Abstract:
A device for printing a substrate web moved in a direction of transport past a printing unit includes a substrate web suction device arranged opposite the printing unit. The substrate web suction device has gas inflow openings that are arranged on a jacket surface of the substrate web suction device opposite the printing unit. An underpressure device sucks in air through the gas inflow openings to achieve suction of the substrate web on the substrate web suction device. Printing can be accomplished by guiding the substrate web using the substrate web suction device. Suction is applied through the gas inflow openings to a first region of the substrate web. The first region of the substrate web is printed while the suction is applied.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority of German Application Number 102011117494.3, filed Oct. 31, 2011, by Dehn et al. This application has related subject matter to U.S. patent application Ser. No. ______, (Attorney Docket Number K000229US01), titled “LIFTING SUBSTRATE WITH AIR CUSHION WHILE PRINTING,” by Dehn et al., filed herewith. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a device and a method for printing web-shaped substrates, in particular substrate webs in a printing press with inkjet printing heads. 
       BACKGROUND OF THE INVENTION 
       [0003]    Transport means for substrate webs which transport a substrate web past a printing unit with the aid of a drum are known in printing technology. With such devices, a high surface precision of the drum is necessary, since any imprecisions occurring in the drum surface would lead to a varying distance between the drum and the printing unit. Imprecisions of this type could lead to a deterioration in the printed image upon printing of the substrate web. 
         [0004]    Furthermore, with the aforementioned drums it is possible that the substrate web is not in contact with the drum in a defined manner over its entire width. 
       SUMMARY OF THE INVENTION 
       [0005]    According to an aspect of the present invention, there is provided a device for printing a substrate web that is moved in a direction of transport past at least one printing unit, the device comprising: 
         [0006]    a substrate web suction device that is arranged opposite the at least one printing unit, wherein the substrate web suction device has gas inflow openings that are arranged on a jacket surface of the substrate web suction device opposite the printing unit, 
         [0007]    an underpressure device that sucks in air through the gas inflow openings to achieve suction of the substrate web on the substrate web suction device. 
         [0008]    According to another aspect of the present invention, there is provided a method for printing a substrate web that is moved in a direction of transport past at least one printing unit, the method comprising: 
         [0009]    guiding the substrate web using a substrate web suction device arranged opposite the printing unit and having gas inflow openings on a jacket surface thereof; 
         [0010]    applying suction to a first region of the substrate web by using an underpressure device to generate negative pressure by suction of air through the gas inflow openings; and 
         [0011]    printing the first region of the substrate web while the suction is applied. 
         [0012]    There is provided a device and a method for transporting a web-shaped substrate in the region of a printing head, in particular an inkjet printing head, with which a defined distance can be maintained between a substrate web and an inkjet printing head over an entire width of the substrate web. 
         [0013]    In various aspects, a device is provided for printing a substrate web that is moved in a direction of transport past at least one printing unit. The device has a substrate web lifting device which is arranged opposite the at least one printing unit and which has a jacket surface opposite the printing unit and air cushion means forming an air cushion between the substrate web and the jacket surface of the substrate web lifting device such that lifting of the substrate web is achieved. 
         [0014]    With a device of this type, it can be assured that the substrate web is transported past the printing units at a constant distance from them. In addition, with an arrangement of this type an at least partial drying of the substrate web can be achieved in the course of printing the substrate web. It should also be noted that the usual transport means for substrate webs should have a high surface precision, as otherwise a defined distance cannot be maintained over the entire width of a substrate web in the region of the printing units. Various aspects are advantageous in this respect too, since the blowing of air against the substrate web enables a precisely defined distance from the printing units to be maintained, irrespective of the surface precision of a substrate web transport means. 
         [0015]    In accordance with one aspect, a rotation of the substrate web lifting device can promote the development of an air cushion between the jacket surface of the substrate web lifting device and the substrate web. The air cushion means can here be formed by at least one groove structure, in particular by a spiral groove structure, in the jacket surface. A groove structure of this type in the substrate guiding surface permits an improved and more uniform distribution of air between the substrate web lifting device and a substrate web guided over it. This allows a reduction in the quantity of energy required for the rotation of the substrate web lifting device to achieve a sufficient air cushion. This can also result in a lower noise emission. In edge regions of the substrate web in particular, the groove structure can provide a controlled air flow, by which any fluttering of the substrate web and an associated noise generation can be reduced. 
         [0016]    In accordance with a further aspect, the substrate web lifting device is a pipe with an interior, where the air cushion means can have at least one fan, in particular a radial compressor, which is arranged inside the pipe and is rotatably connected to the pipe. With this aspect, the substrate web lifting device would also have gas outflow openings that extend from the interior to the jacket surface of the substrate web lifting device and through which air aspirated by the fan/radial compressor is discharged to promote the development of the air cushion between the substrate web and the jacket surface still further. An arrangement of this type does not require any additional blower device to generate blown air/compressed air and thus represents an inexpensive solution. 
         [0017]    In a further aspect, the air cushion means in the interior can have at least two fan wheels which are arranged on opposite ends of the pipe. These can generate a higher back pressure in the interior of the pipe, by which an improvement in the air cushion can be achieved. 
         [0018]    At least one air baffle plate can be arranged adjacent to the substrate web lifting device so that a gas stream flowing out of the gas outflow openings reaches the region between the jacket surface of the substrate web lifting device and the substrate web. This can lead to an improvement in the air cushion, since without such an air baffle plate air flowing out of the gas outflow openings and which flows out of a region of the substrate web lifting device which is not enveloped by the substrate web would be unused. The air baffle plate here guides the air stream in a region formed between the incoming substrate web and the substrate web lifting device. 
         [0019]    In one aspect, at least one displacement unit is provided in the interior of the pipe to displace at least one fan wheel, in order to enable a selective application of air to gas outflow openings via the interior. This makes it possible for gas to be substantially applied to only those gas outflow openings that are covered by a substrate web during operation, in order to reduce leakage flows. It is thus possible to adapt to substrate webs of different widths. This allows a reduction in the entire air quantity and in an associated energy consumption, and possibly also in noise generation. 
         [0020]    According to various aspects, the channel structure inside the jacket surface has a plurality of spaced circumferential channels extending in the circumferential direction of the round jacket surface and at least one transverse channel extending transversely to said circumferential channels, which is in a flow connection to at least two circumferential channels. This permits a good distribution of air between the substrate web lifting device and the substrate web. The at least one transverse channel can here extend in the circumferential direction of the circumferential channels centrally thereto. The circumferential channels are preferably at the same distance relative to one another. However, a different arrangement of the circumferential channels can also be provided. With an arrangement of this type for the circumferential channels and for the at least one transverse channel, supplied gas/air can be readily distributed into the respective channels, so that a uniform air cushion can be achieved between the substrate web lifting device and the substrate web. 
         [0021]    In one aspect, at least some of the gas outflow openings open towards at least one transverse channel in order to enable good distribution of the supplied gas over a width of a substrate web. 
         [0022]    In an alternative aspect, the channel structure has a statistical distribution in the jacket surface. This permits a particularly uniform distribution of supplied gas over the jacket surface. 
         [0023]    The jacket surface can have a plurality of separate channel structure segments that are arranged adjacent to each other over a width of the jacket surface, where a corresponding channel structure is in flow connection to at least one gas outflow opening. The individual channel structure segments can be separated from one another by regions without channels of the jacket surface. The channel structure segments are preferably therefore not in flow connection to one another via channels. An arrangement of this type of channel structure segments enables, in particular with a segmental application to the gas outflow openings, a good adaptation to the width of a web-shaped substrate. The separation of the channel structure segments enables leakage flows to be reduced over the respective channel structure. Gas inflow opening(s) associated with a respective channel structure segment can preferably be supplied with gas in groups. 
         [0024]    In one aspect, the interior that is in flow connection to the gas outflow openings and which can be supplied with gas is subdivided in order to permit ready implementation of individual or grouped controllability of the gas outflow openings. A slide valve can also be arranged inside the interior such that it enables a selective application of gas to gas outflow openings with gas via the interior. A slide valve of this type permits a continuous adjustment of the region of the interior via which gas outflow openings can be supplied with gas. This makes possible an almost continuous adjustment to the width of a substrate web. Two slide valves may be provided which are displaceable from opposite ends into the interior in order to permit adaptation to the length and width of the substrate web. 
         [0025]    Alternatively, or even additionally, a plurality of valves can be provided for the individual or grouped application of gas to gas outflow openings. 
         [0026]    Furthermore, a device is provided for printing a substrate web, the device having a substrate web suction device arranged opposite the at least one printing unit. The substrate web suction device has gas inflow openings arranged on a jacket surface of the substrate web suction device opposite the printing unit. Furthermore, the device has an underpressure device that sucks in air through the gas inflow openings to achieve suction of the substrate web onto the substrate web suction device. The use of such a device enables a defined distance to be readily maintained between the substrate web and the printing unit over the entire width of the substrate web. 
         [0027]    In an alternative aspect of the device, the substrate web lifting device is designed as a rotatable pipe with an interior, said interior being connected to the jacket surface via the gas inflow openings. The blower is here arranged in the interior, and air is aspirated via the interior and via the gas inflow openings into the jacket surface by rotation of the substrate web lifting device. An arrangement of this type does not require an additional suction device to generate underpressure and is therefore an inexpensive solution. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    Various aspects are described below in more detail with reference to the drawings, which show in: 
           [0029]      FIG. 1  is a schematic side view of a printing press with a substrate web lifting device; 
           [0030]      FIG. 2  is a schematic sectional view of a substrate web lifting device, which is rotated in a specific direction; 
           [0031]      FIG. 3  is a schematic plan view of a substrate web lifting device in accordance with a first aspect; 
           [0032]      FIG. 4  is a schematic side view of a substrate web lifting device in accordance with a second aspect; 
           [0033]      FIG. 5  is a schematic sectional view through the substrate web lifting device in accordance with  FIG. 4  along the line  5 - 5 ; 
           [0034]      FIG. 6  is a schematic sectional view similar to that in  FIG. 5  with an alternative aspect of the substrate web lifting device; 
           [0035]      FIG. 7  is a schematic plan view of a substrate web lifting device; 
           [0036]      FIG. 8  is a schematic plan view of an alternative substrate web lifting device; 
           [0037]      FIG. 9  is a schematic detailed view of a channel structure in a surface of a substrate web lifting device in accordance with various aspects; 
           [0038]      FIG. 10  is a schematic sectional view through the substrate web lifting device in accordance with  FIG. 9  along the line  10 - 10  in  FIG. 9 ; and 
           [0039]      FIG. 11  is a schematic detailed view of a channel structure in a surface of a substrate web lifting device in accordance with various aspects. 
       
    
    
       [0040]    In the following description, the position/direction information relates primarily to the representations in the drawings and should therefore not be regarded as restrictive. They can however also relate to a preferred final arrangement. The same reference numbers are substantially used throughout for the drawings in so far as identical or equivalent elements are described. The attached drawings are for purposes of illustration and are not necessarily to scale. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    The following describes devices and methods in which air is expelled from the substrate web lifting device, thereby generating an air cushion between the substrate web and the substrate web lifting device. In various aspects, these devices and methods are also applicable to devices and methods in which the air is sucked into a substrate web suction device, which substantially corresponds in structure to the substrate web lifting device, thereby generating a negative pressure between the substrate web and the substrate web suction device, which in turn leads to a suction of the substrate web onto the substrate web suction device. 
         [0042]      FIG. 1  shows a schematic side view of a printing press  1  with a feeder region  2 , a printing region  3  and a stacker region  4 . 
         [0043]    A substrate roll  5  is provided in the feeder region  2  from which a substrate web  6  is fed to the printing region  3  for printing. A substrate roll  5  is provided in the stacker region  4  to accommodate a substrate web  6  coming from the printing region  3 . 
         [0044]    A plurality of rolls  8  is provided in the printing region  3  to guide the substrate web  6 , as well as a plurality of printing units  10 . Two of the rolls  8  are shown schematically in  FIG. 1 , although a greater number is provided as a rule to transport the substrate web  6  along a non-linear transport path through the printing region  3 . The left-hand one of the two rolls  8  is arranged such that it deflects the substrate web  6  in a lower region towards a substrate web lifting device  20 , such that the substrate web  6  is pressed against the substrate web lifting device  20 . The substrate web lifting device  20 , which is described in more detail below, brings about a controlled lifting of the substrate web in the printing region  3  during a printing process, during which the substrate web  6  is printed. The right-hand one of the two rolls  8  is here arranged such that the substrate web  6  is deflected by this roll  8  such that substrate web  6  can encircle the substrate web lifting device  20  over a range of more than 300°, as shown schematically in  FIG. 1 . In the further course of the description, alternative aspects are described in which an encircling of the substrate web lifting device  20  by the substrate web  6  occurs in an angle range that is markedly lower, preferably in the range of 90° to 180°. 
         [0045]    Two printing units  10 , each for two colors (“C 1 C 2 ” and “C 3 C 4 ”), are shown in  FIG. 1  so that the printing press  1  in accordance with  FIG. 1  would be suitable for four-color printing. However, a different number of printing units  10  can be provided. The printing units  10  are preferably inkjet printing units, but can also be of another digital type. A dryer  15  is further shown in  FIG. 1 . 
         [0046]    The substrate web lifting device  20  is, in accordance with a aspect, coupled to a rotary drive, not shown, that can rotate the substrate web lifting device  20 , for example in the direction shown by arrow C in  FIG. 4 . The rotation can be substantially in the direction of movement of the substrate web, as shown by the arrow C in  FIG. 4 , or substantially in the opposite direction, as indicated by the arrow D in  FIG. 2 . A rotation of the substrate web lifting device  20  sucks air into the encircling region between the substrate web lifting device  20  and the substrate web  6  in order to create an air cushion between them, as indicated by the arrow E in  FIG. 2 . It is an advantage in both cases if the speed of rotation of the substrate web lifting device  20  is substantially greater than the transport speed of the substrate web  6 . 
         [0047]    The substrate web lifting device  20  can have the same basic structure in all cases, so that only different aspects of the substrate web lifting device  20  are described in more detail below. 
         [0048]      FIG. 3  shows a schematic plan view of a substrate web lifting device  20  in accordance with a first aspect. With this aspect, the substrate web lifting device  20  is designed as a rod or a hollow pipe with a jacket surface  35 . A groove structure  37  is formed in the outer jacket surface  35  (see  FIG. 4 ) and as shown has a circumferential spiral groove  38 . This spiral groove  38  promotes, during rotation of the substrate web lifting device  20 , the suction and distribution of air to form an air cushion E between the substrate web lifting device  20  and the substrate web  6 . Although a continuous spiral groove  38  is shown as the groove structure in  FIG. 3 , it should be noted that other groove structures are conceivable, in particular comprising a plurality of different individual grooves which may be completely separate, but which may also intersect. In particular, for example, opposing-direction spiral grooves are conceivable which extend from the ends of the substrate web lifting device to a central region thereof. Transverse grooves, i.e., grooves extending transversely to the direction of rotation of the substrate web lifting device  20 , can promote the suction and distribution of air between the substrate web lifting device  20  and the substrate web  6 . 
         [0049]    Further aspects of the substrate web lifting device  20  are discussed in more detail below with reference to  FIGS. 4 to 6 . 
         [0050]      FIG. 4  shows a schematic sectional view through the substrate web lifting device  20  in accordance with an alternative aspect. In the sectional view, it can be seen how the substrate web  6  is guided around the substrate web lifting device  20 , although only the actual sectional plane through the substrate web lifting device  20  is shown in order to simplify representation. The substrate web lifting device  20  in this aspect is designed as a hollow pipe and has a pipe body  44  having an outer jacket surface  35  and an interior  48  inside it. Gas outflow openings  50  are provided in the pipe body  44  which enable an air flow from the interior  48  to the jacket surface  35 . The jacket surface  35  can be designed substantially smooth, as shown, or can have a structure such as a groove structure  37  as described above for the first aspect. In this case, the gas outflow openings  50  can be arranged such that they open into the groove structure  37 . 
         [0051]    Two fans  60  with lamellae or wings  65  are arranged in the interior  48 , as can be seen in the schematic sectional view in accordance with  FIG. 5 . Only one of the fans is discernable in  FIG. 4 . Axial fans are provided for the aspect shown. The fans  60  can however also be designed as radial compressors, which suck in air in the axial direction and deflect it in the radial direction and compress it, or as axial fans, as described above, which suck in the air axially and transport it in the axial direction. With the use of radial compressors, these should preferably be aligned with the gas flow openings  50  in the pipe body  44 . 
         [0052]    The fans  60  are connected non-rotatably to the substrate web lifting device  20 , so that upon a rotation of the substrate web lifting device  20  they also rotate and thereby transport air into the interior  48  and in particular to the gas flow openings  50  in the pipe body  44 . The fans  60  operate in opposite directions, so that with a corresponding rotation of the substrate web lifting device  20  air is aspirated via axial end openings  66  into the interior  48  and transported to the center of the interior. 
         [0053]      FIG. 6  shows the fans  60  in a displaced position, in which only certain gas flow openings  50  are supplied with air by the fans  60 . The fans can be fixed in the axial direction of the interior  48  or can be displaceable in the axial direction, to enable a selective application of air to the gas flow openings  50  via the fans  60 . In this manner, it is for example possible to supply air only to those gas flow openings  50  that are in the region of the substrate web  6 . 
         [0054]    In various aspects, instead of two fans  60 , it is also possible to provide just one fan  60  and to close off an axial end opening of the interior  48  by means of a corresponding wall element. 
         [0055]    In various aspects, air baffle plate  70  (shown in  FIG. 4 ), which is not shown in the sectional representations of  FIGS. 5 and 6 , is provided adjacent to the jacket surface  35  of the substrate web lifting device  20 . The air baffle plate  70  has a main part  72  following the contour of the jacket surface  35  over a circumferential region thereof, and a part  74  at an angle thereto and extending to the substrate web lifting device  20 . The air baffle plate  70  is arranged adjacent to a region of the jacket surface  35  of the substrate web lifting device  20  which is not encircled by the substrate  6  in operation. 
         [0056]    Referring to  FIG. 4 , the main part  72  is arranged such that a substantially uniform annular gap section is formed between the main part  72  and the jacket surface  35  and is limited in the circumferential direction at one end by the angled part  74 . At the other end, the annular gap section is open, with the opening facing the region in which the substrate is guided around the substrate web lifting device  20 . Air that exits the substrate web lifting device  20  in the region of the annular gap section is thus routed in a targeted manner to the encircling region between the substrate web  6  and the substrate web lifting device  20 , in the circumferential direction corresponding to the direction of rotation C of the substrate web lifting device  20 . In the representation in  FIG. 4 , the direction of movement B of the substrate  6  and the direction of rotation C of the substrate web lifting device  20  are substantially aligned. It is however also possible, as mentioned above, for the substrate web lifting device  20  to rotate counter to the direction of movement B of the substrate web  6 , with the air baffle plate  70  then having to be adapted accordingly. 
         [0057]      FIG. 7  shows a schematic plan view of a further aspect of a pipe-shaped substrate web lifting device  120 . That region of the substrate web lifting device  120  that is encircled by the substrate web  6  during operation of said substrate web lifting device  120  can be seen in particular in the plan view. The substrate web lifting device  120  has in this region a surface referred to below as the jacket surface  130 . The jacket surface has a region  132  in which a continuous channel structure is formed, the structure of which is described further below. The region  132  extends over approximately the entire width of the substrate web lifting device  120 . The region  132 , and hence the channel structure formed therein, extends in the circumferential direction over approximately 180° of the substrate web lifting device  120 . It can preferably extend over more than 180° in the circumferential direction of the substrate web lifting device  120 , depending on the arrangement of the printing units  10 . 
         [0058]      FIG. 8  shows a schematic plan view of a stationary, i.e. non-rotatable, pipe-shaped substrate web lifting device  120  in accordance with an alternative aspect. The region of the substrate web lifting device  120  which is encircled by the substrate web  6  during operation of said substrate web lifting device  120 , can be seen here again in the plan view. The substrate web lifting device  120  here again has a surface that is referred to below as the jacket surface  130 . Continuous channel structures are formed in regions  145 , the structure of which is described further below. The regions  145  are arranged adjacent to one another over the width. Within the respective regions  145 , the channel structures are continuous, i.e. all regions  145  of the channel structure are interconnected via corresponding channels thereof. In contrast, there is no connection to the channel structures of adjacent regions  145 . To do so, regions  146  are provided, each of which is a region of the jacket surface  130  without channels. The jacket surface  130  thus has a plurality of segments or regions  145  with channel structures formed therein and regions  146  lying between them without such channel structures. The regions  145  are arranged adjacent to each other over approximately the entire width of the substrate web lifting device  120 . The regions  145 , and hence the channel structures formed therein, extend in the circumferential direction over approximately 180° of the substrate web lifting device  120 . They should preferably extend far enough over the substrate web lifting device  120  that the substrate web  6  is guided by the channel structure in the region that faces the printing units  10 , so that a controlled lifting of the substrate web  6  can be assured throughout the entire printing process. 
         [0059]      FIG. 9  shows a schematic detailed view of a continuous channel structure  160  in a jacket surface  130  of a substrate web lifting device  120  in accordance with a first aspect. The channel structure  160  in the form shown can be provided in the jacket surface region  132  in accordance with  FIG. 7  as well as in the regions  145  of  FIG. 8 . 
         [0060]    The channel structure  160  has a plurality of parallel-extending circumferential channels  162  as well as a transverse channel  164 , which are respectively provided in the jacket surface  130 . The circumferential channels  162  extend in the circumferential direction of the substrate web lifting device  120 . The respective circumferential channels  162  are connected to one another via the transverse channel  164 , with the transverse channel  164  intersecting the circumferential channels  162  centrally in the circumferential direction of the substrate web lifting device  120 . A plurality of transverse channels could of course also be provided which intersect the circumferential channels  162  in the circumferential direction of the substrate web lifting device  120  at different points. 
         [0061]    The circumferential channels  162  and the transverse channel  164  have the same depth, preferably in the range 0.1 to 1 mm. It is however also possible for the circumferential channels  162  and transverse channel  164  to have different depths. The circumferential channels  162  and transverse channel  164  can, for example, be provided in the jacket surface  130  in a suitable manner by means of laser treatment, etching or milling. The circumferential channels  162  and transverse channel  164  in the jacket surface  130  result in surface elements  170  lying between the circumferential channels  162 . 
         [0062]    A gas outflow opening  168  in the form of a passage opening is provided in the region of the intersections of the circumferential channels  162  and the transverse channel  164 , and connects the interior of the hollow pipe to the outer side, as can be readily seen in  FIG. 10 . The hollow pipe defines internally an interior  180  that is delimited in the radial direction by the inner wall  182 . The gas outflow opening  168  extends here from the interior  180  into the transverse channel  164  in the jacket surface  130 . The section along the line  10 - 10  from  FIG. 9  shown in  FIG. 10  furthermore shows one of the plurality of circumferential channels  162 . It can be readily seen here that the circumferential channel extends over 180° in the circumferential direction of the substrate web lifting device  120 , which in operation corresponds approximately to one encircling region of a substrate web  6 . 
         [0063]    The interior  180  first extends substantially over the entire length of the hollow pipe. The hollow pipe can be sealed at its ends in a suitable manner by end walls. At least one gas inflow opening is provided in the end walls and/or in a circumferential region outside the jacket surface  130  to supply the interior with gas, in particular compressed air. This inflow opening is not visible in this cross-section. The gas outflow openings  168  can here in turn be supplied with a gas flow. 
         [0064]    The interior  180  can also be delimited by displaceable slide elements, not shown, in the longitudinal direction of the hollow pipe. This allows the interior to be changed and thus a selective application to gas outflow openings  168 , for example to provide gas only where the substrate web  6 , because of its defined width, encircles the substrate web lifting device  120 . A selective application of this type also possible by, for example, corresponding subdivisions of the interior with individual gas application to the subdivisions, for example via valves. Direct gas lines could also be provided for the individual gas outflow openings  168  and can be supplied with gas, for example individually or grouped. 
         [0065]      FIG. 11  shows a schematic detailed view of an alternative, continuous channel structure  200  in a jacket surface  130  of a substrate web lifting device  120  in accordance with a second aspect. The channel structure  200  can be formed in the region  245  correspondingly to that in the region  132  in accordance with  FIG. 7  or to the regions  145  of  FIG. 8 . 
         [0066]      FIG. 11  shows a statistical distribution of one or more channels of channel structure  200 , with the following relating to only one channel. The channel is continuous, i.e. formed such that each point within the channel is connected to every other point in the channel via the channel. 
         [0067]    The distribution of the channel forming the channel structure  200  inside the jacket surface corresponds to a statistical distribution. The distribution of the channel structure  200  substantially follows a uniform distribution, but can have any required distribution. The channel forming the channel structure  200  preferably has a depth of 0.1 to 1 mm. 
         [0068]    Gas outflow openings  268  are again provided and open into the channel of the channel structure  200 . The gas outflow openings  168  can also be statistically distributed in the substrate guide surface. The gas outflow openings  168  preferably have a diameter of 0.3 to 0.5 mm. 
         [0069]    The functioning of the device is described in more detail below by reference to the drawings, in particular with reference to  FIG. 1 . 
         [0070]    During in-feed of the substrate web  6 , it is guided first from the feeder region  2  to the substrate web lifting device  20  and the printing region  3 , and from there to the stacker region  4 . For printing, the substrate web  6  is transported by a corresponding transport means through the printing press and in particular through the substrate web lifting device  20 . An air cushion is formed at the substrate web lifting device  20  between the substrate web  6  and the jacket surface  35  of the substrate web lifting device during this transport. This can be achieved by a substrate web lifting device  20  that does not move or a substrate web lifting device  20  that is provided with drives and is rotated with an adequate speed, as a result of which an air cushion is generated. The substrate web lifting device  20  can here be driven either in the direction of movement of the substrate web  6  or counter to this direction. 
         [0071]    The formation of the air cushion can be assisted, depending on the aspect of the substrate web lifting device  20 , by corresponding means, such as the spiral groove  38  in the jacket surface  35  of the substrate web lifting device  20  in accordance with  FIG. 3 , the channel structure in  FIGS. 7-11 , and/or the use of a fan  60  in accordance with  FIGS. 4-6 . In the aspect with fan, air is sucked by the fans  60  into the pipe interior  48  of the substrate web lifting device  20  during rotation of the latter, and is expelled via the gas outflow openings  50 . This assists the formation of the air cushion E ( FIG. 1 ) between the jacket surface  35  of the substrate web lifting device  20  and the substrate web  6 . 
         [0072]    The air cushion E so generated can distribute itself uniformly over the entire jacket surface  35 . The substrate web  6  is thereby transported along the printing units  10  at a controlled distance from them. Displacement of the fans  60  permits a selective activation of individual gas outflow openings  50  above the pipe interior  48 . This enables the gas flow out of the substrate web lifting device  20  to be substantially adapted to a width of the substrate web  6 . 
         [0073]    The substrate web  6  is now printed by the printing units  10 , with the distance between the substrate web  6  and the printing units  10  being kept constant during the printing process as described above. The lifting of the substrate web  6  by means of the air cushion E generated by the substrate web lifting device  20  results at the same time in an at least partial drying of the substrate web  6  during the printing process. 
         [0074]    The invention has been described on the basis of concrete aspects, without being limited to these. In particular, it should be pointed out that the aspects can be freely combined with one another, and individual elements of the different aspects are interchangeable if required in so far as they are compatible. It will be also be understood that variations, combinations, and modifications can be effected by a person of ordinary skill in the art within the spirit and scope of the invention. 
       PARTS LIST 
       [0000]    
       
           1  printing press 
           2  feeder region 
           3  printing region 
           4  stacker region 
           5  substrate roll 
           6  substrate web 
           8  roll 
           10  printing unit 
           15  dryer 
           20  substrate web lifting device 
           35  jacket surface 
           37  groove structure 
           38  spiral groove 
           44  pipe body 
           48  pipe interior 
           50  gas flow opening 
           60  fan 
           65  wings 
           66  end opening 
           70  air baffle plate 
           72  air baffle plate main part 
           74  air baffle plate angled part 
           120  pipe-shaped substrate web lifting device 
           130  jacket surface 
           132  jacket surface region 
           145  region 
           146  region 
           160  continuous channel structure 
           162  parallel-extending circumferential channels 
           164  transverse channel 
           168  gas outflow opening 
           170  surface element 
           180  interior 
           182  interior wall 
           200  continuous channel 
           245  region 
           268  gas outflow opening 
         B movement direction 
         C direction arrow 
         D direction arrow 
         E air cushion