System and Method for the Setting of a Machine for the Conversion of Paper

The present invention relates to the paper converting machines for producing products of different types such as logs of toilet paper, logs of kitchen paper, but also packages of napkins, tissue papers, towels, etc. starting from at least one reel of paper, and in particular it relates to a system for setting the aforementioned paper converting machine.

The invention, furthermore, relates to a method for setting the aforementioned paper converting machine.

As it is known, in the paper industry for producing logs or packages of sheets of paper, for example absorbing paper for toilet paper, or kitchen paper, in particular drying paper, machines exist that work starting from big reels of paper. These are obtained by production plants which gradually reduce the amount of water of a mixture of cellulosic fibres, water, in addition to a series of additives of different types, through a sequence of passages up to reach a consistency such that allows the veil of wet paper to pass through a drying section. This, normally, comprises at least one dryer cylinder, also known as Yankee cylinder, that is made of steel or cast iron and a hood which is fed with hot air. In particular, the worked veil of wet paper is laid on the external surface of the dryer cylinder, whilst the inside of the Yankee cylinder same is heated for example by injecting steam. Because of the heat produced within the Yankee cylinder and the hot air which is blown by the hood on the paper, the veil of wet paper laid on the external surface is gradually dried. When the desired drying value is reached, the veil of paper is removed from the external surface of the Yankee cylinder by a blade, or a doctor blade, or by tensioning, depending on the desired product and in particular crepe paper, or smooth paper.

The veil of dried paper that is so obtained is, then, subjected to a series of intermediate operations and, then, is sent to a winding station for producing the reel of paper of big size. In particular, the production plant provides also to carry out the packaging of the reel of paper by applying a film, or layer, normally made of a transparent material, and the labelling of the same. More precisely, on the label are present some data or parameters which relate to the reel of paper, among which the diameter, the height, and the weight, but also data and parameters which relate to the type of paper of the reel, for example the paper weight, the number of veils, the maximum percentage elongation that can be tolerated, but also the number and the position of any defect detected during the production of the reel of paper. For example, it is possible that during the winding of a reel of big diameter, or mother reel, a breaking of the veil occurs (or of the veils in case of reel formed by more veils) which requires to carry out a joining before starting again and finishing the winding of the reel same up to the final diameter. Furthermore, it is possible that the veil or the veils wound to form the reel of big diameter have tears, or in general defects, due to the fact that the working conditions are not exactly the same during the production process of the veil same.

All these data are, in fact, indispensable because the plant to which the reel of paper is sent to be subjected to a series of operations in order to be converted into the final product, works correctly and at the maximum production capacity, without compromising its functioning.

The aforementioned data are normally consulted for controlling the quality of the reel and, therefore, to verify that the paper of the reel is appropriate for the type of product into which the same has to be converted.

However, these data are not directly used for setting the best working configuration for the aforementioned paper converting machines. Only in some cases it is possible to carry out some operations manually using some information which relate to the defects of the reel that is mounted on the machine. For example, a worker can read from the label or from a mark provided at one side of the reel that at a determined diameter of the mother reel same there is a hole, or a joining of the veils, and, therefore, at that predetermined diameter he/she reduces considerably the speed of production to avoid the breaking of the veils and to discharge the final paper product which contains the veils with the defects. Normally, the worker does not optimally set the converting machine, but reduces the speed of production in order to avoid a stop of production.

These procedures carried out manually by the worker, are subject to errors or oversights which cause the paper converting machine to be stopped for a long time, thus producing economic losses. In addition to the above, a machine which is not correctly set, that means set in a way that does not correspond to the characteristics of the starting reel of paper, can lead to use in a non-optimized way the paper converting machine and, therefore, to have a productivity that is less than the one that could be reached, but also to obtain a product of low quality, up to the damage of the worked paper, which can be broken and jam the different parts of the machine, with consequent loss of productivity and time in order to carry out the necessary extraordinary maintenance interventions to remove the jammed paper and start again the process.

An example of a prior art solution with the aforementioned drawbacks is described in WO2015/160915. In this case a system for producing products made of paper is provided comprising a machine for forming a web of paper provided with a plurality of sections. The machine analyzes the web of paper in order to identify the proprieties and to mark the web of paper same with a series of marks, each of which assigned to a section of the aforementioned plurality. The instrument of analysis assigns a speed to the paper at each section on the basis of the properties of the web of paper identified in that section. However, the solution described in WO2015/160915 in order to detect the data have to unwind the reel of paper. Therefore, if the machine is set on the basis of a web of paper having different properties with respect to the one mounted, a lot of drawbacks can occur, such as paper jam along the line, or tears, or wrinkles, which are not desired on the product with consequence loss of product and productivity for the need of unwinding, extraordinary maintenance interventions are necessary to remove the paper jammed or damaged before starting again the machine.

Other examples of the prior art with analogous drawbacks are described in DE102009029081, DE102009029082, DE102009029083, DE102009029084, U.S. Pat. No. 4,463,251 and EP0875482.

It is, therefore, an object of the present invention to provide a system for setting a paper converting machine starting from a reel of paper, in particular for producing logs of toilet paper, or logs of kitchen paper, but also packages of product, such as packages of napkins, tissue papers, towels and similar products, in particular folded or interfolded, that is able to overcome the aforementioned drawbacks of the prior art solutions.

It is also an object of the present invention to provide a method for setting a paper converting machine starting from a reel of paper having analogous advantages.

an unwinding group configured to unwind said reel of paper obtaining a web of paper; a displacement group configured to cause the aforementioned web of paper to advance through said paper converting machine at a determined advancement speed along a predetermined advancement path; a control unit configured to operate said displacement group in such a way to adjust the advancement speed of said web of paper along said predetermined advancement path;whose main characteristic is that it, furthermore, comprises an optical detection device configured to recognize and acquire said or each graphic element, which is present on said label of said reel of paper. These and other objects are achieved by a system for setting a paper converting machine for producing products made of paper starting from a reel of paper associated to a label on which a plurality of data or parameters related to the same are present, each datum or parameter being graphically represented by at least one alphabetic character or numeric character, said machine comprising:

Other technical characteristics of the invention and related embodiments are defined by the dependent claims.

In particular, the optical detection device can be arranged to recognize and acquire the or each graphic element which is present on the label before actuating the unwinding group for unwinding the reel.

Preferably, each datum or parameter of the reel can be graphically represented by a plurality of alphabetic characters. More in detail, each parameter of the reel can be associated to a respective numeric value which, advantageously, defines the value of the parameter same. In particular, the numeric value can comprise at least one numeric character.

Alternatively, the aforementioned graphic element can be a barcode, or a QR code, or an analogous code.

In particular, the aforementioned optical detection device can be, furthermore, configured to send the or each graphic element to the control unit. More in particular, the aforementioned control unit can be configured to set the machine, for example the displacement group, on the basis of the or each graphic element recognized by the optical detection device.

In addition, or alternatively, the aforementioned optical detection device can be configured to send the or each, detected graphic element to a display device.

Advantageously, the optical detection device can comprise a digital video camera provided with a software for the optical character recognition, or “OCR”.

paper weight; diameter of the reel; number and position of the defects; number of veils; elongation percentage; diameter of the core of the reel; height of the reel; air permeability of paper; residual moisture. In particular, on the aforementioned label can be indicated at least one datum or parameter selected from the group comprising:

Advantageously, on the label can be indicated at least the number and the position of the or each defect, and wherein the control unit can be arranged to operate the displacement group in such a way to reduce or bring to zero the advancement speed when the positions of the or each defect of the web or sheet of paper reaches the predetermined positions of said advancement path.

In some cases, for position of defect is intended the diameter, or radius, of the reel corresponding to the point where the defect is present in the veil of paper. Alternatively, it is possible to indicate the position of the defect with a distance measured starting from the core of the mother reel.

In particular, the control unit can be configured to operate a discharge device to reject at least one product obtained starting from the reel of paper and containing the or each defect of the web of paper.

In a possible embodiment of the invention, the paper converting machine can comprise a tension measurement group configured to measure the tension applied to the web of paper during its movement along the predetermined advancement path. In particular, the tension measurement group can be arranged to generate and send to the control unit data relating to the tension applied to the web of paper. More in particular, the control unit can be configured to operate the unwinding group and/or the displacement group in such a way that said tension measured by the measurement group is kept within a predetermined range of tension values computed on the basis of a value of elongation percentage detected by the optical detection device on the label.

In an alternative embodiment provided, the control unit can be configured to keep the tension of the paper to the desired tension using the value of the elongation percentage to adjust and operate opportunely the displacement group and/or the unwinding group.

In an alternative embodiment of the invention, the paper converting machine can comprise a folding or interfolding group configured to fold or interfold a sheet or web of paper according to a predetermined folding or interfolding configuration. Advantageously, the folding or interfolding group can be operatively connected to a device for generating a determined vacuum degree.

In particular, on the label can be indicated at least the value of the permeability of the paper that is detected by the optical detection device. More in particular, the control unit can be configured to operate the device for generating the determined vacuum degree in such a way to set a determined vacuum degree computed on the basis of the aforementioned permeability of paper value.

Advantageously, the control unit can be configured to store in a database the or each alphabetic and/or numeric character of the or each parameter recognized and acquired by the optical detection device.

In particular, a positioning group can be, furthermore, configured to position the optical detection device and the reel of paper in a predetermined relative position one with respect to the other, in such a way to detect at least one graphic element associated to the or each datum or parameter arranged in a predetermined position.

unwinding said reel of paper obtaining a web of paper; moving said web of paper along said paper converting machine at a determined advancement speed along a predetermined advancement path, said moving step being carried out actuating a displacement group by a control unit; whose main characteristic that it, furthermore, provides the steps of: detecting said or each graphic element associated to at least one datum or parameter of said plurality of parameters which are present on said label of said reel of paper by an optical detection device; acquiring said or each recognized graphic element of said or each datum or parameter of said plurality of data or parameters which are present on said label of said reel of paper by said optical detection device. According to another aspect of the invention, a method for setting a paper converting machine for producing products made of paper starting from a reel of paper associated to a label on which a plurality of data or parameters are present that relates to the same, each datum or parameter being graphically represented by at least one graphic element, said method comprising the steps of:

Preferably, the recognition step can be carried out before starting the unwinding of the reel of paper by the unwinding group.

In particular, the aforementioned recognition step of the or each alphabetic and/or numeric character can be carried out before positioning the reel of paper on the unwinding group.

Alternatively, the aforementioned recognition step can be carried out after having positioned the reel of paper on the unwinding group.

5 16 FIGS.to thediagrammatically show side elevation perspective views of some possible alternative embodiments of the system, according to the invention, or parts of the same, for setting a paper converting machine.

1 FIG. 200 1 10 15 16 10 In, a systemis diagrammatically shown, according to the invention, for setting a paper converting machinefor producing products such as logs of toilet paper, logs of kitchen paper, but also packages of napkins, tissue papers, towels, etc. starting from a reel of paper. This, as known, is associated to a labelon which a plurality of data or parametersrelated to the reelof paper is present, for example reproduced by printing or carving or applying elements in relief.

2 4 FIGS.to 4 FIG. 16 17 19 16 16 10 f In particular, as shown in detail in the, each datum or parameteris graphically represented by at least one graphic element. This can be, for example, an alphabetic characterand/or at least a numeric character, but also a barcode or a QR code or similar codes, cases that are not shown in figure for simplicity. For example, as diagrammatically indicated in, each datum or parameter, in the example the parameter“core” intended as the external diameter of the tubular body about which the paper of the reelis wound, can be

17 17 17 17 16 18 19 19 a n a e a b. 4 5 FIGS., 4 FIG. characters, . . . ,, in the case ofalphabetic characters-. In particular, each datum or parametercan be, furthermore, associated to a respective numeric value, in the case ofcomprising two numeric charactersand

15 16 10 10 1 20 10 100 30 35 100 1 30 100 101 1 30 100 1 16 15 50 17 19 16 15 10 50 15 20 10 2 In particular, on labelat least one datum or parametercan be present that is selected from paper weight, i.e. the weight in grams of a sheet of 1m, the diameter of the reel, the number and the position of the defects, the number of veils, the elongation percentage, i.e. the maximum elongation expressed in % that can be tolerated by the paper, the diameter of the core of the reel, the height of the reel, residual moisture of the or each veil of paper, the air permeability of each single veil of paper, and the height of the reel. More in particular, each parameter can be graphically represented by a series of alphabetic characters and to each parameter can be associated a respective numeric character which, advantageously, defines its value. In general, the machinecomprises an unwinding group, described in detail below, configured to unwind the reel of paperobtaining a web of paper. A displacement groupis, furthermore, provided comprising, for example, a series of rollssome of which operated in particular by motors, some others, instead, idle, which together define a predetermined advancement path for the web of paperalong the machine. In particular, the displacement groupis configured to cause the web of paperto advance at a determined advancement speed along a predetermined advancement paththrough the different sections of the paper converting machine. This can, furthermore, comprise a control configured to operate the displacement groupin such a way to adjust the advancement speed of the web of paperthrough the different sections of machine, in particular according to the aforementioned data or parametersindicated on the label. According to the present invention, an optical detection deviceis, furthermore, provided configured to detect and acquire the or each graphic element indicated on the label, such as one or more alphabetic charactersand/or one or more numeric charactersof at least one datum or parameterof the aforementioned plurality of data or parameters indicated on the labelassociated to the reel of paper. In particular, the optical detection devicecan be arranged to detect and acquire the or each graphic element which is present on the labelbefore actuating the unwinding groupfor unwinding the reel.

50 15 The aforementioned optical detection devicecan comprise a device for acquiring images, for example a digital video camera, advantageously associated to a software for the optical character recognition or OCR. More in detail, the device for acquiring images can be configured to acquire images from the labeland to send corresponding data to a microcontroller configured to process the acquired images with a software of OCR type and to convert the data into at least one alphanumeric character. In an embodiment provided, the image acquisition device can be provided with the aforementioned software for optical character recognition or OCR.

50 10 15 50 55 55 50 56 10 110 10 15 16 FIGS.and 15 FIG. Advantageously, the optical detection devicecan move with respect to the reelin such a way to be able to position at the label. For example, as diagrammatically shown in the, the optical detection devicecan be mounted on a support framein such a way to be able to move with respect to the same. In particular, the support framecan be configured to guide the optical acquisition devicealong at least one sliding directionwith respect to the reel, for example parallel to the longitudinal axisof the reel().

50 15 50 15 50 In particular, the optical detection devicecan be configured to be able to automatically detect the position of the labelonce positioned at the same. Alternatively, the optical detection devicecan be associated to a detection member, not shown in the figures for simplicity, arranged to identify the position of the labeland to transmit the position of the same to a processing unit which, then, causes the optical acquisition deviceto move accordingly, in order to position the same at the aforementioned position.

50 10 55 57 50 57 56 16 FIG. In an embodiment provided, the optical acquisition deviceand the reelcan be adapted to rotate one with respect to the other. In particular, as diagrammatically shown in, the support framecan be provided with a curvilinear guide portionalong which the optical acquisition devicecan slide. More in particular, in this case, can be the curvilinear guide portionto be slidingly mounted along at least the sliding direction.

10 50 In an embodiment not shown in the figure, the reelcan be mounted on a rotating platform, in such a way to rotate with respect to the optical acquisition device.

50 10 15 50 55 55 50 10 Advantageously, the optical detection devicecan move with respect to the reelin such a way to be able to position at the label. For example, the optical detection devicecan be mounted on a support framein order to be able to move with respect to the same. In particular, the support framecan be configured to guide the optical acquisition devicealong at least a sliding direction with respect to the reel.

17 19 50 10 20 10 20 1 In particular, the recognition of the or each graphic element, for example one or more alphabetic charactersand/or one or more numeric characters, can be carried out by the optical detection devicebefore positioning the reel of paperon the unwinding group, for example at a store area. Alternatively, the recognition can be carried out before or after having positioned the reel of paperat the unwinding groupof the machine.

1 FIG. 50 17 19 300 50 17 19 50 15 300 As diagrammatically shown, for example, in, the aforementioned optical detection devicecan be, furthermore, configured to send the or each, alphabetic characterand/or numeric characterof the recognized datum or parameter to the control unit. Alternatively, or in addition, the aforementioned optical detection devicecan be adapted to send the acquired graphic elements, such as alphabetic charactersand/or numeric characters, to a display device. In this case, a worker can be provided for verifying that the optical detection devicehas correctly “read” and acquired the characters indicated on the label. In particular, the worker can, in case, correct any reading errors and confirm the read data or parameters before sending the same to the control unit.

70 71 72 10 71 72 73 74 10 12 10 110 10 20 100 1 71 72 78 10 12 8 FIG. 8 FIG. 8 FIG. In particular, a support groupcomprising a first and a second support memberandcan be provided positioned at opposite sides with respect to the reel. More in particular, the first and second support membersandcan be provided with respective engagement portionsandadapted to engage the reelto a tubular coreof which the same is provided with (), in such a way that the reelis free to rotate about its longitudinal axis. By the unwinding of the reelcarried out by the unwinding group, a web of paperis obtained that is worked through the different sections of the machine. In particular, the first and second support membersandcan be slidingly mounted on a guide(along respective direction parallel to the axial direction of the reelto move from a respective position external to the tubular core(condition indicated inwith a broken line) to a respective position internal to the same (condition indicated inwith an unbroken line).

9 FIG. 9 FIG. 20 22 22 22 22 5 21 21 21 25 23 22 10 10 a e d As diagrammatically shown in, the unwinding groupcan provide at least one unwinding member, advantageously a flexible unwinding member, for example a belt, preferably a plurality of unwinding membersparallel to each other. More in particular, the or each, unwinding memberis mounted on a series of deflection members, for exampledeflection rolls-, at least one of which, in the case ofthe deflection member, operatively connected to a motor, for example by a transmission belt, in such a way to cause the same to rotate about a respective rotation axis. The or each, unwinding memberis positioned in contact with the reeland is, advantageously, provided with a surface having a high friction in such a way to transmit to the reelsame the motion and to cause the same to be unwound.

75 10 22 10 75 75 71 75 72 75 75 71 72 76 77 10 22 10 22 25 100 101 10 75 75 10 22 71 72 76 77 22 10 a b a b a b 9 FIG. A push memberis, advantageously, furthermore, provided configured to keep the periphery of the reelin contact with the or each unwinding memberduring the unwinding of the same in such a way to assure that during the unwinding of the reel, the or each unwinding member is able to exert the unwinding action on the same, in particular for the presence of the high friction surface of which it is provided with. In particular, the push devicecan comprise a first actuatorassociated to the first support memberand a second actuatorassociated to the second support member. More precisely, the first and second actuatorsandare adapted to exert a push action, respectively, on the first and the second support memberand, in such a way that these rotate about a respective fulcrumandto push in a controlled way the reelagainst the or each unwinding member. More in detail, the unwinding of the reelis caused by the or each unwinding memberoperated by the motor. In this way, the web of paperis fed along an advancement path. During the unwinding of the reel, the diameter of the same gradually decreases, but the unwinding action is, however, assured by the action of the first and second actuatorsandwhich cause the reelto lower towards the or each unwinding memberthus causing a rotation of the first and second support membersandabout the fulcraandas described above. Furthermore, a device can be provided for tensioning the or each unwinding member, not shown in thefor reasons of clarity, adapted to contribute to compensate the aforementioned reduction of the diameter of the reel.

22 10 20 110 10 For the aims of the invention, also other types of unwinders of prior art can be used. In particular, an unwinder can be provided which progressively draws each unwinding membernear to the reelas the diameter decreases. Alternatively, it is possible to have an unwinderwhich actuates the reel by putting in rotation the coreof the reeldirectly by a motor. In this case the jargon expression central unwinders is used, whilst in the previous cases, the jargon expression peripheral unwinders is used. It is possible also to use central-peripheral unwinders without changing the aims of the invention.

1 40 100 101 300 300 20 30 40 15 50 100 1 100 100 In particular, the paper converting machinecan comprise at least one tension measurement groupconfigured to measure the tension to which the web of papermoved along the aforementioned predetermined advancement pathis subjected to, and to send corresponding data to the control unit. More in particular, the control unit, in this case, can be configured to operate the unwinding groupand/or the displacement groupin such a way that the value of the tension measured by the tension measurement groupis kept within a predetermined range of values. More precisely, the aforementioned predetermined range of values of the tension can be computed on the basis of the value of the elongation percentage that is read as parameter indicated on the labelby the optical detection device. The tension to which the web of paperis subjected, is a very important operative parameter for the correct functioning of the machineand for obtaining a high quality product and its value have to be kept within a determined range for the reasons indicated below. A too low tension, in particular less than a lower threshold value, can cause the paper to deviate from the correct line, to form wrinkles and to incorrectly work the same in particular at determined sections, such as for example at the printing or the embossing sections. On the other side, if the paper tension is too high, in particular higher than an upper threshold value, the paper can be broken or torn. In this case, it is necessary to move the web of paperagain through the line, at least downstream of the breaking point. This unavoidably implies to stop the machine and to have long stop times during production. The elongation percentage datum is also important at the cutting station in order to divide the webinto a series of sheets of predetermined length. If the paper has a high elongation percentage value and is subjected to a high tension, it is likely that the cut-off, i.e. the length of each single sheet, can be reduced after the cut and, therefore, that, at the suction rolls, if present, some suction holes can be covered causing paper jam due to the fact that the sheets are no more kept by the suction holes on the external surface of the roll same. In practice, if a veil of paper that is very long because of the tension, is cut, it is very likely that after the cut, the paper can go back to a tension equal to zero, thus shortening. The cut-off is, therefore, shorter causing the above disclosed problems.

9 FIG. 40 20 100 101 In the example diagrammatically shown in, a groupfor measuring the tension is provided positioned downstream of the unwinding groupbefore that the webmoved along the advancement path, is positioned at a first working station.

40 100 35 35 30 35 100 101 35 45 35 45 105 110 10 45 47 45 46 45 43 47 45 35 100 In particular, the groupfor measuring the tension of the web of papercan be associated to a deflection member′, for example a deflection roll of a series of deflection membersof the displacement group, preferably deflection rollsadapted to guide the web of paperalong the aforementioned predetermined advancement path. More in detail, the deflection roll′can be supported by at least one support arm, advantageously by two support arms arranged at opposite sides with respect to the deflection roll′. The or each support armcan be hinged about an axisparallel to the aforementioned longitudinal axisabout which the reelrotates during its unwinding. The or each support armis, advantageously, associated to a force detection member, for example a load cell. Furthermore, the or each support armcan be associated to a member for detecting the angular position of the same, for example an encoder. In particular, the or each support armcan be kept in a predetermined position by an actuator. In this way, the or each member for detecting the forceis able to detect the reaction force of the or each support armresponsive to the force exerted by the same by the deflection roll′ which is function of the tension of the web of paper.

50 15 300 100 101 43 45 10 45 105 10 46 300 20 25 22 10 47 According to the present invention, on the basis of the value of the elongation percentage that is read by the optical detection deviceon the label, the control unitis adapted to set a predetermined value of the tension, preferably a predetermined range of values of the tension, to which the web of papercan be subjected to during its movement along the advancement path. In particular, the tension can be controlled setting by the aforementioned actuator, for example a motor, a pneumatic actuator, or other similar devices, a determined intermediate position of the support arm. During the unwinding of the reel, a controlled oscillation of the or each support armabout axiswill occur, with a determined amplitude ta with respect to the aforementioned intermediate position. If, during the unwinding of the reel, the device for detecting the angular position, for example an encoder, detects a deviation from the aforementioned predetermined intermediate position greater than a determined threshold range, the control unitis adapted to operate the unwinding group, more precisely the motorof the same, in order to cause the or each unwinding memberand, therefore, the reel, to accelerate or decelerate, in order to bring the value of the tension measured by the force detection memberback within a predetermined range of admissible values.

50 15 300 43 100 45 100 100 100 30 36 37 56 57 36 37 56 36 56 57 37 58 58 36 37 36 37 40 36 37 100 36 37 100 300 56 100 40 10 FIG. 10 FIG. a b According to the invention, on the basis of the value of the elongation percentage which is read by the optical detection deviceon the label, the control unitis adapted to set a predetermined value of the force that the actuatorhas to exert on the web of paperto which corresponds a determined position of the or each support armand, therefore, a determined tension of the web of paper. In this way, it is possible to control the elongation of the web of paperthus avoiding to have a too high tension applied, for example, to a paper having a high elongation, allowing to avoid the problems above described. Vice versa, it is possible to apply the right tension to a web of paperwhich is very stiff and that have a short elongation, and that, preferably, needs a higher tension, obviously, without reaching the maximum tensile stress of the paper same. In an embodiment provided and diagrammatically shown in, the displacement groupcan comprise a first and a second rolland, at least one of which operatively connected to a motor, for example by a transmission belt, which causes it to rotate about a respective rotation axis. Preferably, however, as in the case of, both the first rolland the second rollcan be motorized, i.e. connected to the motor. For example, the first rollcan be connected to the motorby a transmission beltand can transmit the motion to the second rollby motion transmission gears, advantageously a couple of toothed wheelsand, respectively coaxially arranged with respect to the first rolland to the second roll, that cause a rotation of the same in the opposite direction. The aforementioned first and second rollsandare, advantageously, positioned close to, preferably downstream of, a tension measurement group. In particular, at least one of the aforementioned rollsandcan be provided with an external surface having a high friction, for example covered by rubber, or knurled. Preferably, the web of papercan “bandage” at a certain angle the rolls,in order to optimize the traction exerted on the web of paper. In this case, the control unitcan be configured to accelerate or decelerate the motorand, therefore, the rolls connected to the same in order to increase or decrease the tension of the web of paperif the values of tension received from the groupfor measuring the tension do not belong to the aforementioned range of admissible values.

40 35 45 35 100 100 35 In alternative embodiments, the tension measurement groupcan be formed by a deflection roll, preferably idle, that is mounted with a fixed axis, that means not mounted on the support arms. In this case, the deflection rollon which the web of paperis wound, can be provided with a load cell which measures the load or force exerted by the web of papersame on the idle roll, to which a respective tension of the paper corresponds.

11 FIG. 10 FIG. 9 FIG. 100 80 1 100 40 80 40 40 47 35 45 45 35 47 45 35 100 43 45 47 45 35 100 100 47 b a b Advantageously, as diagrammatically shown in, a first tension measurement group of the web of paperas described above with reference to, can be provided upstream of a section or stationof the machinewhere a predetermined operation is carried out on the worked web of paper, and a second tension measurement groupcan be provided downstream of the same station. Analogously to what has been described above with reference to, the first and second tension measurement groupsecan comprise a force detection memberassociated to a respective deflection roll. This can be supported by at least one support arm, preferably by a couple of support armspositioned at opposite sides of the roll′same. The member for detecting the force, for example a load cell, can be adapted to measure the force of reaction of the or each support armresponsive to the force exerted on the same by the deflection roll′which is function of the tension of the web of paper. Also in this case an actuator, for example a motor, can be provided arranged to keep the or each support armin position in such a way that the detection memberis able to detect the force of reaction of the or each support armresponsive to the force applied on the same by the deflection rollthat is function of the tension of the web of paper. In practice, the higher is the tension on the web of paperthe higher will be the force measured by the member for detecting the force.

40 100 40 a b In an embodiment provided by the invention, a first tension measurement groupcan be positioned upstream of a printing group to apply a predetermined number of colours, in particular from 1 to 4, or even more colours, on a web of paperand a second tension measurement groupcan be positioned upstream of the printing group same. The printers, typically flexographic printers, are known machines and will not be described here in detail.

40 40 100 a b In addition or alternatively, a first tension measurement groupcan be positioned upstream and a second tension measurement groupcan be positioned downstream of an embossing group configured to emboss and join together one or more websof paper. Many embossing devices exist to obtain a great variety of different products which will not be described in detail here.

15 16 300 30 100 101 According to an embodiment of the invention, on the labelat least the number and the position of the or each defect can be indicated as datum or parameter. In this case, the control unitcan be arranged to operate the displacement groupin such a way to decrease or bring to zero the advancement speed when the or each defect of the web of paperreaches predetermined positions of the aforementioned advancement path.

7 FIG. 1 100 150 15 16 300 In the embodiment diagrammatically shown in, the paper converting machinecomprises a folding or interfolding group configured to fold or interfold a sheet or web of paperaccording to a predetermined folding or interfolding configuration in such a way to obtain stacksof folded or interfolded products, such as packages of tissue papers, napkins, towels etc., and wherein on the labelas datum or parameterat least the value of the elongation percentage can be indicated. In this case, the control unitcan be configured to operate the folding or interfolding group in such a way to avoid that the sheet or the web of paper is subjected to a tension such to reach the maximum elongation percentage.

7 FIG. 300 350 50 Still as diagrammatically shown in, the control unitcan be configured to store in a databasethe or each alphabetic and/or numeric character of the or each datum or parameter recognized and acquired by the optical detection device.

15 300 30 100 101 2 In a further alternative embodiment of the invention, on the labelat least the value of the paper weight, in particular expressed in g/m, can be indicated. In this case, the control unitcan be configured to operate the displacement groupin order to increase the advancement speed of the web of paperalong the advancement pathas the paper weight increases and, vice versa, decreasing the advancement speed as the paper weight decreases.

300 15 In general, the control unitcan compute a maximum threshold value or an optimal production speed, on the basis of one or more parameters read on the label.

10 50 15 300 40 45 Advantageously, the values of the paper weight, the number of veils and the width of the reeldetected by the optical detection deviceon the label, can be used by the control unitto set the tension measurement group, in particular to set a starting value of the aforementioned intermediate position of the support arms.

300 10 100 In practice, the control unitaccording to one or more parameters selected among the value of the elongation percentage, the value of the paper weight, the number of veils and the width of the reel, can compute the optimal reference value of the tension of the web of paper.

300 30 100 100 100 40 30 Advantageously, the central control unitcan adjust and operate the displacement groupto keep the tension of the web of paperequal to the computed optimal value. In particular, the central control unit, once computed the optimal value of the tension of the web of paper, executes a control algorithm of known type in loop, for example a PI, PID or an algorithm of another type, to keep the tension of the webequal to the optimal value, showing the actual value of the tension by the tension measurement groupand adjusting the tension by the displacement group.

12 13 FIGS.and 13 FIG. 70 10 50 10 15 300 300 70 10 110 10 10 1 115 10 As diagrammatically shown in the, the aforementioned support groupcan be configured to move, in particular to translate, along a direction axial to the reel. In particular, the optical detection devicecan be adapted to detect at least the value of the height (H) of the reelindicated on the labeland, in case, to send the same to the control unit. In this case, the control unitcan be configured to operate the support groupto move, in particular translate, along the axial direction, to move the reelalong the longitudinal axisup to positioning the reelsame in a predetermined centred position (Pc) at which the reelis axially centred with respect to the machine, that means that the transversal planeof the reelis positioned at the aforementioned centring position Pc (situation shown inwith a broken line).

14 FIG. 1 60 60 80 1 300 50 15 In a further alternative embodiment of the invention diagrammatically shown in, the machinecan be equipped with at least one device for generating a determined vacuum degree, for example a vacuum pump. The device for generating vacuumcan be operatively connected to at least one sectionof the paper converting machine, for example a cutting section at which a cutting roll, or a folding or interfolding section comprising a couple of folding or interfolding counter-rotating rolls can be positioned. In this case, the control unitcan be configured to set the aforementioned vacuum degree on the basis of the value of air permeability and/or paper weight detected by the optical detection deviceon the label.

300 1 10 10 10 300 In a further alternative embodiment of the invention, the control unitcan verify if the type of product to be converted by the paper converting lineis compatible with the reelmounted on the machine according to one or more parameters selected among the value of the elongation percentage, the value of the paper weight, the number of veils, the width of the reel, the typology of paper. In case that the reel of paperis not compatible with the data for producing the paper product, the control unitcan generate an alert to advise the worker to mount a suitable reel or to change the type of product to be produced.

The foregoing description exemplary embodiments of the invention 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 embodiment without further research and without parting from the invention, and, accordingly, it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize 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 that is employed herein is for the purpose of description and not of limitation.