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DE-102021123676-B4 - Sheet-fed printing press with a drying dryer for sheets printed by a non-impact printing unit

DE102021123676B4DE 102021123676 B4DE102021123676 B4DE 102021123676B4DE-102021123676-B4

Abstract

Sheet-fed printing press with a dryer (17) for drying sheets printed by a non-impact printing unit (13), wherein a cooling device (36) is directly downstream of the dryer (17) in the transport direction (T) of the sheets, wherein the cooling device (36) has a transport device extending through it in the form of an endlessly circulating conveyor belt (18), wherein the conveyor belt (18) is designed to transport the printed sheets individually, lying flat, on a section running in the transport direction (T) of the sheets, wherein the cooling device (36) is designed to cool the return section (44) of the conveyor belt (18) transporting the sheets, characterized in that the return section (44) of the conveyor belt (18) is guided through a flow chamber (48) open at the section inlet (46) and at the section outlet (47), wherein a gaseous fluid flowing through this flow chamber (48) is present both on the top and on the bottom. of the returning section (44) of the conveyor belt (18), wherein a flow direction of the fluid flowing through the flow space (48) is opposite to the direction of travel of the returning section (44) of the conveyor belt (18), wherein the dryer (17) is designed to heat the printed sheets to more than 80°C and the cooling device (36) is designed to cool the sheets heated in the dryer (17) down to 30°C.

Inventors

  • André Rossa
  • Maik Walter

Assignees

  • KOENIG & BAUER AG

Dates

Publication Date
20260513
Application Date
20210914

Claims (8)

  1. Sheet-fed printing press with a dryer (17) for drying sheets printed by a non-impact printing unit (13), wherein a cooling device (36) is directly downstream of the dryer (17) in the transport direction (T) of the sheets, wherein the cooling device (36) has a transport device extending through it in the form of an endlessly circulating conveyor belt (18), wherein the conveyor belt (18) is designed to transport the printed sheets individually, lying flat on a section running in the transport direction (T) of the sheets, wherein the cooling device (36) is designed to cool the return section (44) of the conveyor belt (18) transporting the sheets, characterized in that the return section (44) of the conveyor belt (18) is guided through a flow chamber (48) open at the section inlet (46) and at the section outlet (47), wherein a gaseous fluid flowing through this flow chamber (48) is present both on the top and on the underside of the return section (44) of the conveyor belt (18) flows along, wherein a flow direction of the fluid flowing through the flow space (48) is opposite to the direction of travel of the return section (44) of the conveyor belt (18), wherein the dryer (17) heats the printed sheets to more than 80°C and the cooling device (36) is designed to cool the sheets heated in the dryer (17) down to 30°C.
  2. Sheet-fed printing press Claim 1 , characterized in that the dryer (17) is designed as a hot air dryer and/or as a dryer drying by IR radiation.
  3. Sheet-fed printing press Claim 1 or 2 , characterized in that the flow medium flowing through the flow space (48) is ambient air or cooled air.
  4. Sheet-fed printing press Claim 1 or 2 or 3 , characterized in that the transport device of the cooling device (36) has transport rollers (38), wherein these transport rollers (38) are cooled by a roller cooling system.
  5. Sheet-fed printing press Claim 4 , characterized in that the roller cooling is designed as a roller cooling system using water as the cooling medium.
  6. Sheet-fed printing press Claim 1 or 2 or 3 or 4 or 5 , characterized in that the cooling device (36) has several cooling modules (37) arranged in series along a linear transport path, each of these cooling modules (37) being designed as a blow box (41), the respective blow box (41) having blow nozzles (43), wherein cooled air or ambient air is blown through these blow nozzles (43) onto the surface of the respective sheet to be cooled.
  7. Sheet-fed printing press Claim 6 , characterized in that the respective blow box (41) has venturi nozzles (49) in addition to the blow nozzles (43), wherein the venturi nozzles (49) ensure a defined removal of the warming air blown in by the blow nozzles (43).
  8. Sheet-fed printing press Claim 1 or 2 or 3 or 4 or 5 or 6 or 7 , characterized in that the cooling device (36) is either integrated into a frame of the dryer (17) or is designed in a separate frame as an independent machine unit.

Description

The invention relates to a sheet-fed printing machine with a sheet-drying dryer printed by a non-impact printing device according to the preamble of claim 1. The machine arrangement described below, forming a sheet-fed printing press for processing sheet-shaped substrates (hereinafter referred to as sheets), comprises several machine units arranged sequentially in the transport direction of the sheets, with at least one of these machine units having a transport device that moves the sheets along a linear transport path. This transport device is preferably designed as at least one conveyor belt on which the sheets are transported individually, one after the other. While resting on the at least one conveyor belt, the individual sheets are held in place by a suction force, i.e., by a holding force caused by a suction flow, either by friction or force. The suction force is generally generated by a vacuum applied to the respective sheet, adjusted relative to the surrounding barometric air pressure by means of a suction device. Such a transport device is arranged in the sheet-processing machine, including a dryer for drying the sheets. The dryer is thus designed, in particular, as a continuous dryer for single-layer sheets. In a preferred embodiment, a cooling unit for conditioning and/or chilling the sheets heated in the dryer follows the dryer. A suction belt table, for example, is arranged downstream of the cooling unit. Through the DE 10 2016 207 397 A1 A sheet-fed printing machine is known to have a drying dryer printed by a non-impact printing device. Through the US 2015 / 0 117 922 A1 A system is known comprising: an image-generating device comprising a processing stage configured to cause the heating of media sheets; and a device for treating media sheets after an image has been generated on the media sheets by the image-generating device, wherein the device for treating media sheets is arranged on an output side of the image-generating device and comprises: a perforated conveying and support substrate arranged to convey the media sheets through a stabilization zone in which the conveying and support substrate has limited curvature; A suction device configured to apply a vacuum to the perforations of the conveying and support substrate in the stabilization zone to draw the media sheets against the conveying and support substrate, and a cooling system arranged to actively cool the media sheets while the media sheets are drawn against the conveying and support substrate in the stabilization zone, wherein the stabilization zone comprises an inlet side and an outlet side, the conveying and support substrate forms part of an endless conveyor, the cooling system is arranged to cool the conveying and support substrate in a return path from the outlet side to the inlet side, and the media sheets are cooled by thermal contact with the cooled conveying and support substrate, wherein the cooling system comprises a blower, the blower being arranged to blow cold air against the conveying and support substrate. Through the DE 12 93 163 A A device for drying printing ink on a web-shaped printed material, in particular a paper web, is known, comprising a cooling zone following a heating zone, in which cooling air is directed onto the printed material by means of a blower and the used air is extracted, wherein the cooling zone is formed by a hood and a distribution chamber arranged within it at all sides away from its walls, which has a nozzle base that directs the cooling air onto the printed material, wherein the air supply line is led through the top wall of the hood into the distribution chamber and the air extraction line is connected to the hood. Through the DE 39 43 466 A1 A stacking lift on a mobile dryer, especially for multi-colour printed and high-gloss varnished sheets of paper, cardboard or the like, is known, wherein the dryer can be connected to a printing machine with a stacking lift and has a belt conveyor for receiving and transporting the sheets through the dryer. Through the US 2012 / 0 162 304 A1 An image-generating device is known comprising: a liquid droplet ejection device that ejects liquid droplets onto a recording medium; a fixing device that fixes the ejected liquid droplets to the recording medium by heating; an ejection unit on which the recording medium is ejected and stacked successively; and a cooling device that cools the recording medium before the recording medium is stacked on the ejection unit after the recording medium has been heated by the fixing device. Through the DE 10 2011 009 693 A1 A cooling module for cooling substrates is known, into special solar cells printed with paste after passing through a heating module, wherein the cooling module comprises: an elongated cooling chamber with an inlet opening adjacent to the heating module and an outlet opening; a transport unit for transporting substrates through the elongated cooling chamber, wherein the transport unit defines a tra