EP1153747A2 - Device for managing the printing faults detected within a printing machine - Google Patents

Abstract

A device for processing of printing defects detected in a printing machine which in a first phase delivers a printed support. The printing defects (20, 21, 22) on the support (1) are detected in a detection station. A database connected to the detection station can simultaneously store information relating to each detected printing defect. The processing device connected to the database can, in a second phase, process the stored information in order to evaluate the quality of overall printing of the printed support and can use various possible scenarios, even before the support (1) is cut in a third phase, to define all those portions (23) of the support which should be removed in order to improve the final quality of the printed product within the limit of a restriction in the number of portions which it has been agreed to cut out.

Description

The present invention relates to a device for managing printing faults detected in a printing machine delivering a printed product for the packaging industry from a medium such as continuous sheets or strips of paper, cardboard, or other material flexible like polyethylene for example.

The present invention essentially relates to a tool for assisting in the decision allowing in particular to visualize, for example in a form schematic, tabular or in the form of an image, the whole of a support such that a band marred by all its faults previously detected by a conventional device. Thanks to the application of different virtual filters, this tool allows to visualize several representative cases of the level of tape quality and to count and identify in each case all portions of tape covered with too marked defects that should be to eliminate, this even before taking an irreversible action of cutting and ejecting tape faults.

The production of flexible packaging, precisely from strip material, goes through different successive phases which require several consecutive unwinds and windings of coils to pass from the printing of the strip to the packaging of the products for which these packaging is intended.

In a first step, we start by printing the tape to from a blank reel of a width which can generally contain several generally identical packaging imprints. The number of impressions thus arranged side by side over the width of the strip defines the number of tracks in this band. Once printed, the tape is dried and then examined by a device making it possible to detect and recognize and account for all types of printing faults it can present. These faults are identified in a Cartesian system and stored by the detection and localization device which records their position by in relation to an origin, in the longitudinal direction, and in relation to the different tracks they occupy, in the transverse direction. Some devices allow to detect so-called "emerging" faults which generally result from wear or of a drift of one of the organs of the press and which can only increase over the printing. The acknowledgment of any defect will cause intervention of the machine operator who will mark the approximate location where the defect was detected by the installation of a butterfly (cardboard tab) on the strip so that once the strip is rewound, the butterfly protrudes slightly from its edge and is easily spotted. This intervention can also be done through an automatic labeling machine. If necessary, the machine operator will even be forced to stop printing to remedy the possible cause of an emerging defect before it occurs become more tolerable. Once checked, the printed tape is then rewound for machines delivering a wound product, for example opposition to products presented in sheet form.

The second step in the conventional process is to take the printed reel and cut it lengthwise to form thereafter as many new small reels as there are tracks on the tape. To do this, the printed tape will again be unwound gradually when introduced into a rotary cutter which will allow divide in the longitudinal direction along the line defined by the delimitation of tracks it contains. During the tape unwinding phase, the driver should watch carefully when approaching all the butterflies that were previously affixed to the tape. The tape should be stopped at the arrival of each butterfly and the driver will be forced to find the fault found, find where it starts and where it ends before remove by two cross sections in the tracks concerned. Released of their deficient portion, the corresponding ends of these tracks will be glued with adhesive tape for example. All tracks will then simultaneously rewound before being delivered in the form of independent coils, to the customer who will proceed to the packaging of his products by unwinding each of these small coils in a third and last step.

It's in the second stage, before the transformation begins of the printed reel, which the object of the present invention finds mainly its use. We already know detection devices printing errors, such as those previously mentioned and illustrated in patents EP 452 769 and EP 554 811, which allow viewing by the through cameras and fault control screens appearing on a strip or on plate elements during printing.

Printed tapes can either be used as a base material for machines producing packaging produced in the form of elements in plate either be reworked and stored again as coils smaller for packaging products using rolls packaging. If the first category of products produced allows very easy handling, especially when it comes to eliminating and ejecting production line all the defective elements, we understand very well that it is not the same to accomplish such an operation from products stored as continuous strips. In the event that the final product of the packaging production is a continuous strip stored as coil it indeed becomes difficult and much more expensive to remove all portions of the tape that have been found to be defective. During the first stage, the elimination of such portions would require stopping complete printing machine, which of course would seriously hamper the production rate and could cause other successive problems printing during the always delicate phase of restarting the rotary. Elimination of these defective portions during the second stage gives rise to the same problems which relate this time to the rotary cutter. However, this machine has the advantage to be of a simpler and less fragile constitution, causing no particular risk for the band when the band is forced to follow repeated successive stops and starts.

The number of fittings present in the final coil conditions however to a large extent the estimation of its quality and affects naturally its selling price accordingly. For technical reasons easily verifiable, it turns out that the band connections pose regularly problems in packaging machines products which constitute the third stage of use of these coils. As a result of these problems, many customers generally require that these coils do not include more than 2 or 3 fittings at the expense of residual printing defects they may still contain.

No device known to date makes it possible to view the state of the tape in its entirety with its faults in order to be able to manage them by different scenarios, a priori in unlimited numbers. Each of these cases becoming representative of a certain modulation of the degree of tolerance of these faults, in order to optimize production and obtain the best compromise possible between the maximum number of fittings authorized by the customer and the number of residual defects which can still be considered as admissible.

The object of the present invention is therefore to provide a tool to assess the overall print quality of the tape and define, using different possible scenarios and even before undertaking an irreversible cutting action, all the portions that would be appropriate judiciously to delete as a priority from the maximum number of tape fittings accepted by the customer.

This goal is achieved thanks to a device in accordance with what the claim 1.

La figure 1 est une représentation schématique de l'état d'une partie de bande imprimée.

La figure 2 est une représentation schématique des principaux organes intervenant dans la phase, telle que connue à ce jour, de l'impression de la bande.

La figure 3 est une représentation schématique des différents organes intervenant dans la phase de gestion des défauts et de découpage de la bande.

The invention will be better understood from the study of an embodiment taken without any limitation being implied and illustrated by the appended drawings in which:

Figure 1 is a schematic representation of the state of a portion of printed web.

Figure 2 is a schematic representation of the main bodies involved in the phase, as known to date, printing the tape.

FIG. 3 is a schematic representation of the various bodies involved in the phase of fault management and cutting of the strip.

Figure 1 shows in schematic form the state of a part of a strip 1 from a rotary printing machine. This band includes a primer 2 in its downstream part and two edge edges 3, 4 between which is printed a mosaic of patterns 5 left by the cylinder rotary machine printing. The printed patterns can be identical or not but each of them alone will constitute a packaging after the final stage of production. The patterns 5 are carefully aligned and form, in the case shown, three separate tracks 11, 12, 13. Marks marking 14, which may be self-adhesive tabs for example, are affixed in either edge 3, 4 at intervals rigorously regular. Different printing faults 20, 21, 22 are shown schematically in this figure. These faults are different by their degree of importance which is low for printing defects tolerable 20, medium for printing defects 21 considered to be borderline, and high for intolerable printing defects 22. A grouping of several intolerable faults 22 therefore justifies the choice of a portion of strip 23 which it would be desirable to eliminate by a downstream cross section 24 and a section upstream transverse 25. It will be noted that this portion of strip 23 must not necessarily contain all tracks 11, 12, 13 and that only tracks tainted with defects should be skillfully cut by the cuts 24 and 25.

Figure 2 gives a schematic representation of the main organs involved in the printing phase of strip 1, which phase is the first step in the packaging manufacturing process. AT from a blank reel 30, of a width such that it can generally contain several imprints or printing patterns 5, the continuous strip 1 scrolls from upstream to downstream in the direction of travel represented by the arrow 29. This continuous strip passes successively through different stations, the most ordinary of which is an introductory station 31, of which the strip is issued, one or more printing and drying stations 32, a station 33 for detecting and locating printing faults, a traction station or group 34, allowing the belt to be tensioned and compensate for voltage fluctuations using a Walkman, and finally a receiving station 36 in which the continuous strip 1 is stored under in the form of a printed reel 37.

During the printing phase, tape 1 may be marred by various printing defects 20, 21, 22 among which we can cite for example absences, surplus or splashing of ink, oil stains from a part of the machine, or from timing or markings which cause discrepancies between the impressions of the colors of base of the printed motif. Other more progressive printing defects, and less stealth, constitute the so-called "nascent" faults which are the warning of a deterioration in progress due to normal wear of one or more parts of the printing machine such as the ink scraper, the printing form or the pressure roller. Although initially within the tolerance limit, these defects evolve and grow over the printing to become excessive and intolerable.

It is in order to be able to detect all these faults that once printed tape 1 passes through a reading unit 40 consisting of at least minus a camera 41, whose field of vision is made clearly visible by a lighting device 42, and a measuring instrument 43 making it possible to synchronize the acquisition of the image with the scrolling of the tape 1. The camera 41 is connected to a control unit 45 which takes account of these faults and this control unit is connected to a control monitor 44 which allows them to be viewed. A pulse generator 46 connects schematically the printing and drying station 32 per unit command 45. This pulse generator 46 constitutes the station clock 33 for detecting and locating faults. Depending on the speed it compensates for tracking errors that result basically normal variations in tension and length of the tape, which errors thus distort the accuracy of the information transmitted by the measuring instrument 43. The latter simply consisting of a rubberized roller entering, without sliding, in permanent contact with the band 1 and delivering between a thousand and two thousand pulses each turn roulette for example. The pulses from generator 46 are transmitted to the unit 45 which, in combination with the pulses delivered by the measuring instrument 43 can thus locate on a virtual longitudinal axis, representative of the length of the strip 1, the abscissa at which a defect 20, 21, 22 will have been detected. The camera 41 makes it possible to detect in which track 11, 12 or 13 are the faults encountered.

The control unit 45 is therefore thus able to identify, according to two perpendicular axes, the position of the defects 20, 21, 22 on the strip and to inventory them according to their characteristics and their rate of recurrence for example. All this information is stored in a database 47 connected to the control unit 45. The origin of the axis longitudinal used to identify all printing faults is indicated by the first registration mark 14 affixed by a marking device 48 in the edge of the edge, 3, 4 of the strip 1. In order to limit errors systematic and improve the accuracy of fault identification, several marks 14 will be affixed to strip 1 at strictly intervals regular. These registration marks 14 will each constitute a new origin which will be taken as reference in the second stage of the process for developing the strip 1. This device 48 can for example be a labeling machine controlled by control unit 45 according to pulses received both by the measuring instrument 43 and by the pulse generator 46.

Figure 3 is a schematic representation of the different organs involved in the strip 1 cutting phase, which phase is the second step in the packaging manufacturing process such as previously described. The printed reel 37, previously issued from the reception station 36, is placed in a new introduction station 50. The latter is located upstream of a second production line which allows successively to manage, according to the present invention, all data relating to printing faults 20, 21, 22, stored previously, then start cutting the printed tape 1 according to the best compromise evaluated by a device 51 for managing these defaults. This device also makes it possible to control all the operations of cutting of the strip 1 which in the great majority of the time is carried out in the direction of its movement 29 by means of rotary blades of a longitudinal cutting station 52 and sporadically perpendicular to its direction of movement 29, by means of a device transverse cutting 53. It is during the longitudinal cutting that the tracks 11, 12, 13 will be separated from each other and that the edges of bank 3, 4 of strip 1 will be eliminated. These tracks have become independent are going to be finally wound up one last time in a second station reception 55 to form narrower coils 56, 57, 58 constituting the final product of this production line. It goes without saying, of course, that the number of these coils is a direct function of the number of tracks in the tape once printed.

As provided in the embodiment of the present invention, the printing defect management device 51 comprises a unit for reading 60 connected to a management unit 65 and an interface 70 for managing stored data, placed between the database 47 and the management unit 65. The reading unit 60 consists of two reading members, namely one detector 61 of registration marks 14 and a second measuring instrument 62 whose utility is perfectly identical to that of its counterpart 43 described previously. The purpose of detector 61 is to re-synchronize the identification of faults with the sometimes unstable running of the tape, thanks to detections registration marks 14 previously defined as fixed origins perfectly known. The measuring instrument 62 is directly connected to the management unit 65 while the detector 61 is indirectly connected to it by through a second pulse generator 63. The latter aims to provide a digital synchronization top with each pass of a brand marking 14.

The management unit 65 constitutes the pilot element of the entire printing defect management device 51. She orders the advancement and the longitudinal cut of the strip 1, acting on the drive common of the introduction station 50, of the longitudinal cutting station 52 and the receiving station 55, but also drives the blade of the receiving station transverse cutting 53 in the event that the latter is automated. The management unit 65 manages the operation of all these organs in function information it draws from the data management interface 70 relating to the faults treated. This interface indeed includes a unit of treatment 71, comparable to a computer console. It is through this interface 70 that the machine operator can manage and process all information that has been previously collected in the database 47; the latter being connected to the processing unit 71. The interactive dialogue between the machine operator and the processing unit 71 is done through an output device 72, such as a monitor, and an input device 73 can be a keyboard, a mouse or the tactile part of a screen by example. The processing unit 71 is also connected to a bank of filters 74 the use of which is described below. Being composed of units forming a standard computer station, this interface 70 could advantageously be set back from the production line, in a control room away from the noise for example.

The operation of the fault management device 51 is as follows: Having access to all the information that describe in particular the type, importance and location of each of the defects 20, 21, 22 inventoried, the processing unit 71 is capable of returning all this data to the operator who can then view it on the monitor 72. This information may be presented to him in the form of an image or tabular or, like Figure 1, in schematic form more illustrative but always corresponding to the current state of the stored tape in the printed reel 37. The management by the processing unit 71 of information recorded in the database 47 makes it possible to provide additional events arising from statistical results performed on the entire length of the strip. This combination of information provides many advantages which will allow for example to quantify the overall tape print quality, view all areas reviews where the impression turns out to be of poor quality, and to simulate different splitting scenarios depending on the application of a certain number of virtual filters masking faults deemed to be of lesser importance.

For this purpose, the operator can have access to different tools computer which allow to create said virtual filters and then store them at will in the filter bank 74. These virtual filters are presented usually in the form of a list of alphanumeric instructions decodable by a computer system. They group all the conditions which exclude the disclosure of defects defined as secondary according to selected criteria. The application of one or more filters, on the data representative of the printing faults 20, 21, 22, allows to better define the ideal locations of the transverse cuts 24, 25 authorized by the customer in limited number. Knowing all the history printing of the reel 37, the operator will therefore be in the presence of a tool decision support allowing him to optimize the final quality of this coil. Finally, note that the creation and choice of the most appropriate filters could be as well defined manually as chosen automatically through a search algorithm for example.

Once the final configuration of the transverse cuts 24, 25 has been chosen, the printed reel 37 can begin to unwind and the transformation process of this coil can begin. Band 1 first scrolls under the measuring instrument 62 which records its footage from the origin of the longitudinal tracking system once that this has been recognized by the detector 61. This origin is defined the first time by the first registration mark 14 encountered, then successively incremented and replaced by each of the new brands marking 14 recognized as the tape 1 unfolds. In normal times, band 1 continues on its way to pass through the longitudinal cutting 52 before coming out in the form of strips whose width strictly corresponds to that of tracks 11, 12, 13. Knowing each time the abscissa at which is the next transverse cutting 24, 25, the management unit 65 takes care of the data which are transmitted by the measuring instrument 62 while taking into account the number of registration marks 14 already encountered. When the time comes, unity management sends a signal to the tape drive devices in the stations 50, 52, 55 and gradually stops the unwinding of the reel printed 37 so that the downstream cutout 24 provided on the strip 1 stops at the height of the transverse cutting device 53. The latter can be made simply by a sharp instrument such as a blade, arranged perpendicular to the direction of movement of the strip, which will section the track (s) 11, 12, 13 with faults at the chosen location between two adjacent printing patterns 5. The upstream part of band 1 will be then deflected to waste coils 54 which will store the tracks of all the portions of strip 23 which will have to be removed from strip 1. The number of waste reels 54 being of course directly a function of the number of tracks on the tape. The upstream cutting 25 will be carried out in the same way way. It is then enough to reconstruct the continuity of the tracks cut in strip 1 by joining the remaining upstream and downstream parts. Adhesive tape carefully affixed allows this joint to be made very simply.

Aside from the direct benefits of the present invention, it also appears that the latter could also feed a flow of information used for statistical purposes allowing to know the evolution of the quality of the products produced over time in providing, for example, a production traceability report for the end customer or for internal use. This information could also to better manage the maintenance of printing machines and anticipate the appearance of a wear defect before this wear becomes too much important. Therefore, some machine parts could be advantageously replaced in time, even before starting the cycle of printing, thus avoiding the need for very little maintenance work desirable during printing. Finally, on a more qualitative level commercial, said device would also confirm and guarantee, by issuing a certificate for example, the minimum quality required by a customer on the reels 56, 57, 58 which would be delivered to him.

The description of the device of the present invention refers to supports presented in the form of coils and continuous strips but it is quite obvious that these products can be very well substituted by discontinuous sheet elements stored in stack form for example.

Many improvements can still be made to The subject matter of this invention within the scope of the claims.

Claims (10)

Management device (51) for printing faults detected within a printing machine delivering, in a first phase, a printed product (37) obtained from a support (1) which, once printed, comprises on the one hand a plurality of marking marks (14) affixed at strictly regular intervals and on the other hand a mosaic of patterns (5) constituting packages arranged in one or more adjacent rows or tracks (11, 12, 13 ), as well as printing faults (20, 21, 22) which are detected as the support (1) advances in a detection station (33) making it possible to view and locate the locations of the printing faults (20, 21, 22) using a Cartesian tracking system applying to the support (1), which management device (51) being connected to a database (47), it - even connected to said detection station (33), which simultaneously makes it possible to store information tions relating to each of the detected printing faults, characterized in that it is connected to said database (47) so as to be able, in a second phase, to process the stored information in order to assess the quality of printing of the entire printed product (37) and of defining, before even undertaking in a third phase a cutting of this support (1), all the portions (23) of the latter which it would be judicious to eliminate in order to improve the final quality of the printed product (37). Device according to claim 1, characterized in that the processing of the information stored in the database (47) is carried out by a data management interface (70) connecting said database (47) to a management unit (65 ) which allows, during the third phase, to control the progress of the support (1) by acting on the driving members driving the latter, to re-synchronize the identification of printing faults (20, 21, 22) thanks to registration marks (14) affixed during the first phase, and to derive from a processing unit (71) all the data necessary for said support (1) of the printed product (37) to be stopped in a cutting station (53) in line with a downstream cross section (24) and then an upstream cross section (25) which delimit said portion (23) of the support to be cut. Device according to claim 2, characterized in that the portion (23) of the support to be cut is limited to portions of corresponding tracks (11, 12, 13) marred by printing defects. Device according to claim 2, characterized in that the data management interface (70) comprises said processing unit (71) connected to the database (47) and to the management unit (65), a peripheral input (73), an output device (72) making it possible to view all of the printed product (37) marred by all its printing faults and to deliver at least one production report, as well as a bank ( 74) offering a choice of virtual filters which, through the output device (72), make it possible to mask at least one fault which has been detected. Device according to claim 4, characterized in that the choice of virtual filters is made on the basis of at least one exclusion criterion applied to the information stored in the database (47), and in that these virtual filters can be used, created, deleted and modified either manually via the input peripheral (73), or automatically by the processing unit (71) after analysis of the information contained in said database (47). Device according to claim 4, characterized in that the delimitation of the support portion (23) by the downstream (24) and upstream (25) cuts results from a compromise between the number of printing defects remaining after application , on the stored information, of the virtual filter chosen and the impact that a withdrawal of such a portion (23) of support has on the entire printed product (37). Device according to claim 4, characterized in that the virtual filters consist of a list of alphanumeric instructions compatible with the information stored in the database (47) and decodable by a computer system contained in the processing unit (71 ), and in that a virtual filter can result from the combination of several elementary virtual filters. Device according to claim 1, characterized in that the information relating to printing faults (20, 21, 22) stored in the database (47) comprises at least, for each printing defect, the Cartesian coordinates of the location of said printing defect on the support (1), its level of importance and its type defined according to its visual appearance. Device according to claim 2, characterized in that the cutting station (53) of the support portions (23) comprises a cutting element controlled by the management unit (65). Device according to claim 1, characterized in that said printed product (37) is a wound and / or sheet product and in that said support (1) is a continuous strip and / or at least one sheet.

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