EP3461638B1 - Apparatus for drying printed material provided with printing ink - Google Patents

Description

The invention relates to a device according to the preamble of claim 1.

It is known from the prior art that blower units, which are generally components of dryers, are used in order to dry freshly printed printing material. For example, heated air is applied to the printing material so that the solvent present in the still wet printing ink evaporates more quickly. A printing press can be equipped with a large number of such dryers, with at least one such dryer being located behind each printing unit in the transport direction of the printing material.

Devices for drying materials are known from the prior art, for example from DE 692 02 957 T2 , the US 2015/0233637 A1 , the DE 10 2005 031 159 A1 , the DE 10 2006 059 025 A1 as well as the U.S. 2012/0273070 A1 known.

In addition, the DE 10 2004 051 990 B4 a device for drying a printing material provided with printing ink, a gaseous medium being fed to the device via a connecting piece. This gaseous medium then exits this device through openings. The known device essentially consists of four components. Specifically, these are a hollow body, a connecting piece, a cover plate and a perforated or nozzle strip from which the gaseous medium leaves the device in the direction of the printing material. The known device is distinguished by the fact that good flow conditions are created, in particular when exiting the device, as a result of which efficient drying of the printing material can be achieved. It has been shown that the manufacturing process and the manufacturing costs of such a device can still be further optimized.

It is therefore an object of the present invention to at least partially eliminate the disadvantages described above. In particular, it is the object of the present invention to create a device that can be manufactured more cost-effectively.

The above object is achieved by a device having the features of claim 1. Further features and details of the invention result from the respective subclaims, the description and the drawings. Features and details that are described in connection with the patent claims according to the invention naturally also apply in connection with the device according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention is or can always be referred to alternately.

The object is achieved by a device for drying a printing material provided with printing ink for a printing machine with a hollow body which has an elongate air duct area with an opening to conduct a gaseous medium from the hollow body in the direction of the printing material, and a feed opening to direct the gaseous medium into the hollow body. Here it is provided that the hollow body and the air ducting area form a common component of the same material. According to the invention, the gaseous medium enters the device via the opening of the hollow body, the gaseous medium entering the air duct area inside the hollow body in order to exit the air duct area as uniformly as possible and flow onto the printing material. It is particularly advantageous that the hollow body and the air ducting area are made from one component, as a result of which the manufacturing costs can be significantly reduced. The device according to the invention can thus be produced in a few work steps. The elongate extension of the hollow body advantageously corresponds to the elongate extension of the air duct area, so that the printing material can be completely dried by the device according to the invention. Advantageously, the air ducting area directly adjoins the hollow body, wherein the air ducting area can be designed in the form of a nozzle, so that the gaseous medium can reliably leave the device according to the invention in the direction of the printing material from an opening in the air ducting area. The printing machine can be, for example, a flexographic printing machine or a gravure printing machine.

It is also provided that the air duct area has two walls which are at least partially spaced apart from one another, with the walls in particular making contact. On the one hand, the walls form a flow channel for the gaseous medium, with both walls being arranged opposite one another. During operation, the gaseous medium leaves the hollow body in the direction of the air duct area, in which it flows along the walls in the direction of the printing material. The walls are designed to be open on the side opposite the hollow body, as a result of which the opening of the air duct area is formed. The walls are advantageously connected to one another or fastened to one another at defined points. A stable air ducting area is thus formed, which provides a uniform flow and a uniform opening of the air ducting area for the medium exiting in gaseous form.

In addition, according to the invention, the air guidance area has air resistance elements on at least one of the two walls. On the one hand, the air resistance element serves to ensure an optimal flow within the hollow body and/or in the air duct area to be achieved so that an optimal fluid outlet in the direction of the printing material can be achieved. This serves to dry the substrate as efficiently as possible.

In addition, it is advantageous within the scope of the invention that the air resistance element has an elongate extension, which is aligned in the direction of the opening of the air duct area. It has been shown that the longitudinal extent brings about an advantageous equalization of the flow of medium at the outlet of the opening of the air-guiding area, with the pressure losses within the device being kept low at the same time.

According to an advantageous development of the invention, it can be provided that the air duct area has an opening section in the vicinity of its opening, in which there is no air resistance element. The advantage of the outlet section is that the flow of the medium, which is conducted through the air ducting area, recovers in the outlet section, which results in an equalization when the medium exits towards the printing material. The mouth section advantageously extends along the entire length of the hollow body.

According to an advantageous development of the invention, it can be provided that the walls are at a distance X from one another, which is in particular between 1 mm≦X≦10 mm. The distance X is advantageously constant over the entire extent of the air duct area. The distance X is advantageously in a range between 1 mm≦X≦5 mm.

It is also advantageous if, within the scope of the invention, the air ducting area has a length Lw, starting from the hollow body to the opening of the air ducting area, with the mouth section having a length Lm, which runs from the air resistance element to the opening of the air ducting area, with 1.5≦Lw/Lm ≦10, in particular 2≦Lw/Lm≦5. According to the invention, it has been shown that the length of the opening section is important in order to achieve calming of the flow, which is advantageous for the drying effect on the printing material. Compared to the length of the air duct area, the length of the mouth section is to be chosen much smaller in order to equalize the achieve flow. An overall arrangement that is as small as possible can thus be created.

It is also advantageous if, within the scope of the invention, the air resistance element has a contact zone which is attached to the adjacent wall. It has been shown according to the invention that only defined contact zones are necessary in order to reliably attach both walls to one another without jeopardizing the stability of the device according to the invention during operation. The fewer contact zones there are, the less great are the flow resistances in the device according to the invention.

It is also advantageous if, within the scope of the invention, a large number of air resistance elements are provided which are at a distance Y from one another, in particular 0.01≦X/Y≦0.3, in particular 0.03≦X/Y≦0 is .08. The distance X of the opening of the air guiding area, which can also be referred to as the nozzle gap, can vary correspondingly to the distance Y, the distance Y being the distance between two air resistance elements. The distances between the air resistance elements must not be chosen too small, otherwise greater pressure losses will occur within the device. A distance Y that is too large is also disadvantageous, since the air resistance elements serve as fastening means via the contact zone. Too few contact zones could cause possible instability of the device according to the invention during operation, which means that unnecessary turbulence or material vibrations could occur, for example, due to the prevailing medium flow in the air duct area.

Advantageously, it can be provided within the scope of the invention that both walls have air resistance elements which are connected and/or fastened to one another at their contact zones. It can be advantageous to provide both opposite walls with air resistance elements, whereby a stable air flow area is created and a uniform flow is achieved within the device according to the invention. Advantageously, the geometries of the air resistance elements are identical on both walls. the Air resistance elements are located within the air duct area, i.e. on the inside of the respective wall.

Advantageously, it can be provided within the scope of the invention that the hollow body and the air duct area form a common metal part, in particular a stamped and bent part. This has the advantage that the device according to the invention can be designed inexpensively. The metal part here forms a certain stability, which is necessary in order to guide the flow of medium present within the hollow body and the air duct area evenly and reliably out of the nozzle gap in the direction of the printing material. The stamped and bent part can be produced in a few simple production steps, with defined areas of the metal part being attached to the air duct area.

At least one side of the hollow body is closed by a cover element. The side opposite the cover element has at least one corresponding feed opening in order to conduct the gaseous medium into the hollow body. The cover element is advantageously a separate component for the hollow body and the air duct area. The cover element can be fastened to the hollow body in a form-fitting and/or non-positive and/or material manner, in particular the cover element is screwed to the hollow body. A latching connection, such as clipping, etc., is alternatively and/or additionally conceivable. In addition, it is also advantageously provided within the scope of the invention that the feed opening also has a cover element, this cover element having a flow opening through which the gaseous medium can be conducted into the hollow body from the outside. This cover element can be attached to the hollow body in an identical manner to the cover element lying opposite.

According to an advantageous development of the invention, it can be provided that the air resistance element is formed from the metal part, in particular deep-drawn or embossed. Such an embodiment is characterized by low production costs, with the forming process in particular being able to be carried out in a short production time and the reproducibility of the forming result being very high.

According to an advantageous development of the invention, it can be provided that the walls run parallel to one another or the walls run conically to one another, with the distance X becoming smaller towards the opening. Depending on the installation conditions it may be useful for the walls to run conically towards one another, as a result of which a nozzle effect of a confuser is achieved. Due to the tapering cross section in the confuser, the flow speed of the medium increases. This can affect the drying process on the substrate.

According to an advantageous development of the invention, it can be provided that the air resistance element has a depth T that is essentially uniform. This design according to the invention can be realized, for example, when the walls run parallel to one another, with the air resistance elements serving as spacer elements between the walls. The depth T essentially influences the distance X between the walls or the opening of the air duct area where the medium exits.

A further advantage can be that the air resistance element has a depth T, which decreases towards the opening of the air duct area. Such a construction can be useful if the walls run conically towards one another, for example, with the distance X to the opening becoming smaller. It is also conceivable that only one wall is equipped with air resistance elements or both walls each have air resistance elements, with the air resistance elements of one wall being attached to the opposite air resistance elements of the other wall, particularly at the contact zones.

Another advantage is that the contact zone of the air resistance element of one wall runs essentially parallel to the opposite wall or the contact zone of the air resistance element of one wall runs essentially parallel to the contact zone of the opposite air resistance element of the other wall. This means that either the device according to the invention has air resistance elements on each wall or, in a possible variant, has air resistance elements on one wall, with the opposite wall being free of air resistance elements. In both cases, both walls are attached via the air resistance elements.

It can be advantageous if, within the scope of the invention, the two walls are connected to one another in a form-fitting and/or non-positive and/or material-locking manner, in particular that the two walls are welded or clinched. The last two types of fastening are particularly distinguished by their reliability, which means that the fastening effects are long-lasting, even when higher flow velocities prevail in the air duct area.

It can be advantageous that the air resistance elements of one wall are attached to the opposite wall or the air resistance elements of one wall are attached to the air resistance elements of the other wall. The fastening takes place in each case at the contact zone of each air resistance element, whereby the contact zone can accommodate different geometric shapes, such as a circular or oval shape.

In a further possibility it can be provided that a fixing area of the contact zone of one wall is used for fixing to the other wall. The fixing area is advantageously designed to be geometrically smaller than the contact zone. Particularly in the case of welding or clinching, the fixing area can be designed to be significantly smaller than the actual contact zone. However, this also means that the remaining area of the contact zone can continue to rest against the opposite wall.

In a further possibility it can be provided that the fixing area is arranged on the side of the air duct area facing the hollow body. This allows an increased fastening effect to be achieved between the walls. Another advantage is that despite the higher flow speeds within the air duct area, noise development can be kept low. Surprisingly, this latter phenomenon was found in flow tests: by arranging the fixing area as close as possible to the hollow body, the flow is reliably guided between the air resistance elements and no unnecessary turbulence occurs in the area of the air resistance elements, which has a positive effect on noise reduction.

It can be advantageous if, within the scope of the invention, the air resistance element tapers in the direction of the opening. This means that the distance between two adjacent drag elements of a wall can increase. This arrangement resembles a diffuser type nozzle. This embodiment can be combined with a constant distance X between the walls or with a distance X that decreases in the direction of the opening of the air duct area.

It can be advantageous if, within the scope of the invention, the air resistance element is drop-shaped or circular or oval-shaped or the width of the air resistance element is almost constant along its extension in the direction of the opening. Such shapes of an air resistance element can easily be realized via a forming process on the metal part. The metal part from which the hollow body and the air duct area are made is advantageously a flat metal part or sheet metal before the forming process, it advantageously having a rectangular shape. In a first process step, defined areas of the metal are formed in order to introduce the air resistance elements into the metal. The metal part is then bent at defined points, for example using roll profiling. In a further step, it is attached to the air duct area, advantageously by welding or by clinching.

According to the invention, it can be provided that at least one wall has a first and a second air resistance element, the first air resistance element differing geometrically from the second air resistance element, in particular the first air resistance element generating a greater air resistance for the gaseous medium than the second air resistance element. The different design of the geometries has the advantage that good drying effects can be achieved on the printing material, and in particular uniform drying can be achieved. There is no "stripe drying" across the width of the substrate.

In addition, it can be provided that the first air resistance element has the fixing area. As a rule, the first air resistance element has a larger structural structure than the second air resistance element, so that a reliable fixation can be achieved.

The invention can also include that the air resistance elements of one wall are arranged offset to the air resistance elements of the opposite wall, with the air resistance elements in particular being positioned at a common height in the air duct area. It is thus conceivable that each wall has a certain number of air resistance elements, with the fixing area advantageously being on the first air resistance element.

It has been shown that good drying results can be achieved if the offset is 50% of the distance Y between two adjacent air resistance elements of a wall.

According to the invention, the device can be designed in such a way that the hollow body has an opening which is positioned opposite the feed opening, a cover element being attached to the opening and/or to the feed opening, so that the hollow body is closed, the cover element in particular being shaped - And / or non-positively and / or materially attached to the hollow body. The cover element can be designed as an injection molded part. The cover element is advantageously made of a plastic. The plastic advantageously has increased electrical conductivity, so that electrical charging during the drying process on the part of the device according to the invention can be avoided. For example, the cover element is made of a high-temperature-resistant thermoplastic material, such as polyphenylene sulfide (PPS).

According to the invention, it can be provided that the cover element has a double-walled fastening section into which the hollow body extends, with the hollow body being encompassed by the fastening section. The double-walled fastening section is open on one side, so that the hollow body can protrude into this fastening section, which is advantageous for assembly.

In addition, it is conceivable that the fastening section has an inner section and an outer section, with a free space being located between the inner section and the outer section, into which the hollow body extends. Advantageously, the dimensions of the free space are greater than the wall thickness of the hollow body, so that the hollow body can be guided into the free space reliably and without complications.

The device according to the invention can provide that fastening elements are provided in the fastening section, which at the same time are directly operatively connected to the fastening section and to the hollow body. The fastening element advantageously has a fastening effect on the inside of the hollow body and at the same time in the double-walled fastening section of the cover element.

In order to achieve a greater fastening effect of the cover element on the hollow body, provision can be made for the inner section and/or the outer section to have at least one projection which protrudes into the free space. The projection is advantageously made of the same material and/or monolithic to the cover element. In the mounted state, the projection exerts an additional holding force on the hollow body.

According to the invention, it can be provided that a flow element is arranged inside the hollow body, which makes it possible to direct the gaseous medium inside the hollow body in the direction of the opening, with the flow element in particular having a penetration depth into the hollow body that is less than 10% of the total width of the Hollow body, the total width being determined by the distance between the feed opening and the opening of the hollow body. The flow element enables the gaseous medium to be evenly distributed within the hollow body. In particular, the gaseous medium flowing into the hollow body is forced to flow along the air resistance elements at the beginning of the opening in order to leave the hollow body there for reliable drying of the printing material over its entire width.

The cover element can advantageously have the flow element. Advantageously, the flow element forms a material-uniform and/or monolithic component with the cover element.

Advantageously, the air-guiding area has a large number of air resistance elements, which are arranged along the width of the hollow body. It is conceivable here that the air ducting areas have the same geometric shape. It is also possible that several first air resistance elements and second air resistance elements are arranged, which can be provided next to one another in different variations. For example, a first air resistance element and then a second air resistance element and then again a first air resistance element etc. can be provided alternately. Also possible is the combination that first the second air resistance element and then the first air resistance element and then the second air resistance element etc. can be provided. Other conceivable combinations, which also give rise to a certain irregularity, are also possible. For example, two first drag elements followed by three second drag elements, followed by a first drag element, etc., may be used. With all the conceivable combinations, it has been shown that strip drying can be effectively avoided in this way.

In addition, the invention is achieved by a printing press with a plurality of inking units, the drying unit having a plurality of devices according to the invention. In this case, all of the implemented embodiments of the device according to the invention that have already been described can be related to the printing press.

The drying unit advantageously has a large number of devices according to the invention for drying the printing material. Provision can be made for the air resistance elements of the hollow body to be offset in relation to the air resistance elements of the adjacent hollow body. In this case, an offset can be provided which is, for example, 50% of the distance Y, the distance Y being the distance between two adjacent air resistance elements within a hollow body. This also avoids strip drying. The offset can also be dimensioned differently, e.g. B. Y: 4 or Y: 3.

Advantageously, the printing press can be designed in such a way that the drying unit has a plurality of guide rollers, with each guide roller being assigned a device, the drying unit having an inlet through which the printing material can be fed into the drying unit, and an outlet through which the printing material can pass the drying unit leaves, in particular that each opening of the device is aligned with the axis of rotation of the guide roller, the openings of the devices having the smallest distance from the exit and the entrance are aligned with the adjacent guide roller. The different orientation of the devices according to the invention arranged at the edge has the advantage that as little solvent as possible can leave the drying unit through the inlet or outlet. According to the invention, a separate solvent discharge is provided. The peripheral devices cause the gaseous medium to flow in the opposite direction to the inlet or the outlet. The purpose of this is that the solvent located within the hollow body cannot flow in the direction of the outlet or inlet.

Fig. 1

ein mögliches Ausführungsbeispiel einer Vorrichtung zum Trocknen eines mit Druckfarbe versehenen Bedruckstoffes in einer Druckmaschine,

Fig. 2

eine weitere Ausführungsform einer erfindungsgemäßen Vorrichtung gemäß Figur 1,

Fig. 3

eine weitere Ausgestaltungsform einer erfindungsgemäßen Vorrichtung gemäß Figur 1,

Fig. 4

die Ausführungsform gemäß Figur 1 in einem weiteren Ausführungsbeispiel,

Fig. 5

ein weiteres Ausführungsbeispiel einer in Figur 1 dargestellten Vorrichtung und

Fig. 6

ein weiteres Beispiel einer Vorrichtung gemäß Figur 1,

Fig. 7

eine Ausführungsform einer Vorrichtung gemäß der Figuren 1 bis 6 sowie der Figuren 8 bis 15, die für eine Druckmaschine vorgesehen ist,

Fig. 8

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Vorrichtung gemäß Figur 1,

Fig. 9

ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Vorrichtung gemäß Figur 1 mit einem Deckelelement,

Fig. 10

das Ausführungsbeispiel gemäß Figur 9, wobei das Deckelelement am Hohlkörper der Vorrichtung befestigt ist,

Fig. 11

ein weiteres Ausführungsbeispiel der erfindungsgemäßen Vorrichtung mit Deckelelement,

Fig. 12

das Ausführungsbeispiel gemäß Figur 11 in einer weiteren Ansicht,

Fig. 13

ein weiteres Ausführungsbeispiel eines Deckelelementes für eine Vorrichtung gemäß Figur 1,

Fig. 14

ein weiteres Ausführungsbeispiel eines Deckelelementes für eine erfindungsgemäße Vorrichtung gemäß Figur 1,

Fig. 15

eine vergrößerte Darstellung der Öffnung des Luftführungsbereichs des Hohlkörpers.

Further advantages, features and details of the invention result from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. Show it:

1

a possible embodiment of a device for drying a printing material provided with printing ink in a printing press,

2

a further embodiment of a device according to the invention figure 1 ,

3

according to a further embodiment of a device according to the invention figure 1 ,

4

the embodiment according to figure 1 in another embodiment,

figure 5

another embodiment of an in figure 1 shown device and

6

another example of a device according to FIG figure 1 ,

7

an embodiment of a device according to Figures 1 to 6 as well as the Figures 8 to 15 , which is intended for a printing press,

8

a further exemplary embodiment of a device according to the invention figure 1 ,

9

a further exemplary embodiment of a device according to the invention figure 1 with a cover element,

10

the embodiment according to figure 9 , wherein the cover element is attached to the hollow body of the device,

11

a further exemplary embodiment of the device according to the invention with a cover element,

12

the embodiment according to figure 11 in another view,

13

a further exemplary embodiment of a cover element for a device according to FIG figure 1 ,

14

according to a further exemplary embodiment of a cover element for a device according to the invention figure 1 ,

15

an enlarged view of the opening of the air duct area of the hollow body.

figure 1 shows a device 1 for drying a printing material provided with a printing ink in a printing machine 2. The printing machine 2 is shown purely schematically, the printing material with printing ink being explicitly not shown in the exemplary embodiments shown. In the printing machine 2, it can be z. A gravure printing machine or a flexographic printing machine, for example, in which the device 1 according to the invention, which can also be referred to as a blower unit, allows a gaseous medium to flow in the direction of the printing material. Advantageously, heated air is used as the gaseous medium in order to increase the efficiency of drying. As a medium z. As air or other suitable gases can be used. The device 1 according to the invention is preferably connected to a line system 3 which conducts the gaseous medium into a hollow body 10 of the device 1 according to the invention. The device 1 serves, among other things, to distribute the supplied medium evenly over the entire width B of the hollow body, so that the printing material can be dried evenly over its entire width.

The hollow body 10 has a feed opening 11 on one of its end faces, to which the line system 3 can be connected in order to allow the gaseous medium to flow efficiently into the hollow body 10 . A cover element 14 is arranged on the opposite end face, which is shown in an example in figure 2 or figure 3 as well as in the Figures 10 to 12 is shown. This cover element 14 closes the hollow body 10 or its opening 13. The hollow body 10 of the device 1 according to the invention shown can have any cross section. The hollow body 10 is used here as an air-guiding channel, with an air-guiding region 20 being implemented on the hollow body 10 through which the gaseous medium can flow. The air duct area 20 has a common opening 21 along its longitudinal extension, which is also shown in figure 2 and figure 3 is shown. The gaseous medium can leave the device 1 according to the invention through this opening 21 in the direction of the printing material. The feed opening 11 can also be closed by a cover element 12, which will be discussed further below.

The air duct area 20 and the hollow body 10 form a common component of the same material, which is shown in all the exemplary embodiments. The common component is a metal part which, among other things, is temperature resistant. The material can be, for example, steel or sheet metal, which z. B. can have a thickness of 0.3mm to 0.9mm.

The device 1 according to the invention has two walls 22, 24 in the air duct area 20, which are spaced apart from one another. In all of the exemplary embodiments, the wall 22 has a large number of air resistance elements 23 . According to figure 2 the resistance elements 23 can only be found on the wall 22, the opposite wall 24 being designed without the air resistance elements. As well in figure 2 as well as in the following embodiments to figure 12 the air resistance elements 23, 25 have an elongate extension, which are aligned in the direction of the opening 21 of the air duct area 20. All of the exemplary embodiments show that the air duct area 20 has an opening section 26 in the vicinity of its opening 21, in which there is no air resistance element 23, 25. The walls 22, 24 are at a distance X from one another, which is advantageously between 1 mm≦X≦10 mm. In figure 2 the walls 22, 24 run parallel to one another. According to figure 3 on the other hand, the walls 22, 24 run conically towards one another, with the distance X towards the opening 21 becoming smaller.

The air duct area 20 has according to Figure 2 to Figure 3 a length Lw, starting from the hollow body 10 to the opening 21 of the air duct area 20, the mouth section 26 having a length Lm, which runs from the air resistance element 25 to the opening 21 of the air duct area 20. It has been shown that advantageous flow conditions and drying results are achieved when 1.5≦Lw/Lm≦10, in particular 2≦Lw/Lm≦5. This also applies to the exemplary embodiments according to FIG Figure 4 to Figure 15 , which will be discussed further below.

In all the exemplary embodiments, each air resistance element 23, 25 has a contact zone 27 which is attached to the adjacent wall 22, 24. According to figure 2 the contact zone 27 of the air resistance element 23 of one wall 22 runs essentially parallel to the opposite wall 24 . In the exemplary embodiment, the fixing area 28 is welded or clinched to the wall 24 .

In figure 3 the wall 22 has air resistance elements 23 and the wall 24 also has air resistance elements 25 . All air resistance elements 23, 25 are, as in figure 1 shown, along the width B of the hollow body 10 at regular intervals along the air duct area 20 distributed. The contact zones 27 of both air resistance elements 23, 25 run parallel to one another, with each contact zone 27 also having a smaller fixing area 28 here, which, as in FIG figure 2 used for attachment. In both embodiments according to figure 2 and figure 3 the fixing area 28 is arranged on the side of the air duct area 20 facing the hollow body 10 . In figure 2 is the depth of each air resistance element 23 is an amount T, which is essentially the same size over its direction of extension to the opening 21 out. In contrast, the depth T in figure 3 of each air resistance element to the opening 21 of the air duct area 20 from. figure 15 shows in another view how the fixing area 28 of an air resistance element 23.1 is attached to the fixing area 28 of the other air resistance element 25.1. The adjacent air resistance element 23.2, 25.2 has no fixing area 28.

As in figure 1 is shown, the air guiding area 20 can have a multiplicity of air resistance elements 23, 25. Test results have shown that particularly good flow conditions and good drying results can be achieved if the quotient of distance X and distance Y is 0.01≦X/Y≦0.3.

It can be advantageous that the air resistance elements have different geometric shapes, which Figure 4 to Figure 6 as in Figures 8 to 11 is explicitly shown. For example, the air resistance elements 23, 25 can have a teardrop shape, which figure 5 is shown. Alternatively, an almost rectangular shape is appropriate figure 4 conceivable or a circular shape not claimed according to the invention figure 6 .

According to all exemplary embodiments, it is particularly advantageous that the device 1 according to the invention is formed from a metal part and/or is roll-profiled or bent. The air resistance elements 23, 25 are a forming process emerged, in particular via a deep drawing or an embossing process. It is particularly advantageous that the free ends 29 of the air duct area 20 are beaded so that no unnecessary turbulence occurs when the medium exits. In addition, the ends 29 have no risk of injury.

It can be particularly advantageous to arrange a flow element 4 inside the hollow body 10, which enables the gaseous medium inside the hollow body 10 to be directed in a desired direction, for example in the direction of the opening 21 Entire opening area 21 are equalized. In Figure 4 to Figure 6 this flow element is shown as an example, with this flow element 4 also in Figure 1 to Figure 3 can be used, which is not shown as an example.

figure 7 shows schematically a printing press 2 with a drying unit 32, which has a plurality of guide rollers 33. A device 1 is assigned to each guide roller 33, it being possible for the device 1 to be designed in accordance with one of the exemplary embodiments described. The printing material 5 is guided through an inlet 34 into the drying unit 32 and leaves the drying unit 32 at the outlet 35. All openings 21 of the device 1 are aligned directly with the axis of rotation of the guide rollers 33, in the present exemplary embodiment radially with respect to the axis of rotation of the guide roller 33 a good drying effect can be achieved on the printing material 5. Only the device 1 assigned to the input 34 and the device 1 assigned to the output 35 have a different orientation to the axis of rotation of the guide roller 33 . The device 1 of the input 34 is aligned in such a way that its opening 13 is aligned with the adjacent guide rollers 33, in particular the alignment is oriented in the direction of movement of the printing material. The device 1 of the exit 35 is also oriented such that its opening 13 is aligned in the direction of the adjacent guide rollers 33, in particular against the direction of movement of the printing material 5. The direction of movement of the printing material 5 runs from left to right, see arrow illustration. The left-hand and right-hand orientation of the device 1 has the effect that any solvents that may be present in the drying unit 32 cannot flow outwards, in particular through the inlet 34 or through the outlet 35 to the outside. the Drying unit 32 is located either between two inking units 31 or after the last inking unit 31 of printing press 2.

In figure 8 The device 1 according to the invention is shown schematically, the air resistance elements 23 of one wall 22 having an offset Y/2 relative to the air resistance elements 25 of the other wall 24 . All air resistance elements 23, 25 can have the identical geometric shape. It is also conceivable what in figure 8 it is shown that two air resistance elements 23.1, 23.2, 25.1, 25.2, which are designed differently in terms of their geometry, are provided. The first air resistance element 23.1, 25.1 is larger than the second air resistance element 23.2, 25.2. The first air resistance element 23.1, 25.1 offers a greater air resistance for the gaseous medium than the second air resistance element 23.2, 25.2. In the present exemplary embodiment, the larger air resistance element 23.1, 25.1 has a fixing area 28 which is intended for attachment to the opposite wall 22, 24. The attachment of the fixation area 28 can, as in figure 2 or figure 3 is described, be executed. There is advantageously a clinch connection between the fixing area 28 and the respective wall 22, 24. It is also conceivable that only one wall 22, 24 is designed with the differently designed air resistance elements 23, 25, with the fixing areas 28, which are provided at least on some air resistance elements 23, 25, being able to be attached to the opposite wall 22, 24.

In the assembled state of the hollow body 10, the air resistance elements 23, 25 are in all the exemplary embodiments at a common height within the ventilation area 20, as a result of which uniform drying over the entire width of the printing material 5 can be achieved.

In Figure 9 to Figure 12 It is shown that the hollow body 10 can have an opening 13 positioned opposite to the supply opening 11 . The opening 13 and the feed opening 11 can be closed via cover elements 12, 14. The feed opening 11 is closed by the cover element 12, the opening 13 being closed by a cover element 14, which is not explicitly shown. The embodiment of Cover element 12 on the feed opening 11 essentially corresponds to the cover element 14 for the opening 13. A significant difference between the two covers 12, 14, however, is that the cover element 12 has a flow opening 16 so that the gaseous medium can enter the hollow body 10 from the outside . The cover element 14 on the opposite side to the cover element 12 reliably closes the hollow body 10 so that the inflowing gaseous medium can leave the air duct region 20 in the direction of the printing material 5 evenly.

According to Figure 9 and Figure 10 the cover element 12 is fastened to the hollow body 10 in a positive and non-positive manner. The cover element 12 has a double-walled fastening section 15, which Figure 13 and 14 is shown. The fastening section 15 has an inner section 15.1 and an outer section 15.2. Between the inner section 15.1 and the outer section 15.2 there is a free space 15.3, in which the hollow body 10 extends, which in figure 13 is shown schematically. The free space 15.3 serves as an assembly aid, so that a reliable seat of the cover element 12 on the hollow body 10 is ensured. In addition, fastening elements 19.1 are provided, which rest against the inner wall of the hollow body 10 in a positive and non-positive manner. In the present exemplary embodiment, the fastening elements 19.1 are designed as screws which are located in the free space 15.3 and engage via their thread on the inside of the hollow body 10 and on the inner and outer sections 15.1, 15.2. This achieves an effective attachment of the cover element 12 to the hollow body 10 . In order to increase the fastening effect of the cover element 12 on the hollow body 10, one or more projections 19.2 can be formed on the inner section 15.1 and/or on the outer section 15.2. As a result, a higher clamping effect between the cover element 12 and the hollow body 10 can be achieved. The projections 19.2 are shown as an example in figure 14 shown. The projections 19.2 can be designed like ribs and have an extension in the free space 15.3 that is oriented in the width direction B of the hollow body 10.

In Figure 11 and Figure 12 is shown schematically that the cover element 12 can have a locking lug 17 which engages in a locking opening 18 of the hollow body 10 in the inserted state on the hollow body 10 . This also makes it possible to achieve reliable attachment of the cover element 12 to the hollow body 10 .

The described embodiments of the cover element 12 according to Figure 9 to Figure 14 can also refer to the cover element 14 which closes the opening 13 .

In figure 13 the cover element 12 has a flow element 4 which makes it possible to direct the inflowing gaseous medium within the hollow body 10 in the direction of the opening 21 . The penetration depth of the flow element 4 is less than 10% of the total width B of the hollow body 10, the total width B being determined by the distance between the feed opening 11 and the opening 13 of the hollow body 10. The flow element 4 can have a curved course, which is oriented in the direction of the opening 21 of the air duct area 20 . The cover element 12, 14 is made from a plastic injection molded part, which preferably has high electrical conductivity in order to avoid any electrical charging that may occur.

Reference List

X

Distance between the walls 22, 24

Lw

Length of the air duct area 20

Lm

Length of muzzle section 26

B

width, hollow body

T

Depth of the drag element

Y

Distance between two drag elements

1

contraption

2

printing press

3

piping system

4

flow element

5

substrate

10

hollow body

11

feed opening

12

cover element

13

opening

14

cover element

15

attachment section

16

flow opening

17

detent

18

detent opening

15.1

inner section

15.2

outer section

15.3

free space

19.1

fastener

19.2

head Start

20

airflow area

21

opening

22

wall

23

drag element

24

wall

25

drag element

26

estuary section

27

contact zone

28

fixation area

31

inking

32

drying unit

33

idler roller

34

Entry

35

Exit

Claims (23)

1. A device (1) for drying a printing material provided with printing ink for a printing machine (2) with

   a hollow body (10), which has an elongated air guidance region (20) with an opening (21) in order to guide a gaseous medium from the hollow body (10) in the direction towards the printing material (5),

   a feed opening (11) in order to guide the gaseous medium into the hollow body (10), wherein the hollow body (10) and the air guidance region (20) form a common, uniform material component,

   wherein the air guidance region (20) has two walls (22, 24), which are at least partially spaced apart from one another, wherein the air guidance region (20) has air resistance elements (23, 25) at least on one of the two walls (22, 24) and

   wherein the air resistance element (23, 25) has an elongated extension, which is aligned in the direction of the opening (21) of the air guidance region (20).
2. The device (1) according to claim 1,
   characterized in
   that the walls (22, 24) contact each other.
3. The device (1) according to claim 1 or 2,
   characterized in
   that the air guidance region (20) has a mouth section (26) in the vicinity of its opening (21), in which there is no air resistance element (23, 25).
4. The device (1) according to any one of the preceding claims,
   characterized in
   that the walls (22, 24) have a distance X from one another, which in particular is between 1 mm ≤ X ≤ 10 mm.
5. The device (1) according to any one of the preceding claims,
   characterized in
   that the air guidance region (20) has a length Lw starting from the hollow body (10) to the opening (21) of the air guidance region (20), wherein the mouth section (26) has a length Lm, which runs from the air resistance element (23, 25) to the opening (21) of the air guidance region (20), wherein 1.5 ≤ Lw/Lm ≤ 10, in particular 2 ≤ Lw/Lm ≤ 5.
6. The device (1) according to any one of the preceding claims,
   characterized in
   that the air resistance element (23, 25) has a contact zone (27), which is attached to the adjacent wall (22, 24), and/or that a plurality of air resistance elements (23, 25) are provided, which have a distance Y from one another, wherein in particular 0.01 ≤ X/Y ≤ 0.3, in particular 0.03 ≤ X/Y ≤ 0.08.
7. The device (1) according to claim 6,
   characterized in
   that both walls (22, 24) have air resistance elements (23, 25), which in particular in each case are partially connected and/or attached to one another at their contact zones (27).
8. The device (1) according to any one of the preceding claims,
   characterized in
   that the hollow body (10) and the air guidance region (20) form a common metal part, in particular a stamped and bent part, and/or that the air resistance element (23, 25) is formed from the metal part, in particular is deep drawn or embossed.
9. The device (1) according to any one of the preceding claims,
   characterized in
   that the walls (22, 24) run parallel to one another or the walls (22, 24) run conically to one another, wherein the distance X to the opening (21) becomes smaller.
10. The device (1) according to any one of the preceding claims,
    characterized in
    that the air resistance element (23, 25) has a depth T, which is substantially uniform, and/or that the air resistance element (23, 25) has a depth T, which decreases towards the opening (21) of the air guidance region (20).
11. The device (1) according to any one of claims 6 to 10,
    characterized in
    that the contact zone (27) of the air resistance element (23, 25) of the one wall (22, 24) runs substantially parallel to the opposite wall (22, 24) or the contact zone (27) of the air resistance element (23, 25) of the one wall (22, 24) runs substantially parallel to the contact zone (27) of the opposite air resistance element (23, 25) of the other wall (22, 24).
12. The device (1) according to any one of the preceding claims,
    characterized in
    that the two walls (22, 24) are connected to one another positively and/or non-positively and/or materially, in particular that the two walls (22, 24) are welded or clinched.
13. The device (1) according to any one of the preceding claims,
    characterized in
    that the air resistance elements (23, 25) of the one wall (22, 24) are attached to the opposite other wall (22, 24) or the air resistance elements (23, 25) of the one wall (22, 24) are attached to the air resistance elements (23, 25) of the other wall (22, 24).
14. The device (1) according to any one of claims 6 to 13,
    characterized in
    that a fixation region (28) of the contact zone (27) of the one wall (22, 24) is used for the attachment to the other wall (22, 24), in particular that the fixation region (28) is arranged on the side of the air guidance region (20) facing the hollow body (10).
15. The device (1) according to any one of the preceding claims,
    characterized in
    that the air resistance element (23, 25) tapers in the direction towards the opening (21).
16. The device (1) according to any one of the preceding claims,
    characterized in
    that at least one wall (22, 24) has a first (23.1, 25.1) and a second air resistance element (23.2, 25.2), wherein the first air resistance element (23.1, 25.1) differs geometrically from the second air resistance element (23.2, 25.2), and/or that the first air resistance element (23.1, 25.1) has the fixation region (28), in particular the first air resistance element (23.1, 25.1) generates a greater air resistance for the gaseous medium than the second air resistance element (23.2, 25.2).
17. The device (1) according to any one of the preceding claims,
    characterized in
    that the air resistance elements (23, 25) of the one wall (22, 24) are arranged offset to the air resistance elements (23, 25) of the opposite wall (22, 24), and/or that the offset is 50 % of the distance Y between two adjacent air resistance elements (23, 25) of a wall (22, 24), wherein in particular, the air resistance elements (23, 25) are positioned in the air guidance region (20) at a common height.
18. The device (1) according to any one of the preceding claims,
    characterized in
    that the hollow body (10) has an opening (13), which is positioned opposite to the feed opening (11), wherein a cover element (12, 14) is attached to the opening (13) and/or to the feed opening (11) so that the hollow body (10) is closed, and/or that the cover element (12, 14) has a double wall attachment section (15), into which the hollow body (10) extends, wherein the hollow body (10) is encompassed by the attachment section (15), wherein in particular the cover element (12, 14) is attached positively and/or non-positively or materially to the hollow body (10).
19. The device (1) according to claim 18,
    characterized in
    that the attachment section (15) has an inner section (15.1) and an outer section (15.2), wherein, a free space (15.3) is located between the inner section (15.1) and the outer section (15.2), into which the hollow body (10) extends, and/or that attachment elements (19.1) are provided in the attachment section (15), which are directly operatively connected to the attachment section (15) and to the hollow body (10) at the same time.
20. The device (1) according to claim 19,
    characterized in
    that the inner section (15.1) and/or the outer section (15.2) has at least one projection (19.2), which projects into the free space (15.3).
21. The device (1) according to any one of the preceding claims,
    characterized in
    that a flow element (4) is arranged within the hollow body (10), which makes it possible to direct the gaseous medium within the hollow body (10) in the direction of the opening (21), wherein in particular the cover element (14) has the flow element (4) and/or in particular the flow element (4) has a penetration depth into the hollow body (10), which is less than 10 % of the total width of the hollow body (10), wherein the total width is determined by the distance between the feed opening (11) and the opening (13) of the hollow body (10).
22. A printing machine (2) with several inking units (31), wherein a drying unit (32) is arranged between two inking units (31) or after the last inking unit (31), wherein the drying unit (32) has several devices (1) according to any one of the preceding claims.
23. The printing machine (2) according to claim 22,
    characterized in
    that the drying unit (32) has several guide rollers (33), wherein a device (1) is assigned to each guide roller (33), wherein the drying unit (32) has an input (34), through which the printing material (5) can be guided into the drying unit (32), and an output (35), through which the printing material (5) leaves the drying unit (32), in particular that each opening (21) of the device (1) is aligned with the axis of rotation of the guide roller (33), wherein the openings (21) of the devices (1), which have the smallest distance from the output (35) and from the input (34), are aligned with the adjacent guide roller (33).

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