Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
A tab member
FIELD OF THE INVENTION
The present invention retates to a tab member especially for use as a "non-
touch" grip for applying a dressing comprising an adhesive layer and
optionally a
release Liner to the skin without touching the adhesive layer, a method for
manu
factoring such tab member and a dressing comprising the tab member.
BACKGROUND OF THE INVENTION
As it is commonly known thin wound dressings are difficult to apply to wounds,
1 g especially in curved areas, without wrinkling or sticking to themselves or
to the
users, e.g. a nurse or assisting persons fingers. It is desirable to apply all
kinds
of dressings without touching the adhesive layer in order to avoid reducing
the
adhesiueness. Because of the risk of introducing bacteria to the wound it is
desir-
able to apply a dressing to a patient's skin without touching the surface of
the
dressing that is to come into contact with the skin. The prior art discloses
several
methods for facilitating handling of a wound dressing.
GB Patent application No. 2,128,479 describes a surgical dressing having two
release sheets, each covering half of the dressing and having a free edge
curved
at the centre of the dressing. As the curved edges of the release sheets are
2p peeled back, the centre of the dressing is applied over a catheter or to a
wound,
followed by the ends, thereby preserving sterility by eliminating the need to
touch
the adhesive surface of the dressing.
US patent No. 4,753,232 discloses a "handle" portion along one edge of the
dressing. After the dressing is applied, the handle may be removed by tearing,
or
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it may carry an adhesive coating so that it may be adhered to the skin of the
patient.
r
Another known method of avoiding contact with the edges of a bandage by fin-
gers or forceps is disclosed in US Patent No. 4,646,731 disclosing a bandage
b which is coated with an adhesive and the edges of which are protected by a
pair
of folded V-shaped tabs. After removing the backing sheet from the bandage,
one tab is removed and the corresponding end of the bandage is applied to the
skin. The second tab is grasped and removed as the entire length of the ban-
dage is then applied.
European Patent Application No. EP 0 168 174 discloses a dressing comprising
a first adhesive contact layer and an inner surface of a thin film backing. A
re-
lease layer covering the first adhesive layer is removed prior to application
of the
dressing, and the film backing preferable has an edge portion free of adhesive
to
faciliotate the removal of the release layer from the dressing without touch
con-
taminating the underside of the dressing. A relatively rigid carrier section
is se
cured to the outer surface of the film backing by a second adhesive layer, and
the carrier section includes rigid handles keeping the dressing extended
during
application of the dressing to a skin surface and prevents the dressing from
curl
ing or folding up.
US Patent No. 4,744,355 discloses a solution to a problem associated with ex-
cessive peeling force during removal of backings from wound dressings by divid-
ing the release liner in halves. A wound dressing is disclosed in which the
release liner halves are each divided into a release liner main body and a re-
lease finer edge strip. The release liner main body overlaps a portion of the
edge
strip and the two are secured to each other by a flexible hinge. As the
release
liners are pulled away from the wound dressing, the hinge means are employed,
thus reducing the peeling force.
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US patent No. 5,106,fi29 discloses a dressing having a thin transparent film
layer, a stable backing layer over the outer surface of the transparent layer,
and
' a release liner. The backing layer and the release liner each have a corner
tab to
facilitate the peeling of each from the transparent layer.
Published EP application No. EP 0 630 629 discloses a flexible wound dressing
product that includes a thin-film layer, an adhesive layer, a backing layer
which
may be porous, an optional support layer, an optional release liner, and a
hydro-
gel material without the use of an adhesive. The wound dressing may also in-
clude a removable V-shaped tab interposed between the thin film layer and
release liner, providing a grippable surface for the removal of the release
finer
from the transparent thin film layer and to facilitate the handling of said
wound
dressing during application of the dressing to the wound.
~B Patent Application, No. 2 224 445 A discloses an adhesive dressing which
comprises a backing layer having a pressure sensitive adhesive layer over one
surface thereof, a removable protector which covers the adhesive layer and ex-
tends beyond the backing layer at one or more edges and a conformable support
Layer which is reversibly attached to the non-adhesive surtace of the backing
layer and extends beyond the backing layer at one or more of said edges. Said
protector comprises first and second parts, the first part having a portion
extend-
ing away from the adhesive surface and bent back to form a V-shape and the
second part having a portion extending away from the adhesive surface and
overlying the V-shaped first part.
Published International Application No. WO 94/14393 discloses an adhesive
dressing comprising a backing layer, a pressure sensitive adhesive thereon and
a support layer attached to the non adhesive surface of the backing layer. The
' dressing is characterised in having an additional edge strip component on
the
adhesive surface to facilitate application of the dressing to the skin. A
removable
protector covers the adhesive layer and extends beyond the backing layer. The
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removable protector may be divided into two or more pieces, of which the
smaller
one may be folded into a V-shaped handle.
European Patent Application No. EP 0 63Q 629 describes a hydrogel wound
dressing product which includes a thin film layer, an adhesive layer, a
backing
b layer which may be porous, an optional support layer, an optional release
liner,
and a hydrogel material. The wound may also include a removable tap inter-
posed between the thin film layer and release liner, providing a grippable
surface
for the removal of the release liner from the transparent thin film layer and
to fa-
cilitate the handling of said wound dressing during application of the
dressing to
the wound.
A problem associated with the state of the art dressings provided with V-
shaped
tab members in order to provide a "non-touch" grip for applying the dressing
comprising an adhesive layer and a release liner to the skin is that a wide
area
with an undesired air channel is created in front of the edge of the tab
member
being positioned across the dressing.
The wide area with an air channel is created partly during manufacturing of a
dressing product having an incorporated V-shaped tab member and partly during
storage. When manufacturing the V-shaped tab member by bending the area of
the bending zone is subjected external forces which will give rise to an
internal
stress-situation in said area. Prior art V-shaped tab members being bended is
seen to have a certain amount of stored stresses. The outer tip of the fold
will be
influenced by tensile stresses, and the inner tip of the fold will be
influenced by
compressive stresses. Together these stresses will force the two flaps of the
V-
shaped tab member from one another, once the dressing product is produced
and stored. This spreading effect of the flaps may cause the area of the
adhesive
layer to detach along the line of bending of the two flaps from the release
layer, '
enabling air to enter between the two said layers and turning the area into an
un-
wanted air channel.
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A further problem in conventional V-shaped tab members is that the tensile
stresses in the outer tip of the fold and the compressive stresses in the
inner tip
of the fold makes the thickness of the folded area huge. When manufacturing a
dressing, especially when manufacturing a dressing having a thin layer of adhe-
5 slue, this huge fold with a huge thickness will create a stepwise change of
the
thickness in the adhesive material, because the adhesive material will be
forced
to flow to each side of the line of bending of the two flaps, resulting in a
local re-
duced thickness of the adhesive layer. This tendency is even more outspoken
when the dressing during manufacturing is subjected pressure in order to
obtain
~ p bevelled edges along the periphery.
The presence of the wide area with the air channel is followed by a numerous
in-
conveniences. The adhesiveness of the adhesive layer is generally known to be
reduced when the adhesive layer is exposed to air. During manufacture ,the
edges of a dressing are often bevelled in a process applying pressure and op-
~ 5 tionally heat. When performing this bevelling process on a conventional
dressing
with a wide area with the air channel, the adhesiveness of the area with the
air
channel has been seen to be remarkably reduced. This reduction is probably
caused by accelerated oxidation due to the heat, but may also be affected by
aqueous vapour, small fibres and dust in general present in the surroundings.
Zp Further, the air channel allows more aqueous vapour and dust e.g. from
printed
instructions being present in the package to come into contact with the
adhesive
layer during storage. It is a known and used feature in wound dressing technol-
ogy that liquids e.g. wound exudate will reduce the adhesiveness of the
adhesive
layer during use of the dressing. But, having a wide area with reduced
adhesive-
25 ness on a fresh dressing will cause problems with the adhesive when
applying it.
When applying a dressing having a wide area with an air channel on a patients
skin the dressing will have a tendency to detach. This can cause a serious
prob-
fem in case of open wounds where the imperviousness of the dressing is impor-
tant because of the risk of infecting the wound. A dressing having a wide area
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with a channel of air could form a weak point for a leakage of exudate in case
of
a suppurating wound.
In case of a dressing having a very thin layer of adhesive the problem of a
step-
wise change of the thickness creating a locally reduced thickness is even more
pronounced. The problem of the area with the air channel is especially serious
in
case of small dressings e.g, for blisters or corns because the fraction of
area
covered by the air channel compared to the remains of the dressing is greater
for
these small dressings. In this case the dressing could loose the grip after a
shorter period of time.
~p BRIEF DESCRIPTION OF THE INVENTION
The object of the invention is thus to provide a tab member ensuring an easy
handling of a dressing, and in which the problem of a wide area with an air
chan-
nel is avoided.
The present invention relates to a tab member especially for use as a "non-
~5 touch" grip for applying a dressing comprising an adhesive layer and
optionally a
release liner to skin without touching the adhesive surface of the dressing
which
is to come into contact with the skin, wherein said tab member comprises at
least
a first flap member and a second flap member being an integral bended unit or
being joined along one edge thereof so as to form a tab having a V-formed
2p cross-section.
Furthermore the invention relates to a method for manufacturing a V-shaped tab
member by folding a continuous band of a tab material, and then subject the
folded area to heat and pressure.
Still further, the invention relates to a method for manufacturing a V-shaped
tab
Y
25 member by placing at least two continuous bands of tab material on top of
each
other, and then subject the edges to be joined to heat and pressure.
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Finally the invention relates to dressing products incorporating the V-shaped
tab
member.
In accordance with one aspect, the invention provides a tab member for use as
a
"non-touch" grip for applying a dressing comprising an adhesive layer to a
wound or
skin without touching a surface of the adhesive layer. The tab member
comprises at
least a first flap member and a second flap member, the first and second flap
mem-
bars constituting an integral bent unit so that the tab member has a V-shaped
cross-
section which is substantially perpendicular to a line of bending of the first
and
second flap members. The tab member has a thickness reduced by heat and
pressure in an area of the line of bending such that a combined thickness of
the first
and second flap members in the area is less than a thickness of a bent edge of
the
first and second flap members.
According to another aspect, the invention provides a tab member for use as a
"non-
touch" grip for applying a dressing comprising an adhesive layer to a wound or
skin
without touching a surface of the adhesive layer. The tab member comprises at
least a first flap member and a second flap member, the first and second flap
mem-
bars being joined along one edge thereof so that the tab member has a V-shaped
cross-section which is substantially perpendicular to a line of conjunction of
the flap
members. The tab member has a thickness reduced by heat and pressure in an
area of the line of conjunction such that a combined thickness of the first
and second
flap members in the area is less than a combined thickness of the first and
second
flap members outside said area.
According to a further aspect, the invention provides a method for
manufacturing a
V-shaped tab member for use as a "non-touch" grip for applying a dressing com-
prising an adhesive layer on a wound or skin. The tab member comprises at
least a
first flap member and a second flap member, the first and second flap members
constituting an integral unit so that the tab member has a V-shaped cross-
section
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7a
which is substantially perpendicular to a line of bending of the first and
second flap
members. Also, a combined thickness of the first and second flap members in an
area of the line of bending is less than a thickness of a bent edge of the
first and
second flap members. The method comprises folding a continuous band of a tab
member material to form a fold, and thereafter subjecting an area of the fold
to heat
and pressure to reduce a total thickness of the first and second flap members
in the
fold as compared to a thickness of the bent edge.
According to yet a further aspect, the invention provides a method for
manufacturing
a V-shaped tab member for use as a "non-touch" grip for applying a dressing
com-
prising an adhesive layer on a wound or skin. The tab member comprises at
least a
first flap member and a second flap member joined along one edge thereof so
that
the tab member has a V-.shaped cross-section which is substantially
perpendicular to
a line of conjunction of the flap members. Also, combined thickness of the
first and
second flap members in an area of the line of conjunction is less than a
combined
thickness of the first and second flap members outside the area. The method
com-
prises placing at least two continuous bands of tab material on top of each
other,
aligning edges of the bands to be joined, and thereafter joining the edges by
applica-
tion of heat and pressure.
In accordance with another aspect, the invention provides a dressing
comprising an
adhesive layer and at least one V-shaped grip tab member for applying the
dressing
to a wound or skin. The tab member comprises at least a first flap member and
a
second flap member, the first and second flap members constituting an integral
bent
unit so that the tab member has a V-shaped cross-section which is
substantially
perpendicular to a line of bending of the first and second flap members. Also,
the
tab member has a thickness reduced by heat or pressure in an area of the line
of
bending such that a combined thickness of the first and second flap members in
the
area is less than a thickness of a bent edge of the first and second flap
members.
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7b
In accordance with yet another aspect, the invention provides a dressing
comprising
an adhesive layer and at least one V-shaped grip tab member for applying the
dress-
ing to a wound or skin. The tab member comprises at least a first flap member
and a
second flap member, the first and second flap members being joined along one
edge
thereof so that the tab member has a V-shaped cross-section which is
substantially
perpendicular to a line of conjunction of the first and second flap member.
Also, the
tab member has a thickness reduced by heat or pressure in an area of the line
of
conjunction such that a combined thickness of the first and second flap
members in
the area is less than a combined thickness of the first and second flap
members
outside the area.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in detail below with reference to the drawings, in
which
Fig. 1 is a sectional view of an wound dressing having a conventional V-shaped
tab
member according to prior art.
Fig. 2 illustrates a view from below, of the wound dressing in Fig. 1, where
the
release layer and the V-shaped tab member have been removed,
Fig. 3 illustrates a sectional view of a wound dressing having a V-shaped tab
member according to an embodiment of the invention,
Fig. 4 illustrates a view from below of the wound dressing of Fig. 3, where
the
release layer and the V-shaped tab member have been removed,
Fig. 5 and 6 illustrate schematically an example of a method for manufacturing
a
continuous band of V-shaped tab members.
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7c
Fig. 7 illustrates from below a wound dressing having two V-shaped tab members
according to another embodiment of the invention, and
Fig. 8 illustrates a sectional view of the wound dressing of Fig. 7.
DETAILED DESCRIPTION OF THE INVENTION
The tab member according to the invention is characterised in that the
combined
thickness of the two flap members in the area of bending or conjunction is
smaller
than the thickness of a bended edge of the two flap members. This is
particularly
advantageous as a decrease of the thickness of the area of bending
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or conjunction results in a decrease of the area of the adhesive in front of
the
area of bending or conjunction, which may be subjected to air. When decreasing
this area the above problems are diminished considerably.
According to a preferred embodiment of the invention the two flap members may
b constitute one integral bended sheet. In practice, this embodiment is
particularly
easy to manufacture.
According to another embodiment of the invention the two flap members may be
joined along an edge. In practice, this embodiment renders it possible to use
dif-
ferent materials for the two flap members. This is advantageous in a dressing,
in
~ Q which the material of the flap in contact with the adhesive layer should
have dif
ferent characteristics than the material of the flap in contact with the
release
layer.
The thickness of the two flap members may be the same or optionally they may
have different thicknesses.
Moreover, according to yet another embodiment of the invention the two flap
members may be mutually displaced. In this way the stepwise change of the
thickness will be further minimised.
It is preferred that the V-shaped tab member of the invention is made from one
2g or more materials being easily removed from the adhesive of the dressing
and
the release liner, preferably one or more materials selected from the group of
thermoplastic olefins. Common for all the materials used as V-shaped tab mem-
bers is that they are preferably siliconised or treated in another way in
order to
secure an easy release from the adhesive.
2b In a second aspect, the invention relates to a method for manufacturing a V-
shaped tab member, especially for use as a "non-touch" grip for applying a
wound dressing comprising an adhesive layer and optionally a release finer to
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__
the skin, wherein said tab member comprises at least a first flap member and a
second flap member being joined along one edge thereof so as to form a tab
having a V-formed cross-section substantially perpendicular to the line of
folding,
characterised in that a continuous band of a tab material is folded, after
which
" ~ the folded area is subjected to pressure in order to reduce the total
thickness of
the two flap members in the folded area as compared to the thickness of a fold
not subjected to pressure.
It is preferred to reduce the total thickness of the two flap members in the
folded
area by passing the continuous band of folded material through a pair of opti-
~ p mally heated rollers, after which the continuous V-shaped band optionally
can be
cut into appropriate sizes forming the tab members. The temperature of such
rollers will depend on the material and the environmental temperature.
It is advantageous when the folded area is subjected to heat separately before
being subjected to pressure giving the opportunity of a better temperature
15 control.
In a third aspect, the invention relates to a method for manufacturing a V-
shaped
tab member, especially for use as a "non-touch" grip for applying a wound
dressing comprising an adhesive layer and optionally a release liner on a
wound,
wherein said tab member comprises at least a first flap member and a second
~g flap member being joined along one edge thereof so as to form a tab having
a V-
formed cross-section substantially perpendicular to the line of conjunction,
char-
acterised in that, at least two continuous bands of tab material are placed on
top
of each other having the edges to be joined aligned, after which the edges are
joined by the action of heat and pressure.
2g It is preferred to join the edges by sealing and use a pair of rollers to
press the
sealed edges, whereafter the continuous V-shaped sheetband optionally can be
cut into appropriate sizes forming the tab members.
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In accordance with another aspect of the invention the edges are joined by
gluing
before being subjected to pressure.
Instead of using a pair of rollers it is possible to use a system of more
rollers or
to use another mechanical device e.g. a heated press.
~ The heating of a continuous band could be done at the same time as the press-
ing is performed. This could be done by a pair of heated rollers.
The either one or two continuous bands of a film material might in another
method for manufacturing the V-shaped tab member be passed through a
stamping and sealing apparatus. instead the conjunction forming a straight
line, it
q fl could alternatively form a series of cyclic curves, repeating for each
dressing.
The band could optionally still be continuous after the stamping, by the open
edges of the V-shaped member. Further a V-shaped tab member according to
this invention can also be used together with other products including
adhesive
surfaces, e.g. ostomy products and adhesive strips for mastectomy products as
~5 well as industrial adhesive strips.
In a further aspect, the invention relates to a dressing comprising an
adhesive
layer and optionally a release liner and a V-shaped tab member for applying a
dressing to the skin, characterised in that the tab member comprises at least
a
first flap member and a second flap member being an integral bended unit or be-
2p ing joined along one edge thereof so as to form a tab having a V-formed
cross-
section substantially perpendicular to the line of bending or conjunction, and
wherein the combined thickness of the two flap members in the area of conjunc-
tion is smaller than the thickness of a banded edge of the two flap members.
This combination of a dressing and a V-shaped tab member according to the in-
2b vention offers a large number of advantages to the patients.
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In still a further aspect, the invention relates to a dressing comprising an
adhe-
sive layer and optionally a release liner and at least finro V-shaped tab
members
for applying a dressing to the skin, characterised in that each of the tab
members
comprises at least a first flap member and a second flap member being an inte-
' S gral banded unit or being joined along one edge thereof so as to form a
tab hav-
ing a V-formed cross-section substantially perpendicular to the line of
conjunction, and wherein the combined thickness of the two flap members in the
area of the bending zone or conjunction is smaller than the thickness of a
banded edge or the combined thickness of the two flap members
1 p The embodiment with two V-shaped tab members having their zones of conjunc-
tion in close contact has in practice proved to be particularly advantageous
as
the second flap members cover the the whole surface of the adhesive layer ,
therefore the release liner is not necessarily needed and the dressing is much
easier to apply.
1~ Fig. 1 illustrates a prior art wound dressing 1 comprising a top film 2, an
adhesive
layer 3, a protective layer 4 also referred to as the release layer and a
conven-
tional V-shaped tab member 5. The flaps 6, 7 of the conventional used V-shaped
tab member 5 tends to spread from one another forming an angle due to the
memory of the material in the folded area 8 . This spreading tendency results,
as
2a described above, in that the adhesive layer 3 will detach the release layer
4 of
the dressing 1. As mentioned above this detaching of the adhesive layer 3 will
re-
sult in the forming of a channel 9 between the adhesive layer 3 and the
release
layer 4 along the fine of bending of the two flaps 6, 7 of the V-shaped tab
mem-
ber 8, as it is illustrated in Fig. 1.
28 Furthermore the adhesive layer 3 is seen locally to have a reduced
thickness at
11. This stepwise change of the thickness is created because the adhesive ma-
terial in the adhesive layer 3 will be forced to flow to each side of the line
of con-
junction 8 of the two flaps 6, 7. This is even worse when the dressing product
includes bevelled edges along the periphery.
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12
As it can be .seen clearly from Fig. 2 showing the prior art dressing 1
according to
Fig. 1 seen from below, after removing the release layer 4 and the V-shaped
tab
member 5, an unwanted channel 9 is present across the dressing 1. In Fig. 2
the '
adhesive layer 3 is shown with the area 11 influenced by the differences of
the
thickness, and the area 10 influenced by the air channel. The channel 9 will
im- '
mediateiy be filled with air, which will lower the adhesiveness of the
adhesive
layer 3 in the area 10 giving rise to a numerous inconveniences as stated
above.
Fig. 3 illustrates a dressing 21 according to the invention comprising a
topfilm 22,
an adhesive layer 23, a protective layer 24 also referred to as the release
liner
and a V-shaped tab member 25 according to the invention. The dressing may
further comprise a protective layer on fop of the top film. The flaps 26, 27
of the
V-shaped tab member 25 no longer tends to spread from one another.
During manufacturing of the novel V-shaped tab member 25 of the invention from
the continuous band 42, shown on fig. 5, the stored stresses have been
relaxed.
The adhesive layer 23 will hardly detach from the release liner 24 of the
dressing
21 and there is, as shown in Fig. 4, no channel formed between the adhesive
layer 23 and the release liner 24 along the line of conjunction 28 of the two
flaps
26, 27 of the V-shaped tab member 25. The thickness of the area of folding 28
of
the tab member 25 has been diminished considerably, resulting in a reduced
stepwise change of the thickness. The adhesive material in the adhesive layer
23
has almost no tendency to flow to each side of the area of bending 28 of the V-
shaped tab member 25 during manufacture.
According to the invention the V-shaped tab member 25 is made from a material
such as paper, metal, and/or a polymer. E.g. a pofyolefin such as
polyethylene,
polypropylene or polybutylene, preferable a high density polyethylene (HDPE)
which may be sificonised on one side (e.g. HDPE no. 1710) or laminated with '
silicone (e.g. HDPE no. 1800), polyethyleneterepthalate and polyethylene
(PETP/PE}, in a combination of two flaps of different material (PETP/PE) was
used together with (PETP), cast polypropylene film (e.g. PP no. 1015},
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13 '
siliconised cast polypropylene film (e.g. PP no. 1803), or polyesters such as
(e.g.
PETP no. 1019), polyester (e.g. PETP no. 1019), or siliconised polyester (e.g.
PETP no. 1803). The numbers are referring to Europhan numbers.
' In a preferred embodiment of the invention, the material may be siliconised,
on
either one or both sides or treated in a similarly way in order to achieve the
re-
moval of the tab member from the adhesive layer.
The material preferably has a thickness ranging from a few microns to a
millime-
tre. Especially material thickness' in the area of 30 - 60, preferable 36
microns
have proved to be effective.
1 p Fig. 5 and 6 illustrate schematically an apparatus 41 for manufacturing a
continu-
ous band 42 of V-shaped tab members 25. A continuous band 42 wound up on a
roll 43, and continuous is guided over a roller 46 with the purpose of
contacting a
beaded plate 44. By contacting the beaded plate the band is folded in
longitudi-
nal direction, whereafter the band passes through a first pair of rollers 47,
which
applies pressure to the fold. After the band 42 has passed the first pair of
rollers
47 the outer tip of the fold further passes a heating device e.g. a heated
plate 45.
While passing the heated plate 45 the material of the band 42 is heated to a
tem-
perature tying above the softening temperature of the material. The folded
area
of the band then passes through a second pair of rollers 48 applying pressure
to
the fold. Further the folded band 42 is guided over some reeling rollers 49,
50.
Finally the continuous and folded band is optional reeled up on a roll or
directly
used.
Fig. 7 and 8 illustrates a dressing 21 according to the invention comprising a
top-
film 22, an adhesive layer 23 and two V-shaped tab members 25, 25' according
to the invention. The dressing may further comprise a not shown protective
layer
on top of the top film. The flaps 26, 26', 27, 2T of the V-shaped tab members
25,
25' no longer tends to spread from one another close to the line of
conjunction.
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During manufacturing of the novel V-shaped tab members 25,25' of the invention
from a continuous band 42, shown on fig. 5, the stored stresses have been
relaxed.
There is, as shown in Fig. 8, no channel formed between the adhesive layer 23
and the two V-shaped tab members 25, 25' along the line of conjunction 28, 28'
of the two flaps 26, 26', 27, 2T of each of the V-shaped tab members 25, 25'.
The thickness of the area of folding 28, 28' of the tab member 25, 25' has
been
diminished considerably, resulting in a reduced stepwise change of the thick-
ness. The adhesive material in the adhesive layer 23 show almost no tendency
to flow to each side of the area of bending 28, 28' of the V-shaped tab
members
25, 25' during manufacture.
The V-shaped tab members 25, 25' are shown having different size. They may
as well be formed having the same size. The flaps 26, 26' in Fig. 7 and 8 are
smaller than the flaps 27, 2T. The flaps 26, 26' could as well be as long as
the
flaps 27, 2T, or one of the flaps 26, 26' or both flaps 26, 26' could be
longer than
the flaps 27,2T, within the scope of the invention.
MATERIALS AND METHODS
EXPERIMENTAL PART
The invention is explained more in detail below with reference to the Examples
disclosing embodiments of the present invention. The examples are not consid-
ered to be limiting to the scope of the invention which is defined in the
appended
claims.
CA 02245763 2004-05-25
WO 97!28771 PCT/DK97/OOU48
Example 1
Preparation of a V-shaped tab member according to the invention by folding,
heating and rolling.
A roll with a continuous band of siliconised polyethylene (PETP no. 1803) with
a
5 thickness of 36 microns was placed in the apparatus of the type shown in
Fig. 5
and 6, so that the siliconised side faced upward when reeling off the band.
The
continuous band is guided over a roll with the purpose of contacting a bended
plate made from stainless steel. By contacting the bended plate, the band is
folded longitudinally with the sificonised side being outward, whereafter the
band
10 passes through a first pair of rollers, which applies pressure to the fold.
After the
band has passed the first pair of rolls the outer tip of the fold further
passes over
a heated, teflon coated plate. The temperature of the teflon coated plate is
be-
tween 120° and 200° C. While sliding down the heated plate the
material of the
band is heated to a temperature lying above the softening temperature of the
15 material. The folded band then passes through a second pair of rollers
applying
pressure to the fold and thereby deforming that folded area. Further the
folded
band is guided over some reefing rollers. Finally the continuous and folded
band
is optional wound up on a roll or directly used.
Example 2
Preparation of a V-shaped tab member according to the invention by sealing and
subjecting pressure.
A sheet of continuous siliconised polyester (PETP no. 1803) with a thickness
of
36 microns was placed on top of another sheet of the same continuous sili-
Ionised polyester (PETP no.1803). One edge of the two sheets was lead into an
Elwis impulse sealing apparatus (Elwis Pack AIS)*having a sealing strip on
both
jaws and teflon material on top of the sealing strips. The two polyester bands
were heated and sealed together along an edge using a sealing time setting of
*zrademark
CA 02245763 1998-08-07
WO 97/28771 PCTIDK97/00048
16 --
3,1 and a cooling time setting of 4. The apparatus also applied pressure to
the
sealed area as to simulate a pair of rollers. After cooling the continuos
sheet of
V-shaped tab member was cut into pieces of appropriate size. -
Example 3 '
Preparation of a V-shaped tab member according to the invention from two
different materials by sealing and subjecting pressure.
A sheet of Wipak~ (Wihuri Oy Wipak) laminated sterile packaging paper with a
thickness of 100 microns was placed on top of a sheet of siliconised
continuous
polyester (PETP/PE no. 1803) with a thickness of 36 microns. The edge of the
WiPak~ sterile packaging paper being displaced 0,5 mm from the edge of the
polyester. The edges of the sheets were placed in an Elwis impulse sealing ap-
paratus (Elwis Pack A/S). The sealing apparatus having sealing strips on both
jaws, and teflon material on top of the sealing strips. The two polyester
sheets
were heated and sealed together by using a sealing time setting of 3,2 and a
cooling time setting of 4. The apparatus also applied pressure to the sealed
area
as to simulate a pair of rollers. After cooling the continuous band of V-
shaped tab
member was cut into pieces of appropriate size.
Example 4
Preparation of a V-shaped tab member according to the invention from sheets
with different thickness' by sealing and subjecting pressure.
A sheet of continuous polyester (PETP/PE) with a thickness of 47 microns was
placed on top of a sheet of continuous siliconised polyester (PETP) with a
thick-
ness of 36 microns. The edges of the two sheets were placed in an Elwis im-
pulse sealing apparatus {Elwis Pack A/S). The two polyester sheets were heated
and sealed together by using a seating time setting of 3 and a cooling time
set-
ting of 4.
CA 02245763 1998-08-07
WO 97/28771 PCTlDK97100~48
17 '-
The invention has been described with reference to examples of specific embodi-
ments thereof. Many modifications can be carried out without thereby deviating
from the scope of the invention being defined by the scope of the appended
claims.
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