Field of the invention
[0001] The present invention relates to a rewinding method in a rewinding machine for making
logs of sheet or web material, for example used for the production of rolls of toilet
paper, rolls of all purpose tissue paper for household use, non woven fabric, paper
industrial rolls and the like.
[0002] Furthermore the invention relates to a rewinding machine that carries out this method.
Background of the invention
[0003] Rewinding machines are known where the winding step takes place in a special winding
zone comprising an upper roller, a lower roller and a pressing roller.
[0004] For example, in
EP 1232980 in the name of the same applicant, a core of cardboard, located on special movable
support cradle, is brought into contact with the upper winding roller and is therefore
dragged into a winding zone. The rotation of the lower and upper rollers causes the
core to rotate at the same speed thus winding around itself the web of paper.
[0005] Normally, before winding, a certain an amount of glue is previously application the
surface of the tubular core, to allow the web of paper to remain stuck to core same
and to start therefore winding the log.
[0006] To this purpose, glue distribution devices of different kind can be used. For example,
nozzles connected to the structure of the rewinding machine can be used that spray
a measured amount of glue on the core before that the core enters the movable cradle
to start winding. Other devices can be also used such as distributing brush means
or knives. Once the log has achieved the predetermined diameter a cutting step follows
of the web of paper along special perforation lines.
[0007] To this purpose, as described in
EP1554202, a special separation finger is provided brought into rotation at an angular speed
higher than the winding roller about which the web of paper adheres, causing therefore
the tearing of the paper. Then, a speed difference of rotation between lower roller
and pressing roller causes the exit of the formed roll.
[0008] In other cases, a special cutting blade creates a clean cut on the web without any
need of auxiliary devices such as the separation finger above described.
[0009] Always as described in
EP1232980 a core, previously wet of glue, is brought into contact with the upper winding roller
and therefore with the head of the web of paper as obtained from the previous cut
or tearing step of the web same, thus starting to wind a log contemporaneously to
the exit of the final log.
[0010] Said glue distribution systems have drawbacks on final quality of the product. For
example, the glue put on the tubular core of cardboard can cause large droplets of
glue to wet the web of paper during the contact of the core with the roller, in such
a way that the roller is dirtied and the paper is wound about the upper roller instead
of the core. Furthermore, in case of delay of entry of the core with glue in the winding
zone, the glue can dry loosing its effect. This would cause a maintenance stop to
the machine for removing the core and putting in a new one, with high loss of time
and production rate.
[0011] At the end of each winding cycle, the formed log leaves the rewinding machine and
is sent to a machine adapted to glue the free end. The methods of gluing this free
end are many and in any case need an additional gluing section of the machine. For
example, by air specially directioned jets, the free end of the formed log is stretched
on a support plane. Then, gluing systems spread glue for all the length of the free
end sticking the latter on the final log. However, the free end gluing unit, as well
as the gluing step of the starting ed of the log, create relevant problems.
[0012] In fact, the free end cannot be precisely stretched on a support plane, being this
responsive to the direction of the air jets. Therefore the final closure is often
faulty, with presence of large wrinkles and, in particular, of free end portions folded
on themselves.
[0013] In
US 7175126 a system is described adapted to avoid the use of the above described external gluing
units and to provide the application of the glue in the rewinding machine.
[0014] In a first exemplary embodiment, the glue is applied directly on the core in the
cradle by means of two gluing guns. The synchronization of the two gluing guns can
lay glue on the core in predetermined instants such that the rotation of the core
same transfers the glue by contact on the web of paper upstream and downstream of
the desired tearing line. However, this system is not much reliable, since a slip
of the core and therefore a subsequent loss of rotational speed of the core causes
an incorrect distribution of the glue causing, for example, the free nend not to stick
to the roll, or in particular, a faulty start of the new winding cycle.
[0015] The alternative solution provided by the above described patent of spraying the glue
on the paper by means of two gluing guns located in the cradle has relevant drawbacks.
An inaccurate movement of the core in the cradle, or a not controlled of the web of
paper owing to the contact of the core with the web can, in fact, affect the application
of the glue on the paper at predetermined points, causing the core to jam in the cradle
obliging a maintenance stop.
Summary of the invention
[0016] It is therefore a feature of the present invention to provide a rewinding machine
that allows the distribution of the glue near the tearing and/or cutting line of the
paper in an effective way for completing a log and starting a new one.
[0017] It is also a feature of the present invention to obtain log having a high quality
to minimize the number of discarded logs and the time for maintenance stop.
[0018] It is also a feature of the present invention to provide a rewinding machine that
assists remarkably the production process of the log of paper simplifying the structure
of the machine with respect to the machines of prior art.
[0019] It is, furthermore, a feature of the present invention to provide a rewinding machine
that substantially prevents residual glue from entering between the mechanical moving
parts jeopardizing the correct operation and damaging the machine as occurs in the
rewinding machines of prior art.
[0020] These and other objects are achieved by a rewinding machine for making logs of sheet
or web material, for example used for the production of rolls of toilet paper, rolls
of all purpose tissue paper for household use, non woven fabric, paper industrial
rolls and the like, comprising:
- feeding means a web of paper along a feeding direction;
- means for perforating and/or cutting the web of paper adapted to make perforation
lines and/or clean cut along all the width of said web;
- a winding cradle downstream of said feeding means where it is carried out the production
of the log for winding said web of paper about a core;
- means for introducing said core into said winding cradle;
- means for cutting or tearing the web making a formed log tail end and a head end of
the new log,
- means for removing the formed log,
whose main feature is that it comprises, furthermore:
- means for applying a measured amount of glue on a predetermined portion of said web
of paper, said means for applying being arranged upstream from said means for introducing
said core into said winding cradle.
[0021] Advantageously, the measured amount of glue can be applied only downstream of the
perforation and/or clean cut transversal line, i.e. on the portion of the web of paper
corresponding to the formed log tail end to allow closing the log once removed the
formed log after cutting or tearing the web of paper.
[0022] Alternatively, or in addition, the measured amount of glue can be applied upstream
from the perforation and/or clean cut transversal line, i.e. on the portion of the
web of paper corresponding to the head end of the new log that is brought to stick
on a corresponding core once removed the formed log, after cutting or tearing the
web of paper.
[0023] In a further exemplary embodiment, the portion of said web of paper on which the
measured amount of glue is applied can be arranged bridging the perforation and/or
clean cut transversal lines. This way, when separating the log consisting of the new
log of paper, both the formed log tail end and the head end of the new log comprise
glue points. Therefore, it is possible to effect a single application of glue for
both closing the formed log tail end and sticking the head end on the core to start
winding the new log.
[0024] In particular, means can be provided for measuring the length of the web starting
from a large roll of paper operatively connected to the means for applying. More in
detail, the means for measuring operate the means for applying the measured amount
of glue to achieve a measured length of the web of paper.
[0025] Advantageously, the means for applying are movable towards/away from the web of paper
operated by an actuator selected from the group comprised of:
- a pneumatic actuator;
- a hydraulic actuator;
- a electric actuator.
[0026] According to another aspect of the invention, a rewinding machine is provided for
making logs of sheet or web material, for example used for the production of rolls
of toilet paper, rolls of all purpose tissue paper for household use, non woven fabric,
paper industrial rolls and the like, comprising:
- feeding means a web of paper along a feeding direction;
- means for perforating and/or cutting said sheet, or web, of paper adapted to make
transversal perforation lines and/or clean cuts on said sheet, or web, of paper;
- a winding cradle downstream of said feeding means where said log is made by winding
said web of paper about a core;
- means for introducing said core into said winding cradle;
- means for applying a measured amount of glue on a predetermined portion of said sheet,
or web, of paper,
- means for cutting or tearing the web making a formed log tail end and a head end of
the new log,
- means for removing the formed log,
whose main feature is that said means for applying comprises a single application
element adapted to apply said measured amount of glue in at least one of the following
portions of said web of paper:
- upstream from said perforation and/or cut line;
- downstream of said perforation and/or cut line;
- bridging said perforation and/or cut line.
[0027] According to a further aspect of the invention, a rewinding method is provided for
making logs of sheet or web material, for example used for the production of rolls
of toilet paper, rolls of all purpose tissue paper for household use, non woven fabric,
paper industrial rolls and the like, comprising the steps of:
- feeding said sheet, or web, of paper along a feeding direction;
- winding said web of paper about a core at a winding cradle;
- applying a measured amount of glue on said web of paper, said application being carried
out upstream from an introducing zone of said core into said winding cradle.
- cutting or tearing the web making a formed log tail end and a head end of a new log;
- introducing a core into said winding cradle, starting winding the new log, removing
the formed log.
[0028] A winding method, alternative to the previous, for making logs of sheet or web material,
for example used for the production of rolls of toilet paper, rolls of all purpose
tissue paper for household use, non woven fabric, paper industrial rolls and the like,
comprises the steps of:
- feeding said sheet, or web, of paper along a feeding direction;
- winding said web of paper about a core at a winding cradle;
- applying a measured amount of glue on said web of paper;
- cutting or tearing the web making a formed log tail end and a head end of a new log;
- introducing a core into said winding cradle, starting winding the new log, removing
the formed log;
wherein said application is made at said winding cradle owing to a single application
element that spreads said measured amount of glue in at least one of the following
portions of said web of paper:
- upstream from said perforation and/or cut line;
- downstream of said perforation and/or cut line;
- bridging said perforation and/or cut line.
Brief description of the drawings
[0029] Further characteristic and the advantages of the rewinding machine, according to
the invention, will be made clearer with the following description of an exemplary
embodiment thereof, exemplifying but not limitative, with reference to the attached
drawings, in which like reference characters designate the same or similar parts,
throughout the Figs. of which:
- Figures from 1 to 4 show diagrammatically elevational side views of a first succession
of steps through which the rewinding machine, according to the invention, is capable
of making logs of sheet or web material, for example used for the production of rolls
of toilet paper, rolls of all purpose tissue paper for household use, non woven fabric,
paper industrial rolls and the like;
- Figures from 5 to 7 show diagrammatically elevational side views of a succession of
steps alternative to that shown in Figs. from 2 to 4 wherein the rewinding machine,
according to the invention can work;
- Figures from 8 to 10 show diagrammatically elevational side views of a succession
of steps alternative to that shown in Figs. from 2 to 4 and to that shown in Figs.
from 5 to 7 where the rewinding machine can work, according to the invention;
- Figures from 11 to the 13 show three further exemplary embodiments of the rewinding
machine, according to the invention.
Description of a preferred exemplary embodiment
[0030] With reference to Fig. 1, a rewinding machine of a web 1 for making a log 2a comprises
a feeding roller 3 of web 1 and, downstream of it, a winding cradle 4 at which the
production is made of log 2a for winding the web of paper 1 about a core 20. The latter
is supplied into cradle 4 by suitable introduction means, for example a loading unit
that draws the cores 20 from a chute guide, not shown in the figure.
[0031] The cradle 4, according to the prior art, comprises a upper winding roller 5, a lower
winding roller 6 and a pressing roller 7. The latter follows the growth of the log
2 with the task of assuring its continuous contact with the winding rollers 5 and
6 controlling its diameter growth.
[0032] Upstream from the feeding roller a perforation roller 11 3 is provided that acts
in combination with a counter-roller 12 to provide a plurality of transversal perforation
lines 15 on the web of paper 1 defining a plurality of panels 16.
[0033] Among the feeding roller 3 and the upper winding roller 5, furthermore, a cutting
roller 10 can be provided. The latter can work in combination with the upper winding
roller 5 for carrying out a clean cut on the web of paper 1 whenever a number of panels
16 is obtained corresponding to a complete log. By cutting the web of paper 1 two
free ends are generated corresponding to the tail end 1a for log 2a formed and at
the head end 1b for log 2b.
[0034] If cutting roller 10 is not present, the separation of log 2a and 2b is made at determined
perforation lines 15. This is made regulating, as well known, the relative speed of
the winding rollers 5, 6 and 7. Even in this case, the separation made at the perforation
line 15 generates a tail end 1a for formed log 2a and a head end 1b for new log 2b.
[0035] According to the invention, upstream from the means for introducing the core 20 means
are provided 50 for application of a measured amount of glue 55 on a determined portion
of the web of paper 1.
[0036] The means for applying 50 can, for example, provide a screened roller 51 on which
a measured amount of glue is periodically spread by a spreading blade 56 for example
equipped with a duct 57 through which the glue is supplied.
[0037] Upstream from the feeding roller 3 means can be provided for measuring the unwinding
steps of the web of paper 1 starting from a large roll not shown in Fig. advantageously.
The latter is operatively connected to the means for perforation in order to operate
them to provide the perforation lines 15 at predetermined distances, by cutting roller
10, if it is present, to allow separating two consecutive logs, and with the means
for applying 50 in order to operate them for applying a determined amount of glue
at predetermined perforation lines 15.
[0038] More in detail, the means 50 for application are provided movable from a first position,
where the screened roller 51 is distant from the web of paper 1 (Fig. 1) to a second
position, where the roller 51 is next to the web of paper 1 for applying a layer of
glue 55 at predetermined portions of the web 1 (Fig. 2, 5, 8, 11, 12, 13). For example,
the screened roller 51 can be operated in the movement towards/away from the web of
paper 1 by a hydraulic, or pneumatic, or electric actuator.
[0039] In a first exemplary embodiment, shown in Figs. from 2 to 4, the layer of glue 55a
is mounted by the screened roller 51 only at portion 18 of the web of paper 1 arranged
downstream, to determine perforation lines 15'.
[0040] In particular, the perforation line 15' corresponds to the perforation line at which
the cutting roller 10 cuts the web of paper 1 separating it into the tail end 1a of
the formed log 2a and head end 1b of the new log 2b.
[0041] More in detail, the tail end 1a of the log 2a has the layer of glue 55a for stopping
the formed log 2a.
[0042] On cores 20 a layer of glue 53 can be previously applied, for example by a nozzle
sprayer 52 arranged between the feeding means of the core 20 and the cradle 4. In
this case, the core 2b with the layer of glue 53 is put into cradle 4 and then approached
to the web of paper 1 when the portion 17 arranged upstream from the perforation line
15' reaches it.
[0043] The approach of the core 2a to the web of paper 1 can be made, for example by a rotation
about axis 19 of the cradle 4 operated by an actuating rod 9.
[0044] In an alternative exemplary embodiment shown in Figs. from 5 to 7, the roller 51
applies the layer of glue 55 in the only portion 17 of the web of paper 1 arranged
upstream from the perforation line 15'.
[0045] The portion 17 of the web of paper 1 on which the layer of glue 55b is mounted corresponds,
in this case, to the head end 1b that is made by the cut carried out at the perforation
line 15' by the cutting roller 10 (Fig. 6).
[0046] In particular, the layer of glue 55b allows at the head end 1b sticking with core
20b put in cradle 4 when this approaches the winding roller 5, as described for the
previous case. This way, winding the web of paper 1 about core 20b is started forming
a new log 2b.
[0047] In this case, the tail end 1a of each log at the exit of the rewinding machine can
be then connected to the relative log by a gluing machine of traditional type arranged
downstream of the rewinding machine not shown in the figure.
[0048] According to the invention and diagrammatically shown in Figs. from 8 to 10, roller
51 can be also operated for applying a layer of glue 55 both on the portion 17 and
on the portion 18 of the web of paper 1 at the perforation lines 15'.
[0049] In this case, the roller 51 is firstly approached to the web of paper 1 at the portion
18 where a first layer of glue 55a is applied, then arranged according to the withdrawn
position 50a (dotted line) at the perforation line 15', and again approached to the
web of paper 1 at the portion 17 for applying a second layer of glue 55b. This way,
both the tail end 1a of the formed log 2a and the head end 1b of the new log 2b, obtained
by cutting the web of paper 1 through cutting roller 10 (Fig. 9), have respective
layers of glue 55a and 55b. This allows to glue both to the tail end of formed log
2a and the head end of the new log 2b, avoiding then the use of other gluing systems.
[0050] A same result, with possibility to use also a glue of different type, can be obtained
using two different screened rollers 51a and 51b, as diagrammatically shown in Fig.
11. In this case, for applying the glue 55 both on the portion 17 and on the portion
18 of the web of paper 1, it is enough to operate at the same time the screened rollers
51a and 51b working in corresponding positions of the rewinding machine, or operating
only one in two consecutive instants.
[0051] A similar result can be also obtained with the further exemplary embodiment shown
in Fig. 12. In this case, the roller 51 applies the layer of glue 55 bridging the
perforation lines 15. Even in this case it is possible to stop both the tail end 1a
on the formed log 2a and starting winding the new log 2b on the core 20b by sticking
it with the head end 1b.
[0052] Finally, in Fig. 13 an exemplary embodiment is shown that provides arranging the
screened roller 51 at the cradle 4. As shown in figure, the layer of glue 55 can be
mounted by roller 51 downstream of the perforation line 15.
[0053] The rewinding machine above described, assists remarkably the production process
for the log of paper. In fact, it avoids the need of using expensive and bulky gluing
machines usually arranged downstream of and upstream from the machine to provide respectively
the application of glue on the cores and on the end portions of the formed log.
[0054] Furthermore, it reduces remarkably with respect to the prior art rewinding machines
residues of glue that can enter between the mechanical moving parts jeopardizing the
correct operation and causing necessary maintenance stops to avoid damaging the same.
[0055] The foregoing description of a specific embodiment will so fully reveal the invention
according to the conceptual point of view, so that others, by applying current knowledge,
will be able to modify and/or adapt for various applications such an embodiment without
further research and without parting from the invention, and it is therefore to be
understood that such adaptations and modifications will have to be considered as equivalent
to the specific embodiment. The means and the materials to realise the different functions
described herein could have a different nature without, for this reason, departing
from the field of the invention. It is to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of limitation.
1. A rewinding machine for making logs of sheet or web material, for the production of
rolls of toilet paper, rolls of all purpose tissue paper for household use, non woven
fabric, paper industrial rolls and the like, comprising:
- means for feeding said web of paper along a feeding direction;
- means for perforating and/or cutting said web of paper adapted to make transversal
perforation lines and/or clean cuts on said sheet, or web, of paper;
- a winding cradle arranged downstream of said feeding means where said log is made
by winding said web of paper about a core;
- means for introducing said core into said winding cradle;
- means for cutting or tearing the web making a formed log tail end and a head end
of the new log,
- means for removing the formed log,
characterised in that it comprises, furthermore:
- means for applying a measured amount of glue on a predetermined portion of said
web of paper, said means for applying being arranged upstream from said means for
introducing said core.
2. Rewinding machine, according to claim 1, wherein said measured amount of glue is application
said sheet, or web, of paper at least at one of the following web zones:
- upstream from said perforation and/or cut line, whereby it is possible to close
said web of paper on said formed log;
- downstream of said perforation and/or cut line, whereby it is possible to stick
said tail end on the core of the new log;
- bridging said perforation and/or cut line, whereby with a single glue application
it is possible to cause both closing of said web of paper on said formed log and the
sticking of said tail end on the core of the new log.
3. Rewinding machine, according to claim 1, wherein means are provided for measuring
the length of said web starting from a large roll of paper, said means for measuring
driving said means for applying a measured amount of glue to achieve a measured length
of said web of paper.
4. Rewinding machine, according to claim 1, wherein said means for applying are movable
towards/away from said web of paper operated by an actuator selected from the group
comprised of:
- a pneumatic actuator;
- a electric actuator;
- a hydraulic actuator.
5. Rewinding machine for making logs of sheet or web material, for the production of
rolls of toilet paper, rolls of all purpose tissue paper for household use, non woven
fabric, paper industrial rolls and the like, comprising:
- feeding means a web of paper along a feeding direction;
- means for perforating and/or cutting said sheet, or web, of paper adapted to make
transversal perforation lines and/or clean cuts on said sheet, or web, of paper;
- a winding cradle downstream of said feeding means where said log is made by winding
said web of paper about a core;
- means for introducing said core into said winding cradle;
- means for applying a measured amount of glue on a predetermined portion of said
sheet, or web, of paper,
characterised in that:
- said means for applying comprises a single application element adapted to apply
said measured amount of glue upstream from and/or downstream of, or bridging, said
transversal perforation and/or clean cut lines.
6. Method for winding a sheet, or web, for making logs of sheet or web material, for
the production of rolls of toilet paper, rolls of all purpose tissue paper for household
use, non woven fabric, paper industrial rolls and the like, comprising the steps of:
- feeding said sheet, or web, of paper along a feeding direction;
- winding said web of paper about a core at a winding cradle;
- cutting or tearing the web making a formed log tail end and a head end of a new
log;
- introducing a core into said winding cradle, starting winding the new log, removing
the formed log.
characterised in that of providing, furthermore, the step of:
- applying a measured amount of glue on a portion of said sheet, or web, of paper,
said application being carried out in a zone arranged upstream from an introducing
zone of said core into said winding cradle.
7. Winding method, according to claim 6, wherein said application of said measured amount
of glue on a portion of said sheet, or web, of paper is made in at least one among
the following web zones:
- upstream from said perforation and/or cut line, said application allowing to provide,
after a separation, closing said web of paper on said formed log;
- downstream of said perforation and/or cut line, said application allowing to provide,
after a separation, the sticking of said tail end on the core of the new log;
- bridging said perforation and/or cut line, said application allowing to provide,
after a separation, closing said web of paper on said formed log and the at the same
time sticking of said tail end on the core of the new log.
8. Method for winding a sheet, or web, for making logs of sheet or web material, for
the production of rolls of toilet paper, rolls of all purpose tissue paper for household
use, non woven fabric, paper industrial rolls and the like, comprising the steps of:
- feeding said sheet, or web, of paper along a feeding direction;
- winding said web of paper about a core at a winding cradle;
- applying a measured amount of glue on said web of paper;
- cutting or tearing the web making a formed log tail end and a head end of a new
log;
- introducing a core into said winding cradle, starting winding the new log, removing
the formed log;
- characterised in that
said application is made at said winding cradle owing to a single application element
that spreads said measured amount of glue in at least one of the following portions
of said web of paper:
- upstream from said perforation and/or cut line;
- downstream of said perforation and/or cut line;
- bridging said perforation and/or cut line. 1.