ES2371715T3 - CUTTING MACHINE TO CUT COILS OR PAPER ROLLS IN SMALL ROLLS OF LOWER AXIAL LENGTH AND RELATED PROCEDURE. - Google Patents

Abstract

The severing machine comprises an electronic control (30), a feed system (5, 3) for feeding logs (L) to be cut and a cutting member (15). The feed system and the cutting member are controlled by the electronic control so as to subdivide each log into a plurality of small rolls (R). The electronic control is associated with a vision system (33), which detects at least one optically identifiable element on the log (L) so as to phase the cut relative to said optically identifiable element.

Description

Slicer to cut paper reels or rolls into small rolls of smaller axial length and related procedure 5 Technical field

The present invention relates to improvements in machines for cutting rolls of paper or reels, especially made of so-called tissue paper, such as toilet paper, kitchen paper or the like, to subdivide the reels or rolls into small individual rolls intended for already packaged distribution.

The present invention also relates to a process for cutting rolls or reels into small individual rolls of smaller axial length intended for packaging and consumption.

15 State of the art

Particularly in the field of tissue paper conversion, but also in other fields of processing of web products, there is a need for the production of rolls or small rolls of a certain axial length intended for consumption and obtained by cutting or the subdivision of a roll or coil with a greater axial length. Typically in the field of tissue paper conversion to produce rolls of toilet paper, kitchen paper or the like, the bobbins are manufactured by winding a previously established amount of tissue paper, with or without the use of a spindle or winding core. . The coils or rolls obtained have an axial length approximately equal to a multiple of the axial length of the small rolls intended for final consumption, as well as head and tail parts, which must be unloaded as cut-outs.

25 Numerous machines are known for cutting these coils into individual rolls or small rolls of suitable size, which also provide the discharge of head and tail cuts. An example of such a machine is described in US-A-5799555.

These machines include a feeding system for feeding the rolls or reels to be cut, typically consisting of a chain or a plurality of chains that carry a pusher and a cutting element which cuts the head and glue and subdivide the remaining part of each coil into small individual rolls. The feeding movement of the coils by means of the feeding system and the movement of the cutting element are synchronized so that the correct operation of the

35 machine and therefore the elimination of the head and tail trimming and the subdivision of the intermediate part of the coil into small rolls of suitable length.

Recently, rolls or rolls of tissue paper have been manufactured, decorated through band printing or embossing, this is obtained by winding a web material, on which they are printed or embossed adjacent longitudinal areas also with different models or colors from each other, so that parts with different decorative models in design or color are obtained in the same coil or roll. In some cases these bands are mutually separated across white areas so that contamination of the color for printing a band with the color for printing of the adjacent band is avoided. These rolls or coils must be cut in such a way that head and tail cuts are rejected and subdivided.

45 the coil in small individual rolls by means of cuts substantially orthogonal to the axis of the coil according to cutting planes which intersect with the coil in areas of separation between the bands, in particular cuts in correspondence with the white bands that divide an area colored from the other when these bands are provided.

The cutting of these coils in a synchronized manner, this is in a phased manner with the printed models, can present some difficulties, in particular due to the fact that the paper or other web material which is wound in individual coils, it can be displaced transversely in relation to the paper feed direction, so that not perfectly identical reels are sequentially obtained. Therefore, the cutting which is performed in phase in a given coil can be out of phase in relation to

55 the printed models obtained in the reel or subsequent reels, when a displacement occurs or another phenomenon of alteration in the feeding of the paper in the rewinding machine which forms the reels.

Objects and summary of the invention

According to one aspect, the object of the present invention is to provide a machine and a method that entirely

or at least partially overcome at least one of the disadvantages of traditional machines and procedures.

The object of an embodiment of the present invention is to provide a machine which allows an adjustment of

65 correct phase of the cutting of the coils in relation to the models, the printed motifs, the embossed motifs or the like, obtained in consecutive bands on the same roll. The invention is defined in claims 1 and 10.

Substantially, according to claim 1, the present invention provides a cutting machine for cutting coils of rolled web material, comprising an electronic control, a feeding system for

5 feeding the coils to be cut and a cutting element, in which the feeding system and the cutting element are controlled by said electronic control in order to subdivide each coil into a plurality of small rolls; Typically, the electronic control is associated with a vision system, which detects at least one element that can be optically identified in said coil in order to adjust the phase of the cut with respect to said element that can be optically identified.

In some advantageous embodiments of the present invention, the optically identifiable element is defined by a print on the web material, although it would be possible to provide vision systems to see embossed motifs or other features that can be detected. optically in the roll or coil.

In some embodiments of the present invention, the electronic control controls the feeding system and the cutting element such that the coil is subdivided into small rolls in correspondence with annular bands, which subdivide consecutive parts of the coil which they must correspond to small consecutive individual rolls which can be obtained from the cutting of said coil.

For example, the electronic control can be performed for the phase adjustment of the cutting of the coil depending on the position of a separation band, which separates a first part of the coil which must form a first small roll of a second part of the coil which must form a second small roll.

In some embodiments of the present invention, the electronic control is performed for the phase adjustment of the first cut of each coil with a head cutout of the coil, said head cutout being detected by means of said vision system.

In some preferred embodiments of the present invention, the electronic control is designed in such a way that it gradually corrects any displacement between the cut and said at least one element that can be optically identified in said coil, said gradual correction being adjusted such so that the small rolls obtained from the cutting of said coil have variable axial lengths within a previously established maximum tolerance.

The vision system may be positioned away from the area in which the wound coils are cut, but preferably it is arranged near the cutting plane in which said cutting element moves.

According to claim 10, the present invention provides a method for the subdivision of a coil of web material wound into small individual rolls by means of a controlled cutting element in a manner synchronized with the feeding of the coil, in which it is provided for maintenance or phase adjustment between the position of the roll or the coil to be cut and the cutting element through the reading of at least one element that can be optically identified on the surface of said coil using a vision system

Advantageous features and additional embodiments of the process and of the machine according to the present invention are indicated in the attached dependent claims and will be described in greater detail with reference to a non-limiting embodiment of the invention.

Brief description of the drawings

The invention will be better understood by means of the description below and the accompanying drawing, which show a non-restrictive practical embodiment of the invention. More particularly, in the drawing:

Figure 1 shows a schematic side view of a slicer to which the present invention can be applied;

Figure 2 shows a diagram in axonometric view of a roll or coil which should be subdivided into small individual rolls in correspondence with white bands which separate areas or bands decorated with patterns preferably different from each other in the same roll;

Figure 3 shows an axonometric view of a small individual roll obtained by cutting the coil of Figure 2; Y

Figures 4A and 4B show schematic side views of two rolls sequentially obtained by a

65 rewinding machine in which the web material has been displaced between the winding of a roll and the subsequent one.

Detailed description of embodiments of the invention

Figure 1 shows, in a very schematic way, a slicer, indicated globally with the number

5 1, in which the present invention is incorporated. It should be understood that the configuration depicted in Figure 1 is only one of the possible configurations of a cutting machine for rolls or rolls of paper, in particular tissue paper, to which the present invention can be advantageously applied. The structure, the operating characteristics, the mechanical elements and the elements of the slicer can also vary substantially in relation to those illustrated only by way of example in the attached drawing, in order to

10 that falls within the scope of the claims.

Slicers of this type are known to those skilled in the art for example from US-A-5799555 and from other documents, as well as from numerous existing embodiments of machines in this category. Therefore, this description will only describe

Schematically the elements of the slicer necessary for the understanding of the present invention.

The cutting machine, indicated globally with the number 1, comprises a feeding system for feeding coils or rolls L which are to be cut to a cutting head 11. The feeding system can comprise for example a series of pushers 3 forced into a chain 5 driven around wheels

20 7 and 9 supported by a support structure 10. As is known by itself, the slicer 1 may be provided with more feed channels for feeding more rolls or coils R in parallel, in each channel being provided with advantageously a chain 5 with the respective pushers 3, which can also be independent of each other, for example driven by independent motors for each channel, although this is not strictly necessary.

25 The head 11 includes a rotating assembly 13 which carries a cutting blade or other cutting element

15. In the illustrated example, A-A indicates the axis of rotation of the rotating assembly 13 and B-B indicates the axis of rotation, for example parallel to the axis A-A, of the cutting element 15 represented in this case by a knife Rotating disk These axes can be parallel to each other and to the direction of feeding of the coils or rolls L, although this is not

30 necessary, other configurations with oblique axes being known. In some embodiments, the rotating assembly 13 may be provided with an alternative movement back and forth, so as to follow the feeding movement of the coil during cutting.

Other provisions of the cutting system are also possible; The system, for example, can also comprise a band knife, two disc blades instead of one, or any other configuration known per se.

In general, regardless of the configuration of the head 11, the cutting element 15 moves in a cyclic manner so that it acts together with the roll or coil L and subdivides it into small individual rolls R with an axial length equal to the final dimension of the product intended for use. Depending on the

40 longitudinal dimension of the initial roll or coil L, from each coil small rolls R can be obtained even in a large number, due to the fact that modern rewinding machines can manufacture rolls or rolls L with a length even of approximately 5 m.

In general, a feed area is provided along the feed channel for feeding the coil or roll L

45, in which the cutting element 15 acts and preferably in this area elements are provided to transversely retain the coil being cut. In the example shown in Figure 1, the numbers 21 and 22 indicate two retention elements of this type, separated from each other so that they leave between them an area in which the cutting element formed by the disc knife penetrates and moves. fifteen.

In some embodiments of the present invention, the rotation of the rotating assembly 13 is controlled by a motor 23, while the rotation of the cutting element 15 is controlled by a second motor 25. The feeding system 3, 5 for feeding of the rolls or coils L may include an independent motor 27. A central assembly, schematically indicated with the number 30, may be provided in order to control in a synchronized manner the feeding system 3, 5 through the motor 27 and the element cutting 15 through motor 23.

55 Characteristically, according to the present invention, in a suitable position along the advance path of the rolls L, a vision system 33 is arranged. In some embodiments of the present invention, the vision system 33 it can include a camera and preferably a camera for each feed channel for feeding the rolls L. The camera or another vision system 33 may be arranged

60 also upstream of the slicer 1, in a suitable position between the slicer and the station of the paper processing line upward of the slicer or in any other suitable position.

Preferably, as shown in Figure 1, the vision system 33 is placed in the cutting area, for example such that the coil L is seen when moving advancing in the cavity between the elements of

65 transverse retention 21 and 22 which transversely support the coil to be cut.

The function of the vision system 33 will be described in particular with the aid of Figure 2. In this figure a coil L is schematically illustrated, which should be subdivided into five small rolls indicated by R1, R2, R3, R4 and R5. More particularly, the coil L has an RFT head cut and an RFC tail cut, both of which must be removed through the cut by means of the cutting element 15. In fact, these head and

5 of glue have torn and defective areas of the web material with which the roll L is formed. These torn areas are due to irregularities in the longitudinal edge of the web material, to displacements of the web during the manufacturing phases and in particular during rewind, or other factors.

In the illustrated example, the small rolls R1, R2, R3, R4 and R5 are separated by bands F1, F2, F3, F4. It should be understood that the number of small rolls R1-R5 is only an example and that actually a coil or roll L can have a much longer length, resulting in the production of a much higher number of small rolls R.

The small individual rolls R1, R2, R3, R4 and R5 correspond to longitudinal areas of the web material

15 rolled up with printed or embossed patterns which can be equal to each other or different from each other, and preferably are distinguished for example by the color between a small roll and the other. The bands F1 - F4 separate one model from the other, thereby avoiding contamination between the inks of different colors used for the adjacent bands of the roll or coil L. The cutting of the coil L in small rolls R1 - R5 can occur as a result. both in phase with the bands F1 - F4 and additionally you must eliminate the RFT head and RFC tail cuts. All this must occur in such a way that the cuts are adjusted in phase as much as possible with the areas or bands F1-F4, so that in each small roll R1-R5 longitudinal areas of the edge are formed, for example without color and in as much as possible equal to each other at the two ends of the small roll, as shown in particular in Figure 3, in which one of the rolls R1-R5 is represented by way of example and is indicated by R, provided with extreme bands FA - FB.

25 The correct placement of the cutting plane in relation to the RFT, RFC and the F1-F4 bands is obtained due to the effect and with the help of the vision system 33, which forms an interface with a programmable control assembly 30 which, in turn, it controls the motors 27 and 23 described above in this document or other systems for the advance movement and the manipulation of the cutting group.

The vision system, for example a camera 33, allows to observe the coil L, which reaches the defined cutting area between the transverse retention elements 21, 22. The camera detects the image of the coil L and in particular is capable of see the RFT head cut and the point at which the printing model of the first small roll R1 begins, which must be obtained from the cutting of the coil L. The performance of the cutting element 15 can

35 be controlled or adjusted by means of the central control assembly 30 based on this observation. It can be assumed, for example, that the machine 1 is in phase adjustment in a correctly produced coil L, whose RFT head clipping has a previously established dimension. If this dimension changes due, for example, to the effect of a movement of the web material during winding, the phase between the movement of the cutting element 15 and the feeding system 3, 5 must be modified so that the cuts generated are prevented by the cutting element 15 they are out of phase in relation to the position of the bands F1-F4 or of the head and tail cut-outs RFT and RFC.

This adjustment can occur, for example, by the modification in an individual stage (that is, with only an adjustment intervention between a cut of the coil L and the subsequent cut) the movement of the system of

45 feed 3, 5 in relation to the movement of the cutting element 15. Figures 4A and 4B show an example of what can happen in the case of paper shifting with the consequent production of a reel whose RTF head cut has a dimension different from that for which the machine has been synchronized.

Figure 4 shows the situation for which the machine has originally been synchronized. A roll L1 is shown with an RFT head cut and a series of areas from which the small rolls R1, R2, R3, R4 ..., separated by bands F1, F2, F3 ... T1, T2, T3 ... indicate the planes along which the cuts must be made by the cutting element 15 to obtain the correct subdivision of the coil or roll L1 into the small individual rolls R1, R2, R3 ..., so that each small roll has an edge or a suitable extreme white band as depicted in Figure 3.

Figure 4B shows a roll L2 which has an RFT1 head cutout of a larger longitudinal dimension, that is in the axial direction of the roll L2, relative to that for which the machine has been adjusted in phase, this is synchronized . In this case, without proper adjustment, the cut T1 and the cut T2 will form a small roll R1 whose axial length is correct but which will have a white band wider than that due on one side and which will not have the white band in the other side. Also the subsequent small roll R2 will be provided with a wider white band on one side and will not have a band on the other side.

In other words, each small roll R1, R2, R3, will present an out-of-phase model in relation to the front faces of the small roll.

65 To solve this situation, the vision system 33 is used, which is suitable for detecting line 1 which stops the RFT1 head clipping of the decorated area of the first small roll R1 and, based on the signal obtained, by processing the image detected by the camera 33 or other vision system, it is possible, with the central assembly 30, to phase the feeding system 3, 5 in relation to the cutting element 15 and the movement of the disc.

5 The adjustment can occur, as schematically indicated in Figure 4B, causing, between the first cut T1 and the second cut T2, that the small roll L2 moves forward in an entity X greater than the normal length of a small roll R, length which is indicated by LR in Figure 4B. Thus, by returning the forward movement of the subsequent small rolls to the normal length LR, the cuts, subsequent to the cut T1,

10 first performed by the machine, will be arranged in positions T2C and T3C instead of T2 and T3 (Figure 4B). Therefore, the first small roll R1 defined between the cuts T1 and T2C will have a length X greater than the previously established length and will eventually be unloaded since it could cause difficulties during the packing phase. Additionally, it will be characterized by a white band at one end larger than the band due to the changed dimension of the RFT1 head cutout. Vice versa, the subsequent small

15 rolls R2, R3, ... will be cut correctly to the length LR and will have extreme white bands FA, FB placed correctly in relation to the central model.

This mode of operation, that is, this cutting procedure with the phase adjustment between the cutting planes and the position of the decorative band of the small individual rolls has the advantage that, in case of error,

20 adjusts immediately, and therefore only a small roll R1 is discarded in the illustrated example and then subsequent small rolls correctly cut with the correctly centered model between the two white side bands FA, FB are generated.

However, this procedure may have some disadvantages with respect to the management of the cuts. From

In fact, in this case it is necessary that the control system provides the discharge of the first small roll R1, which may have an excessive axial length to be handled in subsequent packaging stations, since its defect in axial length (X - LR) will be greater than the tolerance compatible with the correct operation of the packaging machines.

30 According to a different procedure for cutting and phase adjustment between the cutting planes and the decorative models on the coil or roll L, the adjustment may be gradual. In this case, when an error occurs, and is detected by means of the vision system 33, in the placement between the first cutting plane T1 and the first line I of the decorative model of the small roll R1, instead of using the assembly of control 30 for the total error adjustment by making the coil or roll L increase or decrease the advance of the coil in the necessary entity before cutting

Subsequent in the T2C plane, the adjustment will be made in a gradual manner, subdividing the error into an adequate number of stages, so that each subsequent small roll will be generated with an error equal to a fraction of the error detected globally, so that can be packaged since its difference in length in relation to the normal length LR is compatible with the permissible tolerances in the packaging machines and at the same time the out-of-phase adjustment between the cutting planes and the decorative model of the small individual rolls

40 will be compatible with the aesthetic characteristics of the small individual rolls produced.

In this second mode of operation, the subsequent small rolls will therefore be produced slightly out of phase, that is with the decorative model not centered in relation to the front faces and therefore FA and FB sidebands not perfectly equal for a certain number of small rolls, but (except

45 in exceptional cases) all small rolls can be used in downstream packaging machines, since the adjustment made is within the limits of tolerance in the axial length LR of the small individual rolls, compatible with the needs of dimensional accuracy and regularity required by the downstream packaging machines.

50 In both cases, with the vision system represented by the camera 33 or another suitable system, it is possible to automatically and quickly adjust any error in the placement of the decoration areas of the small individual rolls R1-Rn, and therefore it is possible to reduce defects in small rolls produced and intended for packaging.

It will be understood that the drawing only shows an example provided by way of practical arrangement of the present invention, which may vary in forms and arrangements without however departing from the scope of the invention which is defined by the claims. Any reference number in the appended claims is provided for the sole purpose of facilitating the reading of the claims in the light of the description and drawing and in no way limit the scope of protection represented by the claims.

Claims (8)

1. A cutting machine (1) for cutting coils (2) of rolled web material, comprising an electronic control (30), a feeding system (3, 5) for feeding the coils to be cut Y 5 a cutting element (15), said feeding system and said cutting element being controlled by said electronic control in order to subdivide each coil into a plurality of small rolls (R) characterized in that said electronic control is associated with a system of vision (33) which detects at least one optically identifiable element (F1-F5) in said coil in order to phase adjust the cut with respect to said optically identifiable element.

2.

A slicer as claimed in claim 1 characterized in that said optically identifiable element is defined by an impression on said web material.

3.

A slicer as claimed in claim 1 or 2 characterized in that said control

15 (30) controls the feeding system (3, 5) and the cutting element (15) so that the coil (L) is subdivided into small rolls (R) in correspondence with annular bands (F1 - F5), which divide consecutive parts of the coil that must correspond to small individual consecutive rolls which can be obtained from the cutting of said coil.

A cutting machine as claimed in one or more of the preceding claims characterized in that said electronic control (30) is designed for the phase adjustment of the coil cutting (L) according to the position of a separating band ( F1 - F5) for the separation of a first part of the coil, which should form a first small roll, of a second part of the coil, which should form a second small roll.

A cutting machine as claimed in one or more of claims 1 to 3 characterized in that said electronic control (30) is designed for phase adjustment of the first cut of each coil with a head cut (RFT) of the coil, said head clipping being identified through said vision system (33).

6. A slicer as claimed in one or more of the preceding claims characterized 30 because said electronic control (30) is designed in such a way that it gradually adjusts any displacement between the cut and said at least one optically identifiable element (F1-F5) in said coil, said gradual adjustment being established so that The small rolls (R) obtained from the cutting of said coil (L) have variable axial lengths within a previously established maximum tolerance. A cutting machine as claimed in one or more of the preceding claims characterized in that said vision system (33) is arranged in the vicinity of a cutting plane, in which said cutting element (15) moves.

A cutting machine as claimed in claim 7 characterized in that it comprises retaining elements (21, 22) for transversely retaining the coil in correspondence with a cutting area and in which said emission system (33) comprises an element of vision arranged near said retention elements (21, 22).

A cutting machine as claimed in one or more of the preceding claims characterized in that said vision system (33) comprises a camera associated with a microprocessor in which an image processing program runs.

10. A procedure for dividing a coil (L) of rolled web material into small rolls 50 individual (R) through a cutting element (15) controlled in a synchronized manner with the feeding of the coil characterized by maintenance or phase adjustment between the position of the coil (L) and the cutting element ( 15) through the reading of at least one optically identifiable element (F1-F5) on the surface of said coil (L) using a vision system (33). A method as claimed in claim 10 characterized by the phase adjustment of the first cut of the coil (L) with the head cutout (RFT), which is defined by the optical reading of the longitudinal dimension of said cutout. 12. A method as claimed in claim 10 characterized by the realization of a first 60 cutting for the elimination of the head clipping (RFT) of the coil and by phase adjustment of the subsequent cuts with said at least one optically identifiable element (F1-F5) on the surface of said coil (L ). 13. A method as claimed in claim 10, 11 or 12 characterized by the phase adjustment 65 between the position of the coil (L) and the cutting element (15) in a gradual manner, maintaining the dimension of each small roll (R) obtained from the cutting of the coil within a previously established range of tolerances.