have a tub like
configuration or a flexible rectangular package, both of which are typically
resealable after opening.
A problem with the current wet wipes products is the lack of easy, single
wipe dispensation from the wet wipe stack and or the container. 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 readily needs
to be able to pick up and separate one wipe from the container and the stack
which is unfolded, using only one hand and without the wipe container being
raised from the surface on which it is placed during the removal action. This
however is not achieved satisfactorily with current products.
The problem of the lack of satisfactory single 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 and placed one on top of another to form a stack. The exact
location of the leading edge of the upper most wipe of current stacks is however
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 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 an 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
Another key contributory factor to the problem of single wet wipe
dispensation from the wet wipe stack is the tendency of the wipe substrate
material to adhere to itself This is in particular, 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 composition 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 or pulls the wipe through the dispensing orifice, 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
certain interleaving configurations for the wipes as for example described in JP 08
However, 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. 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.
Another problem with the current stacking of wet wipes is that a large
amount of the substrate material of the adjacent wipe is still exposed through the
orifice after wipe dispensation is complete, particularly for folding configurations
having a large overlap of substrate material between adjacent wipes. As a result,
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.
Alternatively, it has also been proposed to provide specifically designed
dispensing containers, so called pop-up dispensers, to improve dispensing.
These dispensers are comprised of a container having an upper panel having an
orifice. The pop-up dispensers function on the principle of providing a dispensing
orifice which is relatively small, and which is sized and configured so that in
combination with a stack of wipes having a particular folding configuration so that
the upper portion of the adjacent wipe is held within the dispensing. These
containers are thus designed such that during the removal action of the upper
most wipe from the container through the aperture, 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. These type of pop-up dispensers allow the wipes to
be provided either on a continuous roll with perforations therein or as separately
folded wipes as for example described in US 5,560,514.
Unfortunately, the provision of dispensers with typically very small
dispensing apertures is not considered desirable by the consumer. In particular
such small orifices prevent the consumer from being able to see and examine the
inner contents of the container and estimate the number of wipes remaining
therein. In addition if pop up failure occurs and the wipe adjacent to the dispensed
wipe is not elevated from the stack, due to the small dispensing orifice size the
consumer is unable to easily feed the wipe through the dispensing orifice and is
required to dismantle the dispenser itself Likewise a similar problem is
encountered if the consumer inadvertently removes too many wipes than required
from the dispenser and attempts to push them back into the dispenser.
Summary of the Invention
It is therefore on abject of the present invention to provide a wet wipe
dispensing system which facilitates single wipe separation from the stack and
container, such that the wipe is unfolded and ready for use without any of the
Brief Description of the Figures
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 pop up wet wipe dispensing system so as to facilitate ease
of dispensation and separation of a single wipe from the stack of wet wipes within
a dispensing container throughout the diminishing height of the stack. The
dispensing container comprises a container body, said container body comprising
a lower portion and an upper portion, the upper portion comprising a dispensing
aperture having a cross sectional area of from 14cm2 to 65cm2. The wipes have
an average separation force between two wipes as defined by the test method
herein of from 75 g/cm2 to 250g/cm2.
Detailed Description of the Invention
- Figure 1:
- Is a cross sectional schematic illustration of a stack of
wet wipes in a dispensing container 20.
- Figure 2:
- Is a cross sectional illustration showing a wipe 1 having
a leading edge panel 2, a central panel 4 and a trailing
edge panel 3 and folded in a Z fold configuration.
- Figure 3a & 3b:
- Are cross sectional illustrations of preferred folding and
interleaving configurations for wet wipes according to the
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 calliper. Typically, when the substrate is made by a hydroentangling
process, the average substrate calliper is less than 0.8 mm. More preferably the
average calliper of the substrate is from 0.1 mm to 0.4 mm. The substrate calliper
is measured according to standard EDANA non woven industry methodology,
reference method # 30.4-89. The bulk density of the substrate is preferably 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 fibres 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 utilised
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, 1965). 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.
The substrate may be comprised of one or a multiplicity of layer, preferably
two or three layers of material. These layers may be identical in terms of
composition and or manufacturing techniques or a combination of any of the
materials described herein above. Preferably one of the layers may be a scrim
reinforcing layer, as described for example in US Patent Application serial number
According to the present invention the substrate of the wet wipe has a
central panel and two opposing end edge panels, a leading edge panel and a
trailing edge panel. Each of said panels has a first upper surface and a second
Each folded wipe 1 extends lengthwise in the machine direction 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 can include a first panel fold 6
which is generally parallel to the leading edge 2, and which is 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. As used herein a panel is a portion of
the wipe extending between two folds, or between a fold and an edge end.
The folded wipe can also include a second panel fold 7, and a central
panel 8, and a trailing edge panel 10. The second panel fold 7 is generally
parallel to, and spaced lengthwise from, the first panel fold 6. The central panel 8
is joined to the leading edge panel 9, at the first panel fold 6, and extends
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. The trailing edge panel 10 extends between the second panel fold 7
and the trailing end edge 3. The wipe is folded at the first and second panel folds
6 and 7 to provide the leading edge panel, central panel, and trailing edge panels
9, 8 and 10, in a Z-fold configuration, as best seen in Figures 2 and 3. In the Z-fold
configuration, panel 9 is adjacent to and overlies a portion of panel 8, and
panel 10 is adjacent to and underlies a portion of panel 8. However other folding
configurations such as C folds or J folds are equally applicable. Furthermore in
addition to the panels described herein above, the wipe may have 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. 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 form 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.
Referring to Figures 2 and 3, the folded wipes 1 are interfolded between
adjacent folded wipes 1. For instance, a panel such as panel 10 on one folded
wipe 1, could be interleaved between panels 9 and 8 of an adjacent, underlying
folded wipe. According to the present invention the wipes are stacked in groups of
discrete folded wipes. Multiple stacks of the discrete folded wipe can then be
combined one on top of the other to provide a stack as shown in figure 2.
However, the number of wipes in a discrete stack and the combination of stacks
can be varied as required and depending on the container with which they are to
be combined. A particularly preferred folding configuration of the wipes according
to the present invention is described in European Patent Application number
97108388.6, PCT/US98/10603 and EP 747 313 and incorporated herein by
According to the present invention, the overall dimensions of the substrate
material is dependent on the intended application of the wipe and can be selected
accordingly. 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 cm 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 the improved pop up dispensing of the
wipes is provided by the combination of the above described dispensing aperture
of the dispensing container as described herein below with wipes stacked such
that the average separation force between two adjacent wipes is from 75g/cm2 to
250g/cm2, preferably from 100g/cm2 to 200g/cm2 more preferably from 125g/cm2 to
175g/cm2 as defined in the test method hereinafter. Whilst not being bound by
theory it is believed that the upper separation force limit is required in order to
prevent chaining of the wipes whilst the lower limit ensures substrate stability and
prevents fall back of the wipes.
According to the present invention any means by which the separation
force between adjacent wipes can be adapted to meet the requirements above
can be utilised and thus includes both physical or mechanical means, chemical
means and combinations thereof. Preferably these means should be selected so
as to minimise their impact on the characteristics of the substrate material per se
so that the wipe maintains its desirable characteristics such as softness,
absorbency and wet strength and may be provided to the wet wipe panels at any
stage of the manufacturing process.
Suitable physical/mechanical means for providing the surface of the wet
wipe with the separation force include for example embossing, crimping, thermal
bonding, ultra-sonic bonding and printing, for example water jet printing. Such
methods are well known to the skilled person in the art. One preferred method is
provide the surface of the wipe substrate with a surface topography of peaks and
valley, by the use of scrim partially bonded to another layer as described in US
09/133294 incorporated by reference.
Alternatively the fibres of which the substrate material is composed of can
b selected so as to be hydrophobic and or provide a low friction substrate by for
example the reduction in the presence of long or protruding fibres from the
surface of the substrate. Similarly the manufacturing methods employed for the
substrate can also be selected so as to provide the desired separation force. For
example airlaying techniques are considered to raise the separation force whilst
wet laying reduces it.
Suitable chemical means of adapting the separation force between wipes
include lubricants, silicone release coating from Dow Corning of Midland
Michigan available as Syl-Off 7677 to which a crosslinker available as Syl-Off
7048 is added in proportions by weight of 100 parts to 10 parts, respectively.
Another suitable treatment is a coating of a UV curable silicone comprising a
blend of two silicones commercially available from General Electric Company,
Silicone Products Division, of Waterford, NY, under the designations UV 9300
and UV 9380C-D1, in proportions by weight of 100 parts to 2.5 parts, respectively.
When such a silicone blend is utilised on the substrate coating application levels
of at least 0.25 g, preferably 0.5 to 8.0 grams silicone per square meter of surface
area have performed satisfactorily, although other coating levels may prove
suitable for certain applications depending upon for example the nature of the
substrate and the characteristics of the lotion. Other suitable treatment materials
include, but are not limited to, fluorinated materials such as fluoropolymers (e. g.,
polytetrafluoroethylene (PTFE), commercially available under the trade name
TEFLON") and chlorofluoropolymers. Other materials which may prove suitable
include hydrocarbons such as petrolatum, latexes, paraffins, quaternary
ammonium compounds, oils, essences and the like, although silicone materials
preferably long chained and or branched silicones are presently preferred for use
in the wet wipes for their biocompatibility properties. Preferred silicones include
dimethicone copolyols. Others include any of the commercial water repellents
listed in McCutcheon's Volume 2: Functional Materials 1995, McCutcheon's
Division, The Manufacturing Confectioner Publishing Co. (the disclosure of which
is incorporated by reference herein), of which GrapHsize, available from Akzo
Nobel Chemicals Inc., and Norgard 10-T, available from Norman, Fox & Co., are
preferred. Other suitable means include coating with photosensitive resins.
According to the present invention such chemicals may be applied to the surface
of the panel by any means such as coating, spraying, extruding, printing, or
impregnation of the surface per se or of the substrate fibres. These chemicals
maybe added to the substrate as a component of the lotion or independently.
According to the present invention the wet wipes are stacked and then
stored in a rigid dispensing container 20. The container 20 comprises a container
body 21 comprising a lower portion 22 and an upper portion 23. The container 20
may be provided in any shape such as a cuboid, rectangular solid, cylinder and
the like depending on the end use intended and the nature and shape of the wet
wipes themselves. Preferably the container 20 is a rectangular solid and is
typically made of a body portion having a base wall 24, end walls 25, side walls
26 and optionally a top wall 27, which are integrally molded. The container is
preferably molded form any suitable plastic material by thermomolding or injection
molding techniques for example. Suitable plastics include polypropylene,
polyethylene, polystyrene, acrylonitryl butadiene styrene, polyester, polyvinyl
chloride, polycarbonate and high density polyethylene. Preferably the container
20 is formed from polypropylene. Typically these container may have dimensions
of about 30cm by 20cm by 12cm, preferably 25cm by 15cm by 10cm.
In a preferred embodiment the container of the present invention is
provided with a lid 28. The lid 28 is typically mounted onto the container body 21
at the upper portion 23 and may be affixed thereto by means of threads, snap
fitting, interengaging ribs, frictional engagement and the like. Alternatively the lid
28 may be attached to the container body 21 by a hinge mechanism. The wipes
are either placed directly in the container 20 or alternatively, the wipes can be
stacked and then packaged in a moisture impervious wrapper, such as a foil or
polymeric film wrapper, to provide a refill package for use in refilling the container.
The upper portion 23 of the container body 21 which is either integral with
the container body 21 and provided with a top wall 27 or is provided by the lid 28
attached to the container body 21 is provided with a dispensing aperture 29.
According to the present invention the dispensing aperture 29 is selected so as to
provide an open surface area of from 14cm2 to 65cm2, preferably from 15cm2 to
50cm2, more preferably from 20cm2 to 35cm2. The aperture may have any shape
such as circular, rectangular, oval and the like or S shape or may also have wings
as described for example in WO98/199946. Most preferably the aperture has a
rectangular or oval shape. Preferably the aperture should be provided such that it
is rigid and does not alter its shape significantly during use and there should be
no sharp edges or corners upon which the wipes or the consumers fingers could
become snared. The upper portion of the container body may also be provided
with a recess such that any excess wipe substrate protruding from the aperture
can be placed in-between the lid and the body portion.
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 derivatives of siloxanes and mixtures thereof. Examples
include dimethicone (Dow Corning 200 Fluids), cyclomethicone and dimethiconol
(Dow Corning 1401 Fluid), cetyl 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
Fluid), 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
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.
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 roil 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 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.
Separation Force Test Method
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.
Preparing the sample
This method measures the force which is needed to separate wet wipes. It
imitates the machine converting of wipes, however, variables such as
differences in folding or packaging design are eliminated. The test results
are dependent upon the nature of the substrate and lotion but also the
Measuring the separation force
- 1. A stack of 20 dry folded wipes are weighed, and the weight to be
achieved with a given lotion load is calculated. The wipes are put into
a plastic box and soaked with approx. 125 ml of lotion. Half of the
lotion is poured onto the stack, then it is turned over and the
remaining lotion is added. The stack is then squeezed by hand in the
box to make the lotion soak the whole sample.
- 2. The stack is taken out from the plastic box and put onto a plastic
block which is slightly larger than the stack. With another plastic block
the excess lotion is squeezed out until the necessary weight for a
given lotion load (calculated in step one) is reached.
- 3. The wipes are then one by one unfolded and on a plastic foil put on
top of each other with an overlap corresponding to the length of the
overlap of the folding configuration (as illustrated on figure 3a as l1
and l2). The upper surface of the wipe stack is then covered by plastic
- 4. The stack is put on the floor/hard surface. A piece of non-deformable
plastic, at least as big as the overlap area, is put on top of it, and the
stack is compressed with 20 kg for 15 sec. As weight, a canister with
water to give a total weight of 20 kg can be used. Care should be
taken to lower the canister very slowly to ensure that the initial
pressure exerted by the canister does not exceed 20 kg.
- 1. The samples should be measured immediately after converting.
However, preparing two samples at a time, then compressing both,
then measuring both, is acceptable.
- 2. To measure the separation force, the upper plastic foil is opened.
Often, the first wipe remains stuck to it or at least gets looser. In any
case, the first wipe is removed and measuring starts with the pair of
wipe 2 and 3.
- 3. Wipe 3 is carefully separated from the stack and therefore wipe 2 too,
sticking on top of it. The wipes are clamped into the tensile strength
measuring machine. It pulls them apart and gives the needed force in
- 4. The whole stack is measured in pairs. The last wipe is discarded, as
well, so each sample of originally 20 wipes will give 9 data points.
- 5. Standard deviation is usually in a range of approx. 5%.