U.S. patent application number 13/701485 was filed with the patent office on 2013-06-13 for method manufacturing an epilatory strip and strips obtainable by the method.
This patent application is currently assigned to E.V.F. DELACOUR BV.. The applicant listed for this patent is Mamdouh H. Atteia, George Magdy. Invention is credited to Mamdouh H. Atteia, George Magdy.
Application Number | 20130150867 13/701485 |
Document ID | / |
Family ID | 43640706 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130150867 |
Kind Code |
A1 |
Atteia; Mamdouh H. ; et
al. |
June 13, 2013 |
METHOD MANUFACTURING AN EPILATORY STRIP AND STRIPS OBTAINABLE BY
THE METHOD
Abstract
A method for manufacturing an epilatory strip by providing a
first laminate of a pressure-sensitive, hot-melt adhesive
sandwiched between a support layer and a first release liner that
in combination provide a width to the first laminate; delaminating
the width of the first laminate by unwinding the first release
liner and exposing an area of pressure-sensitive, hot-melt
adhesive; applying at least one mask or cover material onto the
pressure-sensitive, hot-melt adhesive on at least one edge area of
the delaminated first laminate to provide a second laminate
presenting an exposed area of pressure-sensitive, hot-melt
adhesive; and providing a second release liner to cover at least a
portion of exposed area of pressure-sensitive, hot-melt adhesive to
provide a width of epilatory strip material. Thus, hypoallergenic,
non-irritant epilatory strips are obtained using the method
according to the invention.
Inventors: |
Atteia; Mamdouh H.;
(Alexandria, EG) ; Magdy; George; (Alexandria,
EG) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Atteia; Mamdouh H.
Magdy; George |
Alexandria
Alexandria |
|
EG
EG |
|
|
Assignee: |
E.V.F. DELACOUR BV.
Apeldoorn
NL
|
Family ID: |
43640706 |
Appl. No.: |
13/701485 |
Filed: |
May 31, 2010 |
PCT Filed: |
May 31, 2010 |
PCT NO: |
PCT/IB10/52422 |
371 Date: |
February 26, 2013 |
Current U.S.
Class: |
606/133 ;
156/247 |
Current CPC
Class: |
A45D 26/0019
20130101 |
Class at
Publication: |
606/133 ;
156/247 |
International
Class: |
A45D 26/00 20060101
A45D026/00 |
Claims
1.-31. (canceled)
32. A method of manufacturing an epilatory strip, which method
comprises: providing a first laminate of a pressure-sensitive,
hot-melt adhesive sandwiched between a support layer and a first
release liner that in combination provide a width to the first
laminate; delaminating the width of the first laminate by unwinding
the first release liner and exposing an area of pressure-sensitive,
hot-melt adhesive; applying at least one mask or cover material
onto the pressure-sensitive, hot-melt adhesive on at least one edge
area of the delaminated first laminate to provide a second laminate
presenting an exposed area of pressure-sensitive, hot-melt
adhesive; and providing a second release liner to cover at least a
portion of exposed area of pressure-sensitive, hot-melt adhesive to
provide a width of epilatory strip material.
33. The method of claim 32, which further comprises obtaining the
first laminate by transfer coating the pressure-sensitive, hot-melt
adhesive onto the support layer from the first release liner by
pressure lamination, optionally using heated pressure lamination
rollers, prior to incorporating the first laminate in the epilatory
strip.
34. The method of claim 32, which further comprises dividing out
individual epilatory strips or lengths of epilatory strip material
by end cutting the width of the epilatory strip material.
35. The method of claim 32, which further comprises providing
rupture lines crosswise the width of epilatory strip material.
36. The method of claim 32, wherein the at least one mask or cover
material comprises two opposing cover ribbons provided along
opposing free edges of the delaminated first laminate; optionally
wherein the at least one mask or cover material is colored or
presents information.
37. The method of claim 32, wherein the second release liner is a
low release liner, optionally at least partly overlaying the at
least one mask or cover material.
38. The method of claim 32, wherein the pressure-sensitive,
hot-melt adhesive which is provided in the first laminate has one
or more of a weight of between 50-55 g/m.sup.2, or a loop tack of
20.+-.4N per 25 mm width of epilatory strip according to FINAT Test
Method no. 9 using a stainless steel plate as pressure plate, or a
peel adhesion of 16.+-.4N per 25 mm width of epilatory strip
according to FINAT Test Method no. 1 using a stainless steel plate
as the test plate and a 20 min. test period, or a resistance to
shear that is .gtoreq.40 min per 25 mm width of epilatory strip
according to FINAT Test Method no. 8 using a stainless steel plate
as the test plate.
39. The method of claim 32, which the support layer has a thickness
of between 50 .mu.m-1 mm.
40. The method of claim 32, wherein the second release liner has
two flaps of release liner, with the flaps optionally
overlapping.
41. The method of claim 32, wherein the at least one mask or cover
material protrudes beyond at least a part of the outer edges of any
of the support layer or the second release liner, with the mask or
cover material optionally protruding by a distance of 1-2 mm.
42. An epilatory strip comprising an adhesive on a support layer,
with the adhesive being a pressure-sensitive hot-melt adhesive
provided as a solitary layer that is coated onto the support
layer.
43. The epilatory strip of claim 42, wherein the
pressure-sensitive, hot-melt adhesive which is provided in the
first laminate has one or more of a weight of between 50-55
g/m.sup.2, or a loop tack of 20.+-.4N per 25 mm width of epilatory
strip according to FINAT Test Method no. 9 using a stainless steel
plate as pressure plate, or a peel adhesion of 16.+-.4N per 25 mm
width of epilatory strip according to FINAT Test Method no. 1 using
a stainless steel plate as the test plate and a 20 min. test
period, or a resistance to shear that is .gtoreq.40 min per 25 mm
width of epilatory strip according to FINAT Test Method no. 8 using
a stainless steel plate as the test plate.
44. The epilatory strip of claim 42, wherein the support layer has
a thickness of between 50 .mu.m-1 mm.
45. The epilatory strip of claim 42, wherein the support layer is a
foam support layer, a plastic film layer or a non-woven layer.
46. The epilatory strip of claim 42, wherein the foam support layer
is a polyethylene foam support layer.
47. The epilatory strip of claim 42, wherein the film support layer
is a polyethylene film support layer or a polyethylene
terephthalate film layer.
48. The epilatory strip of claim 42, wherein the support layer is
at least substantially nonporous, optionally having a zero
porosity.
49. The epilatory strip of claim 42, wherein the support layer is
non-perforated.
50. The epilatory strip of claim 42, wherein the
pressure-sensitive, hot-melt adhesive includes a tackifying resin,
or is hypoallergenic or is free of colophony or has combinations of
the foregoing.
51. The epilatory strip of claim 42, wherein the
pressure-sensitive, hot melt adhesive is covered by at least one
second release liner.
Description
[0001] The present invention relates to a method of manufacturing
an epilatory strip, and epilatory strips obtainable by said
method.
[0002] Epilation is the removal of the entire hair, including the
part below the skin. Pulling the hair out of the hair follicle is
preferred by many people rather than depilation because the hair
removal lasts longer, ranging from several days to several
weeks.
[0003] Self-epilation can be performed using various types of
conventional epilatory means, usually involving use of melted or
heated wax. To that aspect an epilatory strip includes a thick
layer of a sticky wax, which is heated in order to encapsulate and
trap the unwanted hair. Once the hair has a good grip in the wax,
the hairs can be ripped off securely integrated in the wax on the
strip. The strip needs to be left on the skin long enough for the
wax to cool and harden in order to trap the hairs with a strong
adhesive force. Ripping hair off this way causes great pain, and
often sticky debris from the wax is left on the skin, thereby
inducing skin irritation and erythema due to content of colophony.
The common approach to minimize such disadvantages is to reduce
thickness of wax so that cooling can happen faster, which however
compromises the efficiency of the hair removal. Thus,
self-epilation may not only be painful and time-consuming,
self-epilation may also be very ineffective and inflict on the
skin's condition, e.g. causing various kinds of dermatitis or
allergic cutaneous manifestations. Instead many people invest in
epilation performed by skilled persons at high costs, e.g. using
methods such as electroepilation or photoepilation.
[0004] U.S. Pat. No. 3,470,877 describes a method for removing
hairs from the skin by placing a very thin layer of
pressure-sensitive fluid adhesive on the skin to encapsulate the
individual hairs to be removed. A second layer of higher viscosity
pressure-sensitive fluid adhesive is then spread over the first
adhesive layer and pressed against it after which the second
adhesive is peeled away from the skin, which carries away the hairs
and the fluid adhesive. This two step method is difficult for a
person to perform herself, in particular at difficult accessible
skin locations, and there is a risk that the fluid adhesive flows
to unintended locations prior to use.
[0005] International patent application no. WO2009/006681 relates
to an epilatory strip for removing unwanted hair from skin. The
strip comprises a support layer, which has an adhesive coating on
it. The adhesive attaches to hair, and the coating covers a
substantial portion of the area of the support layer. The epilatory
strip also includes a peel-off protective layer, which covers the
adhesive coating and can be removed prior to application of the
strip on to skin. In order to achieve a painless non-irritating
stripping of hair from the skin aloe vera and/or vitamin E is added
to the adhesive, both in concentrations of up to 25% by weight of
the adhesive coating. Thus WO2009/006681 has realized the
noticeable discomforts of using epilatory strips based on adhesives
but provides a solution including additives in high concentrations,
thereby a.o. increasing costs substantially. Even though
hypersensitivity to vitamin E is scarcely reported it is a
well-known realization that the more chemical compounds and the
higher their concentrations in a product are, the higher is the
risk that at least one of the compounds will cause contact allergic
reactions. The user may even be inclined to leave the strip for
longer periods to wait for the suggested beneficial pain-reducing
and irritation-avoiding properties of the epilatory strip disclosed
in WO2009/006681 before ripping off the hair, thereby increasing
the exposure time to the skin.
[0006] Thus the fewer chemical compounds in an adhesive coating the
smaller the risk of allergic skin reactions.
[0007] Due to the disadvantages and short-comings of the prior art
epilatory strips there is a need for alternatives and
improvements.
[0008] In a first aspect according to the present invention is
provided an epilatory strip of the kind mentioned in the opening
paragraph which has a simple structure.
[0009] In a second aspect according to the present invention is
provided an epilatory strip of the kind mentioned in the opening
paragraph which is inexpensive and easy to use.
[0010] In a third aspect according to the present invention is
provided an epilatory strip of the kind mentioned in the opening
paragraph which is skin-friendly and includes a biocompatible
adhesive.
[0011] In a fourth aspect according to the present invention is
provided an epilatory strip of the kind mentioned in the opening
paragraph which is resilient and is able to conform to human body
cavities and/or convexities.
[0012] In a fifth aspect according to the present invention is
provided an epilatory strip of the kind mentioned in the opening
paragraph which embeds and traps hair more reliable than known
epilatory strips.
[0013] In a sixth aspect according to the present invention is
provided a method for manufacturing an epilatory strip.
[0014] The below test methods are defined in FINAT Technical
Handbook 7th edition, 2005. FINAT is the International Federation
of Manufacturers and Converters of Self-adhesive and Heat Seals
Materials on Paper and Other Substrates. The FINAT test methods are
used for testing peel adhesion (FTM 1), resistance to shear (FTM 8)
and loop tack measurement (FTM 9) and values of these parameters
are stated in the present application for the behavior and
performance of epilatory strip test items when tested by the
standard FINAT method, not on the users skin, because the skin is
not a standard reference surface.
[0015] Within the context of the present invention the term "peel
adhesion" is used to express the adhesion power between the
adhesive and a surface. The peel adhesion test (FTM 1) serves to
quantify the permanence of adhesion or peelability of self-adhesive
pressure-sensitive materials. "Peel adhesion" is defined as the
force required to remove pressure-sensitive coated material applied
to a standard test plate under specified conditions from said plate
at a specified angle and speed. The test strip is 25 mm wide and
has a minimum length of 175 mm. The strip is peeled through an
angle of 180.degree. with a jaw separation rate of 300 mm per
minute with an accuracy of .+-.2%. Further test conditions are
temperature (T) 23.degree. C..+-.2.degree. C. and relative humidity
(RH) 50%.+-.5%. The value of the peel adhesion gives an indication
about the force required to pull the strip off an individual's
skin.
[0016] Within the context of the present invention the term
"resistance to shear" refers to the cohesive force between the
molecules of the adhesive. Resistance to shear is measured as
resistance to shear from a standard surface according to FTM 8,
wherein the resistance to shear is defined as the time required for
a standard area of 25 mm.times.25 mm of pressure-sensitive coated
material to slide from a standard flat surface in a direction
parallel to the surface. The resistance to shear test gives an
indication of the likely mode of bond failure, i.e. adhesive
failure or cohesion failure. The test strips are 25 mm wide and
have a minimum length of 175 mm in the machine direction. Further
test conditions are temperature (T) 23.degree. C..+-.2.degree. C.
and relative humidity (RH) 50%.+-.5%. The higher resistance to
shear, the less residues the adhesive leaves on the skin.
[0017] Within the context of the present invention the term "loop
tack" refers to the initial grab or tack of the adhesive once it
touches a surface, such as the individual's skin, and without
applying pressure to the adhesive. Good tack value of a hot-melt
pressure-sensitive adhesive is highly important is highly important
to ensure that hair can be satisfyingly stripped off the skin.
[0018] The "loop" tack value" of a pressure-sensitive material is
defined in FTM 9 and is expressed as the force required to
separate, at a specified speed of 300 mm per minute in the test
machine direction, a test item being a loop made of an
adhesive-coated material strip 25 mm wide and 175 mm long and
folded so that the adhesive faces outermost. In the FTM 9 test the
exposed adhesive is brought into contact with a specified area of a
glass standard surface and then subjected to pulling forces
perpendicularly away from the standard surface until detachment
from said standard surface. Further test conditions are temperature
(T) 23.degree. C..+-.2.degree. C. and relative humidity (RH)
50%.+-.5%.
[0019] The term "adhesive coat weight" refers to the amount in
g/m.sup.2 of dry pressure-sensitive hot-melt adhesive on a standard
area of substrate. Numerical coat weight values are obtained from
cut samples using the test method defined in ISO 536.
[0020] The novel and unique whereby the above and other aspects are
achieved according to the present invention consists in that the
method comprises [0021] providing a width of a first laminate
consisting of a pressure-sensitive, hot-melt adhesive sandwiched
between a support layer and a first release liner, [0022]
delaminating the width of first laminate by unwinding the first
release liner and exposing an area of pressure-sensitive, hot-melt
adhesive, and [0023] providing a second release liner to cover at
least a portion of exposed area of pressure-sensitive, hot-melt
adhesive to provide a width of epilatory strip material.
[0024] The term "pressure-sensitive" indicates, that the bonding
force is influenced by the amount of pressure, which is used to
apply the adhesive to the selected surface. Pressure-sensitive
adhesive are designed to form a bond and hold properly at room
temperatures. Pressure-sensitive adhesives reduce or lose their
tack at cold temperatures and reduce their shear holding ability at
high temperatures. The "hot-melt" adhesives used in the present
invention are thermoplastics, tacky in hot state, sets fast in few
seconds to one minute, are highly cohesive, have long shelf life
and can be disposed of without special precautions. Low-viscosity,
high-tack, pressure-sensitive, hot-melt adhesives such as
styrene-ethylene/butylene-styrene tri-block copolymer and/or
styrene-ethylene/propylene di-block copolymer are preferred.
[0025] Due to being sandwiched inside the first laminate the
pressure-sensitive, hot-melt adhesive is protected on both sides
prior to being incorporated in epilatory strips. The risk that the
pressure-sensitive, hot-melt adhesive becomes contaminated is
substantially eliminated. No pressure-sensitive, hot-melt adhesive
is exposed to the environment for long periods during manufacturing
the epilatory strip, and high bonding and tacking properties of the
pressure-sensitive, hot-melt adhesive are well-preserved. The above
method is simple and fast and uses simple means to make an
inexpensive epilatory strip, which is easy to use by a person
intending to remove hair from a chosen skin area.
[0026] The method may also include to apply at least one mask or
cover material onto the pressure-sensitive, hot-melt adhesive on at
least one edge area of the delaminated first laminate to provide a
second laminate presenting an exposed area of pressure-sensitive,
hot-melt adhesive for tacking hairs. The mask or cover material
expediently serves to prevent the second release liner from bonding
to the masked or covered edge area of the delaminated first
laminate.
[0027] Thus the firm bonding ability of the pressure-sensitive,
hot-melt adhesive is expediently utilized to bond said one or more
mask or cover materials to at least one edge area of the
delaminated first laminate. The user never gets sticky fingers
because the user does not need to touch the pressure-sensitive,
hot-melt adhesive with his/hers fingers. Preferably, the mask or
cover material is permanently bonded to the support layer by means
of the pressure-sensitive, hot-melt adhesive, however even though
it is less preferred the mask or cover material may be combined
with the pressure-sensitive, hot-melt adhesive in a releasable
manner to be able to utilise the entire adhesive area for hair
removal.
[0028] With respect to the first laminate the method can further
comprise obtaining the first laminate by transfer coating the
pressure-sensitive, hot-melt adhesive onto the support layer from
the first release liner by means of pressure lamination, optionally
by means of heated pressure lamination rollers, to ensure that the
pressure-sensitive, hot-melt adhesive sticks to the support layer
with a greater bonding force than to the first release liner. Heat
may be applied to soften the adhesive and expedite the transfer to
the opposite support layer, as well as the lamination rollers
create a bonding force between support layer and
pressure-sensitive, hot-melt adhesive that is sufficient to ensure
that the pressure-sensitive, hot-melt adhesive remains bonded to
the support layer when hairs, entangled and tacked by the
pressure-sensitive, hot-melt adhesive, are ripped off.
[0029] The first release liner, e.g. a paper or silicon release
liner, thus only serves as a temporary carrier of the
pressure-sensitive, hot-melt adhesive, and is selected by its
property to easily let off an adhesive coating or adhesive
deposition. Transfer coating is highly preferred because the
position, the layer thickness, and hardness or softness of the
pressure-sensitive, hot-melt adhesive, used in the present method,
can easily be controlled without using complicated control
procedures and special equipment.
[0030] Individual epilatory strips or lengths of epilatory strip
material can advantageously be divided out of the epilatory strip
material by end cutting said width of epilatory strip material,
e.g. using a die cutter, a punch tool or a blade cutter. Various
sizes of epilatory strips can be made by selecting an appropriate
tool. The length of a simple rectangular epilatory strip can e.g.
be controlled by adjusting the conveying speed in the production
line in relation to end cutting speed. High conveying speed and low
cutting speed produce long epilatory strips and vice versa.
[0031] In an alternative embodiment the epilatory strip material
can be provided with spaced apart rupture lines crosswise the width
of said epilatory strip material. Such epilatory strip material end
product may advantageously be taken-up in rolls. The rolls may be
sized for the user to decollate a length suitable for an intended
use. The suitable length may or may not be the length between two
subsequent rupture lines or include several rupture lines. The
distance between the rupture lines may be selected as appropriate
and desired. The distance can be adjusted in the same manner as
described above for the length of the individual epilatory
strip.
[0032] In a preferred embodiment the at least one mask or cover
material can be two opposing cover ribbons provided along opposing
free edges of the delaminated first laminate, preferably the long
edges of the production direction, i.e. the conveying direction.
Such cover ribbons are easy to apply in a continuous production
line and create, in a simple manner, easy accessible grasping flaps
of considerable size on two opposing edge surface areas of the
epilatory strip.
[0033] The at least one mask or cover material can be colored or
can present an information. For example, a blue color can be used
for epilatory strips especially designed for men, and a red color
indicates that the epilatory strip is for women. Any kind of
information can be provided on or be integrated in the mask or
cover material.
[0034] Information can also be provided on the visible surface on
any of the second release liner or the support layer. Information
can e.g. be directions for use, company logo, or brand name of the
epilatory strip product. Information can be printed or
embossed.
[0035] If the second release liner is a low release liner, it can
be removed without tearing the support layer to pieces or pulling
the pressure-sensitive, hot-melt adhesive along. Prior to removal,
said second release liner also provides structural stability to the
epilatory strip. The second release liner may at least partly
overlap the at least one mask or cover material so that a
peripheral zone or just a part of the mask or cover material are
left free for grasping to facilitate easy removal of the second
release liner. A free overlapping part of the second release liner
can be grasped between two fingers of one hand while taking the
masked or covered edge area between two fingers on the other hand
to peel the second release liner off the pressure-sensitive,
hot-melt adhesive to expose the latter.
[0036] The release liners for use in the method according to the
present invention are preferably silicon paper, siliconized
polyethylene (PE) or siliconized polyethylene terephthalate (PET)
having weights between 70-100 g/m.sup.2, and preferably also being
clear or opaque.
[0037] The preferred weight of the pressure-sensitive, hot-melt
adhesive coating in the first laminate is between 50-55 g/m.sup.2.
Products having different coating weights, including weights
outside the above interval, can also be manufactured using the
method according to the present invention. Epilatory strips
incorporating high amounts of pressure-sensitive, hot-melt adhesive
may be useful on very hairy skin, including hirsutism and male
skins. Epilatory strips incorporating lower amounts of
pressure-sensitive, hot-melt adhesive coating may suffice for women
practicing frequent epilation.
[0038] By using the method according to the present invention it is
possible to obtain an epilatory strip material meeting a number of
valued and beneficial product characteristics that makes the
obtained epilatory strip suitable for efficient but still careful
and gentle epilation of different hair types from different body
parts. Irrespective to the hair having different length, thickness,
being rough, thin, curled or smooth, the epilatory strip obtained
according to the method of the present invention is very effective
in hair removal.
[0039] Product characteristics to be fulfilled by the epilatory
strips according to the present invention include but are not
limited to any of that [0040] the preferred loop tack of the
pressure-sensitive, hot-melt adhesive is 20.+-.4N per 25 mm width
of epilatory strip according to FINAT Test Method no. 9 using a
stainless steel plate as pressure plate, [0041] the preferred peel
adhesion of the pressure-sensitive, hot-melt adhesive is 16.+-.4N
per 25 mm width of epilatory strip according to FINAT Test Method
no. 1 using a stainless steel plate as the test plate and a 20 min.
test period, and/or [0042] the preferred resistance to shear of the
pressure-sensitive, hot-melt adhesive is .gtoreq.40 min per 25 mm
width of epilatory strip according to FINAT Test Method no. 8 using
a stainless steel plate as the test plate.
[0043] The loop tack of the pressure-sensitive, hot-melt adhesive
is high while being cold, but warming increases initial tackiness
of a hot-melt adhesive. Some users may prefer to rub the epilatory
strip between the hands prior to application on the skin.
[0044] The thickness of the support layer may be between 50 .mu.m-1
mm. 50 .mu.m if for example chosen for a polyethylene film support
layer, and 1 mm for a polyethylene foam support layer.
[0045] The second release liner may consists of two flaps of
release liner, optionally overlapping release liner flaps, to
increase user-friendliness of second release liner removal.
[0046] If the at least one mask or cover material protrudes beyond
at least a part of the outer edges of any of the support layer or
the second release liner a protrusion or offset between edges of
adjacent layers is obtained, which protrusion or offset can be used
in tactile location of the second release liner, as well as when
removing the second release liner from the delaminated first
laminate having the mask or cover material on its adhesive edge
area.
[0047] A protrusion between 1-2 mm has turned out to be sufficient
for tactile guidance of the user fingers and facilitation of
removal of the second release liner.
[0048] The invention is also directed to an epilatory strip
obtainable by the method described above wherein the adhesive means
is a pressure-sensitive hot-melt adhesive provided as a solitary
layer that is transfer coated onto the support layer.
[0049] The preferred intervals of the coating weight, the loop
tack, the peel adhesion, and the resistance to shear of the
pressure-sensitive, hot-melt adhesive are as stated above.
[0050] Preferred thicknesses of the various applicable support
layers are between 50 .mu.m-1 mm. Particular preferred support
layers are selected from the group of support layers including a
foam support layer, a plastic film layer or a non-woven layer,
where a foam support layer, such as a polyethylene foam support
layer, typically is thicker than a plastic film layer, such as a
polyethylene film support layer or a polyethylene terephthalate
film layer.
[0051] The pressure-sensitive, hot-melt adhesive needs to be firmly
bonded to the support layer and to stay on the support layer
without percolating, bleeding through or otherwise moving from the
application side of said support layer to the opposite back side of
the support layer, neither during manufacturing nor during storage
of the epilatory strip.
[0052] Thus it is highly important that the pressure-sensitive,
hot-melt adhesive cannot bleed into or onto the support layer, e.g.
in hot weather or under other warm conditions. If bleeding,
percolation or other kinds of moving of pressure-sensitive,
hot-melt adhesive away from a skin-contacting surface of the
epilatory strip take place unknown amounts of said
pressure-sensitive, hot-melt adhesive would be lost and not
available as an epilation layer.
[0053] Thus in the present invention support layers being at least
substantially nonporous, preferably having zero porosity, are the
most preferred. Also, the support layer should be
non-perforated.
[0054] The pressure-sensitive, hot-melt adhesive is free of
colophony. Colophony is highly skin irritants, sensitizing and
known to induce contact dermatitis. At the beginning of contact the
skin becomes red and inflamed, but as the allergic or irritation
reaction progresses blisters turns up and the skin becomes very
itchy. Therefore colophony is not included in the adhesive coating
used in the present epilatory strip.
[0055] Instead a hypoallergenic pressure-sensitive, hot-melt
adhesive is incorporated. The pressure-sensitive, hot-melt adhesive
may however include another tackifying resin to enhance tackiness
to hair, still though is the pressure-sensitive, hot-melt adhesive
of hypoallergenic nature.
[0056] The preferred pressure-sensitive, hot-melt adhesives used in
the epilatory strip and the method for producing the epilatory
strip according to the present invention is Duro-Tak.RTM. 8673 or
Duro-Tak.RTM. 8532 obtainable from Henkel KgaA, Henkelstrasse 67
D-40191 Dusseldorf, Germany. The Duro-Taks.RTM. are very tacky
pressure sensitive hot-melt adhesives that have no content of
colophony.
[0057] The main constituents of the composition of Duro-Tak.RTM.
8673 and Duro-Tak.RTM. 8532 are indicated in Table 1 below. The
composition of Duro-Tak.RTM. 8673 and Duro-Tak.RTM. 8532 differ
only in the percentage of individual constituents.
TABLE-US-00001 TABLE 1 Corresponding Components indicated by
component brand Material CAS no. Percentage CAS no. names Rubber
66070- max 10% Styrene-Ethylene/Butylene- Kraton G-1651 58-4
Styrene tri-block Copolymer From Kraton Styrene-Ethylene/Propylene
Polymers diblock copolymer Kraton G-1702 from Kraton Polymers
Hydrocarbon 68132- max 50% Petroleum hydrocarbon resin ESCOREZ 5600
resin, 00-3 Series from Exxon hydrogenated Mobil Mineral oil,
8042-47-5 max 50% White mineral oil Kaydol from medical grade
Sonneborn Netherlands Antioxidant 89421- max 1% Synergistic blend
of 80% Irganox B 561 from 57-8 Irgafos 168 and 20% Irganox Ciba
(now part of 1010 BASF)
[0058] The pressure-sensitive, hot-melt adhesive may expediently be
covered by at least one second release liner to be removed prior to
application on the skin area from which hairs are to be
removed.
[0059] The invention will now be described in further details below
with reference to the drawing. The drawing shows an exemplary
embodiment of a production line and an epilatory strip manufactured
using the production line by means of the method according to the
present invention. An exemplary epilatory strip is shown in the
figures to be rectangular, but other shapes are encompassed by the
claims of the present application. Also other thicknesses of layers
are contemplated, and the layer thicknesses indicated in the
figures are only for illustrative purposes and should not be taken
as limiting the scope of the present invention. Emphasize is made
that some layers of the epilatory strip may in fact be so thin that
their thickness and presence in the epilatory strip only can be
visualized by illustrative magnification.
[0060] FIG. 1 shows a perspective exploded view of an exemplary
embodiment of an epilatory strip,
[0061] FIG. 2 shows the same in bonded state, and
[0062] FIG. 3 shows schematically a production line according to
the present invention.
[0063] FIG. 1 shows an exploded view of the components for a
preferred rectangular embodiment of an epilatory strip 1 according
to the present invention. The epilatory strip 1 has a polyethylene
foam support layer 2 transfer coated with a layer of
pressure-sensitive hot-melt adhesive 3. The pressure-sensitive
hot-melt adhesive layer 3 on the opposing long edge areas 4,5 of
the polyethylene foam layer 2 is covered with cover ribbons 6,7 of
e.g. polyethylene film. The exposed pressure-sensitive hot-melt
adhesive 3 delimited between the cover ribbons 6,7, are protected
during storage by a detachable release liner 8, e.g. a siliconized
polyethylene liner.
[0064] FIG. 2 illustrates the epilatory strip 1 in an assembled,
bonded state. The detachable liner 8 partly overlaps the cover
ribbons 6,7 in their length direction, thereby providing lengthwise
free finger flaps 9,10 not adhered to the subjacent cover ribbons
6,7. The free finger flaps 9,10 are easy to get hold of, in that
they can just be folded away from the cover ribbons 6,7 in order to
remove the detachable release liner 8.
[0065] A production line 11 for performing the method according to
the present invention is shown in FIG. 3.
[0066] A width of first laminate 12, consisting of the
pressure-sensitive hot-melt adhesive 3 sandwiched between a
protective first release liner 13, and a support layer 2 is
supplied from a first supply roll 15 via conveyer roll 15a, as
shown with arrow A. The pressure-sensitive hot-melt adhesive 3 has
initially been coated on a width of first release liner 13, e.g. a
siliconized polyethylene release liner. Then a width of support
layer 2, e.g. a width of polyethylene foam layer 2, is applied on
top of pressure-sensitive hot-melt adhesive 3. Subsequently the
sandwich of width of first release liner 13, width of
pressure-sensitive hot-melt adhesive 3 and the support layer 2 is
conveyed through pressure rollers (not shown) to transfer coat the
pressure-sensitive hot-melt adhesive 3 onto the width of the
support layer 2.
[0067] The first laminate 12 is delaminated by means of
delamination roll 16 and waste roll 16a that unwinds the first
release liner 13, as indicated with arrow B, to expose the
pressure-sensitive hot-melt adhesive 3 on the width of support
layer 2 and produce a delaminated first laminate 17.
[0068] Cover ribbons 6,7 delivered from supply rollers 18,19,
respectively, as indicated by arrows C and D, are continuously
laminated to opposing adhesive edge areas 3,5 of the delaminated
first laminate 17 by means of first lamination rollers 20 to
provide a second laminate 21 presenting an exposed area 22 of
pressure-sensitive hot-melt adhesive 3 between the cover ribbons
6,7.
[0069] As indicated by arrow E, the second laminate 21 is conveyed
to lamination by second lamination rollers 23, were a width of
second release liner 8, e.g. a siliconised polyethylene liner, is
supplied from supply roll 24, as indicated by arrow F, is applied
on the pressure-sensitive hot-melt adhesive 3 to produce a width of
epilatory strip material 25 that cannot stick unintentionally to
other surfaces. The width of second release liner 8 also serves for
protecting the pressure-sensitive hot-melt adhesive 3 from sticking
to dirt and from desiccation during storage.
[0070] The width of epilatory strip material 25 is transported
further through the production line 11 by means of conveyer rolls
26, as indicated by the arrow G, to be cut into epilatory strips 1,
by means of e.g. a cutting blade. The epilatory strips 1 may then
be wrapped individually or in sets.
[0071] The epilatory strip 1 according to the present invention can
be used on a plurality of different body areas and body parts
including but not limited to toes, feet, lower leg, upper leg,
groin, bikini line, anal area, belly area, back, shoulder, breast,
finger, hand, upper arm, under arm, arm pit, chin, neck, auricle,
ear channel, upper lip, cheeks, nose bridge, eyebrows, and
forehead. Also, the epilatory strip 1 can be made in various sizes
and shapes. Thus, although the above embodiment is shown with cover
ribbons other kinds of masks can also be used. E.g. a width of mask
material having cut out sections corresponding to the area of
pressure-sensitive material to be exposed for use in hair removal
can be applied to the delaminated first laminate. The protected
edge area then may have a different configuration and the final
epilatory strip product also be given different shape than squared,
e.g. oval or circular, which shape can be obtained by die
cutting.
[0072] The final end product epilatory strip may also be provided
with cut out sections that leaves a pattern of hair back after
ripping off the epilatory strip.
[0073] Variations and combinations of the embodiments discussed
above are intended within the scope of the present invention.
* * * * *