METHOD AND INSTALLATION FOR PRODUCING SPOOLS OF WEB LIKE MATERIAL WITH VACUUM DESPOSITION

DESCRIPTION Technical Field This invention deals with installations and methods for producing spools of web like material on which vacuum depositions are performed. Specifically, but not exclusively, this invention deals with installations and methods for producing spools of vacuum metallized web like material. The web like material can be a polymer film, a paper web like material or other manufactured web like material on which vacuum deposition must be performed.

The vacuum deposition can be done to obtain a layer of metallization, but also a barrier or layer of coating of another nature, for example based on metal oxides or other materials, transparent or not. State of the Art In many industrial fields it is necessary to produce polymer film, paper or other web like supports or substrata with a coating obtained by vacuum deposition. For example, for the production of electronic components, like condensers and similar, polymer films are frequently used on which have been made thin conductive layers by means of vacuum deposition. Polymer films with metallic vacuum depositions are also used in the packaging industry. Metal oxide, silicon oxide or similar forms of vacuum depositions, are used in the food industry for packaging and protecting food products against humidity and the oxidising effect of the air.

The web like materials are usually handled in vacuum deposition [PrStelfatiorϊs so called roll-to-roll, where a web like material is unwound by a departure spool and sent around a process roll. Opposite the process roll are one or more sources of vaporisation of the materials due to form the coating on the corresponding face of the web like material. Following deposition of the material forming the layer of coating, the web like material is rewound in a spool of finished material. An example of an installation of this kind, designed specifically for vacuum, metallization is described in WO-A-03038142. Other vacuum deposition installation of the roll-to-roll kind is described in US-A-4, 693,803; US-A-4, 903,165; DE-A-37261J3; EP-A-0437946; EP-A-082654; DE- A-3738722; US-A-4, 962,725.

Vacuum deposition must be the most regular possible, the accepted tolerances being strongly dependent on the final use of the product. For example very high quality standards are required for applications in electronics, while less rigorous standards are\ applied for the production of metallized polymer film used for example for packaging.

In general, in vacuum deposition roll-to-roll installations there are control devices, systems, instruments or regulations of the quality which, continuously, check the web like material coming from the process roll and establish the characteristics of the deposition layer obtained, providing to a control unit associated to the deposition installation information on the kind and location of any defects of deposition on the web like material. These defects can be classified on the basis of their importance and density, i.e. the frequency with which they occur in a set area of the product. This information is used by the operator to subsequently scrap the portions of web like material of each spool with unacceptable defects.

The spools of web like material on which the vacuum deposition has been performed are later processed and sent to so-called slitter-rewinder machines which unwind each spool of web like material, divide it into strips of the length required and rewind each strip onto a spool or end roll. Examples of slitter-rewinder machines for this use are described in GB-A-2274835, US-A- 4055313, US-A-5620151.

For each spool the operator receives an information sheet pertaining to the presence and position of any defects in the spool and consequently intervenes on the slitter-rewinder to interrupt its operation quickly and manually remove the portions of faulty web like material, proceeding to restart norma! operation of the slitter-rewinder.

These operations require a large workforce and slow down production, impacting negatively on the production costs of the finished material.

Moreover, to manage the transformation systems correctly and for the subsequent uses of the materials on which the vacuum deposition has been performed, it is necessary or in any case useful to know of a series of process parameters relating to the materials and the conditions in which the treatment has been performed. Objects and Summary of the invention

An object of an embodiment of the invention is to provide of an installation or production system of spools of web like material with vacuum deposition, which resolve or reduce the problems mentioned above.

A further object of an embodiment of the invention is to provide an installation or a system in which it is possible to have a simpler and more efficient system of managing the information on the processed materials.

Object of a form of execution of this invention is to provide a method for managing installations or systems for producing or rather transforming web like materials on which vacuum depositions are performed, for example metallizations, depositions of barrier layers for packaging film or similar.

Essentially, according to a possible embodiment, the invention provides a method for managing equipment or production and transformation installation or system of spools of web like material with a coating obtained by vacuum deposition, including the steps of: > unwinding a spool of web like material to be treated in a vacuum deposition device, for example of the roll-to-roll kind;

> vacuum depositing a coating on said web like material, on one or both sides of the same, on the full surface, on areas limited according to a pattern, or other way; > detecting any defects of deposition on the web like material and storing information relevant to said defects;

> winding the treated web like material in a spool;

> associating to each bobbin the information on the defects found;

> automatically scrapping portions of web like material showing any defects in a sϋtter-rewrrtder on the basis of the same information, checking the sititer- rewinder automatically and managing its operation by way of such information matched with the respective spool which is put into the machine.

Essentially, according to an aspect, the method of the invention is based on the idea of combining to each single spool the information relevant to the presence of any defects in set portions of web like material of the bobbin itself and to recognise each spool in the respective slitter-rewinder, or in any case to provide automatically for each spool inserted into the slitter-rewinder, the information on the portions of web like material which must be scrapped from such spool due to the presence of defects unacceptable for the specific use to

which the web like material of the spool will be put.

In general the information relevant to the presence and position of the defects can be matched to the spool directly, i.e. it can be put on the specific spool, or stored in one or more electronic elaboration systems, from which such information can be recovered. In the^first case it is not necessary for each spool to be provided with an unequivocal recognition code, at least as regards automatic management of the slitter-rewinder and the automatic scrapping of the portions of faulty web like material, as long as the possibility is not excluded of codifying the spools by means of identification codes. In fact, in this case, the slitter-rewinder can reveal the information on the presence and position of the faulty areas from the spool itself.

In the second case, vice versa, as the information on the presence and position of the defects in the single spools are stored in one or more storage memory supports which are centralized, or in any case not directly located on the spool, the various spools will preferably be marked with a recognition code which makes it possible to match the spool to the respective set of information on defects that may be present in it. Essentially, the spool can be characterised by a recognition code which, on a . centralized or delocalised data base, is matched to the respective information concerning the faults of the specific spool marked with such code.

Thus, according to a possible embodiment, a method including the following steps is envisaged:

> store the information on any faults on a support combined to the respective spool; > transfer the information from the spool directly or indirectly to the slitter- rewinder to automatically check the operation so that the portions of web like material containing possible defects may be scrapped.

According to a different embodiment, the method includes the steps of:

> providing each spool with a recognition code; > combining the information on the defects of deposition in a spool to the recognition code of said spool;

> if required storing such information, matched to a recognition code of the spool, in an electronic file;

> when the spool is inserted into a slitter-rewinder, reading the recognition

code of such spool and recovering the information relating to any possible defects present in it, by means of the said recognition code preferably recovering it from said file;

According to a different aspect, the invention also concerns an installation or a system for producing spools of web like material with a coating obtained by vacuum deposition, including in combination;

> at least one vacuum deposition device, with an unwinder for a spool of web like material to be treated, a winder for a spool of treated web like material, a process roll, at least one source of vaporisation, and instrument to detect any faults of the deposition; and

> at least one slitter-rewinder, in which spools of treated web like material in said vacuurn deposition device are unwound, cut in longitudinal strips and rewound, with removal of any portions of faulty web like material, wherein: said detection instrument detects the presence of any faulty portions or in general one or more characteristics of vacuum deposition on the web like material wound on a spool and generates information on said faulty portions; this information is associated to said spool; and said slitter-rewinder is controlled to scrap any portions of faulty web like material on the basis of said information.

According to how the information on the defects of each spool is stored, it is for example possible to envisage that the slitter-rewinder includes a device able to read the information directly from the spool. To this end, the system can foresee that each spool is provided with an electronic support, like a transponder or an electronic tag or .other, for example applied to the axis or winding spindle of the spool. Data that allows unequivocal recognition of the spool can be stored by means of a recognition code, though this is not strictly necessary. In fact, preferably this electronic support directly stores the information on any presence and position of defects to scrap. The reader on the or each of the slitter-rewinder of the system can then interrogate the electronic system, for example through an antenna for a transponder, and receive directly the information on the presence or position of the portions of web like material to scrap during the rewinding phase. Therefore, in that case it is not necessary for each spool to be characterised by an unequivocal

recognition code. In a possible embodiment of the invention the information can be associated to the spool in print form on labels or other suitable support, with a system of script that is machine-readable, for example in the form of barcode, OCR characters or the like. In that case, the system or reader will include for example a bar code reading laser head, a magnetic system for reading script in magnetic characters, a system for viewing and interpreting OCR or the like.

According to a different embodiment, the slitter-rewinder can include, in addition to or alternatively to the same reader of the information directly from the electronic support on the machine, a device of automatic recognition of the spool of web like material on entry, for example also in this case a simple system of reading of an unequivocal code stored in the transponder, or in an electronic tag of other kind, a reading system for barcode or a code in OCR characters or the like.

In a possible embodiment, in which the spools are identified individually by a recognition code, a storage archive of the information is provided, related to the faults and to their position on each single spool. In this archive there is a database where to each recognition code of each spool processed in the vacuum deposition device or in each vacuum deposition device is matched the information relating to the presence and position of any defects. According to a possible embodiment, the system includes in combination:

> associated to said at least one vacuum deposition device, a first control unit designed to receive information from the detection instrument within the device itself; > associated to said at least one slitter-rewinder, a second control unit configured to receive information relating to each spool that is inserted in the slitter-rewinder and concerning any faults of deposition on said spool, wherein said second control unit is designed to control the slitter-rewinder to automatically scrap the portions of web like material of the spool which contain any defects.

According to a different aspect, the invention also deals more generally with a system for producing spools or rolls of web like material with a coating obtained by way of vacuum deposition^ including in combination; - at least one vacuum deposition device, with an unwinder for a spool of

web like material to be treated, a winder for a spool of treated web like material, a process roll, at least one source of vaporisation, and a first control unit; * at least one slitter-rewinder, including a second control unit, in which spools of web like material treated in said vacuum deposition device are unwound and rewound to form rolls of web like material of size smaller to that of said spools; wherein: said first control unit generates information on at least one process parameter and concerning a spool being processed and associates said information to said spool in a form that is automatically detectable by a machine.

In general, it is possible to store, associating them to the single spool, one or more process parameters, relevant to the kind of material, the conditions in which the vacuum deposition occurred, the quality of the deposition, and then (according to a preferred embodiment of the invention) the presence of defects of deposition and their dislocation within the spool. These defects of deposition can be composed of pinpoint defects or in any case with a limited superficial extension, detectable through a suitable system of vision. More in general, however, a deposition defect can also be understood as an irregularity or non- uniformity of the coating obtained by means of the vacuum deposition. An excessive oscillation of the thickness or optical density of the deposition, i.e. of the coating obtained under vacuum can also be a detectable and storable defect. This can also verify itself on large and extended areas of the web like material, for example due to irregular functioning of one of the sources of vaporisation, of a temporary shutdown, or insufficient distribution of materia! to vaporise. A non-uniformity which gives rise to a defect can also be due to a temporary absence of functioning of the control loop which regulates the power of each single source depending on the optical density and/or thickness of the material forming the deposition, detected through suitable optical systems, radio frequency or similar.

In general, the process parameters, which can be stored with the single spools, can relate to one or more of the following:

- manufacturer of the starting substratum (film, paper or other web like material), on which the deposition is made;

material forming the substratum, including any presence of a preliminary . treatment, on which the coating obtained by means of vacuum deposition is applied; thickness of coating; - uniformity of coating;

- optical density of coating; any temporary disabling of one or more sources of vaporisation with consequent variations of the physical characteristics of the deposition;

- deposited material; - speed of feeding the web like material or substratum and therefore speed of unwinding from the departure spool and /or speed of winding on the spool of coated material;

- draw, i.e. dragging tension, in the web like material;

- presence and position of defects. According to an embodiment of the invention, the method includes the steps of:

> in a vacuum deposition device, unwinding a spool of web like material to be treated;

> vacuum deposition of a coating on said web like material; > detection of at least one process parameter;

> winding the treated web like material to form a spool;

> storing in machine-readable form, associating it to the spool, information on said at least one process parameter;

> using said information in at least one subsequent operation of transformation of the spool.

In a development of the invention, the system or installation of transformation is realized so that the rolls produced by the slitter-rewinder or rewinders-slitters are associated to data or information relating to one or more process parameters. Also in this case the information can be stored in an electronic file, for example in a network server, and possibly transfused to a magnetic, optical or other support, suitable for storing the digital data relevant to the information on one or more rolls. Each roll can be associated to an unequivocal identification code, so that it is possible in the subsequent phases of use to associate the informatioii on the process parameters (stored in a

common support) to a set roll.

According to preferred embodiment, this data is inserted and stored in an electronic support, such as a memory of a transponder, of an electronic tag or similar, bound or matched with the single roll. In this way the association between stored data and roll is immediate and does not require a code.

According to a further aspect, the invention deals with a product in the shape of a spool or roll of web like material with a vacuum deposition, including - associated to it - information on at least one process parameter, said information being in a machine-readable form. In a possible embodiment, the product includes an electronic support with a memory, on which the information of the relevant process parameters is stored.

Further advantageous features and embodiments of the invention are set forth below and described with reference to examples of realisations to which the invention is not limited and are indicated in the claims included, which are part and parcel of this description. * Brief description of the drawings

The invention is better understood following the description and the drawing which shows a practical non-restrictive embodimentof the invention. More specifically, they show: the

Fig. 1 a schematic representation of the installation according to a first embodiment;

Fig. 2 a schematic representation of the installation realised according to the second embodiment of the invention; and Fig. 3 a schematic representation of the operations of rewinding and scrapping of the faulty portions of the single spool in the slitter-rewinder. Detailed Description of Embodiment of the Invention

In the description which follows specific reference will be made to the storage of information relating to the defects of the vacuum deposition of a spool of web like material, detectable through suitable optical detection systems. This information is indeed particularly useful for allowing subsequent processing in a slitter-rewinder and eliminating automatically without the need of intervention of the operator the portion of web like material with the unacceptable defects.

Scrapping of the portion containing the defects can occur by cutting transversally and/or by the longitudinal cutting of an area of the web like material.

The defects, as mentioned previously, can be local defects of small superficial extension, possibly distributed with a variable density which - in certain areas - makes the material unusable due to the concentration of small defects. However, the defects can also consist of unacceptable oscillations of the optical density or of the thickness of the coating, or the total absence of coating, for example due to the accidental turning off of a source. Permanent deformations caused by excessive traction exerted during the unwinding and rewinding of the base material or- substratum on which the deposition is performed can also be considered defects which result in the need to remove portions of web like material.

It must be understood, however, that in general the invention is not restricted to this specific embodiment. In a different embodiment it can be possible to store one or more process parameters, without these being then used to automatically control subsequent operations of transformation, but for example simply to localize and characterize the spools in an installation or a factory or in a distribution network. Generally speaking, therefore, the invention deals with any system that traces the spools with the aid of digital information systems and automatic reading of digital information which allow to identify the spool and associate to it relevant information to one or more process parameters.

Fig. 1 schematically shows an .installation or production system including by way of example two devices for vacuum deposition, in the example illustrated two roll-to-roll systems, identified as 1A and 1B. This installation or production system can also include a different number of vacuum deposition devices, for example also a single device or more than two devices.

The system shown as an example further includes one or more rewinders-slitters, only one of which is shown in Fig. 1 and indicated by 3. The spools of web like material B coming from devices 1 A, 1 B, and on which the deposition has been performed, for example metallization or other, are conveyed to one or the other of the one or more rewinders-slitters 3 present in the installation, to be here unwound and cut longitudinally into more strips

individually rewound on spools or rolls of a reduced axial size.

The structure of each vacuum deposition device is not described here and is known to those skilled in the art. In general devices 1A, 1B can assume any suitable configuration to perform vacuum deposition with the roll-to-roll technique. Devices 1A, 1 B can be realised for example according to the teachings of one or more of the technical documents mentioned beforehand in the introductory part of this description.

To understand the present invention it is enough to note how a detection instrument to detect any defects of deposition is positioned between the process roller, identified by 5 and the spool B of treated web like material in the rewinding phase. This equipment is schematically indicated by 7 and can be of a kind that is familiar and normally used to detect defects that may be present in the web like material and their position along the length of the web like material. In traditional systems this information is then printed on a work sheet, which is matched to the respective spool to inform the operators in charge of the subsequent rewinding operations, who will manually scrap the faulty portions of each spool.

Device 1A, 1B can also be fitted, in a way known per se, with draw detection sensors, i.e. of the tension which the web like material undergoes during processing. These sensors can be composed of load cells on the guide rolls located along the path of the web like material or substratum. Speed detection sensors of the web like material can also be provided in a way known per se. More speed sensors can also be located along different points of the path, to establish any difference of speed in different points of the path, indicative of a lengthening and therefore of a longitudinal deformation of the web like material. Moreover, tools for detecting the characteristics of the deposit, i.e. of the coating or deposition obtained by condensation of the material vaporised under vacuum vacuum, can be used. These are known and can be of an optical, radio frequency or similar kind. Examples of devices, tools or sensors for this purpose are described in WO-A-03095937 and in the patent literature recalled therein. These tools _^ serve in general to control the uniformity of the deposition and provide a control signal on the basis of which a control unit 9 of installation 1A, 1 B controls the operation of the single sources of vaporisation, indicated by 100 in the drawing, for example by regulating the

electrical power supplied for their heating and/or speed of feeding of a metal wire (typically aluminium) to be moulded and vaporised to obtain the coating on the web like material substratum.

According to the invention, at least some of the information from the detection equipment 7 and/or from the other sensors, tools of detection or devices mentioned above, are transferred to control unit 9, which is fitted on each installation or vacuum deposition device 1A, 1B. In this embodiment control unit 9 is connected to a peripheral unit 10 which, through an appropriate antenna 11 , transfers the data on the defects detected by equipment 7 onto an electronic support 13 combined to each spool B produced from deposition device 1A, 1 B. This electronic support can be a transponder.

To each spool B can also be associated, in addition to the relevant data on the faults detectable with equipment 7, information on for example the origin or pertinent information to process parameters different or further to the presence of defects, like for example, the kind and the nature of the materials which form the substratum and/or the coating (data inserted into control unit 9 by the operator), the conditions of unwinding/rewinding (tension in substratum, the so-called "draw"; speed of unwinding, etc.), the greater or lower, uniformity of the coating and characteristics thereof (thickness, optical density, etc.). The process parameters can be used to control subsequent operations connected to the transformation and/or use of the material or simply as information to go with the material and/or track the process.

Each spool B is then transferred to one or the other of rewinders-slitters 3 present in the installation. Each of these rewinders-slitters is fitted with its own control unit 15, below called second control unit, fitted in turn with a reader 17, for example an antenna for reading the information stored on each transponder, electronic tag or similar 13 of the spools B which are inserted in slitter-rewinder 3. In this way, each time a spool B is inserted in slitter-rewinder 3, the latter is able to receive through antenna 17, on its own programmable control unit 15 the information on the presence and position of the faulty zones of the film or other web like material on spool B, portions which must be scrapped in the subsequent rewinding phase, or other information pertaining to the production process. Scrapping is facilitated by the control over the various elements of the slitter-rewinder by control unit 15.

Essentially, as shown in Fig. 3, in the slitter-rewinder spool B is divided into single strips S of web like material, which are wound on spools or rolls B1 of minor height, i.e. lower axial length and/or lower diameter (and therefore containing a smaller length of web like material). Portions P of web like material M containing unacceptable defects D are cut and scrapped based on the information stored on electronic support 13.

The installation shown in Fig. 1 and described to here is managed on the basis of the principle of physically restricting to each spool B a support able to contain the information related to the portions of web like material N to scrap and transfer such information according to second control unit 15 of the slitter- rewinder. This simplifies the overall layout of the installation or production system, though it implies the need to apply an electronic support to each spool B. This electronic support can contain more information than that required to automatically handle the rewinders-slitters 3 to eliminate the faulty portions of web like material. For example each electronic support can contain an unequivocal recognition code of each spool. Within the factory where the various processes are carried out the electronic supports matched to the single spools can in this way be used for other functions, for example to know at any time where a specific spool is, as these systems can be very large and have different temporary storage areas. The electronic supports with the unequivocal recognition codes can also facilitate management in different factories where the various processes on the single spools are performed.

In an alternative embodiment of the invention it is not envisaged to match the information relating to the presence and the position of the faults directly on the respective spool, but rather to manage them through an information system, which includes preferably a server and one or more elaboration units. A configuration of this kind is shown by way of example in Fig. 2 where the same reference numbers indicate equal parts or parts equivalent to those of the shape of implementation shown in Fig. 1 In this example of embodiment, each control unit 9 of vacuum deposition devices 1A, 1B is interfaced for example with a server 20 or more in general with a processingunit, within which is configured a data-base with the information necessary to implement the method according to this invention. Each programmable unit 9 can be* connected to the server or to other

processing unit 20 by a cable, a wireless system or any other criterion or suitable tool. What is important is only the possibility of transferring data from single programmable units 9 to server 20.

Programmable units 9 generate for each spool B processed by single device 1A ₁ 1 B a recognition code which, in the example shown, is printed by a printer 12 in a way that can be read by an electronic reading system for example script in OCR characters, a bar code or similar. An adhesive label E or other suitable support containing the code is then applied by the operator on spool B as it exits from device 1A, 1 B. The possibility that each spool B can also be associated to an electronic tag, transponder or other electronic support is not excluded, where control unit 9 stores a recognition code of the spool. The information on any presence and position of defects on the web like material wound in single spool B is, on the contrary, transferred from each control unit 9 to server 20, matching such information directly or indirectly to the recognition code of the respective spool, to allow subsequent recalling of information matching it with the correct spool.

Spools B are then processed in rewinders-slitters 3 according to the criterion already described with reference to the previous embodiment. In this case, however, control unit 15 of slitter-rewinder 3 to whom specific spool B is addressed works in .he following way: firstly the recognition code applied to support E of the spool is read by a suitable reader. As indicated before, this code can be a code printed on a label E, in which case the reader could be a laser barcode reader or an OCR code reader or other. If, on the contrary, the spool recognition code is stored in an electronic support, control unit 15 will be fitted with an antenna 17 or other system of interrogation arvd receipt of the information by the electronic support matched to spool B.

Having recognised spool B, control unit 15 interrogates the processing unit or main server 20 to receive from its data-base information on any presence and position of faults on relevant spool B. Thanks to the matching between recognition code and information worked by control unit 9 and stored in server 20, control unit 15 is able to recover the correct information and then manage and control the slitter-rewinder by consequence.

In addition to or alternatively to the information relating to the defects of deposition, the information above can contain process data of another kind as

described above.

It must be understood that the two described embodiments are purely by way of example as the criteria set out here can be implemented in effect according to different methods, also combining different methods of labelling of spools and storage of the respective data or information concerning the spools themselves, on the presence of defects, on their size and positioning and so on.

To achieve a further level of automation and to facilitate the use and/or any further operations of transformation of the spools or rolls B1 obtained by cutting and rewinding in slitter-rewinder 3, it is possible to foresee that one or more process parameters concerning the single roll B1 can be in turn stored and associated to the roll itself. This can occur by storing the data on processing unit 20 and, if required, generating an optical support or magnetic support with the data of one or more rolls. The rolls can be fitted with a recognition code to match the data on the support common to the respective roll. Alternatively and preferably through a system of automatic script 16 (for example an antenna for storing on the memory of a transponder) control unit 15 can store the data on single transponders or electronic tags 18 (Fig. 3), which are fitted on each roll or spool B1. The process parameters stored on transponders 18 or in any case associated to rolls B1 can be related to the process implemented in the vacuum deposition device 1A, 1B and/or the process implemented in slitter-rewinder 3 or in any other point of the production and/or transformation cycle which has lead to the production of rolls B1. According to a preferred embodiment of the invention, a system to read and/or control the characteristics of the coating obtained by vacuum deposition can be combined with the slitter-rewinder 3. In fact, manipulation of the web like material in the slitter-rewinder can lead to accidental damage, or even a simple reduction in the quality, for example of the thickness or optical density of the deposition. These process parameters can be controlled by readers 4 connected to the control unit of slitter-rewinder 3, for storing information to match to the rolls or spools produced by the slitter-rewinder, together with any other data, on electronic support, printed label or other means. It is thus possible to obtain on exit finished products with a kind of certificate of

guarantee, or in any case bearing information on the quality and/or any presence of faulty areas or in any case areas characterised by an oscillation of the parameters characteristic of the product.

It is understood that the drawing shows nothing but an example given only as a practical demonstration of the invention, which can vary in the forms and dispositions without getting away from the scope of the concept which is at the basis of the invention.