DE102023103173B3 - Drying device for drying a surface of a sheet-shaped substrate printed and/or painted by a printing press by applying heat - Google Patents

Abstract

The invention relates to a drying device for drying a surface of a sheet-shaped substrate printed and/or painted by a printing press by applying heat, the drying device having a conveyor belt, the conveyor belt being designed to move the printed and/or painted substrate through the drying device, wherein the drying device has, on its side facing the surface of the substrate to be dried, a guide grid arranged at a distance from the conveyor belt and the printed and/or painted substrate lying there, the guide grid having several bearing points for its mechanical fastening in the drying device, only a single one of these Bearing points are designed as a fixed bearing and the remaining bearing points are each designed as a floating bearing.

Description

The invention relates to a drying device for drying a surface of a sheet-shaped substrate printed and/or painted by a printing press by applying heat according to the preamble of claim 1.

Through the US 3,920,328 A An electrostatic copier is known, comprising means for producing a developed image on a sheet of paper, a housing in which the developed image is heatable for sticking to the sheet of paper, electrically excitable means for heating the developed image and a power source, the heating means means for moving the sheet of paper along a predetermined path of movement within the envelope and means for deactivating the power supply to the heating means in response to the sheet of paper becoming jammed within the envelope, the deactivating means comprising: A. switching means for electrically connecting the heating means to the source and disconnecting the heating means therefrom; B. a grille arranged to obstruct the passage of the sheet of paper from the predetermined path of travel, the grille being pivotally mounted on the housing to be able to move in and out of contact with the switching means to the heating means respectively to connect to the source or to separate the heating means from the source, the grid being normally held in contact with the switching means by gravity and being movable out of contact with the switching means by the sheet of paper, and C. an adjustable weight, attached to the grille to balance the weight of the grille about the pivot axis of the grille, the adjustable weight being designed to be sufficiently adjustable to allow adjustment thereof to both bring the grille into contact with the switching device and also to pivot out of this to adjust the setting of the weight of the grid on the switching device to a predetermined level and to ensure a pivoting movement of the grid through the sheet of paper in the event that the paper moves out of the predetermined path of movement and into contact comes with the grid.

Through the subsequently published DE 10 2021 123 678 A1 a drying device in a printing press is known, wherein the drying device is designed to dry a surface printed and/or painted by the printing press of a printing material moved through the printing press by exposure to both infrared radiation and hot air, the drying device being on its surface The side facing the printing material to be dried has a guide surface arranged at a distance from the surface of the printing material with a plurality of nozzles, each of these nozzles having an opening cross-section through which the hot air flows or at least can flow through, the hot air flowing onto the surface of the printing material passing through an opening between the Guide surface and the surface of the printing material formed gap opening flows out.

Through the US 2002/0118986 A1 a digital printing or copying device with a fixing device for fixing a toner image on a substrate is known, the substrate being made in particular of paper or cardboard and being guided along a transport path, where the fixing device contains at least one radiation device for applying electromagnetic radiation to at least one substrate side , and with a device for protecting against excessive heating of the substrate, the protective device having at least one stopper which is fixedly arranged in the radiation path between the radiation device and the transport path of the substrate and which prevents contact between the substrate and the radiation device.

Through the JP 2015-155091 A a drying device with a drying module is known, the drying module having a blow box and a guide surface delimiting the blow box in the direction of the surface of the printing material to be dried, a fan and an air guide grille being arranged as a heating register above the guide surface.

Through the JP H07-186368 A a drying device is known, wherein a gap in the form of an annular gap is formed between a guide surface of the drying device and a conveyor belt of a transport device which transports the printing material to be dried along a drying path through the drying device, this gap having a gap width of up to 30 mm.

The invention is based on the object of creating a drying device for drying a surface of a sheet-shaped substrate printed and/or painted by a printing press by applying heat.

The object is achieved according to the invention by the features of claim 1. The respective dependent claims each show advantageous refinements and/or further developments of the solution found.

The advantages that can be achieved with the invention are, in particular, that so-called sheet stoppers are avoided when moving sheet-shaped substrates through the drying device. Rather, such substrates, each subject to heat, can be guided through the drying device without any problems. Further advantages can be seen from the following description.

An exemplary embodiment of the invention is shown in the drawings and is described in more detail below.

• 1 eine Druckmaschine mit einer erfindungsgemäßen Trocknungseinrichtung;
• 2 ein Leitgitter der Trocknungseinrichtung gemäß 1 in einer Unteransicht;
• 3 einen Ausschnitt des Leitgitters in einem Querschnitt;
• 4 eine Untersicht des Leitgitters mit einem daran entlang geführten bogenförmigen Substrat;
• 5 eine perspektivische Untersicht des Leitgitters mit einem daran entlang geführten bogenförmigen Substrat;
• 6 eine Untersicht des Leitgitters mit mehreren darüber angeordneten Infrarotstrahlungsquellen;
• 7 das Leitgitter mit einer nur in einem einzigen Festlager gelagerten rahmenförmige Einfassung und mit jeweils nur in einem einzigen Festlager gelagerten Führungsstegen;
• 8 eine Anordnung mit mehreren aneinandergereihten Leitgittern;
• 9 einen Ausschnitt aus der Trocknungseinrichtung mit gestuft angeordneten Leitgittern;
• 10 lateral versetzt angeordnete Führungsstege von benachbarten Leitgittern.

Show it:

• 1 a printing press with a drying device according to the invention;
• 2 a guide grid according to the drying device 1 in a subview;
• 3 a section of the guide grid in a cross section;
• 4 a bottom view of the guide grid with an arcuate substrate guided along it;
• 5 a perspective bottom view of the guide grid with an arcuate substrate guided along it;
• 6 a bottom view of the guide grid with several infrared radiation sources arranged above it;
• 7 the guide grille with a frame-shaped enclosure mounted only in a single fixed bearing and with guide webs each mounted in only a single fixed bearing;
• 8th an arrangement with several guide grids arranged in a row;
• 9 a section of the drying device with stepwise guide grids;
• 10 laterally offset guide webs of adjacent guide grilles.

The proposed drying device 01 is generally used in conjunction with a printing press, in particular in conjunction with a printing press designed as a sheet-fed printing press 12, in which sheet-shaped substrates 02 are successively printed and/or painted with a water-based printing fluid, in particular a water-based ink. Immediately after printing and/or painting a surface of these substrates 02, they are fed to the drying device 01, which is preferably arranged in the sheet-fed printing machine 12, in order to evaporate the water contained in the printing fluid. For this purpose, the printed and/or painted substrates 02 are subjected to heat in the drying device 01, this heat being generated by at least one hot air source 09 arranged in the drying device 01 and/or by at least one infrared radiation source 11 arranged in the drying device 01. In addition, at least one UV radiation source can also be provided.

In practice it has been shown that the aforementioned application of heat to a sheet-shaped substrate 02 printed and/or painted by the printing press and moved through the drying device 01 for drying leads to a moisture gradient in the cross section of this substrate 02, so that the substrate 02 in question differs from begins to deform from its edges and / or corners and therefore has at least one curvature. This deformation of the substrate 02, in particular the warping of one of its edges and/or corners, can lead to a collision with its components during further transport of the substrate 02 in question through the drying device 01, which then leads to a so-called sheet stopper, i.e. H. a blockage for the further transport of the substrate 02 in question. In order to avoid such a collision, at least one guide grid 04 is arranged in the drying device 01 in order to also provide a z. B, the substrate 02, which is curved at its edges and/or corners, can be transported through the drying device 01 without any problems.

1. a) eine Anlage 13, die zu bedruckende bogenförmige Substrate 02 einzeln und nacheinander einer Druckeinheit 14 zuführt;
2. b) im direkten Anschluss an die Druckeinheit 14 werden in einer bevorzugten Ausführung der Bogendruckmaschine 12 die bedruckten Substrate 02 einem Trockner 16 mit der vorgeschlagenen Trocknungseinrichtung 01 zugeführt, wobei dieser Trockner 16 insbesondere als ein Durchlauftrockner ausgebildet ist und wobei in der Trocknungseinrichtung 01 z. B. mindestens eine Heißluftquelle 09 und/oder mindestens eine Infrarotstrahlungsquelle 11 angeordnet ist bzw. sind;
3. c) da sich die Substrate 02 bei ihrem Durchlauf durch den Trockner 16 zumindest teils auf z. B. über 80°C erwärmen, kann im direkten Anschluss an den Trockner 16 vorteilhafterweise eine Kühlstrecke mit einer Kühleinrichtung 17 vorgesehen sein, die die bedruckten und getrockneten Substrate 02 wieder auf eine Temperatur von z. B. weniger als 30°C abkühlt;
4. d) nach der Kühlstrecke können die Substrate 02 an eine weitere Anlage 18 oder an einen Ausleger 18 übergeben werden, um diese Substrate 02 z. B. zu einer Lackiereinrichtung oder zu einer mechanischen Weiterverarbeitungseinrichtung zu transportieren.

1 shows, in a schematic representation, an example of a sheet-fed printing machine 12 with the proposed drying device 01. Such a sheet-fed printing machine 12 used in an industrial printing process generally has several machine units one after the other in the transport direction T of the substrates 02, each of which is preferably arranged in its own machine frame and thus each z. B. are designed as an independent module. In the transport direction T the substrates 02 are successively at least z. B. the following machine units are provided:

1. a) a system 13 which feeds sheet-shaped substrates 02 to be printed individually and one after the other to a printing unit 14;
2. b) in a preferred embodiment of the sheet-fed printing machine 12, the printed substrates 02 are fed directly to the printing unit 14 to a dryer 16 with the proposed drying device 01, this dryer 16 being designed in particular as a continuous dryer and in the drying device 01 z. B. at least one hot air source 09 and / or at least one infrared radiation source 11 is or are arranged;
3. c) since the substrates 02 are at least partly on z. B. heat above 80 ° C, a cooling section with a cooling device 17 can advantageously be provided directly following the dryer 16, which brings the printed and dried substrates 02 back to a temperature of e.g. B. cools down to less than 30°C;
4. d) after the cooling section, the substrates 02 can be transferred to another system 18 or to a boom 18 in order to use these substrates 02, for example. B. to transport to a painting facility or to a mechanical processing facility.

The printing unit 14 of the printing press has z. B. at least one non-impact printing device 19, the relevant non-impact printing device 19 printing the sheet-shaped substrates 02 z. B. is designed to be printed in an inkjet printing process. The non-impact printing device 19 in question has e.g. B. at least one inkjet print head 21, preferably several inkjet print heads 21 controlled by a control unit 22. The controlled inkjet print heads 21 apply, in particular, a water-based ink to the surface of the relevant substrate 02 in accordance with a printed image to be created. A printing press with a z. B. non-impact printing device 19, which prints in an inkjet printing process, is also referred to as a digital printing machine.

In a preferred embodiment of the sheet-fed printing machine 12, the substrates 02 are translated, in particular in the machine units designed as a printing unit 14 or as a dryer 16 or as a cooling device 17, on an endlessly rotating conveyor belt of a belt conveyor 23; 24; 26 transported lying flat. Such a conveyor belt is z. B. designed as a suction belt, with a substrate 02 resting on the relevant conveyor belt being held on the relevant conveyor belt by means of a negative pressure set with reference to the surrounding barometric air pressure. This means that while they are resting on the conveyor belt 03, the individual substrates 02 are each influenced by a suction force, i.e. H. can be held on the conveyor belt 03 in a completely flat position in a frictional or non-positive manner by a holding force caused by a suction flow. This suction force is realized by the negative pressure acting on the respective substrate 02, which is or is adjusted by means of a suction device belonging to the respective machine unit.

It has been shown in practice that sheet-shaped substrates 02 printed and/or painted with a water-based printing fluid bulge at their respective edges and/or corners, particularly during their drying in the drying device 01, and thus leave their original flatness. However, substrates 02 that are bulged out of their respective flat position lose their adhesion and/or fixation on the conveyor belt of the respective belt conveyor 23; 24; 26 and can no longer be kept in register and transported, which is very disadvantageous in the further processing of these substrates 02 and leads to waste. Because an at least partial bulging of the relevant substrate 02 to be transported can assume such dimensions that, for. B. a front edge in the transport direction T and / or at least one of the corners of the relevant substrate 02 lose their respective adhesion to the conveyor belt 03. If the conveyor belt 03 is designed as a suction belt, it can then happen that parts of the relevant substrate 02 can no longer be held at all by means of the suction force exerted on the suction belt. The reason for the loss of hold is that the bending resistance force inherent in the curvature of the relevant substrate 02 can no longer be overcome by a height-dependent suction force exerted by a suction belt.

The substrates 02 to be dried in the proposed drying device 01 are preferably rectangular and consist, for example. B. made of paper or cardboard or cardboard. Paper, cardboard and cardboard differ in their respective grammage, ie the weight in grams for one square meter of these substrates. Paper has a basis weight between 30 g/m ² and 150 g/m ² , cardboard has a basis weight between 150 g/m ² and 600 g/m ² and cardboard has a basis weight of more than 600 g/m ² . However, the substrates 02 to be dried in the proposed drying device 01 can also each be made of a plastic and/or as a thin metallic panel and/or as a z. B. a composite consisting of several layers can be formed, these layers being made of different materials.

The at least one infrared radiation source 11 arranged in the drying device 01 is, for. B. designed as an infrared radiator with a heating coil arranged in a glass tube or as an infrared halogen radiator with a heating coil arranged in a glass tube filled with a halogen. Panel radiators with flat heating elements are also suitable. A plurality of LED semiconductor elements each emitting infrared radiation can also preferably be used as the radiation source. If necessary, there is also at least one UV radiation source is each designed as a semiconductor element that emits UV radiation.

In order to ensure trouble-free transport of a substrate 02 lying on a conveyor belt 03 of the relevant belt conveyor 24 through the drying device 01, there is at least one guide grid in this drying device 01 above the surface of the substrate 02 to be dried lying on the conveyor belt 03 of the relevant belt conveyor 24 04 arranged. In the 2 An example of such a guide grid 04 is shown in a bottom view. This guide grille 04 has a circumferential enclosure 06 and, in a surface encompassed by its enclosure 06, several rod-shaped guide webs 07, each arranged at a distance a from one another, the distance a of the mutually arranged guide webs 07 z. B. in the range between 80 mm and 150 mm, preferably around 100 mm. The edging 06 is z. B. in the form of a preferably rectangular, particularly solid frame and has z. B. two mutually parallel cross bars 27 and two mutually parallel longitudinal bars 28. The longitudinal bars 28 extend in the transport direction T of the substrate 02 to be dried and the transverse bars 27 extend transversely thereto ( 7 ). Preferably, several of the guide webs 07 arranged in the area encompassed by the enclosure 06 are each arranged parallel to one another. These guide webs 07 are each at a distance b z. B. arranged parallel to the conveyor belt 03 extending first level E1 such that a part of the conveyor belt 03 lifted from a flat position of the printed and / or painted substrate 02 moved by the drying device 01 is guided in contact with at least one of the guide webs 07. The distance b of the first plane E1, which extends longitudinally and generally at least approximately parallel to the conveyor belt 03, is preferably less than 50 mm and is in particular in the range between 10 mm and 35 mm.

Like from the 2 As can also be seen, the relevant guide grid 04 has a center line M extending in the transport direction T of the printed and/or painted substrate 02 moved through the drying device 01, with guide webs 07 preferably arranged diverging symmetrically to this center line M in the transport direction T of the moved substrate 02 are. Each of the guide webs 07 is preferably at a divergence angle (φ, for example in a range between 5° and 45°, preferably in a range between 10° and 20°) that opens in the transport direction T of the moving substrate 02 away from the center line M arranged to the center line M. If necessary, a guide web 07 running along the center line M is also provided.

The guide grid 04 preferably also has, in its surface enclosed by its enclosure 06, at least one rod-shaped crossbar 08 directed transversely to the transport direction T of the moving substrate 02, in particular several such crossbars 08, each of the guide bars 07 being held by at least one of the crossbars 08 . There are - as in the 3 indicated - all transverse webs 08 are each arranged in the same second level E2 which extends at a distance c parallel to the conveyor belt 03, the distance c from the second level E2 having the transverse webs 08 to the conveyor belt 03 being greater than the distance b of the first level E1 , in which the guide webs 07 are arranged. A difference between the distance c of the second level E2 having the transverse webs 08 and the distance b of the first level E1 having the guide webs 07 forms a height Δh, the guide grid 04 being designed in its preferred embodiment in such a way that a ratio of this height Δh to Distance a of guide webs 07 extending adjacent to one another in the first level E1 is each greater than a value of 1:10. A relationship formed from the height Δh to the distance a in the range between 1:5 to 1:2 has proven to be advantageous, with such a ratio of 1:3 being particularly favorable. The height Δh formed differentially by the distance c of the second plane E2 having the transverse webs 08 and the distance b of the first plane E1 having the guide webs 07 allows an arcuate substrate 02 guided along the guide grid 04 a collision-free passage through the drying device 01 even if an edge and/or a corner of this substrate 02 protrudes beyond the first plane E1 formed by the guide webs 07 in a manner that stands out from the conveyor belt 03 due to a curvature. The proposed arrangement and design of the guide webs 07 and the transverse webs 08 forms, so to speak, an open passage gate for curved, raised edges and / or corners of a substrate 02 to be transported through the drying device 01.

As already mentioned, at least one hot air source 09 and/or at least one infrared radiation source 11 are preferably provided in the drying device 01 for applying heat to the printed and/or painted surface of the moving substrate 02. These at least one hot air source 09 and/or the at least one infrared radiation source 11 are arranged in the drying device 01 to act through the guide grid 04 in the direction of the conveyor belt 03. Therefore, no at least approximately full-surface guide surface is provided, but rather a guide grid 04 formed from guide webs 07 and transverse webs 08, which is between its Guide webs 07 and transverse webs 08 have a large number of openings through which hot air and/or infrared radiation can pass unhindered in the direction of the conveyor belt 03 onto the surface of the printed and/or painted substrate 02. All of the guide webs 07 and transverse webs 08, each of which are rod-shaped, together have an area portion of z. B. of less than 30%, preferably of less than 15%, so that the openings in the conductive grid 04 that are open for the unhindered passage of heat have a total surface area of z. B. at least 70%, preferably more than 85%. The guide webs 07 have z. B. parallel to the conveyor belt 03 extending first level E1 orthogonal to its longitudinal extent preferably has a smaller extent than orthogonal to this first level E1. Likewise, the crossbars 08 in which z. B. parallel to the conveyor belt 03 extending second level E2 orthogonal to its longitudinal extent preferably has a smaller extent than orthogonal to this second level E2. This design of the guide webs 07 and/or transverse webs 08 gives them sufficient flexural rigidity and enables the largest possible area share for the openings in the guide grid 04 that are open for the unhindered passage of heat.

4 shows, by way of example, a bottom view of a guide grid 04 with an arcuate substrate 02 guided along it. Advantageously, the enclosure 06 of the guide grid 04 is designed to be larger in the transport direction T of the moving substrate 02 and transversely thereto than the surface of the respective substrate 02. The enclosure 06 of the guide grid 04 has a width in the transport direction T of the moving substrate 02 in the range of z. B. 700 mm to 1,500 mm and is preferably around 1,000 mm. The frame-shaped enclosure 06 of the guide grid 04 and its guide webs 07 and/or transverse webs 08 are preferably made of a metallic material, in particular as sheet metal parts.

5 shows, by way of example, a perspective bottom view of a guide grid 04 with an arcuate substrate 02 guided along it. For mechanical fastening of the guide grid 04 in the drying device 01, z. B. four bearing points LP1; LP2; LP3; LP4 indicated.

6 shows an example of a bottom view of the guide grid 04 with several, e.g. B. six infrared radiation sources 11 arranged above each and extending transversely to the transport direction T of the moving substrate 02.

In practice it has been shown that the guide webs 07 and/or the transverse webs 08 are exposed to considerable heat input in conjunction with the passage of hot air and/or infrared radiation through the open openings of the guide grid 04, this heat input leading to expansion stresses in the affected guide webs 07 and/or crossbars 08 leads. These expansion stresses can exceed the amount of buckling strength of the guide webs 07 and/or transverse webs 08 in the guide grid 04 and cause at least individual guide webs 07 and/or transverse webs 08 in the guide grid 04 to buckle.

Therefore, for a guide grid 04, which has several bearing points LP1; LP2; LP3; LP4 has, proposed that only one of these bearing points LP1 as a fixed bearing and the remaining bearing points LP2; LP3; LP4 are each designed as a floating bearing. A fixed bearing prevents displacements of a body stored in it in all spatial directions, whereas a floating bearing is also referred to as a displaceable support or plain bearing because it allows displacements of the body stored in it in at least one spatial direction.

As described above, a guide grid 04 mounted in this way with only a single fixed bearing in the drying device 01 has a circumferential enclosure 06 and a plurality of guide webs 07 in the area encompassed by its enclosure 06, with a part of the conveyor belt 03 lifted out of a flat position by the Drying device 01 moving printed and / or painted substrate 02 is guided in contact with at least one of the guide webs 07. The bearing points LP1, which consist of only a single fixed bearing and otherwise only floating bearings; LP2; LP3; LP4 of the guide grille 04 is preferably arranged on the frame-shaped circumferential enclosure 06 of this guide grille 04.

The guide grid 04 also has, in the manner described above, at least one transverse web 08 directed transversely to the transport direction T of the moving substrate 02, each of the guide webs 07 being held by at least one transverse web 08. In a preferred embodiment of the guide grid 04, each of its guide webs 07 is at least two fastening points X; Yn (with n = 1, 2, 3, ...) held by the relevant at least one crossbar 08, ie stored on the relevant crossbar 08, with only one of these fastening points X holding the relevant guide bar 07 as a fixed bearing and all the others its attachment points Yn (with n = 1, 2, 3, ...) each as one Floating bearings are formed. In this case, free bidirectional displaceability of the relevant guide web 07 in its at least one floating bearing is only given in the longitudinal direction of this guide web 07. This situation is in the 7 indicated for example by longitudinal double arrows attached to fastening points Yn (with n = 1, 2, 3, ...) of some guide webs 07. The fixed bearing of the guide web 07 in question is preferably arranged on the circumferential border 06 of the guide grid 04, preferably on the first crossbar 27 of the circumferential border 06 or crossbar 08 of the guide grid 04 in the transport direction T of the substrate 02 to be dried.

In the 7 are also several, e.g. B. four bearing points LP1; LP2; LP3; LP4 of the guide grid 04 shown, for. B. two bearing points LP1; LP4 on a first side S1 of the guide grid 04 with respect to the center line M of this guide grid 04 and z. B. two further bearing points LP2; LP3 on a second side S2 opposite the center line M of the guide grid 04. The bearing points LP2; LP3 on the second page S2 are e.g. B. each arranged at one end of a crossbar 08. Only the bearing point LP1 arranged on the first side S1 is designed as a fixed bearing. The remaining bearing points LP2; LP3; LP4 are each designed as a floating bearing. This is z. B. one of the bearing points LP2, each designed as a floating bearing; LP3; LP4, namely e.g. B. the bearing point LP2 arranged on the second side S2 and thus the fixed bearing on the other side can only be moved bidirectionally in the transverse direction of the frame-shaped border 06 of the guide grid 04, whereas the other bearing points LP3; LP4 e.g. B. have two degrees of freedom and are therefore designed to be bidirectionally displaceable both in the longitudinal direction of the frame-shaped border 06 of the guide grid 04 and transversely thereto. Such storage of the guide grid 04 avoids z. B. thermally induced constraint stresses, in particular in the form of expansions, both in its frame-shaped border 06 and in its guide webs 07 and/or in its at least one transverse web 08. The danger that otherwise exists with a mechanically rigid connection that at least individual guide webs 07 and/or or transverse webs 08 in the guide grille 04 buckling due to the heat input when hot air and/or infrared radiation passes through the open openings in the guide grille 04 is prevented by the proposed storage of the guide grille 04.

Since the drying section in a dryer 16, especially in a dryer 16 designed as a continuous dryer, is often several meters, e.g. B. is between 3 m and 10 m long, it is not recommended to form the guide grid 04 arranged in the associated drying device 01 in one piece. Rather, in the drying device 01, several guide grids 04 of the type described above are advantageously arranged one behind the other in the transport direction T of the substrate 02 to be transported. This is because such an arrangement with several guide grids 04 arranged in a row can be implemented with greater mechanical stability than a one-piece embodiment of the guide grid 04 that extends over the same length of the drying section 8th An example of an arrangement with three guide grids 04 lined up in a row in the drying device 01 is shown.

In order to enable collision-free passage for substrates 02 to be transported through the drying device 01, it must be ensured that bulging parts of these substrates 02, for example. B. at the transition from neighboring ones, i.e. H. do not get caught between the guide grilles 04 that follow one another.

For this purpose, it is proposed to arrange these guide grids 04 in vertical steps at a transition between adjacent, ie immediately successive, guide grids 04. For this purpose, the first plane E1 of each guide grid 04 arranged upstream of another guide grid 04 in the transport direction T of the substrate 02 to be transported, which extends at a distance b from the conveyor belt 03, is at an inclination angle α inclined in the transport direction T of the substrate 02 to be transported to the conveyor belt 03 in a range from Z. B. 0.1 ° to 3 °, whereby at the transition from adjacent, ie immediately successive guide grids 04 a vertical offset V04 between these guide grids 04 in the area z. B. is formed between 1 mm and 10 mm. In a preferred arrangement of the successive guide grids 04, the angle of inclination α is z. B. in the range between 0.1 ° and 0.5 ° and the vertical offset V04 z. B. in the range between 4 mm and 7 mm, each of these guide grids 04 being in the transport direction T of the substrate 02 to be transported over a length L04 in the range z. B. extends between 900 mm and 1,000 mm. 9 shows an example of the vertical offset V04 and the inclination angle α of immediately successive guide grids 04 in a detail from the drying device 01.

Furthermore, in order to ensure a collision-free transport of substrates 02 along a drying section leading through the drying device 01, it is proposed that in immediately successive guide grids 04 their respective guide webs 07 on the cross bars 27 of the respective enclosure 06, ie at the transition of these adjacent guide grids 04, are laterally offset from one another and are therefore not aligned. This exists transversely to the transport direction T of the substrate 02 to be transported lateral offset V07 between guide webs 07 of adjacent guide grilles 04 is in the 10 in a section N from the 1 shown as an example and only schematically and lies in a range of z. B. 3 mm and 10 mm, preferably between 5 mm and 8 mm. The respective guide webs 07 are arranged in a guide grid 04 downstream in the transport direction T of the substrate 02 to be transported, with respect to the corresponding guide webs 07 in an immediately upstream guide grid 04, preferably offset inwards, ie in the direction of the center line M of the relevant guide grid 04.

The proposed lateral offset V07 between guide webs 07 of adjacent guide grilles 04 ensures that these guide webs 07 can expand freely as a result of their respective heating, because these guide webs 07 can freely slide past each other if necessary. In addition, this arrangement of guide webs 07 conveys a z. B. curved front edge in the transport direction T and / or a curved corner of the substrate 02 in question provides sufficient guidance without the risk of snagging. The divergence angle (φ of the guide webs 07) which opens in the transport direction T of the moving substrate 02 away from the center line M of the respective guide grid 04 can be designed to be the same or different from one another in immediately successive guide grids 04.

Reference symbol list

01

Drying facility

02

Substrate

03

Conveyor belt

04

Guide grid

05

-

06

Edging

07

Guide bridge

08

cross bar

09

Hot air source

10

-

11

Infrared radiation source

12

Sheetfed printing machine

13

Attachment

14

Pressure unit

15

-

16

dryer

17

Cooling device

18

Attachment; boom

19

Non-impact printing facility

20

-

21

Inkjet print head

22

Control unit

23

Belt conveyor

24

Belt conveyor

25

-

26

Belt conveyor

27

Crossbar (06)

28

Longitudinal spar (06)

a

Distance

b

Distance

c

Distance

E1

level

E2

level

L04

length

LP1

Storage point

LP2

Storage point

LP3

Storage point

LP4

Storage point

M

Centerline

S1

Page

S2

Page

T

Transport direction

V04

vertical offset

V07

lateral offset

X

Attachment point

Yn

Attachment point

α

Angle of inclination

Δh

Height

φ

divergence angle

Claims (8)

Drying device (01) for drying a surface of a sheet-shaped substrate (02) printed and/or painted by a printing press by applying heat, the drying device (01) having a conveyor belt (03), the conveyor belt (03) carrying the printed and / or painted substrate (02) is designed to move through the drying device (01), the drying device (01) on its side facing the surface of the substrate (02) to be dried having a trans The port belt (03) and the printed and/or painted substrate (02) lying there has a spaced guide grid (04), the guide grid (04) having several bearing points (LP1; LP2; LP3; LP3; LP1; LP2; LP3; LP4), wherein the guide grid (04) has a circumferential border (06) and in the area encompassed by its border (06) has a plurality of guide webs (07), with a part lifted from a flat position by the conveyor belt (03) through the drying device (01) moving printed and/or painted substrate (02) is guided in contact with at least one of the guide webs (07), the guide grid (04) in the area enclosed by its peripheral enclosure (06) having at least one transverse to the transport direction ( T) of the moving substrate (02) has a transverse web (08), each of the guide webs (07) being held by at least one transverse web (08), characterized in that only a single one of the bearing points (LP1) of the guide grid (04) as a fixed bearing and the remaining bearing points (LP2; LP3; LP4) are each designed as a floating bearing, each of the guide webs (07) being held at at least two fastening points (X; Yn with n = 1, 2, 3, ...) by the relevant at least one transverse web (08), whereby only one of these fastening points (X) is designed as a fixed bearing and the remaining fastening points (Yn with n = 1, 2, 3, ...) are each designed as a floating bearing. Drying device (01). Claim 1 , characterized in that the bearing points (LP1; LP2; LP3; LP4) of the guide grid (04) are arranged on its circumferential border (06). Drying device (01). Claim 1 or 2 , characterized in that a free displaceability of the relevant guide web (07) in its at least one floating bearing is only possible in the longitudinal direction of this guide web (07). Drying device (01). Claim 1 or 2 or 3 , characterized in that the fixed bearing of the relevant guide web (07) is arranged on the circumferential border (06) of the guide grid (04) or on one of the transverse webs (08) of the guide grid (04). Drying device (01). Claim 1 or 2 or 3 or 4 , characterized in that the guide grid (04) has its bearing points (LP1; LP2; LP3; LP4) on both sides of a center line (M) extending in the transport direction (T) of the substrate (02) to be dried, at least one of these bearing points (LP1 ; LP2; LP3; LP4) is arranged at one end of a crossbar (08). Drying device (01). Claim 5 , characterized in that the relevant bearing point (LP2; LP3; LP4) arranged at one end of a transverse web (08) is designed as a floating bearing. Drying device (01). Claim 1 or 2 or 3 or 4 or 5 or 6 , characterized in that at least one hot air source (09) and/or at least one infrared radiation source (11) are provided, wherein the at least one hot air source (09) and/or the at least one infrared radiation source (11) forms the circumferential enclosure (06) of the guide grid ( 04) and/or the guide webs (07) and/or the at least one transverse web (08) are each arranged to apply heat. Drying device (01). Claim 7 , characterized in that at least one UV radiation source is additionally provided.

Images