Note: Descriptions are shown in the official language in which they were submitted.
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WASTE MANAGEMENT DEVICE WTTH ADHESIVE FLANGE
Field of the Invention _
The present invention relates to a disposable human waste management
devices such as urine management devices and faecal management device for
babies, children or adults to be attached directly to the skin of the wearer.
The
device utilises an improved adhesive having a specified rheology and
application
thickness in order to attach the device to the skin of the wearer so as to
facilitate
easy application and removal of the device from the wearer without pain,
whilst
ensuring maintenance of the device in the desired position, particularly on
moist
and wet skin for the entire period of wear, including circumstances or periods
of
wear during which the wearer is active, i.e. not bedridden.
Background of the Invention
Urine faecal management devices are known articles of manufacture that
are designed to be worn principally by incontinence sufferers and in
particular by
bedridden patients. Such human waste management devices are attached to the
natural anal region or artificial anus of the wearer and or the uro genital
region
and are intended to entrap and immediately contain faecal material and other
bodily discharges.
Such devices as they are mostly known today are designed to be worn by
bedridden patients. As such the devices are constituted of a relatively long
and
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narrow tube, at one extremity of which there is an aperture and a skin
attachment
device upon which an adhesive can be applied.
Examples of these bags are disclosed for example in US 3,577,989, which
details a disposable elimination-trapping bag for incontinence sufferers
including
a container member having an open-top portion, and a flange secured to the
container member around the open-top portion. The flange may include a layer
of adhesive on its surface as a means of attachment of the bag to the wearer
or
alternatively discloses the use of elastic straps to attach the bag to the
wearer.
US 4,784,656 also describes a receptacle for collecting faecal matter from
incontinence sufferers. The faecal collector comprises a gasket, conduit means
or a cylinder and a receptacle; the receptacle and conduit means are each
formed from two sheets of odour barrier thermoplastic film that are heat
sealed
along their side edges, respectively and the side surface of the gasket is
coated
with a layer of adhesive; GB 2 152 387, teaches a faecal collector for
incontinence sufferers comprising a collection bag and a ring, which is
provided
with an adhesive. The faecal collector comprises a pair of panels of
thermoplastic sheet material joined at their margins to define an elongate bag
having an opening at one end. GB 1 078 588 describes a urine collector
comprising a liquid proof bag of tube like configuration having in opening
surrounded by an attachment means in the form of an adhesive material.
Other types of faecal management bags having a flatter shape are known
from EP 245 064. EP 245 064 discloses bags having a front and a rear wall, the
front wall containing the aperture and attachment means to the body. The
attachment means is a skin compatible water resistant material such as a
hydrocolloid and a water insoluble viscose elastic binder.
Due to their typical elongated shape and dimensions, such devices
particularly when worn by active wearers, such as infants or non bedridden
incontinent adults, can readily twist around the thighs of the wearers andlor
can
cause the formation of folds and kinks in the devices themselves. Under such
circumstances the pressure and stress exerted upon the bag will naturally
increase due to the movement of the wearer and the pressure of the wearer's
body upon the bag. Consequently, the likelihood that the faecal material once
excreted and contained within the bag will be caused to exert pressure upon
the
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attachment means of the device will increase and as a result not only will the
storage capacity of the device be detrimentally affected but also more
importantly it may result in unintentional detachment of the device from the
wearer during use. Such an occurrence is unacceptable causing distressing
consequences for both the wearer and the carer.
Hence, it is critical that the urine and/or faecal management devices are
designed such that they are securely attached to the skin of the wearer and do
not become unintentionally unattached during all circumstances of use.
In order to provide the desired level of adhesion of the device to the wearer,
the prior art typically discloses the utilisation of certain adhesives having
very
high cohesive strengths such as rubber based adhesives and acrylics. These
adhesives are then applied as thick layers over the entire surface of the
flange of
the device to maximise the adhesive force by which the device is secured to
the
skin of the wearer. Indeed it is apparent that these devices and in particular
the
adhesives have been designed for use on faecal management devices utilised
by bedridden patients particularly those having an artificial anus whereby
maximum adhesion takes priority over any other criteria such as patient
comfort.
However, the adhesive must have a skin compatible composition and not
be harsh or aggressive towards the skin or cause skin irritation or
inflammation.
Also it is preferred if the adhesive is compliant with the skin of the wearer
such
that maximum skin surface contact between the adhesive and the skin is
achieved. Moreover, it is also desirable to provide an adhesive such that the
device can be readily removed from the wearer, without the wearer experiencing
any unacceptable pain level. This is particularly important under
circumstances,
where the device is misplaced, and removal and reappiication of the device
once
or even a number of times is required and or to ensure the application of such
devices on sensitive skin and wearer groups such as infants. However, on the
other hand the desired level of adhesion, albeit painless should of course
also
be maintained during such multiple applications of the device.
The problem of the achieving the desired adhesion level is further
exacerbated under wet skin conditions. Typically, prior to the placement of
the
device, the skin is cleaned and is usually as a result moist. The currently
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available adhesives, such as hydrocolloids, however often do not immediately
strongly adhere to the skin and may need to be held in place until sufficient
minimum adhesion occurs. Moreover, the overall adhesive ability of such
adhesives tends to be significantly reduced on wet skin surfaces per se, so
that
the device will typically not remain attached to the skin during wearer if any
pressure is exerted onto the device, for example by the movement of the wearer
or during the defaecation process.
Moist and wet skin however is not just a problem which is prevalent at the
device application stage, as a significant amount of moisture is also
generated
during the use of the device from the wearer by perspiration and from the
material contained in the bag. The resulting humid environment naturally
further
increases when the device is utilised in combination with a diaper. Under such
circumstances current adhesives typically cannot absorb this moisture and
again
the adhesive strength is reduced to such an extent that the device will often
become detached under exertion of pressure during wear. It is hence very
important to provide an adhesive which maintains its adhesive strength on wet
skin.
None of the prior art in the field of faecal management bags however even
recognises or addresses the problem of providing these devices with an
adhesive which meets these criteria.
The prior art in the general field of adhesives for attachment to the skin is
in
contrast more developed in the field of articles such as band-aids, plasters
and
bandages. These articles are however typically applied in an emergency
situation, where for example, a cut into the skin of the wearer has occurred
and
absorption of the body liquids emanating from a wound is desired. In this
context
performance aspects of the article such as easy application and use of the
product, comfortable wear as well as painless removal, and discreteness are
again sin subordinate, to other criteria in this case such as sterility,
healing
support, and mechanical protection of the wound.
WO 97/42985 discloses a wound dressing comprising a layer of absorbent
foam material which is coated with a layer of skin adhering hydrophobic get
which have a lower specific adhesivity.
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Another field wherein the use of such adhesives has been disclosed is in
absorbent such as for example sanitary napkins, as described in for example US
statutory invention registration H1602 or WO 96/33683 and WO 95/16424. The
5 latter discloses sanitary articles having a topical adhesive which is
applied on
the wearer facing side of a sanitary napkin along the entire periphery.
WO 96/13238 discloses a topical adhesive which is described in terms of
frequency dependency. EP-638 303 discloses the use of a topical adhesive on
side cuffs of sanitary napkins in order to keep the cuffs in an upright
position.
Swiss publication CH-643730 discloses the use of a very long sanitary napkin
having chamfered outer edges with a topical adhesive at the four corners of
the
outer edges in order to provide a topical adhesive area well outside the
region of
pubic hair growth.
However all of these disclosures typically disclose a product which is
designed to be utilised in combination with an undergarment and hence the
degree of adhesion actually provided is very low and is not designed to
withstand any excessive pressure. Moreover the adhesive is only discussed in
general terms or concentrates on the area of application of the adhesive to
the
article. The nature of adhesive per se other than the basic physical
requirements
such as pressure sensitivity are not discussed in particular with reference to
the
chemical composition or the adhesive criteria.
Similarly from the field of urinary management devices it is known, for
example from WO 92/'11825, to provide a urinary incontinence pad having a
resilient body on the exterior surface of which is applied a layer of adhesive
such
as a hydrophilic hydrogei adhesive. However again urinary absorbent devices
have to meet entirely different functional criteria than the faecal devices of
the
present invention. In particular, faecal management devices contain solid or
semi
solid waste which can readily move within the confines of the bag and exert
pressure upon the orifice and thereby cause dis-attachment of the device from
the wearer. In contrast such urinary pads can readily absorb the liquid such
that
it will not flow out of the absorbent and therefore such devices are not
designed
to be able to withstand the pressures commonly exerted within a faecal
management device.
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Hence there still exists a need to provide a human waste management
device having an adhesive for the secure attachment and painless removal of
the device from the skin in-between the buttocks of the wearer so as to be
suitable for use of sensitive skin of an infant and it is thus an object of
the
present invention to provide such as device.
It is another aspect of the present invention to provide an adhesive that
exhibits an ability to adhere to skin upon reapplication, particularly
multiple
reappiication for example when the device is misplaced is maintained, whilst
still
allowing painless removal. It is yet another objective to provide an adhesive
which does not leave residues after removal.
It is yet a further aspect of the present invention that the adhesive will
adhere to moist or wet skin, independent of whether this is direct application
of
the device onto wet skin, or moisture which is generated on the skin surface
during the wearing period of the device.
In addition to the above aspects of the present invention it is also
desirable for the adhesives to provide additional benefits such as
deliveryldispersal of a compound or composition which is beneficial for the
skin
or for the body in general.
It has now been surprisingly found that the above drawbacks will be
substantially alleviated by providing the flange of the device with an
adhesive as
defined hereinafter. The adhesive provides secure attachment, is pleasing to
the
skin upon application, and yet causes no discomfort upon removal. This is
achieved by selecting the characteristics of the topical adhesive,
particularly in
terms of the viscous modulus G° of the topical adhesive and the
thickness~C of
the layer of topical adhesive applied to the device.
In a particularly preferred embodiment of the present invention, the overall
performance of the devices is further improved, if the bags are provided with
a
particular configuration, thus allowing the utilisation of the devices for a
number
of wearer groups such as babies, children and active adult incontinence
sufferers, in addition to bedridden adult incontinence suffers.
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In another aspect of the present invention, the faecal management device
with its specific adhesive can be advantageously used in combination with a
reusable underwear garment or preferably with a disposable diaper.
Brief description of the drawings
It is believed that the invention will be better understood from the foregoing
description in conjunction with the accompanying drawings in which:
l0 Figure 1 is a perspective view of a faecal management device in
accordance with the present invention.
Figure 2 shows a perspective view of the faecal management device in
conjunction with a disposable diaper; and
Figure 3 is a partially cut-away perspective view of a disposable diaper
embodying the present invention.
Figure 4 is a plan view of a disposable urine management device of the
present invention.
Summary of the Invention
Any human waste management device such as a urine management device
or a faecal management device known in the art can be provided with the
adhesive according to the present invention. Typically these devices comprise
a
bag (11 ) having an aperture (21 ) and a flange (12) surrounding the aperture
for
adhesive attachment to the uro genital area and or the perianal area of a
wearer
as visible from Figure 1. The adhesive allows attachment of devices to the
skin
of the wearer, the adhesive being provided as a layer having a certain
thickness
or calliper C measured in millimetres (mm), typically on at least part of the
wearer facing surface of the flange.
Detailed analysis of the sequence of common situations occurring from the
application of a human waste management device to the time of removal of such
a device has shown that specific adhesive characteristics need to be
preferably
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8
satisfied in order to achieve the desired performance objectives, in
particular to
secure initial attachment, secure attachment during use and painless removal
after wear. The characteristics which have been considered in this context are
the elastic modulus describing the elastic behaviour of the material and the
viscous modulus which describes the viscous behaviour of the adhesive
material.
The viscous behaviour of the adhesive can be interpreted to represent an
indication of the ability of the adhesive to quickly attach and securely
adhere to a
l0 particular surface. The elastic behaviour can be interpreted as an
indication of
the "hardness" behaviour of the adhesive. Its value is also critical for good
initial
attachment. Their combination is believed to be an indicator of the required
force
upon removal. The relation between elastic and viscous moduius is considered
to be an indication on which fraction of the removal energy will be dissipated
within the adhesive and which fraction is available to trigger the actual
removal.
In order to provide topical adhesives for secure initial and prolonged
attachment and easylpainless removal the relation between the elastic modulus
and the viscous modulus as well as their dynamic behaviour is also of
importance.
The adhesive has an elastic modulus at a 'temperature of 37°C
(100°
Fahrenheit) abbreviated G'3~, a viscous modulus at a temperature of
37°C (100°
Fahrenheit) of G"3~, and a viscous moduius at a temperature of
25°C
(77°Fahrenheit) of G°2s.
The adhesive according to the present invention preferably satisfies the
following conditions;
G'3~ (1 rad/sec) is in the range 1500 Pa to 20000 Pa,
preferably 1500 Pa to 15000 Pa, most
preferably 3000 Pa to 10000 Pa.
G"3, j1 rad/sec)is in the range 1D0 Pa to 15000 Pa,
preferably 100 Pa to 10000 Pa, most
preferably 300 Pa to 5000 Pa.
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and the ratio of G'3~ (1 radlsec) / G"3~ (1 radlsec) is in the
range of 1 to 30.
The rheological behaviour can also be related to the values of the Glass
Transition Temperature Tg. For topical adhesives according to the present
invention Tg should preferably be less than -15°C, more preferably less
than
20°C and most preferably less than -25°C.
The rheological behaviour and acceptance of a adhesive can also be
related to the specific heat capacity. Preferably the specific heat capacity
of the
adhesive is less than 4 J/gIK, more preferably less than 3 J/g/K and most
preferably less than 2 J/g/K.
The rheological behaviour and acceptance of a topical adhesive can also
be related to the specific heat conductivity of the adhesive. Preferably the
specific heat conductivity is as low as possible, preferably between 1 and 0.1
W/m/K, mast preferably between 0.6 and 0.1 W/mIK.
Provided the above rheologicai conditions are satisfied the adhesives will
also satisfy conditions such as sufficient cohesiveness (to prevent residue of
adhesive on the skin) which are critical for commercial use of such adhesives
and apparent to those skilled in the art. Adhesive compositions which satisfy
the
above criteria can be used as adhesives for the flange provided they also
satisfy
the common requirements of being safe for use on human or animal skin during
use and generally after disposal of the device.
Often the criteria of hygienic appearance such that adhesive compositions
which are transparent or white upon application are preferred.
The above rheological criteria and other considerations can be satisfied by
adhesive compositions which are medically suitable substantially water
insoluble
pressure sensitive adhesives comprising a polymer which forms a 3-dimensional
matrix, and comprising less than 10%, preferably less than 5% by weight of
said
adhesive of hydrocolloids. The polymeric compound or composition is preferably
selected from the group consisting of acrylics, sulphonated polymers, vinyl
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IO
alcohols, vinyl pyrrolidine, polyethylene oxide, or combinations thereof. The
adhesive also preferably comprises a plasticiser. The plasticising compound or
composition is preferably selected from the group consisting of water,
alcohols
(preferably glycerol), glycols, polyglycols, or combinations thereof.
According to the present invention, it has been discovered that the relation
between the thickness or calliper C, measured in millimetres (mm), of the
layer in
which the adhesive is provided, typically onto at least a portion of the
wearer
facing surface of the flange, and the viscous modulus G"z5 at about 100
radlsec
IO of the topical adhesive, is relevant to the scope of providing an easy and
painless removal from the wearer's skin of such a topical adhesive applied on
at
least part of the wearer facing surtace of a faecal management device for
attachment of said device to the skin of a wearer.
I S The adhesive of the present invention is provided as a layer having a
thickness C such that the viscous moduius G"zs (100 rad/sec) and the thickness
C satisfy the following empirical equation:
G"zs <_ [(7.00 + C) x 3000] Pa
and preferably also the following empirical equation:
G"zs <_ [(5.50 + C) x 1700] Pa
Detailed Description of the Invention
According to the present invention the adhesive can be utilised on faecal
management devices (10) which are applied to the perianal area of a wearer as
visible from Figure 1 and for urine management devices as shown in figure 4.
The word "skin" according to the present invention does not only relate to the
specific derma of the user but includes the mucous tissue as well as the hair
which is typically found in the genital region.
The adhesive is provided with the preferred pattern, typically on the wearer
facing surface (23) of the flange (12) of the device (10), as a layer having a
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thickness or calliper C that is preferably constant. The layer can be
preferably
continuous or alternatively discontinuous, e.g. in form of dots, spirals, or
stripes.
Even though adhesives are used like pressure sensitive adhesives on
human skin hair and mucous tissues, it is understood that the topical adhesive
compositions could only with difficulty be considered typical pressure
sensitive
adhesives (referred to as PSA hereinafter) on the basis of the most
characteristic
rheological behaviours identifying such materials.
l0 In fact as the person skilled in the art of adhesives knows, the most
characteristic feature that distinguishes a PSA from other substances that can
temporarily adhere objects (e.g. water between two glass plates could) is the
fact
that their rheological parameters and especially the Elastic Modulus G' vary
greatly with the frequency of applied stresses. More in particular, G' of PSA
can
increase over some orders of magnitude, while the frequency of applied
stresses
varies from typical bonding frequency to typical debonding frequency, i.e. 1
radls
to 100 rad/s as indicated below.
As a first consequence, it is therefore inadmissible to define materials
intended for use as "adhesives" by giving values of rheological parameters and
especially of G' at a fixed value of frequency. This can be misleading because
in
the absence of other characteristics it will include materials which have no
practical value. It is hence necessary that rheological characterisation must
be
on the basis of dynamic considerations. This not only applies to the Elastic
Modulus G' but also to the viscous modulus G" and hence also for tan (d) = G"
I
G'.
It is well known that typical PSAs have not only a high variation of G' across
the considered frequencies, but also that there is an even higher variation of
G"
which can get close or become even higher than the value of G', i.e. tan (d)
becomes about or even greater than 1, in particular at the frequencies that
are
typical of debonding.
Without wishing to be bound by theory this can be interpreted as meaning
that a high fraction of the energy applied for the debonding is dissipated
within
the adhesive (so it is not effective in causing the debonding) and through the
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12
interface of the adhesive and the skin, while this fact causes macroscopically
the
recording of a very high level of adhesive force.
As indicated above materials useful as adhesives according to the present
invention have rheological characteristics which are measured at a reference
temperature of 37°C (as usual body temperature of humans) and in a
range of
frequencies. It has been found that upon application of a human waste
management device with a adhesive the adhesive contact is formed at a low
frequency, while debonding happens at the speed of removing the device. This
speed is expressed as a frequency of 100 rad/s, while the low frequency of
forming the adhesive bond has been found to be on the order of 1 radls.
Therefore, the frequency range for use according to the present invention is
between 1 and 100 radls.
It is believed that the adhesive bonding characteristics are selected most
appropriately at human body temperature. Since the adhesive according to the
present invention is used directly on skin and the person skilled in the art
is
directed to select the adhesive composition to have a small specific heat
capacity (e.g. preferably less than 4 J/gIK) the actual temperature of the
adhesive will reach 37°C very quickly or even be warmed up by a human
prior to
application.
In order to provide good conditions of bonding, i.e. at a frequency of about
1 radlsec, the absolute values of the elastic modulus should not be ~ too
high,
otherwise the adhesive is too hard and it is not able to intimately join or
mold to
the surface to which it is expected to adhere. It is also important to have a
low
absolute value of G" in order to have good cohesion which is particularly
valuable for use with faecal management while the material remains soft and
capable of gently adhering to skin.
The ratio of G'3~ (1 radlsec) over G"37 (1 rad/sec) is important to ensure
that
these two values are balanced upon adhesion to the skin.
Importantly, the ratio of G'3~ ('100 rad/sec) - G"37 (100 radlsec)
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G'3~ ( 1 rad/sec) - G"3~ ( 1 radlsec)
needs to be large enough to ensure that the dynamic behaviour of both the
elastic and the viscous module are maintained in a relationship which provides
secure adhesion and painless and easy removal.
Finally the person skilled in the art will also recognise that the Glass
Transition Temperature Tg of the adhesive composition, the specific heat
capacity, and the specific heat conductivity are parameters which are useful
to
more fully define the group of useful adhesives.
The following set of characteristics should preferably be satisfied for the
adhesive of the present invention:
G'3~ (1 rad/sec) is in the range 1500 Pa to 20000 Pa,
preferably 1500 Pa to 15000 Pa, most
preferably 3000 Pa to 10000 Pa.
G"3~ (1 rad/sec) is in the range 100 Pa to 15000 Pa,
preferably 100 Pa to 10000 Pa, most
preferably 300 Pa to 5000 Pa.
the ratio of G'3~ (1 rad/sec) ! G"3~ (1 radlsec) is in the
range of 1 to 30.
the ratio G'3~ (100 radlsec) - G"3~ (100 rad/sec)
G'3~ ( 1 rad/sec) - G"3~ ( 1 rad/sec)
is not less than 0.5, preferably in the range 0.7 to 3,
most preferably in the range 1 to 1.8.
The value of the ratio G'3,/G"3, at least for the frequency range from above
1 radls up to 100 rad/s should preferably be 3.3 or above, more preferably 5
or
above, most preferably 10 or above, while not exceeding about 30, preferably
20, anywhere in the frequency interval.
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The rheological behaviour can also be related to the values of the Glass
Transition Temperature Tg. For topical adhesives according to the present
invention Tg should preferably be less than -15°C, more preferably less
than -
20°C and most preferably less than -25°C.
The rheological behaviour and acceptance of a adhesive can also be
related to the specific heat capacity. Preferably the specific heat capacity
of the
topical adhesive is less than 4 JIg/K, more preferably less than 3 JIgIK and
most
preferably less than 2 J/g/K.
The rheological behaviour and acceptance of a topical adhesive can also
be related to the specific heat conductivity of the adhesive. Preferably the
specific heat conductivity is as low as possible, more preferable between 1
and
0.1 W/m/K, mast preferably between 0.6 and 0.1 WImIK.
In order to provide adhesive compositions which satisfy the requirements of
the above rheological and physical characteristics of an adhesive any
medically
suitable substantially water insoluble pressure sensitive adhesives comprising
a
polymer which forms a 3-dimensional matrix, and comprising less than 10%,
preferably less than 5% by weight of said adhesive of hydrocolloids, meeting
the
these characteristics may be utilised .
The term hydrocolloid as used herein refers to colloidal absorbent
materials, mixtures of colloidal absorbent materials selected from starch,
modified starches such as dextrin, cellulose ester such as
carboxymethycellulose, natural gums such as pectin karaya, gelatin, guar gum,
gum arabic, locust bean gum, and carboxypolymethyiene.
According to the present invention the 3 dimensional matrix also referred to
herein as a gel; comprises as an essential component a polymer which can be
physically or chemically cross linked. The polymer may be naturally or
synthetically derived. The uncrosslinked polymer includes repeating units
derived from vinyl alcohois, vinyl ethers and their copolymers, carboxy vinyl
monomer, vinyl ester monomers, esters of carboxy vinyl monomers, vinyl amide
monomers, hydroxy vinyl monomers, cationic vinyl monomers containing amines
or quaternary groups, N-vinyl lactam monomer, polyethylene oxides,
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IS
polyvinylpyrrolidon (PVP), acrylics such as hydroxyethylmethacrylate,
methoxydiethoxyethyl methacryiate and hydroxydiethoxyethyl methacrylate and
sulphonated polymers such as acrylamide sulphonated polymers and mixtures
thereof. Alternatively, the uncrosslinked polymer may be a homopolymer or
copolymer of a polyvinyl ether, or a copolymer derived from half ester of
malefic
ester. Similarly any other compatible polymer monomer units may be used as
copolymers such as for example polyvinyl alcohol and polyacrylic acid or
ethylene and vinyl acetate.
As another alternative, the polymers may be block copolymer thermoplastic
elastomers such as ABA block copolymers such as styrene-olefin-styrene block
copolymers or ethylene-propylene block copolymers. More preferably such
polymers include hydrogenated grade StyroI/Ethylene-Butylene/Styrol (SEES),
Styrene/Isoprene/Styrene (SIS), and Styrol/Ethylene-Propylene/Styrol (SEPS). -
IS
Particularly preferred polymers are acrylics, sulphonated polymers such as
acrylamide sulphonated polymers, vinyl alcohols, vinyl pyrrolidine,
polyethylene
oxide and mixtures thereof.
According to the present invention the 3 dimensional adhesive matrix also
essentially comprises a piasticiser, which is preferably a liquid at room
temperature. This material is selected such that the polymer may be
solubilized
or dispersed within the plasticiser. For embodiments wherein irradiation cross
linking is to be carried out, the plasticiser must also be irradiation cross
linking
compatible such that it does not inhibit the irradiation cross linking process
of the
polymer. The plasticiser may be hydrophilic or hydrophobic.
Suitable plasticisers include water, alcohols, polyhydric alcohols such as
glycerol and sorbitol, and glycols and ether glycols such as mono- or diethers
of
polyalkylene gyicol, mono- or diester polyalkylene glycols, polyethylene
glycols
(typically up to a molecular weight of about 600), glycolates, glyceril,
sorbitan
esters, esters of citric and tartaric acid, imidazoline derived amphoteric
surfactants, lactams, amides, polyamides, quaternary ammonium compounds,
condensation products of polyethylene imine and epichlorohydrin, liquid
polybutenes, esters such phthalates, adipates, stearates, palmitates,
sebacates,
or myristates, natural or synthetic oils such as vegetable oils, mineral oils,
and
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16
combinations thereof. Particularly preferred are polyhydric alcohols,
polyethylene
glycol (with a molecular weight up to about 600), glycerol, sorbitol, water
and
mixtures thereof.
Typically the adhesive comprises a ratio of polymer to plasticiser by weight
of from 1: 100 to 100:1, more preferably from 50:1 to 1:50. However, the exact
amounts and ratios of the polymer and plasticiser will depend to a large
extent
on the exact nature of polymer and plasticisers utilised and can be readily
selected by the skilled person in the art. For example a high molecular weight
l0 polymer material will require a greater amount of plasticiser than a low
molecular
weight polymer.
In addition to the polymer and plastisicer.components of the adhesive, the
adhesive may comprise a number of optional additional components for example
the composition may comprise from 0% to 50% by weight of the composition, of a
tackifying resin. Such tackifying resins are particularly useful in
combination with
ABA block copolymer adhesive compositions. Suitable tackifying resins include
for example rosin derivatives, terpene, and terpene-phenolic resins,
hydrocarbon
resins such as Cs and C~ICs resins, aromatic resins and hydrogenated resins.
Other suitable optional ingredients include from 0% to 10 % and more
preferably form 0% to 5 % by weight of substances for further facilitating and
stabilising the 3-dimensional matrix and the matrix forming process. For
example
for hydrophobic adhesive compositions these may be fatty acids of Cg to C22,
their metallic salts and their polyoxo-derivatives; lanolin derivatives;
silica;
bentonite, montmorillonite and their derivatives; waxes or mixtures thereof.
Other common additives known in the art such as preservatives,
antioxidants, anti UV agents, pigments, mineral fillers and mixtures thereof
may
also be comprised within the adhesive composition in quantities up to 10% each
respectively.
According to the present invention the polymer component of the adhesive
can be physically or chemically cross linked in order to form the 3
dimensional
matrix. Physical cross linking refers to polymers having cross links which are
not
chemical covalent bonds but are of a physical nature such that there are areas
in
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17
the 3 dimensional matrix having high crystailinity or areas having a high
glass
transition temperature. Chemical cross linking refers to polymers which are
linked by chemical bonds. Preferably the polymer is chemically cross (inked by
radiation techniques such as thermal-, E beam- , UV-, gamma or micro-wave
radiation.
In addition when chemical crosslinks are formed in the system, a
polyfunctional cross linker andlor a free radical initiator may be present in
the
premix to initiate the crosslinking upon irradiation. Such an initiator can be
present preferably in quantities up to 5% by weight.
The resulting adhesive compositions may be divided into three family types;
hydrophilic, hydrophobic and mixed phase compositions dependant upon the
nature of the components of the adhesive.
Hydrophilic adhesives are compositions in which typically the plasticiser is
water or glycerol or glycol and/or mixtures thereof and the polymeric phase is
of
synthetic (e.g. polyacrylics). Optionally such compositions may comprise up to
10% by weight of colloid natural gums.
Hydrophobic adhesives are compositions in which the plasticiser is typically
an oil or blend of oils of vegetable or mineral origin and the polymer is
usually a
synthetic polymer, preferably an elastomer, which is soluble or dispersible in
such oils.
Mixed phase adhesives are compositions in which both hydrophobic and
hydrophilic components, possibly in both plasticisers and polymers, form two
or
more separate phases. In such cases an emulsifier is preferably present at a
suitable level to form stable emulsions between the incompatible phases.
The preferred adhesive compositions for use in the present invention are
hydrophilic as these are particularly effective in adhering to wet skin.
Suitable adhesives for use herein include Promeon, available from
Promeon Division of Medtronic Inc., Minneapolis Minnesota, USA and hydrogel
adhesive available from 3M.
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The adhesive is provided, typically on at least a portion of the wearer facing
surface of the flange, as a layer having a thickness or calliper C that is
preferably
constant, or that alternatively can vary over the surface interested by the
application of the adhesive.
When considering particularly the removal phase of an adhesive
composition for attachment to the skin of a wearer, it is commonly recognised
that good conditions of removal, i.e. at a frequency of about 100 radlsec, of
the
topical adhesive applied to at least part of the wearer facing surface of the
flange, are achieved when the adhesive can be easily removed from the skin,
and particularly from the bodily hair that are typically located on this area
of the
skin where the flange contacts the body, without causing pain to the wearer,
therefore without adhering too hard upon removal, to the skin and the hair of
the
wearer. Moreover, a good removal implies that the adhesive does not leave
residues on the skin or on the hair.
According to the present invention, the relationship between the thickness
or calliper C measured in millimetres (mm) of the layer in which the adhesive
is
provided, typically onto at least part of the wearer's facing surface of the
flange
of the faecal management device, and the viscous modulus G"25 at 25°C
and at
about 100 radlsec of the topical adhesive gives an indication on the painless
and
easy removal of the adhesive from the skin.
Without being bound to any theory, it is believed that for higher values of
G"25 at 100 rad/sec, which overall correspond to a higher adhesiveness of the
composition, a thicker calliper or thickness C of the adhesive layer is needed
so
that the energy applied for the removal is more evenly distributed within the
mass of the adhesive, and is therefore transferred smoothly to the skin, so
avoiding peaks of energy that typically cause the pain sensation to the
wearer. In
other words, thinner Layers of the adhesive necessitate an adhesive with a
lower
G"25 at 100 rad/sec to achieve a reduced pain sensation upon removal of the
device.
According to the present invention, the adhesive of the present invention
provided as a layer having a thickness C measured in millimetres (mm), is such
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19
that the viscous modulus G"zs (100 radlsec) and the thickness C of the
adhesive
layer satisfy the following empirical equation:
G"zs <_ [(7.00 + C) x 3000] Pa
and preferably the following empirical equation:
G"zs <_ [(5.50 + C) X 1700] Pa
While in a preferred embodiment of the present invention the thickness C of
the adhesive layer is constant, such adhesive layer can also have different
thicknesses in different portions of the wearer facing surface of the flange
where
it is applied, provided that the above mentioned relationship between C and
G"zs
is in any case satisfied.
In order to evaluate the effect of the thickness C of the adhesive layer in
its
relationship with the viscous modulus G"zs (100 radlsec) of the topical
adhesive
of the present invention on the removal of the topical adhesive used for the
attachment of a disposable absorbent article to the skin of a wearer, a
Removal
Pain Grade Test has been developed. In this test the adhesion of standard
substrates, on which the same topical adhesive has been provided in layers
having different thicknesses, on the skin of the forearm of members of a
sensory
panel is achieved, and upon successive removal the pain is evaluated in terms
of pain grade as described herein after.
According to the present invention any disposable human waste
management device known in the art can be provided with the adhesive
according to the present invention.
Typically urine faecal management devices (10) comprise a bag {11 )
having an aperture (21 ) and a flange (12) surrounding the aperture for
preferably
adhesive attachment to the perianai area of a wearer as visible from Figure 1.
Any faecal or urine management device known in the art can be provided
according to the present invention.
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The bag (11 ) as used herein is a flexible receptacle for the containment of
excreted faecal matter. The bag (11 ) can be provided in any shape or size
depending on the intended use thereof, i.e. whether the device is intended for
bedridden patients or active patients suffering from incontinence or requiring
an
5 artificial bowel or for infants. For example, elongated bags which are
principally
tubular or rectangular are typically utilised by bedridden patients and
elderly
incontinence sufferers. For more active wearers whether infants or adults, the
disposable human waste management device should preferably be anatomically
shaped such that the device follows the contours of the body and can be worn
10 inconspicuously by the wearer under normal garments.
Particularly, preferred shapes are flat circular type bags, cone shaped
bags, truncated shaped bags and pyramidal or truncated pyramidal shaped
bags. !n a most preferred embodiment of a faecal management device of the
15 present invention, the bag (11 ) has a substantially truncated cone shape.
A
preferred shape for urine bags is shown in figure 4. Typically the bags will
have
a wearer facing portion (16) and a garment facing portion (17). The wearer
facing portion (16) of the human waste management device (10) is disposed
adjacent the buttocks of the wearer. As such, the wearer facing portion (16)
20 amply covers the buttocks of the wearer and does not hang between the
thighs
of the wearer.
in addition, the bag ( 11 ) is preferably shaped to allow at least partial
insertion and retention of the bag in-between the buttocks of the wearer and
thereby ensure good contact between the flange and the skin of the wearer. For
example, the bag (11 )may be provided with a neck portion or conduit.
The bag (11 ) is preferably designed to provide sufficient volume for
excreted material under a variety of wearing conditions, also when worn by a
freely moving, i.e. not bedridden wearer. Sitting on the bag, for example,
will
result in a largely reduced volume in some areas of the bag. Thus, the bag (
11 )
is preferably shaped to provide sufficient volume in areas which are not
subjected to much pressure in wearing conditions such as sitting.
The bag (11 ) is designed to safely contain any entrapped material, typically
it will be liquid impermeable, yet it may be breathable. The bag (11) is
designed
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21
of sufficient strength to withstand rupture in use, also when pressure on the
bag
(11 ) is exerted in typical wearing conditions, such as sitting.
According to the present invention, depending on the shape of the bag (11 )
required, the bag (11 ) may be provided from a unitary piece of material or
from a
number of separate pieces of material, which may be identical or different and
which are sealed at their respective peripheries.
In one preferred embodiment the bags herein have a wearer facing portion
l0 (16) and a garment facing portion (17) which comprise separate pieces of
material. The wearer facing portion (16) and the garment facing portion (17)
are
sealed at the periphery of the bag (11), thus creating a bag peripheral rim
(18).
As is visible from Figure 1, the wearer facing .portion (16) of the bag (11)
may
comprise two further sections (19), which are secured to each other by mean
known to the man skilled in the art, such as adhesive, thermobonding or
pressure bonding in order to provide the desired bag configuration. Said rim
(18)
may also be inside the bag, thus being coextensive with the inner surtace (15)
of
the bag (11 ) rather than with the outer surface (30) of the bag (11 ).
Preferably
the bag (11 ) is asymmetrical to the transversal axis, so that the distance
measured in the longitudinal direction from the centre of the aperture (21 )
to the
front end of the bag (11 ) is shorter than the distance measured to the rear
end of
the bag (11 ).
According to the present invention the bag (11 ) can comprise one or
multiple layers, preferably two or three layers. The layer on the inside of
the bag
(11 ), which will typically at least partially come in contact with excreted
material
is called the inner layer. The outermost layer of the bag, which will
typically at
least partially come in contact with the skin to the wearer and the garments
of the
wearer, is called the outer layer.
The layers of the bag material may be provided from any material,
preferably so that the bag is liquid impervious. The layers may in particular
comprise any material such as non-wovens or films. In a preferred embodiment
of the present invention a laminate may be formed from a non-woven layer and a
film. The laminate can be formed by means known to the man skilled in the art.
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Any non-woven layer can comprise felt fabrics, spunlaced fabrics, fluid jet
entangled fabrics, air-laid fabrics, wet-laid fabrics, dry-laid fabrics, melt-
blown
fabrics, staple fibre carding fabrics, spunbonded fabrics, stitch-bonded
fabrics,
apertured fabrics, combinations of the above or the like.
Suitable film materials for any of said layers preferably comprise a
thermoplastic material. The thermoplastic material can be selected from among
all types of hot-melt adhesives, polyolefins especially polyethylene.
polypropylene, amorphous polyolefins, and the like; material containing
meltable
components comprising fibres or polymeric binders including natural fibres
such
as cellulose - wood pulp, cotton, jute, hemp; synthetic fibres such as
fibreglass,
rayon, polyester, polyolefin, acrylic, polyamid, aramid,
polytetrafluroethylene
metal, polyimide; binders such as bicomponent high melt/low melt polymer,
copolymer polyester, polyvinyl chloride, polyvinyl acetatelchloride copolymer;
copolymer polyamide, materials comprising blends wherein some of the
constituent materials are not meltable; air and vapour permeable materials
including microporous films such as those supplied by EXXON Chemical Co., III,
US under the designation EXXAIRE or those supplied by Mitsui Toatsu Co.,
Japan under the designation ESPOIR NO; and monolithic breathable materials
such as HytrelT"" available from DuPont and PebaxT'~" available from ELF
Atochem, France.
In a preferred embodiment a film, which is comprised in any layer, is
preferably permeable to gases such as air and to vapour such as water vapour
in
order to avoid the problem of entrapment and condensation of moisture vapour
given oft by the body of the wearer and thus, the hot, clammy and
uncomfortable
conditions after a short period of use.
The outer layer of the bag is preferably provided with a non-woven layer.
Such material layers present an uneven surface to the skin of the wearer and
thus reduce significantly the problem of occlusion and greatly improve skin
healthiness.
In one preferred embodiment of the present invention the bag comprises
two layers. Preferably the outer layer comprises a non-woven layer and the
inner
layer comprises a film.
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23
In yet another preferred embodiment of the present invention, the bag (11 )
comprises three layers, preferably one film and two non-woven layers. In an
even more preferable embodiment the film is interposed between the two non-
woven layers. This sequence of layers results in a closed fibrous structure,
which
has a particularly pleasing sensation on contact with the skin of the wearer.
In
yet another preferred embodiment the inner layer comprises a film and the
other
two layers comprise non-wovens.
l0 The non-woven layer or the non-woven layers comprised by the bag (11 )
may be hydrophobic or hydrophilic. If the bag (11 ) does not comprise a film
layer,
preferably at least one non-woven layer is hydrophobic. As a consequence,
fluid
penetration is resisted through the wearer facing portion ( 16) and the
garment
facing portion {17) of the human waste management device (10). If the bag-
comprises a film or a hydrophobic non-woven layer, further non-woven layers
may be hydrophilic.
Typically, the non-woven layer is treated with a surface active material,
such as a fluorchemical or other hydrophobic finishings, to provide the
requisite
hydrophobicity. The non-woven layer, however, may equally be treated with
coatings of liquid impervious materials such as hot-melt adhesives or coatings
of
silicone or other hydrophobic compounds such as' rubbers and vegetable and
mineral waxes or it may be physically treated using nano-particulates or
plasma
coating techniques, for example.
The non-woven layer can also be treated with agents to improve the tactile
perceivable softness of the wearer facing portion (16) and the garment facing
portion (17). The agents include but are not limited to vegetable, animal or
synthetic oils, silicone oils and the like. The presence of these agents are
known
to impart a silky or flannel-like feel to the non-woven layer without
rendering it
greasy or oily to the tactile sense of the wearer. Additionally, surfactant
material,
including anionic, non-ionic, cationic and amphoteric surfactants, may be
added
to further enhance softness and surface smoothness.
Furthermore, the non-woven layer may be impregnated with a lotion to
provide desirable therapeutic or protective coating lotion benefits. The
lotion
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24
coating on the wearer facing portion (16) and the garment facing portion (17)
is
transferable to the skin of the wearer by normal contact and wearer motion
andlor body heat. Generally, mineral oil in the form of a lotion is recognised
as
being effective in imparting a soothing, protective coating to the skin of the
wearer. It is also possible to impregnate the non-woven layer with a solid oil
phase of cream formulation or to incorporate into the non-woven layer an array
of pressure- or thermal- or hydrorupturable capsules containing for example,
baby oil.
l0 In one embodiment of the present invention the bag (11 ) may contain
absorbent material. The absorbent material may comprise any absorbent
material which is capable of absorbing and retaining liquids. The absorbent
material may comprise a wide variety of liquid-absorbent materials commonly
used in disposable diapers and other absorbent articles such as comminuted-
I S wood pulp, which is generally referred to as airfelt. Examples of other
suitable
absorbent materials include creped cellulose wadding; meltblown polymers,
including coform; chemically stiffened, modified or cross-linked cellulosic
fibers;
tissue, including tissue wraps and tissue laminates; absorbent foams;
absorbent
sponges; superabsorbent polymers; absorbent gelling materials; or any other
20 known absorbent material or combinations of materials.
The absorbent material may be positioned in the bag (11 ) in any suitable
manner. For example, the absorbent material may be loosely arranged within the
bag or may be secured to the inner layer of the bag (11). Any known techniques
25 for securing absorbent material to nonwoven and film substrates may be used
to
secure the absorbent material to the inner layer of the bag. The absorbent
material may also be arranged to have any desired shape or configuration
(e.g.,
rectangular, oval, circular, etc.).
30 In the embodiment shown in Figure 4, the outer surface of bag (11 ) is
provided with patches of adhesive (40) for securing the bag (11 ) to the body
of
the wearer. Preferably, the patches of adhesive (40) are positioned on the
outer
surface of bag (11 ) such that they are secured to the abdomen of the wearer
in
use. Any number, size and shape of adhesive patches (40) may be used
35 depending on the intended use of the device.
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The human waste management device in particular urine management
devices according to the present invention also preferably comprise an
additional acquisition layer. The acquisition layer is typically secured to
the
inner surface of bag. However, the acquisition layer may also be secured to
the
5 flange, or both the flange and the inner surface of bag. The acquisition
layer is
preferably positioned such that it separates the genitalia of the wearer from
coming into direct contact with the absorbent material. The acquisition layer
is
fluid pervious allowing urine to readily pass through so that it may be
absorbed
by absorbent material.
The acquisition layer may be manufactured from a wide range of materials,
such as porous foams; reticulated foams; apertured plastic films; or woven or
nonwoven webs of natural fibers (e.g., wood or cotton fibers), synthetic
fibers
(e.g., polyester or polypropylene fibers), or a combination of natural and-
synthetic fibers. If the acquisition, barrier layer includes fibers, the
fibers may be
spunbond, carded, wet-laid, meltblown, hydroentangled, or otherwise processed
as is known in the art.
The acquisition layer is designed to have a pore size such that the
absorbent material is not allowed to pass through and contact the wearer's
skin.
While designed not to have to large of a pore size which permits the passage
of
absorbent material, the acquisition layer preferably has a pore size which is
greater than the pore size of the absorbent material.
Preferably, the acquisition layer is less hydrophilic than the absorbent
material. The acquisition layer may be treated with a surfactant to increase
its
initial wettability. When treated with surfactant, however, the acquisition
layer
should still be less hydrophilic than the absorbent material. Suitable methods
for
treating the acquisition layer with a surfactant include spraying the
acquisition
layer with the surfactant and immersing the material into the surfactant.
Alternatively, a surfactant may be incorporated into the acquisition layer.
As shown in Figure 1 the bag (11 ) is provided with an aperture (21 )
whereby excreted matter is received from the body prior to storage within the
bag
cavity. The aperture (21 ) is surrounded by a flange (12) and may be provided
in
any shape or size, such as circular, oblong, heart shaped and may be
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26
symmetrical or asymmetrical, preferably the aperture has an oblong
configuration either in the longitudinal or in the transversal direction or in
both
directions, e.g. the contours of the aperture are in the shape of two ellipses
with
the respective main axes being substantially perpendicular.
The flange (12) is attached to the bag (11) according to any means known
to the man skilled in the art which may provide permanent or releasable
attachment. Preferably however, the flange is attached to the bag by adhesive.
Typically, the bag will be attached to the flange, towards the outer periphery
of
l0 flange so as not to cause any obstruction for the entering excreted matter.
The flange may be provided in any size depending on the wearer group for
which the device is intended. Similarly the flange may be provided in any
shape
and preferably has a symmetrical shape preferably comprising a plurality of
lobes (13). The flange (12} may comprise a front projection (28) and a rear
projection (29) to the perineal and coccygeai area of a wearer.
The flange comprises a garment facing surface (22) and a wearer facing
surface (23). In an preferred embodiment these are two large, substantially
flat
surfaces, however, the flange may also comprise projections designed to fit
the
perineal or coccygeal area of the wearer.
The flange (12) should be made of soft, flexible and malleable material to
allow easy placement of the flange to the perianal area. Typical materials
include
nonwoven materials, wovens, open celled thermoplastic foams, closed-cell
thermoplastic foams, composites of open celled foams and stretch nonwoven,
and films. A closed-cell foam of polyethylene has been found effective, but
more
preferably an open celled polyurethane foam is used. Preferably, such foams
have a thickness within the general range of 0.1 to 5 millimetres and a basis
weight of 5 to 250 g/m2, more preferably 50 glm2. Other thermoplastic foam
materials, or other suitable plastics sheet materials having the described
properties of such foams (i.e., softness, pliability, stretchability, and
contractability) might also be used. Preferably, the material of garment
facing
surface (22) of the flange (12) may extend into the defined aperture area so
as to
form a skirt or flap of material which prevents unintentional adhesion of the
surface edges of the flange defining the aperture to oneanother during use.
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27
According to the present invention the adhesive (20) is preferably covered
with a release means (not shown) in order to protect the adhesive (20), such
as
siliconized paper. The adhesive (20) can cover the entire wearer facing
surface
(23) of the flange (12) or more preferably have at feast one, preferably two
to six
non-adhesive portions. These portions may be adhesive free or may contain
inactivated or covered adhesives. As is evident from Figure 1, the adhesive is
in
one preferred embodiment not applied to the entire wearer facing surface area
of
the flange (12), so as to provide lobes (13) on either side of the flange (12)
which
are non-adhesive and can thereby serve to facilitate placement and removal of
the device whilst avoiding contact with the adhesive. These lobes are however
preferably also covered by the release means. Before application of the human
waste management device ( 10) to the skin of the wearer, the release means if
present is removed.
The adhesive (20) can be applied to the wearer facing surface of the flange
(12) by any means known in the art such as slot coating, spiral, or bead
application or printing. Typically the adhesive is applied at a basis weight
of from
20g/m2 to 2500g/m2, more preferably from 500g/m2 to 2000gIm2 most preferably
from 700g/mz to 1500g/m~ depending on the end use envisioned. For example,
for human waste management devices ( 10) to be used for babies the amount of
adhesive may be less than for human waste management devices (10) designed
for active adult incontinence sufferers.
The disposable human waste management device (10) of the present
invention has bean found to be particularly useful and beneficial when used in
conjunction with a garment, or diaper (50), preferably a disposable diaper -
refer
to Figure 2. The human waste management device (10) is preferably first
positioned in the perianal area of the wearer before the disposable diaper
(50) is
applied. In particular, the diaper (50) is positioned over the human waste
management device (10) and fastened in a conventional manner around the
body of the wearer. It has been found that, in addition, to providing
excellent
separation between urine and faecal material, the combined human waste
management device (10) and diaper (5~) system actually reduces skin
irritation,
which may at times occur, especially since the group of typical wearers
includes
the very ofd, the very young and the unhealthy wearers. in effect, the
presence
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28
of the human waste management device (10) permits the formation of a
separation layer between the skin of the wearer and the diaper (50), i.e. a
part of
the absorbent core (58) of the diaper (10). The diaper (50) can be of the
conventional type (an embodiment of which is described below although not a
limiting example by any means) or can be adapted to contain in an effective
and
comfortable manner the human waste management device (10) according to the
teachings of the present invention.
As used herein, the term "disposable diapers" refers to articles which
absorb and contain body extrudates; and more specifically, refers to articles
which are placed against or in proximity to the body of the wearer to absorb
and
contain the various extrudates discharged from the body and which are intended
to be discarded after a single use (i.e., they are not intended to be
laundered or
otherwise restored or reused) and, preferably, to be recycled, composted oT
otherwise disposed of in an environmentally compatible manner. As used herein,
the term "diaper' refers to a garment generally worn by infants or
incontinence
sufferers that is drawn up between the legs and fastened about the waist of
the
wearer.
Figure 3 is a partially cut-away perspective view of a diaper (50) embodying
the present invention prior to it being placed on the wearer over the faecal
management device (10). As is visible from Figure 3, a preferred diaper (50)
comprises a body portion (52) and a refastenable mechanical fastening device
(54}. A preferred body portion (52) comprises a liquid pervious topsheet (56),
and absorbent core (58), a liquid impervious backsheet (60), and elastically
contractible leg cuffs (62); each leg cuff (62) preferably comprising a side
flap
(64) and one or more elastic members (66). For simplicity purposes, only one
elastic member (66) is shown in the side flap (64). While the topsheet (56},
the
absorbent core (58), the backsheet (60), the side flaps (64), and the elastic
members (66) may be assembled in a variety of well-known configurations. A
preferred disposable diaper configuration is shown and generally described in
US 3,860,003, an even more preferred disposable diaper configuration is shown
and generally described in WO 93116669. In this preferred diaper
configuration,
the backsheet (60) is joined to the topsheet (56); the absorbent core (58) is
positioned between the topsheet (56) and the backsheet (60); the side flaps
(64)
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29
extend outwardly from and along each side edge of the absorbent core (58); and
the elastic member (66) is operatively associated with each side flap (64).
Figure 3 shows the body portion (52) in which the topsheet (56) and the
backsheet (60) are coextensive and have length and width dimensions generally
larger than those of the absorbent core (58). The topsheet (56) is superposed
on
the backsheet (60) thereby forming the periphery (68) of the body portion
(52).
The body portion (52) has an inside surface (74) and an outside surtace
to (76). When a backsheet (60) is used, it typically forms the outside surface
(76) of
the body portion (52). The inside surface (74) is that surface of the diaper
(50)
opposite the outside surface (76) and in the embodiment shown is typically
formed by the topsheet (56). In general, the inside surface (74) of the diaper
(50)
is that surface coextensive with the outside surface (76) and which is for the
greater part in contact with the wearer when the diaper (50) is worn.
The absorbent core (58) of the body portion (52) may be any absorbent
means which is generally compressible, conformable, non-irritating to the skin
of
the wearer, and capable of absorbing and retaining liquids such as urine and
other certain bodily discharges. The absorbent core (58) may be manufactured
in
a variety of sizes and shapes (for example, rectangular, hour-glass, '?"-
shaped,
asymmetric, etc.) and from a wide variety of liquid absorbent materials
commonly
used in disposable diapers and other absorbent articles such as comminuted
wood pulp which is generally referred to as airfelt. Examples of other
suitable
absorbent materials include creped cellulose wadding, meltblown polymers
including coform, crosslinked cellulosic fibers, tissue including tissue
wraps,
absorbent foams, absorbent sponges, superabsorbent polymers, absorbent
gelling materials, or any equivalent materials or combinations of materials.
The
configuration and construction of the absorbent core (58) may also be varied
(far
example, the absorbent core (58) may have varying caliper zones, hydrophilic
gradients, superabsorbent gradients, or lower average density and lower
average basis weight acquisition zones;. or may comprise one or more layers or
structures). Further, the size and absorbent capacity of the absorbent core
(58)
may be varied to accommodate wearers ranging from infants to adults.
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The backsheet (60) is impervious to liquids (for example, urine) and is
preferably manufactured from a thin plastic film, preferably a thermoplastic
film,
although other flexible liquid impervious materials may also be used. As used
herein, the term "flexible" refers to materials which are compliant and which
will
5 readily conform to the general shape and contours of the human body. The
backsheet (60) prevents the exudates absorbed and contained in the absorbent
core (58) from soiling articles which are in contact with the diaper (50) such
as
undergarments and bedding. The backsheet (60) may thus comprise polymeric
films such as thermoplastic films of polyethylene or polypropylene, or
composite
10 materials such as film-coated non-woven material. Exemplary films are
manufactured by Tredegar Industries, Inc. of Terre Haute, Ind., USA or BP-
Chemical PIasTec, Rotbuchenstrasse 1, D-8000 Munchen, Germany.
The backsheet (60) is preferably textured to provide a more ciothlike
15 appearance. Further, the backsheet (60) may also permit vapours to escape
from the absorbent core (58) while still preventing exudates from passing
through the backsheet (60) by, for example, being supplied with
microapertures.
The size of the backsheet (60) is dictated by the size of the absorbent core
(58)
and the exact diaper design selected.
The topsheet (56) of the diaper is compliant, soft feeling and non-irritating
to the skin of the wearer. Further, the topsheet (56) is liquid pervious
permitting
liquids (for example, urine) to readily penetrate through its thickness. A
suitable
topsheet (56) may be manufactured from a wide range of materials, such as
porous foams, reticulated foams, apertured films; or woven or non-woven webs
of natural fibres (for example, wood or cotton fibres) or from a combination
of
natural and synthetic fibres. Preferably, it is made of a material that
isolates the
skin of the wearer from liquids retained in the absorbent core (58).
There are -a number of manufacturing techniques which may be used to
manufacture the topsheet (56). For example, the topsheet (56) may be a non-
woven web of fibres. An exemplary topsheet (56) is carded and thermally bonded
by means well-known to those skilled in the fabric art. A suitable topsheet
(56) is
manufactured by, for example, Veratec Inc., a division of International Paper
Company, of Walpole, Mass., USA. A topsheet (56) particularly preferred for
incontinence garments comprises a formed thermoplastic film.
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31
According to the present invention the adhesives meeting the defined
theological properties may in addition to their utilisation in faecal
management
devices also find application to attach other articles to the skin. Suitable
articles
may be disposable absorbent articles such as sanitary napkins and panty
liners.
The present invention may also find utility to attach to the skin or wear
protective
articles such as genital-, knee- or elbow-protectors or bandages; clothing
such
as bras, surgical gowns, or parts of garments during fitting at a tailor;
nasal
plasters; prosthesis such as breast replacements or wigs; heat wraps, pads,
l0 andlor packs, e.g. for topical relief of pain or simply to provide warmth;
cold
wraps e.g. to provide pain relieve from bruises and to reduce swelling;
hearing
aids; protective face masks; ornamental articles such as jewellery, earrings,
guises, tattoos; goggles or other eye wear. Such articles are non-absorbent
for
bodily liquids. .
Removal Pain Grade Test
The Removal Pain Grade Test is utilized to evaluate the pain during
removal from the skin of a wearer of a sample provided with a layer of a
adhesive and previously attached to the wearer's skin. The test specifically
evaluates the pain upon removal of each sample as compared to the pain
obtained by removing a reference sample constituted by a commercial strong
medical plaster.
Sample preparation.
The test is performed on rectangular samples 60x20 mm made of a
polyester film 23 Nm thick, such as that sold by Effegidi S.p.A. of Colorno
(Parma, Italy), provided on one side with a continuous layer of the topical
adhesive having the selected thickness, applied with an Acumeter Model LH-1
extruder. The reference sample is a 60x20 mm sample of a of an adhesive non
woven fabric available from Beiersdorf A.G. Hamburg, Germany under the
Tradename Fixomull stretch.
Test method.
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32
A panel of six graders is selected for the test. The test is performed in a
climatically controlled laboratory maintained at a temperature of 23 °C
and a
Relative Humidity of 50%. No special treatment of the wearer's skin is
required
beyond normal cleaning/washing with water and soap. The skin is then allowed
to dry for at least two hours before the test to allow the skin to reach
equilibrium
with the room conditions. Different adhesive are evaluated in the test in
comparison with the reference sample R. Each sample is applied by hand by an
operator to the inner part of the grader's forearm, being centred between the
wrist and the elbow, with the short side of the sample aligned with the length
of
l0 the arm. The operator exerts on each sample with the palm of the hand the
same
pressure that is typically applied to cause a medical plaster to adhere to the
skin.
Each sample is worn for the prescribed time, and then it is removed from the
grader's skin by the operator with a slow and smooth pull.
Four series of one reference sample R and the test samples are each
applied, worn and then removed from the wearer's skin; each sample is worn for
one minute, with a 5 minute wait between two subsequent samples of the same
series, and a 15 minute wait between two different subsequent series. The
reference sample R is always applied, worn and removed as the first sample of
its respective series. The sequence of applicationlwear/removal of the test
samples in each of the first three series is random, provided that no
repetition in
each series is allowed, and that no sequence is repeated in the first three
series.
In the fourth series one of the test samples is tested twice, the reference R
always being the first one. Overall each sample has to be tested an equal
number of times (24 times).
The graders were asked to evaluate each sample using a pain scale
ranging from 0 to 10, where 0 corresponds to no pain and 10 corresponds to the
pain upon removal of the reference sample R. The pain values for each sample
were obtained as a mean of 24 observations.
The results collected from the test were analysed by a statistical analysis
program "Comparison of Population Means - Paired Samples", that showed that
the differences between the pain values of the samples are statistically
3 5 significant.
