EP3411236B1 - Printing press and method for drying a web-like material of a printing press - Google Patents

Description

The present invention relates to a printing machine comprising an apparatus for drying a strip material with a first drying nozzle and a second drying nozzle, wherein the first drying nozzle and the second drying nozzle are each adapted to apply drying air to the strip material, and wherein the first drying nozzle is formed such in that it applies drying air in a first feed direction to the strip material and discharges it from the strip material in a first discharge direction, and the second drying nozzle is designed such that it applies drying air in a second feed direction to the strip material and removes it from the strip material in a second discharge direction.

For drying strip materials in printing machines, drying nozzles are arranged one behind the other in a housing at more or less large intervals. These blow warm air on the belt material to dry the substances on the material.

A major disadvantage in the prior art is that the drying length and thus the installation space of drying devices is relatively large. The consequence is a large heat radiation and thus high energy costs.

From the publication DE102012220431A1 a drying device is known, wherein the drying device comprises a heatable roller and a blowing device having an outlet opening, the outlet direction is aligned with at least one component of the outlet opening on a lateral surface of the temperature-controlled roller and wherein the outlet direction of the at least one outlet opening a component in a Direction, which is oriented parallel to a tangent to a provided for a printing operation direction of rotation of the next opening area of the outlet area of the lateral surface of the temperature-controlled roller.

Furthermore, from the document EP 0 103 876 A2 a printing machine and a drying method according to the preamble of claims 1 and 12 known.

It is the object of the present invention to overcome the drawbacks known from the prior art and to provide a printing machine and a method for drying a strip material, which allow a short drying length and an associated space reduction and a reduction of energy costs.

According to the invention, the object is achieved by a printing machine with a first drying nozzle and a second drying nozzle according to claim 1, wherein the first drying nozzle and the second drying nozzle are each adapted to apply drying air to the strip material, and wherein the first drying nozzle is designed such that they Drying air in a first feed direction on the strip material and discharges in a first discharge from the strip material, and the second drying nozzle is adapted such that it applies drying air in a second feed direction on the strip material and dissipates in a second discharge from the strip material, said first discharge direction of the first drying nozzle and the second discharge direction of the second drying nozzle are arranged to extend in a discharge channel between the first drying nozzle and the second drying nozzle. As a result, the technical advantage is achieved that the first and the second drying nozzle are arranged very compact. This reduces the space of the device and thus the Total drying length. The consequence is of a reduced Heat radiation and thus from reduced energy costs. Another advantage is achieved in that a better adaptation to customer needs can take place.

In order to realize the discharge of the drying air as controlled and easy as possible, the outflow channel is preferably arranged orthogonal to the strip material.

As a result, unnecessary air turbulence can be prevented and the drying performance is thereby increased.

According to the invention, the outflow channel is formed by housing sections of the first drying nozzle and the second drying nozzle. This additionally favors the controlled discharge of the drying air from the strip material. It would also be conceivable here for the housing sections to be able to absorb part of the heat of the discharged drying air and to supply it to the drying nozzles. This could save additional energy costs.

In order to maximize the drying performance of the device and to allow the most compact possible device, the first feed direction and the second feed direction can be arranged orthogonal to each other. This additionally reduces the installation space length of the entire device.

According to a further preferred embodiment, the first drying nozzle and the second drying nozzle are arranged to apply drying air to a pressure side of the strip material. This ensures optimum drying performance, since the drying air of the first drying nozzle and the second drying nozzle comes into direct contact with the substances located on the strip material.

In order to enable the orientation of the strip material or to ensure an optimum angle of the drying air from the first drying nozzle and the second drying nozzle, the first drying nozzle and the second drying nozzle are associated with a guide roller. In accordance with the invention, the guide roll for guiding the strip material is here at a rear side of the strip Band material formed. Thus, the orientation of the strip material and thus an improved drying of the substances on the strip material can be realized.

It is advantageous if the guide roller supports the strip material only with a wrapping angle of at most 90 degrees, in particular of at most 45 degrees (according to the invention of at most 20 degrees). It is advantageous that the drying air assumes a deviating from a perpendicular loading angle to the strip material. Thus, the drying air can be better derived via the outflow channel. An air turbulence is prevented by this measure, so that ultimately the drying performance can be increased.

According to a further embodiment, the guide roller is adjustable. Thus, it is possible to vary a distance between the strip material and the drying nozzles of the first drying nozzle and the second drying nozzle. This can also be done during operation of the drying device or the entire printing press, without interrupting the operation.

In order to maximize the drying performance, a geometric intersection of the first feed direction and the second feed direction is arranged on a side facing the rear side of the strip material. This makes it possible to increase the drying area in which drying air from the first drying nozzle and the second drying nozzle impinge on the strip material. As a consequence, the effective exposure time of the drying air to the strip material within the device is prolonged.

In a further embodiment of the invention, it is provided that a geometric intersection of the first feed direction and the second feed direction lies on an imaginary line between the axis of rotation and the peripheral surface of the guide roller. This means that the feed directions are not only not orthogonal to the guide roll, but also not orthogonal to the strip material. This in turn favors the outflow of drying air and thus the drying performance.

In a further embodiment, it may even be provided that the geometric intersection point lies on the half of the imaginary line closer to the peripheral surface. This arrangement describes an even stronger inclination, which causes a further increased drying performance.

In order to realize a flexible adaptation of the device to the strip material or to the substances applied to the strip material, the first drying nozzle and the second drying nozzle are adjustable, in particular designed to be pivotable. For this purpose, an adjusting device, in particular a pivoting device is used.

According to a particularly advantageous embodiment, the device has a control in order to set the first drying nozzle and the second drying nozzle in a continuous pivoting movement. On the one hand, this increases the flexibility of the device and, on the other hand, it can additionally increase the drying performance. In particular, the embodiment offers the possibility of reducing a temperature load on the strip material at elevated drying air temperatures.

In order to further increase the drying performance, the apparatus has a plurality of drying nozzles, each applying drying air to the strip material and derived by appropriately trained outflow channels between the drying nozzles. As a result, more than just two drying nozzles per device can be arranged. By deriving the drying air from the strip material between the drying nozzles, all advantages are retained and the drying performance is further increased.

Furthermore, a drying module according to the printing press according to the invention comprises at least two devices arranged in series according to one of the preceding embodiments. As a result, for example, a simplified or reduced maintenance is possible since if necessary, entire drying modules can be replaced. Two or more devices arranged in series can be combined into a model. In the printing machine can then be provided depending on, for example, the number of printing or inking units, the maximum printing speed, the maximum printing length, the maximum printing width and / or the diameter of the impression cylinder one or more such modules. Such a modular design of a drying device allows a series production of individual modules, but still an adjustment of the required dryer performance in the press in question by arranging several modules, as described above.

According to the invention, the drying module is seen in the transport direction of the strip material - behind the last color or printing unit of the printing press. This printing press is preferably a flexographic printing press, in particular a central cylinder flexographic printing press. In the latter case, such a drying device is often referred to as a bridge dryer.

The object stated above is also achieved by a method for drying a strip material of a printing press according to claim 12.

With this method, the same advantages are achieved as with a printing press according to the invention.

Fig. 1

eine schematische Darstellung einer Vorrichtung zum Trocknen eines Bandmaterials einer erfindungsgemäßen Druckmaschine

Fig. 2

eine weitere schematische Darstellung dieser Vorrichtung zum Trocknen eines Bandmaterials,

Fig. 3

eine weitere schematische Darstellung der Trocknungsvorrichtung

Fig. 4

eine schematische Darstellung eines Trocknungsmoduls, und

Fig. 5a-c

schematische Darstellungen von Mehrfachanordnungen von Trocknungsmodulen.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the figures, various embodiments are explained in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or for any combination of mentioned features. Within the scope of the entire disclosure, features and details described in connection with the method according to the invention apply, of course also in connection with the printing press according to the invention and in each case vice versa, so that reciprocal reference is always made to the disclosure of the individual aspects of the invention can. Show it:

Fig. 1

a schematic representation of an apparatus for drying a strip material of a printing machine according to the invention

Fig. 2

a further schematic representation of this device for drying a strip material,

Fig. 3

a further schematic representation of the drying device

Fig. 4

a schematic representation of a drying module, and

Fig. 5a-c

schematic representations of multiple arrangements of drying modules.

The FIG. 1 shows a schematic representation of an apparatus 100 for drying a strip material 101. The apparatus 100 includes a first drying nozzle 103 and a second drying nozzle 105, each applying drying air to the strip material 101. The first drying nozzle 103 applies drying air to the strip material 101 in a first feeding direction 107, and the second drying nozzle 105 applies drying air to the strip material 101 in a second feeding direction 109. The discharge of the drying air via an orthogonal to the strip material 101 arranged discharge channel 115, which between the first drying nozzle 103 and the second drying nozzle 105 extends. Also arranged orthogonal to each other are the first feed direction 107 and the second feed direction 109. However, a feed angle between the first feed direction 107 and the strip material 101 and between the second feed direction 109 and the strip material 101 is in each case in the range of 35 ° to 55 °, preferably Range of 40 ° to 50 °, in particular at about 45 °. With this feed angle is achieved that the drying air escapes through the discharge channel 115 in an optimal manner. The drying air is applied through the first drying nozzle 103 and the second drying nozzle 105 on a pressure side 119 of the strip material 101, while the first drying nozzle 103 and the second drying nozzle 105 are associated with a common guide roller 121. The guide roller 121 is arranged to guide the strip material 101 on a back side 123 of the strip material 101. A vertical distance a (see FIG. 2 ) between the drying nozzles 103, 105 and strip material 101 is dimensioned such that a geometrical intersection point 125 of the first feed direction 107 and the second feed direction 109 is arranged on the back side 123 of the strip material 101 or on the side of the guide roller 121. The perpendicular of the respective tangent, which bears against the imaginary roller 121 at the imaginary impingement point of the drying air along the respective feed direction 107 or 109, encloses with the respective feed direction an angle which is greater than 0 °. This measure supports the discharge of the drying air through the discharge channel 115.

The point of intersection 125 lies on an imaginary line between the axis of rotation 130 and the peripheral surface 131 of the guide roller 121. It is advantageous if the imaginary line can be divided into two equal halves and the intersection point 125 is half, that of the peripheral surface 131 closer lies. This half of the imaginary line 132 is denoted by reference numeral 133 in the FIG. 1 characterized. The division of the imaginary line into two halves is indicated by the line 134.

The FIG. 2 shows a further schematic illustration of an apparatus 100 for drying a strip material 101. The FIG. 2 are exact geometric dimensions, which have been found to be particularly advantageous. Thus, a vertical distance a between the first drying nozzle 103 and the second drying nozzle 105 and strip material 101 is 3 mm to 20 mm. On the other hand, a horizontal distance b between the first drying nozzle 103 and the second drying nozzle 105 is 10 mm to 100 mm, and a distance c between the drying nozzles 103, 105 and the strip material in the respective feeding direction 107, 109 is 5 mm to 50 mm. These geometric conditions promise an optimal drying effect of the device 100 and ensure a greatly reduced space. In the FIG. 2 In addition, the wrap angle α is reproduced. The wrap angle is the angle in the circumferential direction of the guide roller 121 between the point of impact of the strip material on the guide roll and the separation point of the strip material from the guide roll. It should be emphasized that even in the case of a one-dimensional description of the device and the method, the two-dimensional description should also be included throughout the present application. Thus, the strip material is particularly pronounced as a flat path. In addition, for example, the guide roller 121 has an extension along its axis of rotation, which is preferably at least five times its diameter. The drying nozzles 103, 105 extend parallel to the guide roller 121.

The FIG. 3 shows one of the FIG. 1 Similar view of the device 100 for drying the strip material 101. In contrast to FIG. 1 this illustration illustrates the adjustment possibilities of the drying nozzles 103 and 105. Relative to guide roller these drying nozzles are adjustable in height, ie their distance is adjustable relative to the guide roller 121. This purpose, a displacement device, such as the rails 140 shown, on which associated with the drying nozzles slide in the direction of the double arrow 141 - preferably vertically to the strip material 101 - are displaced. The drying nozzles can also be arranged pivotable relative to the guide roller 121. An example of a pivoting device is the pivot bearing 142, with which the respective drying nozzle can be pivoted. The displaceability and the pivotability of the drying nozzle can be combined with each other. Thus, the pivot bearing 142 may be disposed on the above-mentioned carriage.

The FIG. 4 shows a schematic representation of a drying module 200 with three devices arranged in series 100. The devices 100 are also shown schematically and are respectively associated with schematically illustrated guide rollers. Under no circumstances, however, is the drying module 200 limited to three in-line devices 100. Likewise, the number of drying nozzles within a device 100 may include two or a plurality of drying nozzles each applying drying air to the strip material 101. The outflow of the drying air is carried out by appropriately trained outflow channels between the drying nozzles.

The FIGS. 5a to 5c show schematic representations of multiple arrangements of drying modules 200. Depending on the number of drying modules 200, which are combined into a multiple arrangement, a corresponding reduction in length can be realized. Starting with a drying modulus of 1.3 m (see FIG. 5b ) is the length reduction in FIG. 5a in a multiple arrangement of three drying modules 200 about 50 cm, since the total length can be reduced by the inventive arrangement of the drying nozzles from about 4.5 m to 4 m. According to the FIG. 5b the length reduction in a multiple arrangement of four drying modules 200 is about 70 cm, since the total length can be reduced by the inventive arrangement of the drying nozzles from about 6 m to 5.3 m. According to the Figure 4c the length reduction in a multiple arrangement of five drying modules 200 is about 140 cm, since the total length can be reduced by the inventive arrangement of the drying nozzles from about 8 m to 6.6 m.

All features explained and shown in connection with individual embodiments of the invention may be used in different combinations in the be provided subject matter according to the invention in order to realize their beneficial effects simultaneously.

LIST OF REFERENCE NUMBERS

100

device

101

band material

103

First drying nozzle

105

Second drying nozzle

107

First feeding direction

109

Second feed direction

111

First discharge direction

113

Second discharge direction

115

outflow channel

117

housing sections

119

Print side of the strip material

121

guide roll

123

Back of the band material

125

intersection

130

Rotary axis of the guide roller 121

131

Peripheral surface of the guide roller 121

132

imaginary line between the rotation axis 130 and circumferential surface 131

133

Half of the imaginary line 132

134

Division of the imaginary line 132 in two halves.

140

rail

141

double arrow

142

pivot bearing

200

drying module

α

Wrap angle of the strip material around the guide roll

a

Vertical distance between drying nozzle and strip material

b

Horizontal distance between first and second drying nozzle

c

Distance between drying nozzle and strip material in the feed direction

d

Distance between two devices

m

Trocknungsmodulmaß

Claims (12)

1. A printing press, in particular flexographic printing press, with a drying module (200), which is arranged behind the last inking- or printing unit, comprising at least two devices (100) connected in series for drying a strip stock (101), wherein each of the devices (100) comprises a first drying nozzle (103) and a second drying nozzle (105), wherein the first drying nozzle (103) and the second drying nozzle (105), are each designed to apply drying air to the strip stock (101), and wherein the first drying nozzle (103) is designed in such a manner that it applies drying air to the strip stock (101) in a first feed direction (107) and discharges drying air from the strip stock (101) in a first discharge direction (111), and the second drying nozzle (105) is designed in such a manner that it applies drying air to the strip stock (101) in a second feed direction (109) and discharges it from the strip stock (101) in a second discharge direction (113),
   wherein
   the first discharge direction (111) of the first drying nozzle (103) and the second discharge direction (113) of the second drying nozzle (105) are arranged in an outflow channel (115) extending between the first drying nozzle (103) and the second drying nozzle (105),
   wherein the outflow channel (115) is formed by housing sections (117) of the first drying nozzle (103) and the second drying nozzle (105), characterized in that the first drying nozzle (103) and the second drying nozzle (105) are assigned to a single guide roller (121), wherein the guide roller (121) is designed to guide the strip stock (101) from a rear side (123), wherein the guide roller (121) supports the strip stock (101) at an angle of contact (α) of at most 20 degrees.
2. The printing press according to Claim 1, characterized in that the outflow channel (115) is arranged orthogonally to the strip stock (101).
3. The printing press according to any one of the preceding claims, characterized in that the first feed direction (107) and the second feed direction (109) are arranged orthogonally to one another.
4. The printing press according to any one of the preceding claims, characterized in that the first drying nozzle (103) and the second drying nozzle (105) are arranged in order to apply drying air to a printing side (119) of the strip stock (101).
5. The printing press according to any one of the preceding claims, characterized in that the guide roller (121) is designed to be adjustable.
6. The printing press according to any one of the preceding claims, characterized in that a geometrical point of intersection (125) of the first feed direction (107) and the second feed direction (109) is arranged on a side facing the rear side (123) of the strip stock (101).
7. The printing press according to any one of the preceding claims, characterized in that a geometrical point of intersection (125) of the first feed direction (107) and the second feed direction (109) lies on an imaginary line (132) between the axis of rotation (13) and the circumferential surface (131) of the guide roller (121).
8. The printing press according to any one of the preceding claims, characterized in that the geometrical point of intersection (125) lies on the half of the imaginary line (132) which lies closer to the circumferential surface (131) of the guide roller (121).
9. The printing press according to any one of the preceding claims, characterized in that the first drying nozzle (103) and the second drying nozzle (105) are designed to be adjustable.
10. The printing press according to any one of the preceding claims, characterized in that the device (100) has a control, in order to set the first drying nozzle (103) and the second drying nozzle (105) into a continuous pivoting movement.
11. The printing press according to any one of the preceding claims, characterized in that the device (100) has a plurality of drying nozzles (103, 105), which in each case apply drying air to the strip stock (101) and discharge said drying air through appropriately designed outflow channels (115) between the drying nozzles (103,105).
12. A method for drying a strip stock (101) of a printing press with a drying module (200), which is arranged behind the last inking- or printing unit, comprising at least two devices (100) connected in series for drying a strip stock, wherein in the method in each case drying air is applied to the strip stock (101) with a first drying nozzle (103) and with a second drying nozzle (105), wherein with the first drying nozzle (103) drying air is applied to the stock material (101) in a first feed direction (107) and is discharged from the strip stock (101) in a first discharge direction (111), and with the second drying nozzle (105) the drying air is applied to the strip stock (101) in a second feed direction (109) and is discharged from the strip stock (101) in a second discharge direction (113),
    wherein
    the drying air of the first discharge direction (111) of the first drying nozzle (103) and the drying air of the second discharge direction (113) of the second drying nozzle (105) is discharged in an outflow channel (115) between the first drying nozzle 103) and the second drying nozzle (105),
    wherein the outflow channel (115) is formed by housing sections (117) of the first drying nozzle (103) and of the second drying nozzle 105), characterized in that the first drying nozzle 103) and the second drying nozzle (105) are assigned to a single guide roller (121), wherein the guide roller (121) guides the strip stock (101) from a rear side (123), wherein the guide roller (121) supports the strip stock 101) at an angle of contact (α) of at most 20 degrees.

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