WO2014102685A2

WO2014102685A2 - A gluing device for a roll of a wound web material

Info

Publication number: WO2014102685A2
Application number: PCT/IB2013/061199
Authority: WO
Inventors: Giuseppe Mazzotti; Renato Albino DEL MONTE; Dario DAL CANTO
Original assignee: Maflex S.R.L.
Priority date: 2012-12-24
Filing date: 2013-12-20
Publication date: 2014-07-03
Also published as: WO2014102685A3; ITPI20120118A1

Abstract

A device (100) for gluing the tail end of a log (30) of a wound web material comprises an introduction means (10) for introducing the log (30) into the device (100) and a glue dispenser (140) arranged to supply glue to the log (30) along a longitudinal line (s) of the log (30). The dispenser (140) comprises in turn a gluing element (143) which is wet of glue and is arranged to cause the log (30) to move on the gluing element (143) and to become wet of glue along said line (s). The dispenser (140) also comprises a movable glue container (141) that has a translational vertical degree of freedom, and that is configured to carry out an oscillation, at a predetermined frequency, between a raised position, where the glue present in the container (141) submerges the gluing element (143), and a lowered position, where the glue present in the container (141) uncovers the gluing element (143) and the log (30) can roll on said gluing element (143) for becoming wet of glue along said line (s).

Description

TITLE

A GLUING DEVICE FOR A ROLL OF A WOUND WEB MATERIAL

DESCRIPTION

Field of the invention The present invention relates to a device for applying glue to a roll of a wound web material, such as a roll or log of toilet paper or kitchen paper.

In particular, the invention relates to a glue dispenser of such a device, for gluing the tail end of a roll, or for gluing a winding core before introducing it into a rewinding machine for making a roll or log of paper.

Background of the invention

In the paper industry, the use is known of rewinding machines that, starting from at least one big roll of paper, make logs of smaller diameter, i.e. of a diameter as large as the diameter of the end-user product, such as rolls of toilet paper, of kitchen paper and the like. Afterwards, these logs are cut perpendicularly to their axis into rolls to be packaged and sold.

Gluing devices are currently known, as described in EP

US5242525 or in EP0699168.

US5242525 describes a paper log gluing system for gluing the tail end of a log a web material, comprising a log conveying means for moving the log, a log unwinding means for unwinding the tail end of the web material when the log is in an unwinding position; a glue dispenser, for applying the glue to the log, that is located downstream of of the unwinding position; and a rewinding means for rewinding the tail end after applying the glue. The dispenser includes a fixed portion that protrudes from the rolling plane for the log and that has an upward-oriented slit through which the glue is dispensed. This protruding fixed portion belongs to a glue container and the glue is pushed towards the upward-oriented slit. This way, the glue is dispensed to the log when the log passes at the slit.

In EP0699168, the glue dispenser includes a fixed glue container that has an upward-oriented slit, and a movable element located 'within the container, which is soaked in the glue present in the container and that is pushed through the slit so as to protrude out in order to apply the glue to the log when the latter passes at the slit and touches the glue- carrying protruding movable element.

However, the latter solution is affected by some technical drawbacks. In particular, since the gluing element is movable, the same must be structurally light, with the drawback of having low flexural strength when bearing the weight of the log. Moreover, due to the movement of this element, a precise mutual position of the elements involved in the movement cannot be maintained for a long time, which causes these elements to lose their alignment and gives rise to backlash not provided for by the design.

Moreover, the apparatus of EP0699168 may lead to an unsatisfatory gluing when light logs are treated, since the movement of the gluing element can displace the log itself with respect to a prefixed trajectory, so that a less precise gluing line is obtained on the log. A further drawback of both US5242525 and EP0699168 depends upon a tendency of the glue contained in the fixed container to settle, which requires a stirrer to continuously stirs to keep the glue fluid. Obviously, such a stirrer increases both the cost and the maintenance of the dispenser .

Summary of the invention

It is therefore a feature of the present invention to provide a gluing device that overcomes the above-described technical drawbacks.

This and other objects are achieved by a device for gluing the tail end of a log of a wound web material, comprising :

- an introduction means for introducing the log into the device;

- a glue dispenser arranged to supply glue to the log along a longitudinal line (s) of the log;

wherein the dispenser comprises a gluing element which is wet of glue and is arranged to cause the log to move on the gluing element and to become wet of glue along the line (s) ;

whose characteristic is that the gluing element does not translate vertically and that said dispenser also comprises a movable glue container having a translational vertical degree of freedom.

Such container is configured to carry out an oscillation, at a predetermined frequency, between a raised position, where the glue present in the container submerges the gluing element, and a lowered position, where the glue present in the container uncovers the gluing element and the log can roll on the gluing element for becoming wet of glue along the line.

This way, thanks to the container that oscillates in the raised position, the gluing element is fully arranged in the container and, when the container moves to the lowered position, the gluing element, which is wet of fresh glue, is ready to receive the incoming log and to wet it with glue.

Advantageously, the gluing element is fixed, according to both a translational degree of freedom and a rotational degree of freedom.

This solution presents many advantages with respect to the prior art. In particular, since the gluing element is fixed, it can be made of a stiff material and then resistant to bending, so that it does not deform when the log strikes on it, while the glue is applied. Moreover, since the gluing element is fixed, it does not suffer from backlash and does not leave the prefixed position where it was initially located, in such a way that misalignment and clearances are unlikely with respect to the surrounding elements, avoiding the risk of worsening the quality and the precision of the glue line (s) .

In addition, a movable glue container prevents the glue from settling on the bottom thereof, which would otherwise require a stirrer for continuously stirring the glue. The continuous oscillation movement causes the glue to move continuously, and makes a stirrer unnecessary.

Advantageously, the introduction means comprises a loading table from which the log is introduced into the device .

In particular, the introduction means also comprises:

- a tilter arranged to bring the log from the loading table to the glue dispenser by a rotation of a predetermined amplitude about a rotation axis;

- at least one pneumatic cylinder arranged to cause the above-described rotation of a predetermined amplitude of the tilter about its rotation axis.

Advantageously, the device also comprises an upper roller and a lower roller that are moved mechanically, and that are arranged to constrain and to cause the rotation of the log, in order to unwind a wing portion from the log itself. The upper roller is also mounted to a rotating arm arranged to adjust the distance between the upper roller and the lower roller, so that the two upper and lower rollers can support and displace logs of different diameters and, moreover, the log can be disengaged from such rollers once the unwinding of the log portion has been accomplished and the log can be laid onto the glue dispenser.

As an alternative, two lower rollers may be provided that are mechanically moved and are fixed on their own axes, and are also arranged to cause the rotation of the log. This solution is less expensive than the solution providing a lower roller and an upper roller, since no rotating arms are required for adjustment of the device to different log diameters .

In particular, the device also comprises at least one pneumatic nozzle arranged to assist unwinding the wing portion from the log, exploiting the rotation applied to the log itself by the upper roller and the lower roller.

Advantageously, the device also comprises a suction device arranged to introduce and to capture the unwound wing portion in a suction chamber applying a suction force of a predetermined intensity.

In particular, the oscillation at a predetermined frequency is generated by a mechanism selected from the group consisting of:

— a crank mechanism;

— a cam mechanism;

— a linear actuator.

Advantageously, the device also comprises at least one exit table arranged to allow the log to roll about iself owing to the rotational movement received from the above- described rollers, so that the log is discharged from the device and, at the same time, rewinds the wing portion, against the suction force, and causes the wing portion to adhere to the zone where the glue has been previously dispensed.

In particular, the device also comprises at least one driven belt arranged to keep the rotational movement received by the log from the above-described rollers.

Advantageously, the movable glue container, in addition to the translational vertical degree of freedom, also has a translational horizontal degree of freedom, in such a way that the movable glue container can carry out an oscillation according to a combination of said degrees of freedom. In particular, the movable glue container can carry out a linear and/or elliptical trajectory, in order to improve the mixing of the glue in the movable container, further reducing a troublesome glue settling at the bottom.

Advantageously, the gluing element comprises a first head and at least one second head arranged to selectively come into contact with the log, in order to wet the log itself with glue at the line (s) . In particular, the first and the second heads are configured to provide a contact surface of different sizes, in order to apply to the log a predetermined required amount of glue. For instance, the first head may be thicker than the second head, in order to increase the thickness of the strip of glue laid on the line (s) .

The invention also provides the use of a plurality of small heads, each of a different size, in order to adjust the glue thickness along the line s.

In particular, the first head and the second head are adapted to rotate about a centre of rotation of the gluing element, in order to move from a first configuration, where the log can roll on the first head, to a second configuration, where the log can roll on the second head.

Advantageously, four small heads are provided, each having a different thickness, which are angularly spaced by 90° about the centre of rotation.

Advantageously, an optical sensor is provided, such as a photocell, that is configured to detect the presence of the unwound wing portion in the suction chamber, in such a way that the suction device blocks the suction force as soon as this detection occurs. This way, the wing is prevented from being damaged or torn in the suction chamber by the suction force.

Brief description of the drawings

Further features and/or advantages of the device for gluing a log of wound web material, according to the present 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:

- Fig. 1 shows the gluing device in a first exemplary embodiment, highlighting both the positions (in a continuous line and in a dashed line, respectively) of the container of glue, for the sake of clearness;

- Fig. 2 shows a roll, or log, of wound web material, highlighting the gluing line s and the unwound wing portion;

- Figs. 3A, 3B, 3C and 3D show subsequent working steps of the gluing device, in the exemplary embodiment of Fig. 1;

- Fig. 4 shows an exemplary embodiment of the device, in which, while unwinding, the wing portion is unwound but remains upstream of the log;

- Fig. 5 shows a preferred exemplary embodiment of the gluing device, comprising complementary elements for the exemplary embodiment of Fig. 1;

- Fig. 6 shows a first possible exemplary embodiment of the actuation mechanism of the movable glue container; - Fig. 7 shows a second possible exemplary embodiment of the actuation mechanism of the movable glue container;

- Fig. 8 shows a preferred exemplary embodiment of the gluing device, where the gluing element comprises four small heads;

- Fig. 8B is an enlarged view of a detail of Fig. 8. Description of a preferred exemplary embodiment

With reference to Fig. 1, a device 100 for gluing the tail end of a log 30 of a wound web material comprises a glue dispenser 140 and an introduction means 110 for log 30.

In particular, glue dispenser 140 comprises a movable glue container 141 that has a translational vertical degree of freedom, to carry out an oscillation at a predetermined frequency. Movable glue container 141 has an upward oriented slit 142, from which a gluing element 143 protrudes periodically.

More in detail, whenever a log 30 rolls at slit 142, movable container 141 is moved towards below, and gluing element 143 protrudes from this slit 142 for laying a strip of glue s onto roll 30, in particular at the zone from which a wing portion 31 has been previously unwound (Fig. 2).

Introduction means 110, in an exemplary embodiment of Fig. 1, comprises a loading table 111 arranged to cause log 30 to be placed proximate to glue dispenser 140.

Subsequent steps of the operation of device 100 are shown in Figs. 3A, 3B, 3C and 3D.

In a first step (Fig. 3A) , a log 30 rolls on loading table 111 and comes in a proximity of glue dispenser 140. At this point (Fig. 3B) , a wing portion 31 is unwound and is inserted between loading table 111 and movable glue container 141. At the same time, movable glue container 141 vertically translates downwards, and causes gluing element 143 to protrude. The latter, which is wet of glue, comes into contact with log 30 at the area at which wing portion 31 was unwound, and dispenses the glue along a strip s (Fig. 3C) . Finally (Fig. 3D) , log 30 continues to roll downstream while rewinding wing portion 31 about itself, so that the wing portion adheres onto strip s, and is stuck onto roll 30. In the meantime, gluing element 143 translates upwards again, and a new log 30 is introduced by loading table 111.

An exemplary embodiment of the device is shown In Fig. 4, while carrying out an unwinding step in which wing portion 31 is unwound from log 30, like in Fig. 3B. As an alternative to the step of Fig. 3B, in this exemplary embodiment wing portion 31 is unwound and remains upstream of log 30. Wing portion 31, like in Figs. 3C and 3D, will be rewound about log 30 by adhering onto strip s.

With reference to Fig. 5, in a preferred exemplary embodiment, device 100 also comprises:

- a tilter 112 that is arranged to move log 30 from loading table 111 towards movable container 141, by a rotation of a predetermined amplitude about a rotation axis σ;

- a pneumatic cylinder 113 arranged to cause tilter 111 to rotate by a predetermined amplitude about its own axis an upper roller 121 and a lower roller 122 that are moved mechanically and that are arranged to constrain log 30 and to cause it to rotate;

a rotating arm 123, to which upper roller 121 is mounted and that is configured to adjust the distance between two rollers 121,122, so that they can support and displace logs 30 of different diameters. Moreover, due to arm 123, log 30 can be disengaged from rollers 121,122 once log portion 31 has been unwound, so that the log can be laid on slit 142;

a pneumatic nozzle 124 arranged to unwind wing portion 31 from log 30, exploiting the rotation of log 30 caused by rollers 121,122;

a suction device 130 arranged to capture and to keep unwound wing portion 31 in a suction chamber 131. Suction device 130 is adjusted to apply a predetermined suction force, that can be overcome when rewinding log 30, without tearing portion 31;

an electric motor 145 and a crank mechanism 146 arranged to generate the oscillation at a predetermined frequency, to move container 143;

an exit table 151 arranged to allow log 30 to roll about itself due to the rotation movement caused by rollers 121,122. This way, log 30 can be discharged from device 100 and, at the same time, can receive wing portion 31 rewound about itself, exceeding the force of suction device 130, and causing wing portion 31 to adhere on line s .

a driven belt 152 that makes it possible to maintain the rotational movement of log 30, caused by rollers 121,122.

In Figs. 6 and 7 two exemplary embodiments are shown, as an alternative to Fig. 5, of the actuation mechanism of glue container 141.

In particular, in Fig. 6 this mechanism comprises a cam mechanism 161, while in Fig. 7 it comprises a linear actuator.

With reference to Figs. 8 and 8B, a preferred exemplary embodiment of the gluing device, provides a gluing element 143 comprising four small heads 144a, 144b, 144c, 144d that are angularly spaced by 90° with respect to one another, that are hinged about a centre of rotation 145. In particular, small heads 144a, 144b, 144c, 144d have a thickness different from one another.

This way, when movable container 141 is in the raised position (dotted line of Fig. 8), the small heads 144a, 144b, 144c, 144d can be put into rotation so that the head of a desired thickness can be brought to the upper position, in order to adjust the thickness of glue line s laid onto roll 30, as desired.

The foregoing description of a specific exemplary 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 in various applications the specific exemplary embodiments without further research and without parting from the invention and, accordingly, it is meant 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.

Claims

A device (100) for gluing the tail end of a log (30) of a wound web material, comprising:

- an introduction means (10) for introducing said log (30) into said device (100) ;

— a glue dispenser (140) arranged to supply glue to said log (30) along a longitudinal line (s) of said log (30);

wherein said dispenser (140) comprises a gluing element (143) which is wet of glue and is arranged to cause said log (30) to move on said gluing element (143) and to become wet of glue along said line (s) ;

characterized in that said gluing element (143) does not translate vertically and said dispenser (140) also comprises a movable glue container (141) having a translational vertical degree of freedom, and configured to carry out an oscillation, at a predetermined frequency, between a raised position, where the glue present in said container (141) submerges said gluing element (143) , and a lowered position, where the glue present in said container (141) uncovers said gluing element (143) and said log (30) can roll on said gluing element (143) for becoming wet of glue along said line (s) .

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, wherein said introduction means (110) comprises a loading table (111) from which said log (30) is put into said device (100) .

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 2, wherein said introduction means (110) also comprises:

— a tilter (112) arranged to bring said log (30) from said loading table (111) to said glue dispenser (140) by a rotation of a predetermined amplitude about a rotation axis ;

- at least one pneumatic cylinder (113) arranged to cause said rotation of a predetermined amplitude of said tilter (111) about said axis.

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, said device (100) also comprising an upper roller (121) and a lower roller (122) that are moved mechanically and that are arranged to constrain and to cause the rotation of said log (30), in order to unwind a wing portion (31) from said log (30), said upper roller (121) mounted to a rotating arm (123) , said rotating arm (123) arranged to adjust the distance between said upper roller (121) and said lower roller (122), so that said upper and lower rollers (121,122) can support and displace logs (30) of different diameters, and so that said log (30) is disengaged from said upper and lower rollers (121,122) once the unwinding of said winding portion has been accomplished (31), and can be laid onto said glue dispenser (140) .

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 4, said device (100) also comprising at least one pneumatic nozzle (124) arranged to assist unwinding said wing portion (31) from said log (30), exploiting the rotation applied to said log (30) from said upper (121) and lower (122) rollers.

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 4, said device (100) also comprising a suction device (130) arranged to introduce and to keep said unwound wing portion (31) in a suction chamber (131), said suction device (130) calibrated for applying a suction force of a predetermined intensity.

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, wherein said oscillation at a predetermined frequency is generated by a mechanism selected from the group consisting of:

- a crank mechanism (160) ;

- a cam mechanism (161);

- a linear actuator (162) .

The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, said device (100) also comprising at least one exit table (151) arranged to allow the log (30) to roll on iself owing to the rotational movement given to said log (30) by said rollers (121,122), so that said log (30) is discharged from said device (100) and, at the same time, rewinds said wing portion (31), against said suction force, and causes said wing portion (31) to adhere on the zone where the glue has been previously dispensed.

9. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 8, said device (100) also comprising at least one driven belt (152) arranged to keep the rotational movement received by said log (30) from said rollers (121,122).

10. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, wherein said gluing element (143) is fixed.

11. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, wherein said movable glue container (141), in addition to said translational vertical degree of freedom, also has a translational horizontal degree of freedom, in such a way that said movable glue container (141) can carry out an - oscillation according to a combination of said degrees of freedom.

12. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 1, wherein said gluing element (143) comprises a first head (144a) and at least one second head (144b) arranged to selectively come into contact with said log (30) so as to wet said log with glue (30) at said line (s) , said first and said second head (144b) configured to have a contact surface of different sizes, in order to apply on said log (30) a predetermined required amount of glue.

13. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 12, wherein said first head (144a) and said second head (144b) are adapted to rotate about a centre of rotation (145) of said gluing element (143), in order to move from a first configuration, in which said log (30) can roll on said first head (144a) , to a second configuration, in which said log (30) can roll on said second head (144b) .

14. The device (100) for gluing the tail end of a log (30) of a wound web material, according to claim 6, wherein an optical sensor is provided configured to detect the presence of said unwound wing portion (31) within said suction chamber (131), said suction device (130) arranged to stop said suction force as soon as said detection of said unwound wing portion (31) within said suction chamber (131) occurs.