Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F3/00—Cylinder presses, i.e. presses essentially comprising at least one cylinder co-operating with at least one flat type-bed
  • B41F3/46—Details
  • B41F3/54—Impression cylinders; Supports therefor
  • B41F3/56—Devices for adjusting cylinders relative to type-beds and setting in adjusted position
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F33/00—Indicating, counting, warning, control or safety devices
  • B41F33/0009—Central control units
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F21/00—Devices for conveying sheets through printing apparatus or machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F5/00—Rotary letterpress machines
  • B41F5/24—Rotary letterpress machines for flexographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F21/00—Devices for conveying sheets through printing apparatus or machines
  • B41F21/10—Combinations of transfer drums and grippers
  • B41F21/102—Combinations of transfer drums and grippers with pneumatic means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/02—Letterpress printing, e.g. book printing
  • B41M1/04—Flexographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/06—Lithographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/10—Intaglio printing ; Gravure printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41P—INDEXING SCHEME RELATING TO PRINTING, LINING MACHINES, TYPEWRITERS, AND TO STAMPS
  • B41P2200/00—Printing processes
  • B41P2200/10—Relief printing
  • B41P2200/12—Flexographic printing

Definitions

• the present invention relates to a method for automatically adjusting a printing machine of plate elements.
• the invention relates to an adjustment arrangement for a plate element printing machine.
• the invention also relates to a printing machine having an adjustment arrangement.
• a printing machine is used in the packaging industry for printing plate elements, such as sheets of paper or cardboard.
• the machine comprises several successive stations.
• a first station located furthest upstream is an introductory station successively introducing the sheets one after the other from the bottom of a stack.
• the introductory station supplies several printing stations, in the form of one or more printing units placed one after the other. Each printing group prints a color.
• a receiving station that collects the printed sheets is provided at the end of the machine.
• a flexo machine includes one or more printing units, depending on the number of colors desired.
• a printing unit includes in particular a platen cylinder around which is wound and is stretched a flexible snapshot. This photograph prints the sheet after being coated with ink thanks to a screen cylinder called anilox and an inking device. The sheet passes between the forme cylinder and a pressure roller. The impression is made from the underside of these leaves, the transport of the leaves is thus done from above.
• a forme cylinder prints one or more patterns with the same color during each rotation.
• the pictures are made with a frame that is a grid of more or less fine points. This frame is used to transform an original semitone, for example a photo, into a printable dotted image. Round dot frames are the most frequently used in flexography. The dots allow a better reproduction of the details and a better transition between the tones.
• the sheets are conveyed by a vacuum system using either a belt, flat belts, or driven steel rollers to move the sheets longitudinally from one printer unit to another from the upstream to the downstream, from the introductory station to the receiving station.
• a vacuum system using either a belt, flat belts, or driven steel rollers to move the sheets longitudinally from one printer unit to another from the upstream to the downstream, from the introductory station to the receiving station.
• the basic principle is that transport ensures the most consistent sheet speed possible.
• a main object of the present invention is to develop a method for adjusting a plate element printing machine.
• a second objective is to improve and keep the print quality of a printing machine constant.
• a third objective is to reduce the adjustment time or downtime, as well as the number of printed plate elements for setting a printing machine.
• a fourth objective is to implement a method to automatically, simply and quickly adjust a machine through a specific arrangement.
• a fifth objective is to provide a control method to avoid the disadvantages of processes and arrangements of the state of the art. Another objective is that the operator manages to tune a machine before starting printing in production.
• an adjustment method is for a plate element printing machine, equipped with at least one rotary printing cylinder.
• the adjustment process comprises several steps consisting of:
• the operating speed of the plate member printing machine is such that the speed of the plate member is substantially equal to the tangential speed of the rotary printing cylinder or printing cylinders rotatable.
• the actual speed of the machine is regulated to avoid a difference in speed between the speed of the plate member and the tangential speed of the image carried by the printing cylinder, which causes a poor print quality because the weft points are distorted.
• the speed of the transported plate element is perfectly synchronous with the tangential speed of the rotary printing cylinder and therefore with the tangential speed of the image fixed on the rotary printing cylinder.
• the tangential velocity of the rotary printing cylinder and thus with the tangential velocity of the image fixed on the rotary printing cylinder is perfectly synchronous with the speed of the transported plate element.
• an adjustment arrangement for a plate element printing machine is for carrying out the method.
• an adjustment arrangement for a plate element printing machine equipped with at least one rotary printing cylinder comprises:
• detection means able to detect the passage of a plate element and to send a detection signal
• a calculation and control unit connected to the detection means, receiving the signal coming from the detection means, and able to calculate the speed of the plate element passing through the plate-element printing machine and automatically generating an operation signal for the printing machine, so that the operating speed of the plate member printing machine is such that the speed of the plate member is substantially equal to the tangential speed of the rotary printing cylinder or printing cylinders rotatable.
• a printing machine comprising at least one printing unit provided with a rotary printing cylinder, is characterized in that it comprises an adjusting arrangement having one or more of the technical characteristics. described below and claimed.
• the sheet or sheet element is defined, by way of non-exhaustive example, as being of a material such as paper, cardboard, corrugated cardboard, laminated corrugated cardboard, flexible plastic, for example polyethylene (PE), polyethylene terephthalate (PET), bioriented polypropylene (BOPP), or other polymers, or other materials having an ability to be printed.
• a material such as paper, cardboard, corrugated cardboard, laminated corrugated cardboard, flexible plastic, for example polyethylene (PE), polyethylene terephthalate (PET), bioriented polypropylene (BOPP), or other polymers, or other materials having an ability to be printed.
• the longitudinal direction is defined by reference to the direction of movement of the plate member in the machine along its median longitudinal axis.
• the upstream and downstream directions are defined with reference to the direction of movement of the element, along the longitudinal direction in the entire printing machine.
• the leading edge of the element is defined with reference to the direction of travel in the longitudinal direction throughout the printing machine.
• FIGURE represents a synoptic side view of a printing machine comprising an adjustment arrangement according to the invention.
• a printing machine 1 such as a flexo printing machine, comprises:
• printer groups in this case five printer groups 4, 6, 7, 8 and 9, successive and arranged in line, printing five different colors, for example black, blue, red, green and yellow, and a machine output or receiving station 11 (in dotted lines).
• the insertion station 3 receives a stack of plate elements, for example in the form of sheets of corrugated cardboard 12, without printing, and sends them one after the other in the first printing unit 4. At the output of the machine 1 the receiving station 11 then retrieves the printed sheets 13.
• the sheets 12 and 13 pass (Arrow F) from one printing unit to another, from the insertion station 3 to the receiving station 11 in the longitudinal direction.
• the sheets 12 and 13 pass being transported by means of drive means in the form of the upper drive roller trains 14.
• the rollers 14 are rotated by a motor 15, its drives and the necessary gears and transmissions (see for example EP-0,363,662).
• the sheets 12 and 13 are pressed against the rollers 14 by means of a series of vacuum aspirations 16 arranged between the printing units 4, 6, 7, 8 and 9.
• a printing unit may comprise an inking device 17 with a lower ink tank 18, a pump 19, ink circulation means 21 and a doctor chamber 22 (last two printing units 8 and 9).
• a printer unit may also include an inking device 17 with a lower ink tank 18, a pump 19, ink circulation means 21 and an inking roller bubbling in an ink tank 23 (first three printing units 4 to 7).
• the inking device 17 makes it possible to ink an anilox cylinder 24.
• the anilox roll 24 ink-coated the plate 26 mounted on the outer surface of a printing cylinder plate holder 27.
• the plate cylinder 27 is rotated (Arrow R) by rotation means such as a motor, its drives and the necessary gears and transmissions, which allows an adjustment of the angular position and / or the speed of the plate 26 in relation to the sheet 12.
• the operating speed of the machine 1 is adjusted by the drive means 14 and 15.
• the new speed of passage of the sheet 12 is synchronized with the speed tangential to the plate or plates 26 attached to the respective plate cylinder or cylinders 27.
• the method is implemented by means of a speed adjustment arrangement of the drive means 14 and 15 in the machine 1.
• the operating speed of the machine 1 is adjusted by means of rotating the one or more forme cylinders 27.
• the new tangential velocity of the plate (s) 26 fixed on the respective plate cylinder (s) 27 and the speed The tangential of the forme cylinder (s) 27 are synchronized with the speed of passage of the sheet 12.
• the method is implemented by means of an arrangement for adjusting the speed of the means for rotating the forme cylinder (s) 27 in the machine 1.
• the adjustment arrangement comprises detection means capable of detecting the passage of the sheet 12 and 13.
• the detection means are formed by a front edge sensor 28 of the printed sheet 13.
• this sensor 28 is installed downstream of the last forme cylinder 27, corresponding to the output of the last printing unit 9.
• this sensor 28 is installed as far as possible downstream of the 3, and just upstream of the receiving station 11.
• the detection means, ie the sensor 28, send a detection signal 29 as soon as the printed sheet 13 passes.
• the detection means are preferably formed by two front edge sensors of the unprinted sheet 12 and the printed sheet 13.
• the first of these two front edge sensors is similar to the sensor 28 of the first exemplary embodiment.
• the second of these two front edge sensors is formed by a front edge sensor 31 of the sheet 12.
• This second sensor 31 is installed upstream of the first forme cylinder 27, corresponding to the input of the first printing unit 4. For a good accuracy of speed calculation, this sensor 31 is installed as far as possible upstream of the receiving station 11, and just downstream of the insertion station 3.
• the detection means, ie the second sensor 31, send a detection signal 32 as soon as the unprinted sheet 12 passes.
• the adjustment arrangement further comprises a calculation and control unit 33.
• the unit 33 is both connected to the detection means, ie to a sensor 28 or both sensors 28 and 31. and in the drive means 15 of the rollers 14.
• the unit 33 is both connected to the detection means, ie to a sensor 28 or to both sensors 28 and 31, and to the setting means. in rotation of the forme cylinder (s) 27.
• the unit 33 receives the signal from the detection means 28, or 28 and 31.
• the unit 33 is able to calculate the speed of the unprinted sheet 12 and the printed sheet 13 passing in the machine 1 and is able to generate a control signal for an operation of the machine 1.
• the unit 33 is accordingly able to automatically generate an adjustment signal 34 for the drive means 15.
• the adjustment signal 34 serves to equalize the the speed of the sheet 12 or 13 with the tangential speed of the plate (s) 26 on its respective plate cylinder (s) 27.
• the unit 33 is consequently able to automatically generate an adjustment signal for the means for rotating the forme cylinder (s) 27.
• the adjustment signal 34 makes it possible to equalize the tangential speed of the plate (s) 26 on its respective plate cylinder (s) 27 with the speed of the sheet 12 or 13.
• the adjustment signal 34 makes it possible to equalize the speed of the drive means 15 with the tangential speed of the forme cylinder (s) 27.
• the method of setting the machine 1 comprises several successive steps, positioned after the steps of printing the pattern or patterns on the sheets 12.
• a first step the speed of the unprinted sheet 12 and printed 13 passing F in the machine 1 is measured.
• This step of measuring the speed of the sheet 2 or 13 passing F in the machine 1 can be implemented by calculation by determining the passage time of the sheet 12 or 13 between a machine input, ie the insertion station 3 , and a machine output, ie the receiving station 11.
• This step of measuring the speed of the sheet 12 or 13 passing F in the machine 1 can be implemented by calculation by determining the passage time of the sheet 12 or 13 upstream and downstream of the cylinder or cylinders 27.
• This step of measuring the speed of the sheet 12 or 13 passing F in the machine 1 can also be implemented by transmitting and then receiving waves, for example light or radar, reflected by the sheet 12 or 13.
• a starting signal of the sheet 12 is sent by the introduction station 3 of the machine 1 or by the machine 1 itself.
• This starting signal is analogous to a starter.
• the passage of the sheet 12 is detected downstream of the forme cylinder (s) 27 of the printing unit (s) 4, 6, 7, 8 and 9 respectively, thanks to the sensor 28 which generates its detection signal 29.
• the actual speed of the sheet 12 or 13 is calculated by knowing the distance between the insertion station 3 and the sensor 28.
• the passage of the sheet 12 is detected upstream of the forme cylinder (s) 27 of the printing unit (s) 4, 6, 7, 8 and 9, thanks to to the second sensor 31 which generates its detection signal 32.
• the passage of the sheet 12 is detected downstream of the or cliché cylinders 27 or printing groups 4, 6, 7 , 8 and 9, thanks to the first sensor 28 which generates its detection signal 29.
• the actual speed of the sheet 12 or 13 is calculated, knowing the distance between the forme cylinder (s) 27 or between the two sensors 28 and 31.
• an adjustment signal 34 is generated by the unit 33 and is sent to the drive means 15.
• This signal 34 is a function of the passage time F measured for the unprinted sheet 12 and printed 13 , ie the calculated speed, and the speed of rotation of the forme cylinder (s) 27.
• the calculated and actual speed for the unprinted sheet 12 and printed 13 is compared with the tangential speed of the forme cylinder (s). 27.
• the speed of the drive means 15 is adjusted according to the generated adjustment signal 34.
• the generated adjustment signal 34 takes a value corresponding to a deceleration of the driving means 15. If the calculated and actual speed for the unprinted sheet 12 and printed 13 is less than the tangential speed of the plate (s) 26 on the respective forme cylinder (s) 27, the generated adjustment signal 34 takes a value corresponding to an acceleration of the drive means 15. If the calculated and actual speed for the unprinted sheet 12 and printed 13 is equal to the rotational speed of the plate (s) 26 on the or the respective plate cylinders 27, the generated adjustment signal 34 takes a zero value.
• the new speed adjusted for the drive means 15 is such that the new speed of passage of the sheet 12 or 13 is equal to the tangential speed of the plate or cliches 26 on its forme cylinder (s) 27.
• the speed of the means for rotating the forme cylinder (s) 27 is adjusted according to the generated adjustment signal.
• the generated adjustment signal takes a value corresponding to an acceleration of the means of rotation of the If the calculated and actual speed for the unprinted sheet 12 and printed sheet 13 is less than the tangential speed of the forme cylinder (s) 27, the adjustment signal generated takes a value corresponding to a deceleration of the means for rotating the cylinder or cylinders If the calculated and actual speed for the unprinted sheet 12 and printed 13 is equal to the rotational speed of the forme cylinder (s) 27, the generated adjustment signal takes a value of zero.
• the new tangential speed adjusted for the means for rotating the forme cylinder (s) 27 is such that the new tangential velocity of the plate (s) 26 on its forme cylinder (s) 27 is equal to the passage rate calculated for the unprinted sheet 12.
• Sensors can be installed after each printer group 4, 6, 7 and 8 and their information can be used to adjust the transport speed of the printed sheets 13.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Rotary Presses (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (2)

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• 2012
  • 2012-10-08 CN CN201280060898.0A patent/CN103987524B/zh active Active
  • 2012-10-08 EP EP12770426.0A patent/EP2771188B1/de active Active
  • 2012-10-08 WO PCT/EP2012/004204 patent/WO2013060416A2/fr active Application Filing
  • 2012-10-08 ES ES12770426.0T patent/ES2631985T3/es active Active
  • 2012-10-08 US US14/353,737 patent/US9895873B2/en active Active

Non-Patent Citations (1)

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