Note: Descriptions are shown in the official language in which they were submitted.
CA 02511994 2012-04-05
tesa Aktiengesellschaft
Hamburg
Description
Adhesive tape for producing a splice
The invention relates to an adhesive tape for producing
a splice.
Flat web materials, in particular paper, are wound up
onto. reels, in order for example to be supplied to a
paper-processing machine or a printing and packaging
machine. In order to permit continuous operation of
the plant, it is necessary that, as soon as a first
reel of the flat web material has been used up, the
start of a further material web, which is unwound from
a new reel., be placed on the end of this material web
in a flying change and connected thereto in a suitable
way without having to stop the high-speed machines when
changing the reels. This procedure is known as splicing
to splice"). For this purpose, primarily in the paper
industry, use is made of double-sided adhesive tapes
which are highly sticky/tacky and which consist
substantially of a carrier layer which is provided with
a self-adhesive compound on its upper and lower side in
each case, in order in this way to produce.a connection
between the end of the old material web and the start
of the new material web. In the process, the end of the
old material. web is adhesively bonded to. the start of
the new material web.
As a rule, the adhesive tapes. are stuck to the web
start manually and. the adhesive bonds are relatively
thick as a result of a sequence of two paper webs and
an adhesive strip in each case, a result which is
undesired in the paper/printing industry. Furthermore,
CA 02511994 2005-07-13
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the production of such a splice is very complicated and
holds a certain potential for error.
To this end, different procedures and different
adhesive tapes are known to those skilled in the art,
attention having to be paid to exact execution of the
bonding, since tearing of the web material would lead
to undesired and costly machine stoppages and the new
material web would have to be threaded manually into
the machine.
In order to improve the result, an adhesive tape having
a cleavable system is described in DE 198 41 609 Al, a
contact adhesive element consisting of a base element
and a top element. The base element consists of a
material which divides between the upper side and lower
side under the stress of a normal force, which means
when a tensile force is exerted on the adhesive tape
substantially perpendicular to the main plane of the
latter. Applied to the upper side and the lower side
are a large number of adhesive layer elements which,
after the division of the connection, are in each case
covered by the constituents of the base element which
remain on the adhesive layer elements, so that these
areas cannot remain stuck to further parts of the web
material. This adhesive tape is stuck under the
uppermost layer of a new reel of the web material and,
during the cleaving process, fibres are torn out of a
paper carrier lying above this layer by the adhesive
layer elements applied in the manner of spots. A
comparable adhesive tape is disclosed by EP 057 657 Bi.
In this case, two polymer layers coated over the entire
surface separate and in this way expose the web start
of the new paper reel.
DE 199 02 179 Al describes a single-sided adhesive
tape, under whose underside a double-sided adhesive
tape in strip form is stuck, having a carrier of a
cleavable paper. The latter cleaves under the action
CA 02511994 2005-07-13
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of the force of the flying reel change and in this way
exposes the new paper reel and, at the same time, using
the cleaved papers, covers the adhesive compounds, so
that no disruptions occur as they pass through the
machine.
In DE 101 23 981 Al, an adhesive tape has two cleaving
strips, which can have different cleavage forces, in
order to be able to react to different grammages of the
material to be spliced.
In the case of all the aforementioned adhesive tapes,
these are stuck under the outer layer on the reel of
web material. In this case, however, care must be
taken that this outer layer nevertheless rests on the
reel without creases, so that these adhesive tapes can
be applied to a reel only with a great deal of effort.
Furthermore, adhesive tapes are known which, at the
transition between the outer layer of the reel and the
layer of the reel located underneath, must be stuck
onto the reel directly at the cut edge or at the end of
the outer layer, covering this transition. For this
purpose, the adhesive tape, whose length substantially
corresponds to the width of the reel, has two different
self-adhesive systems on its underside and on the
underside of the carrier layer. The first system is a
non-cleavable system and is stuck onto the outside of
A the reel in the region of the cut edge. The second
system is a cleavable system and is stuck onto the
layer or winding of the web material located underneath
on the reel, likewise in the region of the cut edge or
of the transition from the outer layer to the layer
located underneath. The upper side of the adhesive
tape is designed to be self-adhesive in a manner known
per se and, during the flying reel change, the end of
the web material of the used reel is pressed against
this upper side of the adhesive tape and bonded. Thus,
the web material is pulled off the new reel by the web
CA 02511994 2005-07-13
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end of the empty reel and the second system is cleaved
at the transition, the residue of an adhesive remaining
on the layer underneath being covered by the cleaved
system. In this case, it is to be seen as
disadvantageous that the cut edge of the new reel has
to be executed exactly, since the two systems are at
only a short distance from each other, in order to
avoid coming into contact with the second self-adhesive
system of the adhesive tape and, as a result, the outer
layer being torn as the web material is unwound from
the new reel. This is possible only with the use of
precise cutting tools or machines and with
corresponding effort.
Adhesive tapes which are stuck onto the uppermost paper
layer from above are described in DE 198 60 673 Al, but
this adhesive tape also has considerable weaknesses
because of the product structure and the adhesive
bonding which is therefore complicated, since this
adhesive tape must be adjusted very accurately for
satisfactory functioning although here, nevertheless,
automatic application is possible. This adhesive tape
must be stuck flush with the leading paper edge of the
new paper reel, since otherwise the self-adhesive
compound on the underside of the main carrier also
bonds the second paper layer, which then leads to
uncontrolled opening and thus to breaks.
t Furthermore, an adhesive tape is proposed which is
applied from above, namely to the uppermost and second
layer of a new paper bale. This adhesive tape, coated
on one side with a self-adhesive compound on a main
carrier, bears on its non-adhering rear side a self-
adhesive cleavable system S2 which has a paper carrier
that is easy to cleave and covers the respective
adhesives. In order to permit application from above to
the uppermost layer of the new web, the adhesive tape
bears a non-cleaving, self-adhesive system S1 on its
non-adhering rear side. This adhesive tape is stuck to
CA 02511994 2005-07-13
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the uppermost layer (Fig. 8), as described in the
following text:
Firstly, the outermost turns of the paper bale,
5 which may have been damaged or soiled during
transport, are removed.
The now outermost, topmost layer of the new paper
bale must be cut off in a straight line, if
possible approximately but not exactly at right
angles to the side edges of the paper bale. In
order to permit reliable application, the paper
must be cut off very accurately. Inaccuracies in
the cut line must have dimensions here no greater
than the distance Al of the two self-adhesive
systems Sl and S2 to the adhesive tape to be
applied. However, this is quite difficult in
practice and, as a rule, makes the use of a knife
or the like necessary.
The adhesive tape is then stuck in a straight line
with the self-adhesive, non-cleavable system S1
onto the topmost layer and with the cleavable
self-adhesive system S2 onto the second topmost
layer of the paper bale in such a way that the web
start, the cut edge of the paper, lies exactly
between the two self-adhesive systems S1 and S2,
and the start of the new web lies on the non-
.# adhering part between them. As soon as any
displacement of the adhesive bond takes place,
which would lead to part of the self-adhesive
system S1 or of the self-adhesive system S2 being
stuck beyond the start of the paper web, this
leads to failure of the splice in every case,
which in turn results in expensive machine
stoppages.
Thus, application of such an adhesive tape is possible
only by machine, since sticking manually with this
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accuracy is impossible, even in the case of small web
widths. The use of automated machines is in turn
firstly costly and requires additional space, so that
such a product is not suitable for many potential
users.
On the basis of this prior art, those skilled in the
art are presented with the task of specifying an
adhesive tape with which a flying reel change can be
carried out in a straightforward manner, reliable and
destruction-free unwinding of the web material from the
new reel being ensured. In addition, the adhesive tape
should be capable of being handled without the use of
machines and the intention is to enable manual, simple
application from above to the uppermost layer of the
material to be spliced.
This object is achieved by the features specified in
Claim 1.
The basic idea of the invention is that, for example
during the production of a connection between two flat
web materials wound up onto reels, during a flying reel
change, a cleavable system is applied to the underside
of the carrier layer and is in turn provided with a
further self-adhesive compound to be connected to the
different layers of the new reel of web material. In
this case, the adhesive tape is arranged and stuck over
the transition between the overlapping part and the
overlapped part located underneath in such a way that
this transition, viewed over the width of the reel, is
covered by the adhesive tape over the entire area or
part of the area. If, then, in a manner which is known
per se for the flying reel change, the fresh reel
provided with the adhesive tape is moved in the
direction of the web end of an empty reel or vice
versa, then, by means of the self-adhesive compound on
the upper side of the carrier layer, an adhesive
connection or splice with the web end of the old reel
CA 02511994 2005-07-13
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takes place. As soon as the web end has been drawn, for
example, into a paper-processing machine, the start of
the web on the new reel is pulled off via this adhesive
connection and the adhesive tape. As a result of the
tensile forces acting on the cleavable system
substantially in the normal direction, that is to say
radially outwards, cleavage of the cleavable system is
carried out, the lower part of the cleavable system
remaining on the self-adhesive compound arranged
underneath, and the upper part of the cleavable system
being pulled off upwards with the carrier layer and the
self-adhesive compound arranged above. It goes without
saying that the adhesive forces of the self-adhesive
compounds are in each case set appropriately.
in, this case, the cleavable system cleaves exactly as
far as the web start of the outermost wound layer. As
a result of the outermost wound layer being lifted in
the radially outwardly oriented direction, the lower
part of the cleavable system and the self-adhesive
compound located underneath, which is located on the
second layer of the reel, tears exactly at the web
start. The said parts do not remain sticky, since the
cleavable system covers the self-adhesive compound.
The part of the cleavable system which has not cleaved
and the self-adhesive compound located underneath on
the outermost layer of the reel are connected to the
outgoing web via the carrier and the self-adhesive
compound located on the upper side of the latter.
In this case, the cleavable system and the self-
adhesive compound located underneath and the cleavage
of the lower part of the cleavable system can be formed
and carried out, respectively, in any manner known per
se or as described in the following text.
According to the latter, the adhesive tape according to
the invention is formed in such a way that it can be
applied from above to the uppermost layer of the flat
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web material wound up, for example the paper web
material. The present invention provides an adhesive
tape which, on account of its construction, has a
substantially lower thickness than the adhesive tapes
which are normally currently used.
Located on the underside of the adhesive tape is the
cleavable system, preferably over the entire width of
the adhesive tape, which is likewise finished in a
self-adhesive manner on the exposed side. This
cleavable system cleaves during the splice in such a
way that no tacky residues remain and hinder the
passage of the splice through the machine.
The material used for the carrier layer can be paper or
plastic film which, in particular, can be coated and/or
metallized. It is obvious to those skilled in the art
that the papers or films have adequate tearing
strengths. For example, slightly creped papers,
machine-finished body papers, single-side coated
smooth body papers, two-side coated, densified,
printable decor papers, single-side coated woodfree
high-gloss kraft papers, papers laminated to metal
foil, polyester films, MOPP films, metallized films or
the like can be used.
In an extension to the invention, the carrier layer of
the adhesive tape is finished in such a way that it is
used for detection by machine. In an advantageous
embodiment of the invention, the adhesive tape has at
least one detectable additive. It is finished with a
detectable feature that can be detected by machine.
This is in particular an optical marking, for example a
coloured marking, and/or a marking that can be detected
by electromagnetic means, such as a metal thread.
Thus, in the automatic reel change, the web start can
be detected automatically by the marking in the
adhesive tape and, consequently, the reel can be moved.
CA 02511994 2012-04-05
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Use is advantageously made of a cleavable system which
has a considerably lower cleavage strength than the
carrier which has to absorb tensile forces. The
cleavable system comprises at least two layers which
5. separate-from each other under the action of a specific
force, such as occurs during the flying reel change, it
being possible for one of the two layers to be formed
from the material of the main carrier, such as is the
case, for example, if the main carrier. used is a paper
laminated to a metal foil or a film.
The 'advantage of the invention is that the adhesive
tape can be stuck over the end of the overlapping part.
and the outer layer of the reel of web material in a
simple way and without excessive precision, it merely
being necessary to ensure that the adhesive tape also
makes an adhesive connection to the web located
underneath. The transition edge, which does not
necessarily have to be made exactly in a straight line,.
must merely be arranged within the longitudinal edges
of the adhesive tape. In addition, it is consequently
possible to reduce the width of the adhesive tape
considerably, so that up to a 50% saving in materials
can be achieved as compared with adhesive tapes which
are applied under the uppermost layer. This adhesive
tape can also be 'designed to be substantially thinner
than comparable adhesive tapes, so that the adhesive
tape cannot, lead to undesired thickening of the wound
material-and thus to problems in the further-processing
machine.
According to a further refinement according to the
invention, it is proposed that the further self-
adhesive compound on the underside of the adhesive tape
be segmented. This can be achieved, for example, by
the self-adhesive compound being assembled from a large
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number of adhesive spots and/or adhesive strips
arranged closely adjacent to one another, each of the
adhesive spots being stuck either to the outer layer or
to the layer of the reel located underneath. If, then,
the upper part of the adhesive tape is pulled off the
old reel, in the region of the adhesive spots which are
stuck to the layer of the new reel located underneath,
cleavage of the cleavable system occurs and, at the
transition to the overlapping part of the reel lying
above, tearing off occurs in the self-adhesive compound
and the plurality of adhesive spots and the lower part
of the cleavable system. Likewise, the ability to be
segmented can also be implemented with a frangible
varnish system, described below, which is applied to a
carrier layer.
In order to permit application from above to the
uppermost layer of the wound flat web material, use is
made of a cleaving system which cleaves accurately as
far as the transition from the second layer to the
uppermost layer, that is to say the start of the web
material, the cleavage process stopping exactly at this
point.
This is achieved by the adhesive tape according to the
invention in that a frangible varnish system is applied
to a coated or metallized paper carrier or film
carrier, the separating force between the varnish layer
and the carrier having to be set in such a way that,
when the new reel of web material is accelerated, the
varnish layer is so high that cleavage is avoided but,
secondly, cleavage occurs as soon as the old web of
flat web material sticks to the upper side of the
adhesive tape and forces act on the bond which result
in cleavage between the carrier and the varnish layer,
the cleavage process being interrupted exactly at the
transition from the second to the uppermost layer of
flat web material.
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In the process, in the adhesive compound coated in
segments, the varnish always tears at the points at
which adhesive compound is applied and covers the
latter in such a way that they do not remain adhesive.
This cleavage process runs reliably always only as far
as the transition from the second to the uppermost
layer. Once the uppermost layer has been reached, the
cleavage process is interrupted and the adhesive
compound on the upper side of the carrier material
produces the secure connection between the uppermost
layer of the new reel and the old reel.
In the case of coating the entire area with adhesive
compound, the varnish always cleaves over the entire
area from the carrier as far as the transition from the
second to the uppermost layer. The use of fibres
and/or fillers in the self-adhesive compound enables
the adhesive compound to tear off exactly at the
transition from the second to the uppermost layer.
The fact that the cleavable system has a varnish layer
means that the separating force between the varnish
layer and the carrier layer can be set in such a way
that, during the acceleration of the new reel of web
material, the varnish layer has sufficient adhesive
forces to prevent cleavage of the cleavable system.
This means that the adhesive tape does not cleave
prematurely as a result of the centrifugal forces.
Cleavage of the cleavable system occurs only when the
upper side of the adhesive tape additionally sticks to
the web end of the old reel and, as a result, greater
forces are exerted in the radial direction, here, too,
the cleavage process in the cleavable system being
interrupted exactly at the transition from the
overlapped part to the overlapping part of the web
material. In this case, in the self-adhesive compound
coated in segments, the varnish always tears at the
points at which self-adhesive compound is applied, so
CA 02511994 2005-07-13
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that the self-adhesive compound is covered by the
remaining varnish.
As a result of the cleavage, which can be set in a
defined manner as far as the web start of the outermost
wound layer, the adhesive tape according to the
invention provides the possibility of being able to be
applied manually from above to the new reel of flat web
material without the use of automatic application aids,
since the bonding is very simple, because the web start
of the new web must merely be located somewhere within
the longitudinal edges of the adhesive tape. It is not
necessary to position this adhesive tape very
accurately. Secondly, the width of the adhesive tape
can be reduced by the part which, in the variants to be
stuck underneath, is needed in order to fix the
uppermost layer, which can mean up to 50% width
reduction. Therefore, the adhesive tape provides a
considerable advantage as compared with the prior art.
In order to apply the self-adhesive compound to the
underside of the adhesive tape and the lower part of
the cleavable system, it is proposed that this be
carried out by the screen printing process. This makes
it possible to obtain a sufficiently large number of
mutually separated adhesive spots which, nevertheless,
permit bonding of the adhesive tape to the web material
over the entire area.
According to a further alternative refinement, the
self-adhesive compound is applied by strip coating, the
strips running substantially in the longitudinal
direction of the adhesive tape and therefore parallel
to the transition between the various layers on the
reel.
In both methods, the choice relating to processing
suitable self-adhesive compounds having adequate
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adhesion forces is possible for those skilled in the
art.
The materials used for the self-adhesive compound
preferably include, inter alia, acrylic contact
adhesive compounds, which can comprise both water-
soluble and water-insoluble acrylates and their
dispersions. Furthermore, natural and synthetic rubber
compounds and their dispersions are proposed. In
principle, all types of contact-adhesive compounds
which fulfil the inventive criteria can be used.
The materials used for the cleavable system are
preferably acrylic dispersions and/or polyvinyl
alcohols and/or methyl cellulose and/or their
derivatives. If the carrier used is, for example, a
paper carrier, the cleavable system can be formed from
an acrylic dispersion applied to this carrier and from
a further layer of methyl cellulose applied to this
layer.
By means of the application of the self-adhesive
compound by screen printing or strip printing or by
other coating techniques which permit coating over less
than a complete area, the intended rupture points in
the self-adhesive compound in the bonded state on the
new reel are predefined since, exactly at the gaps
between adjacent points of the self-adhesive compound,
at which the transition in the various layers of the
new reel is arranged, tearing occurs both in the layer
of self-adhesive compound and in the lower part of the
cleavable system immediately adjacent to this layer.
It is obvious to those skilled in the art that, for the
purpose of handling and/or storage of the adhesive
tape, the self-adhesive compounds on the upper side and
underside can each be provided with strip-like or web-
like covering elements, also called "liners", which are
pulled off by hand before the bonding operations.
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The adhesive tapes can be used for bonding paper and/or
plastic film webs or other web material.
An exemplary embodiment of the invention will be
explained in more detail below by using the drawings,
in which:
Fig. 1 shows an adhesive tape in a perspective
illustration,
Fig. 2 shows a reel of a web material,
Fig. 3 shows the adhesive tape stuck to the reel,
Fig. 4 shows the old and the new material web with the
adhesive tape before bonding,
Fig. 5 shows the bonded material webs,
Fig. 6 shows the cleavage of the adhesive tape,
Fig. 7 shows a cleaved adhesive tape,
Fig. 8 shows an adhesive tape according to the prior
art.
The exemplary embodiment of the invention illustrated
in Figs 1 to 7 is an adhesive tape 20 which comprises a
carrier layer 22, for example of coated and/or
metallized paper or plastic film, to whose upper side a
self-adhesive compound 21 of a self-adhesive material
that is suitable for this purpose is applied,
substantially over the entire area. In order to handle
the adhesive tape, the self-adhesive compound 21 is
covered with a covering element 26, for example
likewise a coated paper or a coated film, in order to
avoid the adhesive tape 20 sticking firmly at undesired
points. Arranged on the underside of the carrier layer
22, over the entire area, is a cleavable system 23, 24
which substantially comprises two layers 23, 24 which
can be cleaved from each other and is fixed in any
desired way to the carrier layer 22, for example in
turn bonded firmly with a self-adhesive compound. The
lower part of the cleavable system 23, 24, namely the
layer 24, is in turn provided on its underside with a
CA 02511994 2005-07-13
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further self-adhesive compound 25, in order to stick
the adhesive tape 20 to a reel of web material, as
described below. The dividing plane 27, at which the
system 23, 24 is subsequently cleaved or divided, is
formed between the layers 23, 24 of the cleavable
system.
The illustration in Fig. 2 reveals a reel of a flat web
material such as, inter alia, a paper reel, which is
assigned to a paper processing machine, a printing or
packaging machine or the like. On the reel, the web
material is wound up in layers which rest closely on
one another, the overlapping part 10 at least partly
covering the overlapped part 12 arranged underneath.
The end of the web material forms a transition 11
between the overlapping part 10 and the overlapped part
12 located underneath.
In order to prepare for the splicing or bonding of the
web start or of the overlapping part 10 on the reel to
the web end of an empty reel in order to carry out a
flying reel change, in order that continuous operation
of the machine downstream is ensured, the transition 11
has the adhesive tape 20 stuck over it in such a way
that it is stuck between the two longitudinal edges
20a, 20b of the adhesive tape 20. This means that the
transition 11 runs within the longitudinal edges 20a,
20b and is covered by the adhesive tape 20. Thus, this
transition 11 does not have to be made exactly in a
straight line by machine but, instead, can be torn, for
example manually, or executed with a cutting knife.
This state is revealed by the cross-sectional
illustration in Fig. 4. The overlapping part 10 ends
at the transition 11, the overlapping part 10 covering
the overlapped part 12 located underneath only as far
as this transition 11. The adhesive tape 20 is stuck
to the web material in such a way that a section of the
adhesive tape 20 is stuck on the outer layer 10 and the
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other section on the layer 12 located underneath; this
is carried out with the self-adhesive compound 25.
In order to permit a seamless transition from the old
web 30 to the overlapping part 10 of the new reel,
first of all the new reel is accelerated to a
sufficient angular speed, which is indicated by the
arrow X1, in order that, in the region of the
transition, the new web material has substantially the
same speed as the old web material 30, specifically up
to 120 km/h in the case of a paper-processing machine,
as illustrated by the arrow X. As soon as this speed
has approached the intended speed, the old material web
30 is moved in the Y direction until the exposed self-
adhesive compound 21, the covering 26 having previously
been removed, comes into contact with the web 30 and
sticks firmly to the latter. This state can be seen
from Fig. 5.
As soon as the adhesive bond between the self-adhesive
compound 21 and the old web 30 has been produced, on
account of the circular movement, relative to the
substantially linear movement of the old web 30, of the
new web material wound onto a reel and stuck firmly to
the latter by the adhesive tape 20, there follows the
exertion of a tensile force on the adhesive tape 20, as
illustrated by the arrow F in Fig. 6. As a result of
this tensile force, cleavage of the cleavable system
23, 24 takes place along the dividing plane 27, which
runs through the adhesive tape 20 in the direction of
arrow P.
In the process, as a result of the forces acting
radially outwards in the self-adhesive compound 25, an
intended rupture point is produced, which has the
effect that the cleavage process, as soon as the
transition 11 between the overlapping part 10 and the
overlapped part 12 located underneath is reached, the
self-adhesive compound 25 tears off at the intended
CA 02511994 2005-09-28
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rupture point produced there. At the same time, the
lower layer 24 of the cleavable system 23, 24 is
designed in such a way that, at the point at which the
self-adhesive compound 25 tears off, the lower layer 24
also tears off and, accordingly, the cleavage operation
is interrupted at this transition from the uppermost to
the second layer. This therefore achieves a situation
where the outer overlapping part 10, as depicted in
Fig. 7, is lifted off the' overlapped part 12 located
underneath and is pulled in the linear direction by the
old web 30, for example into a paper-processing
machine.. In this case, 24a designates the part of the
cleavable system 23., 24 which covers in a non-adhesive
manner the part of the self-adhesive compound 25a
remaining on the overlapped part 12. 24b is the
uncleaved part of the cleavable system 23, 24, which
remains_on the layer 23 on the carrier 22. The part of
the self-adhesive compound 25 that produces the
connection of the adhesive tape 20 to the overlapping
part 10 or material is indicated at 25b.
On account of the configuration of the adhesive tape
20, this can be designed to be substantially thinner
than comparable adhesive tapes, so that there is no
undesired thickening of the wound material in the
machine downstream. In addition, by means of the
remaining section of the layer 24a, which remains
firmly bonded to the section of the self-adhesive
compound 25a on the web 12 located underneath, it is
ensured that this self-adhesive compound 25a cannot
come into adhesive contact with further parts.
In order to form the intended rupture points in the
self-adhesive compound 25, it is proposed that the
self-adhesive compound 25 be applied either by screen
printing or by strip printing to the layer 24 of the
cleavable system 23, 24 or in another manner that can
be configured by those skilled in the art in order to
obtain a large, number of mutually separated adhesive
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spots or adhesive strips, the intended rupture point in
each case being formed between the adhesive spots
which, on one side, are stuck to the outer overlapping
part 10 and, on the other side, are stuck to the
overlapped part 12 located underneath. In order to
tear off the lower layer 24, either suitable papers are
chosen in which the self-adhesive compound 25 which is
stuck to the overlapped part 12 located underneath
exerts such a tensile force on the layer 24 that, at
the transition, fibres are torn out of the paper layer
24 and the latter is sheared off. Likewise, the layer
24 can be implemented in the form of a frangible
varnish which, in the region of the transition 11,
breaks out in the desired manner in order to tear off
the layer 24, so that the part of the self-adhesive
compound 25 which remains on the overlapped part 12 is
covered by the layer 24 remaining thereon.
CA 02511994 2005-07-13
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LIST OF REFERENCE SYMBOLS
Overlapping part (= outer layer)
11 Transition
5 12 Overlapped part (= lower layer)
Adhesive tape
20a, 20b Longitudinal edges of the adhesive tape
21 Self-adhesive compound
22 Carrier layer
10 23 Upper part of the cleavable system
24 Lower part of the cleavable system
24a The part of the cleavable system which covers
in a non-adhesive manner the part of the
self-adhesive compound (25a) remaining on the
15 overlapped part 12
24b The uncleaved part of the cleavable system
(23, 24), remains on the layer (23) on the
carrier (22)
Further self-adhesive compound
20 25a Self-adhesive compound that has remained on
the overlapped part
25b The part of the self-adhesive compound (25)
producing the connection between the adhesive
tape (20) and the overlapping material (10)
25 26 Covering element
27 Dividing plane
Old web
X, X1, Y Directions of movement
1 P Cleavage direction
30 F Tensile force
