Note: Descriptions are shown in the official language in which they were submitted.
CA 02239185 1998-06-O1
WO 98/17564 PC"T/FI96/OOS58
1
Method in winding of a web, in particular of a paper or board web
The invention concerns a method in winding of a web, in particular of a paper
or
board web, in which method the web is wound onto a roll spool or equivalent
through a nip between a roll or equivalent and the roll spool or equivalent.
The machine reel produced in a paper machine is often slit into component webs
in
a slitter-winder, out of which component webs customer rolls or commercial
rolls of
desired width are formed. In the commercial rolls formed in the slitter-
winder,
automatic fixing of the cutting point, i. e. the tail end of the web, to the
full roll after
winding and the fixing of the initial end of the web to the new roll spool are
to-day
ever more important properties in further processing of the paper. This comes
from
the fact that, at present, ever fewer people work at the slitter-winder, and
the roll
changes, web threading, and other necessary operations require such a high
propor-
tion of the working time of said people that there is hardly time for manual
fixing of
the final ends / initial ends of the rolls by means of tape or equivalent.
Moreover,
rolls whose final ends have not been fixed produce difficulties on the
conveyors.
Likewise, it is a problem that a roll whose final end has not been fixed has
time to
become loose before packaging.
With respect to the prior art, reference is made to the FI Patent 91, 054, in
which a
method and a device are described for automatic cutting and winding of a
product
web. In said paper, a solution is also suggested for fixing the end of the
web, in
which solution the web is weakened and strips of adhesive material are
provided at
the forward side and at the rear side of the weakening area. However, one
problem
in this prior-art solution, in particular with thicker paper grades, is ply
separation of
the paper, i.e. the paper is separated from the roll or spool in spite of the
adhesive
fixing. Ply separation of paper means that, while the paper is fixed by gluing
onto
the spool from one side, rigid paper and, especially, board grades tend to
straighten
CA 02239185 2001-05-02
2
themselves to their linear form present on the machine reel and are split
starting
from the end of the web, in which case the starting of winding can fail
completely
or a fold is formed on the bottom of the roll. It can also be difficult to
find a
correct degree of weakening of the web when paper grades of different
strengths
5 are run.
The present invention is directed towards the provision of a method in
which the drawbacks of the prior-art solutions are not present and by whose
means
the ends of the web can be fixed automatically to the roll and to the spool,
respectively, simply and reliably.
10 The present invention is directed towards creating a solution that is
suitable
for use in connection with a slitter-winder when the slitter-winder slows down
and
stops for roll change.
In accordance with one aspect of the present invention, there is provided a
method for changing the winding of a web from a first roll spool about which a
15 first roll is formed to a second roll spool, comprising the steps of:
attaching a first
edge of a material strip having a set length in a running direction of the web
to the
web at a first point at a location before the web is wound about the first
roll spool,
the first edge of the material strip being oriented in a direction
substantially
transverse to a running direction of the web, attaching a second edge of the
20 material strip to the web at a second fixing point at a location before the
web is
wound about the first roll spool such that the length of the material strip
between
the first and second fixing points is greater than the length of the web
between the
first and second fixing points, the second edge of the material strip being
oriented
in a direction substantially transverse to a running direction of the web,
cutting the
25 web between the first and second fixing points after the edges of the
material strip
are attached to the web at the first and second fixing points, and severing
the
material strip after the web is cut such that a first portion of the material
strip
winds about the first roll spool and a second portion of the material strip
attaches to
the second roll spool.
30 The method in accordance with the invention, therefore, is mainly
characterized in that, in the method, when the roll that is formed on the
spool
becomes complete, a material strip with one adhesive face is fixed to the web
at its
CA 02239185 2001-05-02
3
edges transverse to the running direction of the web to fixing points so that
the
edges of the material strip are placed on the web at the fixing points at a
distance
between said fixing points in the running direction of the web that is shorter
than
the length of the material strip in the running direction of the web.
S According to the invention, a material strip with one adhesive face is fixed
to the face of the web, the length of said material strip in the running
direction of
the web being larger than the distance between its fastening points, and the
web is
cut off at a suitable point between the fastening points. After this, the
material
strip with one adhesive face is cut off so that one of its parts fixes the
final end of
10 the web to the complete roll and the other part fixes the initial end of
the web to a
new roll spool or equivalent.
According to the invention, the slitter-winder is stopped for the roll change,
and the material strip with one adhesive face, preferably a one-sided tape, is
fixed
to the face of the web from two zones separate from one another. After this,
the
15 web is cut off between the tape fixing points. Since the length of the tape
in the
running direction of the web is longer than the distance between the fastening
points, "unused" tape remains between the ends of the cut-off web. A part of
this
tape is used for fixing the tail of the roll to the roll, and the rest is used
for fixing
the web onto the roll spool, respectively.
20 In an embodiment of the invention the tape has been weakened in advance
at the point at which it is supposed to be split between the fastening of the
roll tail
and the fastening of the web onto the spool.
The fixing by means of the method of the invention is reliable, because it is
earned out across the cut-off area, whereby the risk of ply separation is
eliminated
25 fully.
In accordance with another aspect of the invention, there is provided an
arrangement for changing the winding of a web from a first roll spool about
which
a first roll is formed to a second roll spool. comprising: attaching means for
attaching a material strip to the web at a location before the web is wound
about
30 the first roll spool, the material strip having first and second edges
oriented in a
direction substantially transverse to a running direction of the web, the
attaching
means being arranged to attach the first edge to the web at a first fixing
point and
CA 02239185 2001-05-02
3a
the second edge to the web at a second fixing point spaced from the first
fixing
point a distance less than the length of the material strip in the running
direction of
the web such that the length of the web between the first and second fixing
points
is less than the length of the material strip between the first and second
fixing
5 points, and cutting means for cutting the web between the first and second
fixing
points after the first and second edges of the material strip are attached to
the web
at the first and second fixing points, the material strip being severed after
the web
is cut such that a first portion of the material strip winds about the first
roll spool
and a second portion of the material strip attaches to the second roll spool.
10 In the following, the invention will be described in more detail with
reference to the figures in the accompanying drawing, the invention being,
however, in no way supposed to be strictly confined to the details of said
illustrations.
Figure 1 is a schematic illustration of the stage of the method of the
15 invention in which the slitter-winder has been stopped for the purpose of
cutting
off the web and fixing the tape.
Figure 2 is a schematic illustration of the stage of the method of the
invention in which the web is cut off.
Figure 3 is a schematic illustration of the stage of the method of the
20 invention in which the web has been cut off and the tape has been fixed
between
the final portion and the initial portion of the web.
Figure 4A is a schematic illustration of an exemplifying embodiment of
cutting off the tape and fixing the tape to the face of a full roll.
CA 02239185 1998-06-O1
WO 98/17564 PCT/FI96/00558
4
Figure 4B is a schematic illustration of a second exemplifying embodiment of
cutting
off the tape and fixing the tape to the face of a full roll.
Figure 5 is a schematic illustration of the stage in the method of the
invention in
which one part of the tape has fixed the f nal portion of the web to the face
of the
complete roll and the other part of the tape has fixed the initial portion of
the web
onto a new roll spool.
According to Fig. 1, the web W is wound over a roll I I or equivalent onto the
roll
spool 13, around which the roll 12 is formed. The winding takes place through
the
nip N between the roll 1I and the paper roll 12. In the situation as shown in
Fig. l,
the web W has been stopped between the upper and lower holding members 24,25
of the web W cutting and tape fixing equipment 23. The tape or equivalent
material
strip with one adhesive face, to be fixed to the web W, is denoted with the
reference
numeral 22, and the web W cutting blade with the reference numeral 21. As
comes
out from Fig. 1, the Length Y (Fig. 3) of the tape 22 is larger than the
length X of
the web portion that remains between the tape 22 fixing points 26,27, because
the
tape 22 has been bent into a curved or equivalent form.
As comes out from Fig. 2, after the ends of the tape 22 have been fixed at the
points
26,27 to the web W face, the web 21 is cut off between the fastening points.
After this, as is shown in Fig. 3, the web is moved in the direction S, in
which case
the tape 22 is tightened between its fixing points and becomes straight, the
adhesive
face being placed as the bottom face viewed in the direction of the figure.
According to the exemplifying embodiment shown in Fig. 4A, in the next stage,
when the tape approaches the nip N between the roll 11 and the roll 12, the
nip is ,
opened, i.e. the roll 12 shifted to a distance apart from the nip contact with
the roll
11, and when the tape is between the roll l I and the roll 12, it is cut off
by means
of the blade 31, the first part 22A of the tape 22 being guided onto the roll
face, and
CA 02239185 1998-06-O1
WO 98/17564 PCT/FI96l00558
by means of the press member 32 it 22A is pressed into contact with the roll
2i
face, whereby the final end of the web has been fixed.
In the exemplifying embodiment shown in Fig. 4B, the tape 22 has been
provided,
5 for example, with a weakening, in which case, when the web W is tightened,
the
tape 22 is cut off at the weakening. The operations to be carried out after
this are
similar to those illustrated in Fig. 4A.
As comes out from Fig. 5, after one part 22A of the tape has fixed the final
portion
of the web W to the complete customer roll, the other part 22B of the tape 22
is
fixed to a new roll spool I3B, and after this the winding of the web W is
continued
onto the new roll spool I3B through the nip N between the roll II and the
spool
I3B. After the roll formed on the spool 13B has reached the desired size, the
steps
of the method in accordance with the invention are carried out starting from
Fig. 1.
Above, the invention has been described with reference to one preferred
exemplify-
ing embodiment only, the invention being, however, by no means supposed to be
strictly confined to the details of said embodiment.
Many variations and modifications are possible within the scope of the
inventive idea
defined in the following patent claims.
