Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
  • B41F23/04—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing by heat drying, by cooling, by applying powders
  • B41F23/044—Drying sheets, e.g. between two printing stations

Definitions

• the invention relates to a dryer device within a sheet-fed printing machine according to the preamble of claim 1.
• the printed sheets are conveyed through cylinders and drums through the individual printing units and after the last printing unit through one or more coating and other finishing devices.
• the sheets are transported by chain systems from a last drum to the delivery stack.
• drying devices are provided at a large number of locations.
• the drying devices are intended to dry the paint / varnish as quickly as possible, so that touching the printed sheet side with sheet guide plates or other stationary parts does not cause any damage to the printed side and thus waste.
• Solvent-based printing inks or varnishes give off solvent vapors when drying.
• Such a drying process can be accelerated by IR emitters, since the heat input accelerates the evaporation of the solvent.
• Such a drying process is further accelerated if the printed product is additionally subjected to hot air, since the solvent vapor escaping from the printing material due to the heat input is removed.
• the air saturated with solvent and water vapor is also sucked out, which is done by a special suction device.
• DE 195 25 453 A1 discloses a drying method for high-speed material webs, in which an electrode connected to a high-voltage source is provided in addition to the drying devices.
• the current on electrical charge carriers moved by the electrode in the direction of the printing material (high-speed material web) destroys the laminar boundary layer entrained by the moving web.
• This laminar boundary layer entrained by the printing material (material web) inhibits the mass transfer of solvent or water vapor from the printing material, i.e. the mass transfer coefficient is reduced.
• this drying principle by means of a high-voltage electrode can only be used with high-speed material webs and cannot be used in the known form in sheet-fed printing machines.
• the object of the present invention is therefore to expand a dryer device according to the preamble of claim 1 in such a way that, while avoiding the foregoing mentioned disadvantages an improvement in the drying effect is achieved.
• the dryer device is associated with an electrode (E), which is connected to a high-voltage source (HV) and which, depending on the operation of the sheet-fed printing press and / or the length of the sheets (B), acts on it with high voltage, as well as the counter electrode.
• a suction device is preferably also assigned to this device, by means of which the vapors released by heat and air from the printing material and ink can be extracted.
• the drying device is preferably assigned a device designed as an IR radiator, so that the printing material, in addition to the ink and / or lacquer layer, can be acted upon in a targeted manner at a wavelength that excites the solvent.
• the moving sheets are irradiated with IR rays on a wavelength on which only the solvent is heated. Due to the electrode positioned at a short distance from the surface of the arch, which is located downstream of the IR emitter in the direction of movement of the arch, the laminar air layers above the surface of the arch destroy the material transfer coefficient, which improves the material removal (outgassing) of solvent.
• An additionally applied preheated air stream makes it easier to degas solvent from the substrate and at the same time that with the solvent / water enriched air transported away.
• a suitable device is used to extract the air enriched with solvent / water from the area of the drying device and ultimately also from the printing press.
• the drying device which is expanded according to the invention with an electrode and counter electrode, can be used at a large number of locations within the sheetfed offset printing press. It is envisaged that the electrode is applied by means of high voltage as a function of the printing speed and / or the length of the printing sheet (format). It must also be ensured that the distance between the electrode and the surface of the sheet always assumes the required value. It should be noted that devices holding the bow, e.g. the gripper fingers of the cylinders guiding the sheet or the gripper systems of the boom do not come into collision with the electrode or the counter electrode. It can be provided here that the electrode or the support of the electrode or the counter electrode assigned to the electrode is suspended in a movable manner and during the passage of the
• Gripper or the devices holding the bow perform evasive movements.
• Such a movable suspension of the electrode or the entire dryer device, which is controlled as a function of the sheet movement, is to be provided in particular if the dryer device according to the invention in the delivery of the printing press (sheet emergence) is to be assigned to the face side of the sheets.
• the gripper systems that hold the bow can control the corresponding evasive movements of the electrode via sensors attached to the intended locations. The evasive movement of the electrode u./o.
• the electrode according to the invention to support the drying process is provided with at least one device which preferably supplies the air with warm air.
• the air flow caused by this device is preferably such that it is not possible to touch the arc, and in particular the arc end, with the parts assigned to the electrode or the electrode.
• the electrode according to the invention together with the drying device can be arranged at a multiplicity of locations within a sheetfed offset printing press. It is thus possible to provide these in the sheet guide in front of the first offset printing unit. Such an installation is particularly preferred if a primer in the form of a flexo printing unit is connected upstream of the printing units.
• the dryer device according to the invention can also be assigned between the printing units within the sheet guide, the face side of the sheets.
• the installation takes place here directly in the sheet guide plates opposite the counter pressure cylinder.
• the electrodes can be installed by interrupting the sheet metal sheet guide and using a non-conductive material made of plastic or ceramic, for example, in which the electrode is embedded.
• the Counter pressure cylinder serves as counter electrode and must be switched electrically accordingly (earthing).
• the dryer device according to the invention can be used between the printing units in the sheet guide on the reverse side.
• two channels can be inserted into the impression cylinder with a 180 ° offset, in which the electrode, surrounded by non-conductive material, is embedded.
• the counter electrode is then in a non-conductive embedding in the sheet guide.
• the distance between electrode and arc can be set precisely.
• Installation between the coating units in the sheet guide on the face side is also possible. In this case, the installation is carried out as in the case of installation between the printing units.
• the dryer device according to the invention is also possible to arrange the dryer device according to the invention as a fixed device in a delivery drum or a sheet guide stream el.
• the sheet conveyed over the delivery or sheet guide drum is then subjected to the ion radiation from the electrode and, since the electrode is stationary and the sheet is moving, it is swept in strips.
• the drying device according to the invention can also be carried out accordingly between two or more coating units.
• one or more drying devices designed according to the invention can be assigned to the front printing side of the sheets. These are preferably adjustable in height from the printing material (distance).
• One or more dryer devices designed according to the invention can likewise be arranged in the take-off drum and in the subsequent conveying path of the chain system.
• a drying device acting on the face pressure side of the sheet can be movably suspended in accordance with the sheet movement.
• the counter electrode assigned to the electrode can be the pressure or Impression cylinder (its metallic surface), a sheet guide plate or a metal surface attached to a sheet guiding cylinder. It is also possible to assign the dryer device to a turning drum. The counter electrode assigned to the stationary electrode is then preferably formed by the surface of the drum.
• Fig. 1 is a sheetfed offset printing machine with a last printing unit, an extension module, a coating unit and a delivery
• Fig. 2 shows the components of an inventive
• Drying device as this is arranged at various points in the printing press according to FIG. 1, and
• the impression cylinder 2 is preceded by a transfer drum 1 which transports the sheets from the preceding printing unit.
• the sheets conveyed via the transfer drum 1 are supported by a sheet guide 11 from the reverse side.
• Downstream of the impression cylinder 2 of the last printing unit is a coating unit with an impression cylinder 2, a forme cylinder 5, an applicator roller 6 and a chamber doctor blade 7 which interacts with the rastered applicator roller 6 fed to the impression cylinder of the coating unit.
• the sheets located in the coating unit on the impression cylinder 2 are fed to the take-off drum 9 of a delivery arm via a further transfer drum 1 and a sheet guide drum 8 of an extension module.
• the sheets are fed from the take-off drum 9 to the delivery stack via gripper systems 10.
• the transfer drums 1, the sheets on the backing sheet supporting sheet guides 11 are assigned. Furthermore, the take-up drum 9 is assigned a sheet guide 12.
• the sheet guides 11, 12 can be suction and / or Act sheet air guide sheets, sheet guide rods or the like that can be blown with air.
• FIG. 2 shows the components of the dryer device that are preferably to be provided in the invention.
• An arc B moves in the direction of the arrow.
• the dryer device T consists of a radiator ST, which is preferably designed as an IR radiator, downstream of this in the sheet running direction a blowing device TL acting on the sheet B with diffuse warm air, an electrode E shown only in principle in FIG. 2, and a suction device downstream of the aforementioned devices in the sheet running direction S.
• the electrode E is connected to a high voltage source HV.
• This in turn is connected to a control SHV, so that the times and the amount of voltage applied to the electrode E can be triggered in a targeted manner by the control SHV.
• the control SHV for the electrode E is in signal connection with the machine control SM, which is indicated by the lines.
• the machine controller SM in turn has an angle encoder WG, which is attached in particular to a single-speed shaft. The signals from the angle encoder can be used to determine the times for the voltage application of the electrode E at a predetermined installation location via the machine control SM and the control of the high voltage source SHV.
• the signals from the angle transmitter WG can be used to determine when a gripper system in the delivery path 10 of the arm passes the electrode E, and consequently an actuator assigned to the electrode E has to lift the electrode E.
• the signals from the angle transmitter WG can be used to control the high-voltage source HV in such a way that the sheet B, depending on the printing speed and its length, is supplied with the required ion current and positively influencing the drying behavior. is struck.
• the distance between the electrode E and the arc or the counterelectrode (not shown in FIG. 3) can also be set by the control SHV according to predetermined values.
• Figure 1 shows preferred installation locations of the drying device shown in principle in Figure 2.
• one or more drying devices T can be assigned to the sheet guide 11 of the last printing unit, the coating unit and the extension module. Furthermore, it is also possible to assign a drying device T to the surface of the impression cylinder 2 of the last printing unit, downstream of the blanket cylinder 3. Furthermore, one or more drying devices T can also be assigned to the surface of the sheet-guiding cylinder 8 in the coating module. Like the impression cylinder 2 of the last printing unit, one or more drying devices can also be assigned to the impression cylinder 2 of the coating unit, downstream of the forme cylinder 5.
• the dryer devices T assigned to the impression cylinders 2 or sheet guiding cylinders 8 are preferably suspended adjustable at a distance from the cylinder surface.
• the sheet guide 12 in the take-up drum 9 can also be arranged in accordance with the invention with one or more dryer devices T acting on the counterpressure side of the sheet.
• one or more drying devices T can also be arranged in the access of the delivery system 10, these drying devices acting on the front printing side of the sheet and being suspended in a controlled manner in order to enable the gripper systems holding the sheets to pass through.
• a sheet-fed offset Printing machine for face and reverse printing also act on reversing drums.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
• Drying Of Solid Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7648653

Family Applications (1)

Country Status (10)

Families Citing this family (12)

Family Cites Families (8)

• 2000
  • 2000-07-12 DE DE10033839A patent/DE10033839A1/de not_active Withdrawn
• 2001
  • 2001-06-12 DE DE50114219T patent/DE50114219D1/de not_active Expired - Lifetime
  • 2001-06-12 AT AT01951577T patent/ATE404366T1/de active
  • 2001-06-12 US US10/332,514 patent/US6877251B2/en not_active Expired - Fee Related
  • 2001-06-12 CN CNB018126812A patent/CN1192882C/zh not_active Expired - Fee Related
  • 2001-06-12 JP JP2002508899A patent/JP2004502574A/ja active Pending
  • 2001-06-12 CZ CZ20030090A patent/CZ300667B6/cs not_active IP Right Cessation
  • 2001-06-12 WO PCT/EP2001/006612 patent/WO2002004212A1/fr active IP Right Grant
  • 2001-06-12 RU RU2003104023/12A patent/RU2003104023A/ru not_active Application Discontinuation
  • 2001-06-12 CA CA002415418A patent/CA2415418C/fr not_active Expired - Fee Related
  • 2001-06-12 EP EP01951577A patent/EP1303407B1/fr not_active Expired - Lifetime

Non-Patent Citations (1)

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