US20100237179A1

US20100237179A1 - Rewinding method and rewinding machine that carries out this method

Info

Publication number: US20100237179A1
Application number: US12/679,532
Authority: US
Inventors: Alessandro De Matteis
Original assignee: MTC Macchine Trasformazione Carta SRL
Current assignee: MTC Macchine Trasformazione Carta SRL
Priority date: 2007-10-02
Filing date: 2008-10-02
Publication date: 2010-09-23
Also published as: EP2045201A1; EP2205513B1; WO2009044264A3; WO2009044264A2; EP2205513A2; ES2430845T3

Abstract

Rewinding method and rewinding machine of a paper web (1) for making a log (2 a) comprising a feed roller (3) for feeding the web (1) and a winding cradle (4) in which a log (2 a) is formed winding the paper web (1) about a core (20). The latter is supplied into the cradle (4) by introduction means by a loading unit that draws the cores (20) from a chute guide. Upstream from the feed roller (3) a perforation roller (11) is provided that acts in combination with a counter-roller (12) to make a plurality of transversal tear lines (15′) on the paper web (1) forming a plurality of panels (16) connected to each other united by the tear line. Upstream from the means for introducing the core (20), furthermore, a gluing means is provided (50) for application of a measured amount of glue (55) on a determined portion of the paper web (1), in particular upstream from (Ia), down-stream of (Ib), or bridging the tear line or clean cut (15). Such lines are made by cutting means, which make either a tear line or clean cut (10″), in coincidence or direct vicinity with the gluing means for applying the glue (50, 10′). The gluing means (50) can, for example, provide a pad (10′) that receives the glue by a gluing roller (51).

Description

FIELD OF THE INVENTION

The present invention relates to an improved rewinding method for making logs of paper from a paper web and that is used, for example, 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.
Furthermore the invention relates to an improved rewinding machine that carries out this method.

BACKGROUND OF THE INVENTION

Rewinding machines are known where the winding step takes place in a special winding zone that comprises an upper roller, a lower roller and a pressing roller.
In particular, in EP1232980 a core of cardboard, which is located on a special movable support cradle, is brought into contact with the upper winding roller and is therefore dragged into a winding zone, wherein glue is previously spread on the surface of the tubular core, to let the paper web to remain stuck to the core and start winding the log.
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, which spray a measured amount of glue on the core before that it enters the movable cradle and start winding. Other devices can be also used, such as glue distributing brushes or blades.
Once the log has achieved the predetermined diameter a cutting step follows of the paper web along special tear lines. 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 speed, about which the paper web adheres causing therefore the paper to be torn. A further increase of rotation speed difference, between lower roller and pressure roller, causes then the exit of the formed roll.
In other machines, a special cutting blade creates a clean separation cut of the web without any need of auxiliary devices such as the separation finger above described.
Always as described in EP1232980 a core, previously sprayed with glue, is brought into contact with the upper winding roller and therefore with the paper web head that was just obtained from the previous cutting or tearing step of the web same, thus starting to wind a new log contemporaneously to the exit of the final log.
However, such glue distribution systems have relevant drawbacks concerning the final quality of the products. In particular, the amount of glue sprayed on the tubular cardboard core can be too much so that iy risks to soak too much the paper web during the contact of the core with the roller. Furthermore, this contact dirties the winding roller and can cause the paper to stick on the upper roller instead of the core. Furthermore, in case of a delay of the new core with glue entering the winding zone, the glue can dry loosing its effect. This would cause a maintenance stop of the machine for removing the core and putting in a new one, with loss of time and reduced production rate.
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 various, and in any case an additional gluing section of the machine is needed. For example, by specially oriented air 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 end of the log, create relevant problems.
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 them.
In U.S. Pat. No. 7,175,126 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.
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 spread 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 very reliable, since a slip of the core and therefore a subsequent loss of rotational speed of the core determines an incorrect distribution of the glue causing, for example, the free end not to stick to the roll, or in particular, a faulty start of the new winding cycle.
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 position 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 and obliging a maintenance stop. This causes loss of time with reduced production rate and increase of costs.
It is known, furthermore, from EP1702873, a rewinding machine with a gluing device, having a core introduction system, a paper cutting system, and a system to close the exiting log and to engage a new the core with the paper to start a new log. The gluing device is similar to a printing unit, by a printing roller that receives the glue from a transfer roller, which is associated to a glue supplier, and that transfers the glue on the paper passing on a support roller. This way, on the paper a pattern of glue can be transferred of whichever shape. Furthermore, since the printing roller is an actual printer, it is possible that the roller prints on the paper desired signs, transferred on the roller print by printing means. The glue can be colored in order to highlight the printed signs.

SUMMARY OF THE INVENTION

It is therefore a feature of the present invention to provide an improved rewinding machine that allows the distribution of glue near the tear line or clean cut line in an effective way for completing a log and starting a new one.
It is also a feature of the present invention to obtain a log of paper having high quality to minimize the waste and the time for maintenance stop.
It is another feature of the present invention to provide an improved rewinding machine that assists remarkably the production process for the log of paper simplifying the structure of the machine with respect to the machines of the prior art.
It is, furthermore, a feature of the present invention to provide an improved rewinding machine that substantially prevents residual glue from entering between mechanical moving parts of the machine, thus jeopardizing a correct operation and damaging the machine, as it may occur in the rewinding machines of prior art.
These and other objects are achieved by an improved 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 for feeding said paper web along a feeding direction;
- means for making a transversal division line in the paper web between a tail end of the log just formed and a head end for a new log being formed;
- start up means for starting the production of a new log;
- a winding cradle downstream of said start up means in which said log grows for winding of said paper web up to obtaining a formed log;
- moving means for moving said formed log;
- gluing means for applying glue on a predetermined portion of said paper web, said gluing means arranged upstream from said start up means;
  wherein said gluing means and said means for making a transversal division line are arranged in coincidence with each other on a support roller so that said means for making a transversal division line create said division line and at the same time said gluing means applies a measured amount of glue near said line.

Advantageously, said means for making a transversal division line in the paper web are selected from the group comprised of:

- means for making a clean cut on the paper web;
- means for perforating the paper web that is eventually torn near said start up means;
- means for tearing the paper web adapted to tear the paper at a tear line previously made on said web;

In particular said start up means comprises means for introducing a core in said winding cradle.
Advantageously, said gluing means and said means for making a transversal division line are arranged in coincidence with each other in order to apply the measured amount of glue bridging said line.
This way, when separating the formed log from the new log to be formed, both the tail end of the formed log and the head end of the new log comprise points spread of glue. Therefore, it is possible to carry out in a single step the cut and the application of the glue, both for closing the tail end on the formed log, and for causing the head end to stick on a core and start winding a new log.
Alternatively, said gluing means and said means for making a transversal division line are arranged in coincidence with each other in such a way to apply the measured amount of glue downstream of said line.
In this case, the measured amount of glue is applied only downstream of the tear or clean cut transversal line, i.e. on the portion of the paper web corresponding to the tail end of the formed log, to eventually cause said tail end to stick on said formed log, without the need of an auxiliary gluing machine to apply glue on the tail of the log.
Further alternatively, said gluing means and said means for making a transversal division line are arranged in coincidence with each other in order to apply the measured amount of glue upstream from said line.
In this case, instead, the measured amount of glue is applied only upstream from the tear or clean cut transversal line, i.e. on the portion of the paper web corresponding to the head end of the log being formed, and the head end is caused to stick on a core to start winding a new log without the need of an auxiliary gluing step in the cradle, when introducing the core or beforehand on the core same.
It is possible that the measured amount of glue is applied in a selective way only either upstream, or only downstream, or bridging the tear or clean cut transversal line, i.e. on the portion of the paper web corresponding only to either the tail end of the formed log or the head end of the log being formed or both portions.
Advantageously, means are provided for measuring the unwound length of said web from a paper roll, said means for measuring providing a signal for driving said gluing means when a measured length of paper web has been unwound.
In particular said gluing means and said means for making a transversal division line, in particular a blade, are movable towards/away from said paper web operated by an actuator selected from the group comprised of:
a pneumatic actuator;

- an electric actuator;
- a hydraulic actuator.

In the many cases of actuation, the actuator is advantageously of cam type, and can be selected from the group comprised of: a single actuator for said pad and said blade, with a delayed actuation of the blade with respect to the actuation of the pad; two independent actuators for both the blade and the pad. In particular in the presence of two pads, that are arranged respectively one upstream and one downstream of the blade, they can comprise a single actuator, in order to apply the glue on both sides of the blade, or two independent actuators, in order to apply the glue either upstream, or downstream, or bridging the blade in a selective way.
In this case, program means can be provided for activating selectively said actuators.
In an alternative embodiment of the present invention, an improved rewinding machine of a paper web for making a log, in particular for making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial rolls and the like, comprises:

- feeding means for feeding said paper web along a feeding direction;
- means for making a clean cut or a tear line in the paper web between a tail end of the log just formed and a head end for a new log being formed;
- start up means for starting the production of a new log;
- a winding cradle that is arranged downstream of said start up means in which said log grows by winding said paper web up to obtaining a formed log;
- means for removing said formed log;
- gluing means for applying glue on a predetermined portion of said paper web, said gluing means arranged upstream from said start up means;
- wherein said gluing means and said means for making a clean cut or a tear line are arranged in a direct succession to each other on respective support rollers so that said gluing means applies a measured amount of glue near a division zone of said web and said means for making a clean cut or a tear line immediately after or immediately before said application of the glue make a clean cut or a tear line on said division zone.

Advantageously, the measured amount of glue is applied in a selective way by said gluing means so that when a clean cut is made said glue is applied only either upstream, or only downstream, or bridging the clean cut transversal line, i.e. on the portion of the paper web corresponding to either the tail end of the formed log or the head end of the log being formed or both portions.
According to another aspect of the invention, a method for winding a paper web for making a log, in particular for making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial rolls and the like, comprises the steps of:

- feeding said paper web along a feeding direction;
- starting the production of a new log;
- winding said paper web at a winding cradle up to obtaining a formed log;
- creating a transversal division line in the paper web between a tail end of the formed log and a head end for a new log along a transversal line of said web;
- applying a measured amount of glue on a predetermined portion of said paper web, said step of applying glue being made previously to said step of starting a new log in said winding cradle;
- removing said formed log;
  wherein said step of application of a measured amount of glue and said step of creating a division line are made in coincidence to each other to make said transversal division line and at the same time to execute said application of a measured amount of glue near said line.

Advantageously, said step of application of said measured amount of glue on a portion of said web is carried out on at least one among the following portions:

- downstream of said tear line or clean cut line, in order to eventually cause said tail end to stick on said formed log;
- upstream from said tear line or clean cut line, in order to cause said head end to stick on a core and start winding a new log;
- bridging said tear line or clean cut line, in order to eventually cause said tail end to stick on said formed log and the at the same time cause said head end to stick on a core and start winding a new log.

In particular said step of starting the production of a new log comprises a step of introducing a core in said winding cradle.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristic and the advantages of the improved 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 designed the same or similar parts, throughout the figures of which:

FIGS. 1 to 5 show diagrammatically elevational side views of a first succession of steps through which the improved rewinding machine, according to the invention, is capable of making a log through cutting and gluing operations made contemporaneously;

FIG. 5′ shows a cross sectional view of an actuating device that moves the cutting blade;

FIG. 5″ shows a diagrammatical view of an actuating mechanism that operates the two pads for application of the glue contemporaneously to, the step of creating a division line;

FIGS. 6 to 10 show diagrammatically elevational side views of an alternative succession of steps through which the rewinding machine, according to the invention, is capable of making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial rolls and the like;

FIGS. 11 to 13 show diagrammatically elevational side views of a further succession of steps of the production process that use a different gluing and cutting system;

FIGS. 14 to 15 show diagrammatically elevational side views of a succession of steps where the formed log, once separated from the head end, is going to leave the winding process and the new core enters the winding cradle;

FIGS. 16 to 18 show three further exemplary embodiments of the rewinding machine with different cutting and gluing steps that are carried out not contemporaneously to each other.

DESCRIPTION OF A PREFERRED EXEMPLARY EMBODIMENT

With reference to FIGS. 1 to 5, a rewinding apparatus machine of a paper web 1 for making a log 2 a comprises a feed roller 3 of web 1 and, downstream of it, a winding cradle 4, in which the production of log 2 a is carried out for winding web 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 figures. Alternatively, in a way not shown but known to a skilled person, a log can be formed without a core. In this case, the web is wound on itself to start forming a new log that then is wound in cradle 4.
Cradle 4, according to the prior art, comprises a upper winding roller 5, a lower winding roller 6 and a pressure roller 7, which follows the growth of log 2 a with the object of assuring its continuous contact with winding rollers 5 and 6, for controlling its progressive diameter growth.
Upstream from feed roller 3, instead, a perforation roller 11 is mounted that acts in combination with a counter-roller 12, to provide a plurality of transversal tear lines 15′ on paper web 1 such that a user can separate it into a plurality of panels 16.
Furthermore, between feed roller 3 and upper winding roller 5 a gluing device is provided, in particular a double pad 10′ arranged bridging a cutting blade 10″, and is mounted in coincidence on a support roller 10 so that, when cutting blade 10″ is moved, at the same time gluing device 10′ works, applying a predetermined amount of glue either upstream, or downstream, or bridging a new tear or clean cut transversal line 15 caused by blade 10″. A detailed description of the actuating device of pads 10′ and of blade 10″ is made with reference to FIG. 5′, which represents a cross sectional view thereof.
Instead of cutting blade 10″, a perforating blade can be provided, adapted to make a tear line 15 that is different from tear lines 15′ and possibly with low resistance against tearing in the winding cradle. In this case, before entering the winding cradle 4, as well known, for example when a core 20 b is put in, the web is torn forming a front end 1 a and a tail end 1 b at this new tear line 15, weaker than tear line 15′.
In a further alternative embodiment, at cutting blade 10″ a tearing device can be provided between the gluing device 10′, for example a padding that brakes the paper, tearing at a tear line 15′ previously made at rollers 11 and 12.
During the operation of the machine according to the invention, support roller 10, in synchronism with upper winding roller 5, when making the clean cut or tear line 15, has a speed corresponding to that of paper web 1, in order to execute a clean cut or tear line on paper web 1, when a complete log is wound, which is formed by a desired number of panels 16 of web 1 having tear lines 15′. In particular the speed of support roller 10 is kept fixed at a speed identical to the rotation of the upper winding roller 5. The clean cut or tear line 15 of paper web 1 generates, thus, two free ends corresponding to tail end 1 a for formed log 2 a and head end 1 b for new log 2 b.
To allow gluing, behind support roller 10 a gluing roller 51 is provided, on which a layer of glue is distributed by a doctor blade 56 that is equipped with, for example, a duct (not shown) through which the glue is supplied.
More precisely, gluing roller 51 is movable from a first position, where roller 51 is distant by support roller (FIG. 1), to a second position, where roller 51 is next to support roller 10 same for laying the glue 55 on pads 10′ that then spread glue on paper web 1 (FIG. 5). For example, gluing roller 51 can be operated towards/away from support roller 10 by a hydraulic, or pneumatic, or electric actuator.
Alternatively, pads 10′ have a withdrawing movement from gluing roller 51 and the paper, whereas gluing roller 51 has fixed axis.
As above said, contemporaneously to the application of glue on paper web 1 a division line is made on the paper by blade 10″.
This way, when separating the formed log from the new log being formed, both tail end 1 a of the formed log and head end 1 b of the new log comprise points spread of glue. Therefore, it is possible to provide with a single step the cut and the application of the glue, both for closing tail end 1 b on the formed log, and in order to cause said head end to stick on a core and start winding a new log. The final result is a high reduction of the time for making each log in addition to a reduction of the costs.
In further exemplary embodiments, the glue 55 can be applied only downstream of the transversal tear line or clean cut line 15, i.e. on the portion of paper web 1 corresponding to tail end 1 b of the formed log, so that it is possible to close the log, once withdrawn the formed log 2 a, without the need of a auxiliary gluing machine for gluing the tail end of the log.
Instead, if the glue 55 is applied only upstream from the transversal tear line or clean cut line 15, i.e. on the portion of paper web 1 corresponding to head end 1 a of the log being formed, the adhesion of the new core is obtained without the need of an auxiliary gluing device in cradle 4 or on core 20 b same.
Obviously, as above said, if the glue is applied bridging the transversal tear line or clean cut line 15, according to the preferred exemplary embodiment described above, both the advantages described above are obtained.
According to a further possible application (not shown) the glue can be applied in a selective way only either upstream, or only downstream, or bridging the transversal tear line or clean cut line 15.
Concerning the operation of blade 10″, FIG. 5′ shows a cross sectional view of an actuating device 90 that moves the blade same. In particular this device has an actuator (not shown) pivoted eccentrically to a connecting rod 61 that rotates about an axis 61′ and moves an actuating bar 62. Actuating bar 62 is connected in turn to a lever 66 on which blade 10″ is mounted. This way, the translational movement of actuating bar 62 moves lever 66 that rotates about a fulcrum 66′, thus moving blade 10″ from a rest position to a cutting position. Furthermore, device 90 has a joint 62′ between actuating bar 62 and connecting rod 61 that allows, through a plurality of bearings 72, to transfer to actuating bar 62 only translational movements in two opposite directions, as indicated in FIG. 5′ by arrow 70. Bearings 72 do not transfer to actuating bar 62 the rotational movement of connecting rod 61 that would cause vibrations and shocks to actuating bar 62. For stabilizing actuating bar 62 a further unit 65 is present having bearings 75 opposite to each other that ensure a precise and stable movement to actuating bar 62 and to lever 66. Therefore, by synchronizing the speed of support roller 10 with the speed of support 5 and by setting the distance between a tear line or clean cut and a successive tear line or clean cut, it is possible to provide a precise separation without working defects.
FIG. 5″ shows a diagrammatical view of the actuating device 90 described in FIG. 5′ and of an actuating mechanism 80 that operates the two pads 10′ contemporaneously to the step of creating a division line 15. Both are mounted integral to support roller 10 and allow carrying out, as above described, the cut and gluing step of paper web 1. In particular, mechanism 80, which is diagrammatically shown in FIG. 5″, is a crank-connecting rod mechanism that moves a linking element 81 integral to the two pads 10′.
As above described, in a first instant blade 10″ is located in a rest position and pads 10′ receive glue from roller 51, whereas, in a second instant, blade 10″ is in cutting position and pads 10′ act contemporaneously to apply the glue on paper web 1.
To sum up, in the many cases of actuation, the actuator is advantageously of cam type, and can be selected from the group comprised of: a single actuator for pad 10′ and blade 10″, with a delayed actuation of the blade with respect to the actuation of the pad 10′, or two independent actuators for blade 10″ and for pad 10′.
In particular, in the presence of two pads 10′, that are arranged respectively one upstream and one downstream of the blade, they can comprise a single actuator, in order to apply the glue on both sides of the blade, or two independent actuators, in order to apply the glue either upstream, or downstream, or bridging the blade in a selective way.
With reference to FIG. 6, a rewinding machine is shown alternative to that of FIGS. 1 to 5, where a web 101 for making a log 102 a is associate to a feed roller 103 of web 101 and, downstream, to a winding cradle 104 in which log 102 a is formed by winding paper web 101 about a core 120. The latter is supplied into cradle 104 by suitable introduction means, for example a loading unit that draws the cores 120 from a chute guide, not shown in the figures.
Also in this case, the cradle 104 comprises an upper winding roller 105, a lower winding roller 106 and a pressure roller 107. The latter follows the growth of log 2 with the task of assuring its continuous contact with winding rollers 105 and 106, controlling its diameter growth.
Upstream from feed roller 103 a perforating roller 111 is provided that acts in combination with a counter-roller 112 to make a plurality of transversal tear lines 115′ on paper web 101 for a plurality of panels 116.
Between the feed roller 103 and the upper winding roller 105, furthermore, a cutting roller 110 is provided. The latter can work in combination with the upper winding roller 105 to cause blade 110″ making a clean cut on paper web 101 as soon as a number of panels 116 corresponding to a complete log has been unwound. Cutting paper web 101 generates two free ends, corresponding to tail end 101 a for formed log 102 a and head end 101 b for new log 102 b.
If cutting roller 110 has not a blade, but a tearing device 110″, the separation two logs 102 a and 102 b is obtained at determined tear lines 115′. This is achieved, as well known, by adjusting the relative speed of the winding rollers 105, 106 and 107. Even in this case, the separation made by blade 110″ at tear line 115′ generates a tail end 101 a for formed log 102 a and a head end 101 b for new log 102 b being formed.
According to the invention, upstream from the means for introducing the core 120, means are provided 150 for application of a measured amount of glue 155 on a determined portion of paper web 101.
The gluing means 150 can, for example, provide a gluing roller 151 on which a measured amount of glue is laid by a doctor blade 156, for example equipped with a duct 157 through which the glue is supplied.
Upstream from feed roller 103, means can be provided for measuring the paper web 101 unwound from a supply roll, not shown in the figure. The means for measuring is operatively connected to the cutting means, in order to operate them to make tear lines 115′ at a predetermined length, and to cutting roller 110, if this is present, to allow separating two consecutive logs, and to the gluing means 150, in order to operate it for applying a determined amount of glue at predetermined tear lines 115.
More in detail, the gluing means 150 are provided movable from a first position, where the gluing roller 151 is distant from paper web 101 (FIG. 6), to a second position, where roller 151 is next to paper web 101 same for applying a layer of glue 155 at predetermined portions of web 101 (FIG. 7, 10, 13, 16, 16, 18). For example, gluing roller 151 can be operated in a movement towards/away from paper web 101 by a hydraulic, or pneumatic, or electric actuator.
In a first exemplary embodiment, shown in FIGS. 7 to 9, the layer of glue 155 a is applied by gluing roller 151 only at portion 118 of paper web 101 arranged downstream of tear lines 115′ or cut or tear line 115.
In particular, in one case tear line 115′ corresponds to the tear line at which cutting roller 110 cuts paper web 101 it into a tail end 101 a of log 102 a and a head end 101 b of the next log 102 b.
In another case, cut or tear line 115 is new and independent from line 115′, and represents an actual division between tail end 101 a of log 102 a and head end 101 b of next log 102 b.
More in detail, tail end 101 a of log 102 a has a layer of glue 155 a for closing formed log 102 a.
On cores 120 a layer of glue 153 can be previously spread, for example by a nozzle 152 arranged between core feeding means 120 and cradle 104. In this case, core 102 b with layer of glue 153 thereon is put into cradle 104 and then approached to paper web 101 when head portion 117 that is upstream from the tear line 115′ reaches it.
The approach of the core 102 a to paper web 101 can be obtained, for example, by a rotation about its axis 119 of the cradle 104, operated by an actuating rod 109.
In an alternative exemplary embodiment shown in FIGS. 10 to 12, roller 151 applies a layer of glue 155 in the only portion 117 of paper web 101 arranged upstream from tear line 115′.
Portion 117 of paper web 101 on which the layer of glue 155 b is applied is, in this case, head end 101 b, which is created by tear line 115′ or by cut or tear line 115 made by cutting roller 110 (FIG. 11).
In particular the layer of glue 155 b allows head end 101 b to engage with core 120 b put in cradle 104 when it approaches to winding roller 105, like it has been described for the previous example. This way, paper web 101 is started winding about core 120 b, to form new log 102 b.
In this case, tail end 101 a of each log at the exit of the rewinding machine can be then stuck to the relative log by a gluing machine of traditional type arranged downstream of the rewinding machine, not shown in the figures.
According to the invention and as diagrammatically shown in FIGS. 13 to 15, roller 151 can be also operated for applying a layer of glue 155 both on portion 117 and on portion 118 of paper web 101 at tear or cut lines 115′.
In this case, roller 151 is firstly approached to paper web 101 at portion 118 where a first layer of glue 155 a is applied, and secondly it is withdrawn 150 a (dotted line) at tear line 115′, and again approached to paper web 101 at portion 117 to apply a second layer of glue 155 b. This way, both tail end 101 a of formed log 102 a and head end 101 b of new log 102 b, obtained from the cut or tear line on paper web 101 by cutting roller 110 (FIG. 14) through blade or tool 110″, have respective layers of glue 155 a and 155 b. This allows both to end formed log 102 a and to start winding new log 102 b, thus avoiding the use of other gluing systems.
A same result, with possibility to use also different kinds of glue, can be obtained using two different gluing rollers 151 a and 151 b, as diagrammatically shown in FIG. 16. In this case, for applying glue 155 both on portion 117 and on portion 118 of paper web 101, it is enough operate at the same time gluing rollers 151 a and 151 b in corresponding positions of the rewinding machine, or to operate a single gluing roller in two consecutive instants.
A similar result can be also obtained with the further exemplary embodiment shown in FIG. 17. In this case, roller 151 applies the layer of glue 155 bridging the tear lines 115′, or bridging a position where clean cut 115 is made by blade 110″. Even in this case it is possible both to cause tail end 101 a to stick on formed log 102 a and to starting winding new log 102 b on next core 120 b by the engagement on it of head end 101 b.
Finally, in FIG. 18 an exemplary embodiment is shown that provides arranging gluing roller 151 at cradle 104. As shown the figure, the layer of glue 155 can be applied by roller 151 downstream of tear line 115.
The improved rewinding machine as 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 that are 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.
Furthermore, it reduces remarkably, with respect to the rewinding machines of prior art, the risks that the glue can dirt the mechanical moving parts, jeopardizing a correct operation and causing need of maintenance work.
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.

Claims

1. An improved rewinding machine of a paper web for making a log, in particular for making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial paper rolls and the like, comprising:

feeding means for feeding said paper web along a feeding direction;

means for making a transversal division line in the paper web between a tail end of the log just formed and a head end for a new log being formed;

start up means for starting the production of a new log;

a winding cradle that is arranged downstream of said start up means in which said log grows by winding said paper web up to obtaining a formed log;

means for removing said formed log;

gluing means for applying glue on a predetermined portion of said paper web, said gluing means arranged upstream from said start up means;

characterised in that said gluing means and said means for making a transversal division line are arranged in coincidence with each other on a support roller so that said means for making a transversal division line create said transversal division line and at the same time said gluing means applies a measured amount of glue near said line.

2. The improved rewinding machine, according to claim 1, wherein said means for making a transversal division line in the paper web are selected from the group comprised of:

means for making a clean cut on the paper web;

means for perforating the paper web that is eventually torn near said start up means;

means for tearing the paper web adapted to tear the paper at a tear line previously made on said web.

3. The improved rewinding machine, according to claim 1, wherein said gluing means and said means for making a transversal division line are arranged in coincidence with each other in order to apply the measured amount of glue bridging said line.

4. The improved rewinding machine, according to claim 1, wherein said gluing means and said means for making a transversal division line are arranged in coincidence with each other in order to apply the measured amount of glue downstream of said line.

5. The improved rewinding machine, according to claim 1, wherein said gluing means and said means for making a transversal division line are arranged in coincidence with each other in order to apply the measured amount of glue upstream from said line.

6. The improved rewinding machine, according to claim 1, wherein said measured amount of glue is applied in a selective way only either upstream, or only downstream, or bridging the transversal tear line or clean cut or tearing line, i.e. on the portion of the paper web corresponding to either the tail end of the formed log or the head end of the log being formed or both portions.

7. The improved rewinding machine, according to claim 1, wherein said start up means comprises means for introducing a core in said winding cradle.

8. The improved rewinding machine, according to claim 1, wherein means are provided for measuring the unwound length of said web from a paper roll, said means for measuring providing a signal for driving said gluing means when a measured length of paper web has been unwound.

9. The improved rewinding machine, according to claim 1, wherein said gluing means and said means for making a transversal division line, in particular a blade, are movable towards/away from said paper web operated by an actuator selected from the group comprised of:

a pneumatic actuator;

an electric actuator;

a hydraulic actuator.

10. The improved rewinding machine, according to claim 9, where in any cases of actuator type, the actuator is advantageously of cam type, and can be selected from the group comprised of: a single actuator for said pad and said blade, with a delayed actuation of the blade with respect to the actuation of the pad; two independent actuators for both the blade and the pad, in particular in the presence of two pads, that are arranged respectively one upstream and one downstream of the blade, they can comprise a single actuator, in order to apply the glue on both sides of the blade, or two independent actuators, in order to apply the glue either upstream, or downstream, or bridging the blade in a selective way.

11. An improved rewinding machine of a paper web for making a log, in particular for making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial rolls and the like, comprising:

feeding means for feeding said paper web along a feeding direction;

means for making a clean cut or a tear line in the paper web between a tail end of the log just formed and a head end for a new log being formed;

start up means for starting the production of a new log;

means for removing said formed log;

characterised in that said gluing means and said means for making a clean cut or a tear line are arranged in a direct succession to each other on respective support rollers so that said gluing means applies a measured amount of glue near a division zone of said web and said means for making a clean cut or a tear line immediately after or immediately before said application of the glue make on said division zone a clean cut or a tear line.

12. The improved rewinding machine according to claim 11, wherein said measured amount of glue is applied in a selective way by said gluing means so that when a clean cut is made said glue is applied only either upstream, or only downstream, or bridging the clean cut transversal line, i.e. on the portion of the paper web corresponding to either the tail end of the formed log or the head end of the log being formed or both portions.

13. A method for winding a paper web for making a log, in particular for making rolls of toilet paper, towel paper rolls or non woven fabric for household use, industrial rolls and the like, comprising the steps of:

feeding said paper web along a feeding direction;

starting the production of a new log;

winding said paper web at a winding cradle up to obtaining a formed log;

creating a transversal division line in the paper web between a tail end of the formed log and a head end for a new log along a transversal line of said web;

applying a measured amount of glue on a predetermined portion of said paper web, said step of applying glue being made previously to said step of starting a new log in said winding cradle;

removing said formed log;

characterised in that said step of application of a measured amount of glue and said step of creating a division line are made in coincidence to each other to make said transversal division line and at the same time to execute said application of a measured amount of glue near said line.

14. A winding method, according to claim 12, wherein said step of application of said measured amount of glue on a portion of said paper web, is carried out on at least one among the following portions:

downstream of said tear line or clean cut line, in order to eventually cause said tail end to stick on said formed log;

upstream from said tear line or clean cut line, in order to cause said head end to stick on a core and start winding a new log;

bridging said tear line or clean cut line, in order to eventually cause said tail end to stick on said formed log and the at the same time cause said head end to stick on a core and start winding a new log.