EP1864800B2 - Method for determining the operating parameters of a printing press - Google Patents

Abstract

The method involves determining a value of degree of dryness of the painting material defined by the dryer device, optimizing the drying process. The material stream influencing the drying process is determined an area (B1) of the printing machine, which comprises the drying device. A substance describes features of the determined material stream visually. The humidity setting of a supply air (20) and the humidity setting of an exhaust air (30) of the drying device are determined. An independent claim is also included for a printing machine, which has controlling device, sensors, an arithmetic and logic unit.

Description

The invention relates to a method for determining operating parameters of a printing press, in which the parameters determining the degree of drying of the printing material are determined and used to optimize the drying process.

In sheet-fed rotary printing machines, in particular sheet-fed offset machines with coating units and drying devices, a large number of parameters must be optimized during operation in order to achieve good printing results and the lowest possible waste. It is difficult to get the sheet dry, especially with a high amount of varnish, so that the laid out sheets do not stick together later in the stack. At the same time, a flawless, mostly high-gloss varnish layer is expected, which cannot easily be achieved both in the case of insufficient, incomplete drying, but also in the case of too fast drying or too high temperatures in the dryer. Production should then be carried out at the highest speed in order to produce as much as possible in the shortest possible time. Against this background, it is difficult for the operating personnel in the printing works to have an overview of all the necessary printing parameters or machine settings and to make them optimally. Every printer has his own understanding of the process of painting and drying and with this understanding he adjusts the printing machine and the dryer. This also leads to fundamentally wrong settings. The printer often does not know whether it is working at or near the optimum of the individual settings. If waste is then produced, due to the complexity of the influencing parameters, there is little opportunity for him to understand the faulty processes.

It is true that the control of modern sheet-fed offset printing machines provides for the storage of parameters for follow-up orders. Apart from the fact that this measure only helps if a follow-up job is actually printed, the ambient conditions are not always identical even for the same jobs. For example, the temperature and humidity of the ambient air in the press room can fluctuate, the humidity of the paper to be printed can vary in the system stack and much more.

It is also known to provide characteristic curves for the dryer in which, for example, the required dryer output is plotted as a function of the machine speed. However, this only helps the printer in one area, namely when setting the two parameters that are correlated with one another via these characteristic curves.

It is already, for example in the EP 1 142 711 B1 It has been proposed to control the dryer of a sheet-fed offset printing machine with the aid of sensors with which the temperature inside and outside the printing machine and the printing speed are measured, taking into account the ink or varnish dosage, which can be subject-dependent. With such a method, however, the problems mentioned at the outset cannot be eliminated, so that the control system claimed in the patent has not yet become widespread.

In the EP 0 025 878 A1 describes an inkjet printer in which the energy consumption and the dwell time of the sheet on the fusing drum are set by a control system that takes color density, color type and ambient humidity into account. Here the ambient humidity sensor controls the time that the sheet has to stay on the fusing drum before it is allowed to enter the dryer.

In the DE 196 16 692 describes a control for the microwave dryer of a printing machine that works on the basis of the water content of the printed ink.

The known methods and devices are not suitable for solving the problems outlined above. The known methods do not help, particularly in sheet-fed offset printing machines with coating units in which dispersion coatings are applied and dried with hot air or infrared radiation.

It is therefore the object of the present invention to create a method of the type mentioned at the beginning with which printing machines with dispersion coating units and thermal dryers can be operated more safely.

This object is achieved with the measures specified in claim 1. A printing press suitable for carrying out the method is specified in claim 18.

According to the invention, in order to optimize the drying process, the essential material flows influencing the drying process are determined in the area of the dryer device of the printing press. These material flows are primarily the air humidity of the supply air and the air humidity of the exhaust air of the dryer device as well as the moisture transported with the printing material, primarily the paint application. The moisture balance and thus the degree of dryness of the printing material transported through the dryer can be determined from these parameters, with the reliability of the method also increasing if the material moisture of the printing material itself is determined before and after printing or painting and drying. It is particularly advantageous and helpful for the operating personnel of the printing machine if the essential characteristic data of the material flows determined are visually displayed on a screen. This can be done not only by displaying the bare numerical values, but also by means of a corresponding graphic preparation and representation in the form of measuring bars, which show at which points or with which material flows there are opportunities for intervention, and if so in which direction, and whether and how far the material flows from theirs have removed the respective optimum in reality. As an alternative, the changes in the displayed values to either specified norms or setpoints set by the printer itself can also be displayed. It is also advantageous to determine limit values below which the process runs stably for e.g. B. the amount of moisture removed, the amount of lacquer and / or the temperature of the printed sheet.

The printing press suitable for carrying out the method therefore has sensors for measuring the essential material flows influencing the drying process as well as a computing unit in which the measured values are prepared or further processed and / or the moisture balance of the material flows can be determined. However, since it is important not only to determine the relative humidity e.g. B. to measure the supply and exhaust air of the dryer, but the flow of the water actually conveyed in via the supply air and the exhaust air, d. H. the amount of water, the temperature and the volume flow of the incoming and outgoing air is expediently measured in order to determine the amount of water vapor discharged in connection with the relative humidity. This amount of water vapor plus that in the material of the printing sheet, i.e. H. Part of the water thrown into the paper corresponds roughly to the amount of water carried in via the coating when the printing material leaves the dryer with a well-dried coating.

Figur 1

ist eine schematische Darstellung einer Bogenoffsetdruckmaschine in Reihenbauweise, in der die wesentlichen Stoffströme durch Pfeile symbolisiert sind.

Figur 2

zeigt einen Ausschnitt der Druckmaschine nach Figur 1 in dem Bereich, in dem die Trocknereinrichtungen angeordnet sind.

Figur 3

ist eine vereinfachte Skizze der Druckmaschine aus Figuren 1 und 2, in der die Anordnung der Sensoren skizziert ist.

Figur 4

stellt ein Mollier-H,X-Diagramm für die durch den Trockner 10a in Figur 1 hindurchgehende Luft dar.

Figur 5

zeigt ein Blockschaltbild der zur Ermittlung der Stoffströme aus Figur 1 benutzten Sensorik und Recheneinheit.

Figur 6

zeigt ein alternatives Beispiel für die Bildschirmdarstellung der Kenngrößen für die Stoffströme im Bereich B1der Druckmaschine nach Figur 2.

Figur 7

ist eine vereinfachte Skizze für eine Messzelle zur genauen Bestimmung der relativen Luftfeuchte.

Further advantages of the invention emerge from the following descriptions of exemplary embodiments on the basis of FIG Figures 1 to 6 of the attached drawings.

Figure 1

is a schematic representation of a sheet-fed offset printing machine in series design, in which the essential material flows are symbolized by arrows.

Figure 2

shows a section of the printing machine Figure 1 in the area in which the dryer devices are arranged.

Figure 3

is a simplified sketch of the printing press Figures 1 and 2 , in which the arrangement of the sensors is sketched.

Figure 4

FIG. 10 shows a Mollier H, X diagram for the through the dryer 10a in FIG Figure 1 passing air.

Figure 5

shows a block diagram for determining the material flows from Figure 1 used sensors and computing unit.

Figure 6

shows an alternative example for the screen display of the parameters for the material flows in area B1 of the printing press Figure 2 .

Figure 7

is a simplified sketch for a measuring cell for the precise determination of the relative humidity.

Figure 1 shows an offset printing machine 1 in a row design with a feeder 2 in which the unprinted paper stack 3 is located, six printing units 8a to 8f for the four basic colors and optionally two further special colors, a first coating unit 9a, followed by two dryer units 10a and 10b, a second Painting unit 9b and a delivery 5 with the sheet delivery stack 6. In the area of the chain guides of delivery 5, four further dryer units 11a to 11d are arranged one behind the other in the sheet transport direction. Such a printing machine is offered, for example, under the name Speedmaster XL105-6-LYYLX3 from Heidelberger Druckmaschinen AG. In the area labeled 50, arrows pointing inwards or outwards symbolize the points in the printing press at which moisture is introduced into or discharged from the printing process.

The arrow 4 symbolizes the moisture that is already in the printing material sheets stacked in the feeder 2. At this point, moisture is understood to mean the material moisture content of the paper, i.e. the amount of water that is bound in the paper per unit of quantity. A material moisture of 8% in the feeder paper stack means that a paper sheet of 100 grams contains 8 grams of water. If the stack of paper is in the "state of equilibrium" with the ambient air in the pressroom after its acclimatization, the equilibrium moisture content can be determined via the sorption isotherms of the paper with knowledge of the relative humidity and temperature of the air in the pressroom. However, such acclimatization of the paper stack in the feeder has often not taken place at all. Because it does happen that stacks of paper are brought from a warehouse to the printing press at short notice and the material moisture of the paper then corresponds to the climatic conditions in the storage room. Therefore, to determine the material moisture, it is more advantageous to use a measuring method which directly detects the moisture in the paper. For this purpose, methods based on high-frequency, microwave or infrared absorption measurements are known.

The printing units 8 are printing units for wet offset, d. H. they have a dampening unit that dampens the printing plate prior to inking, with part of this dampening water reaching the sheet to be printed via the blanket cylinder in the printing unit. This entry of moisture is symbolized by arrow 18.

The arrow 13 represents the proportion of water that comes from the ink printed on the sheet itself. This is naturally low with the oil-based offset printing inks. The arrow 12 takes into account that during the transport of the printed sheet through the machine a certain amount of evaporation takes place because the printing unit wetted with ink and dampening solution and the printed sheet are more humid than the surrounding air in the printing machine.

However, the most important moisture flows are formed by the lacquer layers applied to the printed sheet in the lacquering units 19a and 19b, at least when it is not UV-curable lacquers, but water-based lacquers such as. B. dispersion paints. This is symbolized with the arrows 19a and 19b.

Another very important exchange of moisture takes place in the dryer units 10a and 10b and 11a to 11d. These dryer units are supplied with air from the environment (arrows 20 and 21) with a relative humidity of approx. 50% prevailing in the pressroom, which is then heated up (in the case of hot air dryers) when it enters the dryer 10a, 10b, 11a to 11d, or for IR radiation dryers when it enters the drying room. After part of the lacquer application or the moisture of the lacquer has penetrated the paper material of the printing sheet, the exhaust air (arrows 30 and 31) should then, if possible, discharge the amount of water contained in the lacquer layer in the form of steam from the dryer units 10 and 11, so that the coated sheets do not block on the stack. This moisture content of the printed sheet conveyed on is symbolized by the arrow 7. In addition, moisture is also introduced into and discharged from the printing press 1, albeit to a lesser extent, via the powder flow (arrow 15) in the boom of the printing press and via escaping defective air (arrow 16).

It has now been shown that in a printing press of the type mentioned, d. H. an offset printing machine 1 with a varnishing unit 9a, 9b that prints water-based varnish, and one or more thermal dryer units 10, 11, i.e. hot air or infrared dryers, the varnish application and the supply air 20 and the exhaust air 30 of the dryer units 10a, 10b have the greatest moisture or moisture discharges into the machine, that is to say that these are the most important moisture flows in the balance area labeled B1, in which the moisture of the printed sheet running through can be changed. It is assumed here that the moisture contained in the paper fiber and in the printing ink cannot be expelled from the printed sheet by the dryer devices 10a, 10b anyway. In a machine with a double coating unit like the one shown here, before the second coating layer is applied with the coating unit 9b, the first coating layer should be dried through with the aid of the dryer devices 10a and 10b to such an extent that the coating layer added in the second coating unit 9b is easily overlaid. For example, the second lacquer can also be a UV lacquer that should / must not react with a water-based lacquer that is still damp. But even if the second coating unit is also aqueous dispersion coating, the first coating layer must already be solidified so that the second coating layer, e.g. B. for the production of particularly thick overall paint layers, can be applied without any problems.

The amount of paint applied can be adjusted in the printing machine. In order to optimally dry the sheet with the selected coating application, knowledge of the essential operating parameters, in particular of the dryer units 10a and 10b, as well as the machine speed, can easily achieve an optimal result. To do this, however, it is necessary to know the essential parameters in the moisture balance.

For this purpose, a number of sensors are provided in the area of the printing press designated B1, with which these variables can be measured. This is explained below using Figure 3 explained. To measure the relative humidity RH _L1 and the temperature T _{L1 of} the supply air flow 20, a humidity sensor 120a and a temperature sensor 120b are arranged in the vicinity of the air inlet ducts 121 for the dryers 10a and 10b.

Since the relative humidity of the ambient air in the print shop is measured here, a humidity sensor and a temperature sensor may be sufficient.

Furthermore, corresponding humidity sensors 130c and temperature sensors 130d as well as pressure sensors 130a and flow sensors 130b are arranged in the exhaust air duct of dryer 10a and dryer 10b. With these sensors, the amount per unit of time of the moisture flow discharged from the machine can be clearly determined as the difference between the air humidity flowing into the machine and flowing out of the machine again. In particular, it is also possible to get by with the four named sensors 130a to d for the exhaust air if the exhaust air ducts 131 of the two dryers 10a and 10b are combined. To measure the relative humidity, the dew point or the absolute humidity, capacitive sensors, aspiration psychrometers or sensors can be used, for example, which measure the humidity via the absorption of infrared radiation in the water bands.

Sensors that measure the relative humidity can also be arranged in a cooled measuring air flow branched off from the exhaust air flow to increase the measuring accuracy. This is because when the air flow is cooled, the relative humidity increases, so that the measured humidity values move into an area where the measurement inaccuracy is lower, provided that there is no condensation of the humidity in the measurement air flow. A suitable measuring cell that prevents the latter is based on the Figure 7 described at the end of the illustration.

The amount of water introduced via the paint application is measured with flow sensors 119 in the inflow and return of the paint supply device of the printing press 1. Instead, the amount of lacquer or its water content in chamber doctor blade systems can also be derived from the difference in the delivery rates Paint feed pump and paint suction pump are determined. Taking into account the type of paint or its water content, which is usually 60% for dispersion paints, the amount of water introduced at this point can be easily calculated. Another possibility for measuring the amount of paint used is to record the weight or the decrease in weight of the paint storage container with a load cell.

To refine the method, further sensors are optionally provided with which the already existing water content of the sheet 14 entering the coating unit can be determined more precisely. A sensor 118 is used for this purpose, which determines the dampening solution input 18 from the dampening solution consumption in the six printing units 8a to f. Furthermore, two temperature sensors 114 and 117 are provided which determine the temperature of the sheet entering the coating unit and that of the sheet leaving the dryer 110b. These temperature sensors are used to determine the entry and exit temperatures of the sheets. Building on the moisture balance, an energy balance of the drying process can be drawn in addition to the temperature difference that the material flow experiences. For this purpose, sensors can be used, for example, which measure the temperature of the sheet in a contactless manner via the infrared radiation emitted by the sheet. Finally, to measure the material moisture in the feeder stack 3 or delivery stack 7, a mobile electronic measuring device, for example a sword sensor or an attachment sensor 103, which works for example on the principle of microwave absorption or conductivity of a hygroscopic electrolyte, can be used.

The signals from the sensors are processed in a computing unit 301 ( Figure 5 ), for example a commercially available measuring PC to which the above-mentioned sensors are connected via the appropriate interface adapter. The memory 302 of the computer 301 stores parameters and conversion factors relevant to the drying process, such as the water content of the paint, the mathematical relationships for converting relative humidity ϕ into absolute humidity, as shown in the Mollier diagram Figure 4 are illustrated, to name a few.

The keyboard of the computer is designated by 303 and the screen is designated by 304. The essential characteristics of the current painting and drying process are now graphically presented on this screen as a setting aid for the printing staff. Thus, the bar 220 represents a measure of the amount of water flowing into the dryer 10 with the supply air 20, while the bar 230 indicates the amount of water discharged via the exhaust air. Both are proportional to the air flow F through the dryer, while the bar 230 can also be enlarged within certain limits by increasing the temperature T or the heating power of the hot air dryer or by increasing the thermal radiation of the IR dryer.

The possibly still existing "dryer reserve", i. H. the possibility of further increasing the water content of the exhaust air by increasing the temperature or the IR radiation or the air flow is shown on the display 304 as a further partial bar labeled 240.

The next bar 219 describes the amount of water still contained in the applied lacquer layer after subtracting the amount of water entered in the sheet of paper and knocked away. Experience has shown that this is approx. 50 to 60% of the total amount of water applied to the sheet via the coating.

A sheet with a dry lacquer layer is obtained when the upper edge of the beam 219 does not or does not significantly exceed the upper edge of the beam 230. As the difference, the residual moisture of the lacquer layer of the sheet leaving the dryer 10b is shown in a further bar 200. This residual moisture can be reduced on the one hand by reducing the paint application or by reducing the machine speed. This information is given as an aid to the user in the form of corresponding symbols -L and -V with a downward pointing arrow. On the other hand, the residual moisture 200 can also be reduced by increasing the dryer temperature + T or increasing the air throughput + F, which is again symbolized by corresponding symbols on the bar 230.

Pop-up menus 306 also serve to display the exact measured values in the supply air or exhaust air duct of the dryer when the bar is approached with the mouse pointer 309.

A good drying result for the sheet is obtained if the amount of water applied by the application of varnish in the varnishing unit 19a (100%) is approximately the sum of the amount of water discharged as steam in the dryer (50 to 60%) and the amount of water that is thrown into the paper below the varnish layer ( 40 to 50%). With the Speedmaster XL105 printing machine mentioned above, operated at the maximum production speed of 18,000 sheets per hour in sheet format 105 cm by 75 cm with a typical wet coating of 3.5 µm, this corresponds to an F _H20 water entry of 29 l / h, of which experience has shown Fold 50% into the paper and so 50% remain in the paint. This empirical value can be determined or verified more precisely if the paper moisture content of the sheet is measured after it has left the dryer or in the waste pile. Therefore, the dryer units 10a and 10b are expediently operated in such a way that 50% of the water input symbolized by the arrow 19a is largely discharged again in the form of steam by means of the first layer of paint in the two dryers 10a and 10b.

These relationships are in the Mollier diagram after Figure 4 reproduced. The air in the pressroom has a relative humidity of 51% at an ambient temperature of 25 degrees Celsius. This corresponds to a load of 10 grams of water per kilogram of dry air (point A).

In the hot air dryer 10a or 10b, this supply air is heated to 80 degrees Celsius and then still has a relative humidity of 3.4% (point B). However, this does not change anything about the load with 10 grams of water per kilogram of dry air.

After the heated supply air comes into contact with the moist, coated sheet, the exhaust air extracted from the dryer units 10a and 10b has a temperature of 58 degrees Celsius and a relative humidity of 12.7%. This corresponds to a load of 14.5 grams of water per kilogram of dry air (point C). The relative humidity can also be measured in a cooled exhaust air bypass at 35 degrees Celsius. There it then has a relative humidity of ϕ = 0.4, but this does not change anything about its load of 14.5 grams of water per kg of dry air (point D).

During operation at a production speed v of 18,000 sheets per hour, the fans of the dryers 10a and 10b blow a volume flow of V = 3000 cubic meters of air per hour or 3300 kilograms (dry) air per hour through the dryer units. In this way, measured as the difference to the water or moisture flow already contained in the supply air, 15 kilograms of water vapor per hour leave the printing machine in the area of the dryer.

The representation after Figure 5 clearly shows that the residual moisture of the sheet leaving the dryer 10b can be influenced not only by increasing the heating power or the amount of water or water vapor discharged via the exhaust air, but also by influencing a number of other variables. For example, in addition to the classic measures such as reducing the amount of paint applied or reducing the machine speed, the use of pre-dried air or a reduction in the moisture of the sheet entering the coating unit can be used to influence the drying result in a comprehensible way.

An alternative way to visualize the measurement results of the sensors is in Figure 6 shown. There the part of the printing press 1 containing the dryers 1 0a and b as well as the coating unit 9a is shown and the measured values of the sensors are shown in terms of values, with arrows directly showing the connection between the measuring locations of the sensors and the displayed measured values for the relative humidity RH, temperature T , Pressure p and paint flow rate F _L. In this representation it is possible to switch from the display of the actual values to a display of the deviation from self-set or - for example, setpoint values for temperature, humidity and paint quantity determined from an earlier order and then stored. Error messages can also be made visible on the screen if tolerance limits are exceeded.
In the same way as for the balance area for painting and drying via the first coating unit 9a of the printing press 1, a balance area B2 for the second coating unit 9b and the dryers 11a to d for the printing machine 1 can also be set up and displayed. For the graphic representation of the second balance area on screen 304 ( Figure 5 ) the computer 301 can switch the screen display accordingly through appropriate inputs via the keyboard 303 and switch to the sensors arranged in the supply air 21 or exhaust air 31 and measuring the paint flow 19b.

In addition, the computer 301 has a data line 307 which connects it to the machine control of the printing machine. In this way, changes made interactively on the screen 304 in the heating power or the air volume flow of the dryer, the amount of paint applied and the machine speed can be transferred directly to the machine control and do not have to be made there separately.

In Figure 7 describes a measuring cell for the more precise measurement of the relative humidity in the exhaust air of the dryer 10a / 10b: The measuring cell has a pot-like or box-shaped housing 401, which has an air inlet nozzle 402 on the bottom and is offset approximately in the middle with respect to the wall of the pot-shaped or box-shaped Housing has an air outlet nozzle 403. The air inlet connector 402 has a much larger cross-section than the air outlet connector 403 in order to ensure that the pressure level in the measuring cell does not change, but rather corresponds to the pressure of the main flow of the dryer exhaust air from which the measurement flow is branched.

A coarse grille 404 in the air inlet nozzle prevents foreign bodies from entering the measuring cell. A finer dust filter 405 divides the measuring cell between the air inlet nozzle and the air outlet nozzle. Because of its large diameter, which corresponds to that of the measuring cell, the dust filter 405 does not represent any significant flow resistance. It divides the volume of the measuring cell into an entrance area 415, in which the air still has the temperature and humidity of the main exhaust air flow, and into a measuring volume 416, in which the air is cooled as detailed below and measured with regard to temperature and relative humidity.

The cover of the measuring cell is formed by a ring 418 in which a Peltier element 410 is received. The Peltier element is provided with heat sinks on both sides, the heat sink 414 keeping the “hot” side of the Peltier element at ambient temperature, which is supported by a fan 413. Peltier element 410, heat sink 414 and fan 413 form a commercially available structural unit such as is used, for example, for cooling electronic components. Such building units are available relatively inexpensively.

The intermediate ring 418 is made of heat-insulating material in order to prevent a thermal short circuit between the two sides of the Peltier element.

A grid 406 made of metal rests on the heat sink 407 on the “cold” side of the Peltier element 410. The grating 406 is relatively coarse-meshed and allows air to pass between the measurement volume 416 and the sensor area below. The grid 406 is in thermal contact with the heat sink 407 and therefore assumes its temperature. Due to the very large surface of the heat sink 407 and grille 406, the air passing from the measurement volume 416 through the grille 406 and reaching the sensor 408 assumes the temperature of the heat sink. This is kept at approx. 35 ° C in order to prevent the moisture in the air from condensing out in the area of the sensor.

The sensor 408 is an inexpensive, commercially available sensor for measuring the relative humidity and temperature, as it is e.g. B. by the company Sensirion Inc., Westlake Village, California, USA, is sold under the name SHT75. Both values, the value of the relative humidity and the measured temperature value, serve to determine the absolute humidity in the exhaust air of the dryers 10a / 10b, as described with reference to the other figures. At the same time, the temperature measuring element on the sensor 408 is used to regulate the temperature in the measuring cell to values between approx. 25 ° to 40 ° C. that are uncritical with regard to the condensation of water vapor with the aid of the Peltier element 410. Additional protection against condensation can be achieved by also taking the measurement signal of the relative humidity into account. For example, if RH> 80% is exceeded, the temperature in the measurement volume 416 can be increased by using the Peltier element 410 for heating after reversing the polarity of the current. In this case, the Peltier element 410 can be controlled and regulated with the aid of the humidity signal and the temperature signal of the sensor 408 so that the sensor always works in a climate range that is uncritical with regard to the condensation of steam, but optimal with regard to the accuracy of the humidity measurement.

In the present example, the invention was described on the basis of a created moisture balance, since when using dispersion varnishes the essential material flows contain water. In addition, it is possible in the same way, for. B. when using paints based on (organic) solvents, the entry and discharge of solvents, z. B. the IPA (isopropanol) to balance and to make this balance visually available for optimization by the printer.

List of reference symbols

1

Offset printing machine

2

Investors

3

unprinted paper stack

4th

Arrow (feed paper moisture)

5

boom

6

Sheet delivery pile

7th

Arrow (paper damp boom)

8a to 8f

Printing units

9a

first paint shop

9b

second coating unit

10a, 10b

Dryer units

11a to 11d

Dryer units

12

Arrow (evaporation)

13th

Arrow (fountain solution)

14th

Arrow (bow)

15th

Arrow (powder flow)

16

Arrow (leaking air)

17th

Arrow (moisture bow)

18th

Arrow (dampening solution entry)

19a, 19b

Arrows (amount of paint)

20, 21

Arrow (supply air)

30, 31

Arrow (exhaust air)

103

mobile electronic measuring device

114, 117

Temperature sensors

118

sensor

119

Flow sensor

120a

Humidity sensor

120b

Temperature sensor

121

Air inlet duct

130a

Pressure sensor

130b

Flow sensor

130c

Humidity sensors

130d

Temperature sensors

131

Air outlet duct

219

Bar (amount of water in paint layer)

220

Bar (exhaust air volume)

230

Bar (supply air volume)

240

Partial beam

301

Arithmetic unit

302

Storage

303

Computer keyboard

304

screen

306

Popup menu

307

Data line

308

mouse

309

cursor

401

Measuring cell

402

Air inlet port

403

Air outlet nozzle

404

Grid

405

dust filter

406

Grid

407

Heat sink

408

sensor

410

Peltier element

413

Fan

414

Heat sink

415

Entrance area

416

Measurement volume

418

ring

B1, B2

Balance area

V

Air flow

T

temperature

RH

relative humidity

p

Air pressure

F.

Flow rate (paint / water)

v

Print speed

Claims (34)

1. Method of determining operating parameters of a printing press (1), in particular a sheet-fed offset printing press, including at least one control device, a number of printing units (8a-8f) as well as at least one varnishing unit (9a, b) and at least one dryer device (10, 11), wherein parameters (V, T, rF, p) determining the degree of drying of the printing material are established and used to optimize the drying process, wherein the essential material flows that influence the drying process are determined for at least that region (B1, B2) of the printing press (1) that contains the dryer device (10, 11, respectively),
   characterized
   in that at least the moisture content of the supply air (20) and the moisture content of the exhaust air (30) of the dryer device (10a, b) are determined.
2. Method according to claim 1,
   wherein essential characteristic data of the determined material flows (19, 20, 30) are displayed visually.
3. Method according to claim 1 or 2,
   wherein additionally the moisture (14, 18) brought in by the printing material, in particular that of the applied varnish (18), is determined.
4. Method according to any one of claims 1 to 3,
   wherein additionally the dampness (17) of the printing material exiting the dryer device (10b) and/or the printing press is determined.
5. Method according to claim 1 or 2,
   wherein the amount of water introduced into the dryer device (10a, b) per unit of time and/or the amount of water discharged per unit of time are determined.
6. Method according to claim 5,
   wherein to establish the amount of water, the volume flows of the supply air (20) and of the exhaust air (30) and/or the amount (19) of applied varnish are measured.
7. Method according to any one of claims 1 to 6,
   wherein additionally the temperature (T) of the supply air (20) and the temperature of the exhaust air (30) of the dryer device (10a, 10b) are measured.
8. Method according to any one of claims 1 to 7,
   wherein additionally the temperature (T) of the printing material is established before and/or after it passes through the dryer device (10, 10b).
9. Method according to any one of claims 1 to 8,
   wherein essential parameters of the established material flows (14, 17, 19, 20, 30) are used to control the drying power and/or the machine speed (v).
10. Method according to any one of claims 1 to 9,
    wherein a moisture balance for one or more regions (B1, B2) of the printing press is determined form the material flows.
11. Method according to claim 2,
    wherein the displaying (304) of the material flows is done using symbols (219, 220, 230) that are variable in size.
12. Method according to claim 2,
    characterized
    in that when the characteristic data of the material flows is displayed, the measured values of the characteristic data and the location of measurement are displayed.
13. Method according to any one of claims 2 to 12,
    characterized
    in that when the characteristic data is displayed, deviations from desired values are displayed at least partially.
14. Method according to any one of claims 1 to 12,
    wherein the printing press includes several dryer devices (10a, b; 11a-d) and wherein partial material flows (30, 31) are determined for the different dryer devices.
15. Method according to any one of claims 2 to 14,
    characterized
    in that when the characteristics are displayed, limiting values are shown within which the drying process operates in a stable way.
16. Method according to any one of claims 1 to 12,
    characterized
    in that the progress of the measured characteristic data of the material flows is logged.
17. Method according to any one of claims 1 to 12,
    wherein the printing press has at least one varnishing unit (9a, 9b) for dispersion varnishes and a thermal dryer device (10, 11), and wherein at least the air humidity in the exhaust air of the dryer device is measured.
18. Printing press, in particular sheet-fed rotary printing press (1), having at least one control device assigned to the printing press, several printing units (8a-d) as well as at least one varnishing unit (9a, b) and at least one dryer device (10a, b; 11a-d) as well as sensors (117, 118, 119, 120, 130, 106, 103) for measuring parameters that determine the drying process of the printing material, wherein sensors (117, 118, 119, 120, 130, 106, 103) are assigned to the dryer device (10a, b) to establish measured values for the determination of the essential material flows that influence the drying process and wherein a computing unit (301) is present in which the values measured by the sensors to establish the material flows are processed,
    characterized
    in that sensors (120a, 130a) are provided to determine the moisture content of the supply air (20) and of the exhaust air (30) of the dryer unit (10a, b).
19. Printing press according to claim 18,
    characterized
    by a display device (304) connected to the computing unit (301) to visually display the characteristics of the established material flows.
20. Printing press according to any one of claims 18 to 19,
    wherein additionally, at least one sensor (118) is provided to measure the amount of varnish applied per unit of time.
21. Printing press according to any one of claims 18 to 20,
    characterized
    by at least one sensor (103, 118, 106) measuring the moisture of the printing material transported into the dryer device and/or exiting the dryer unit.
22. Printing press according to any one of claims 18 to 22,
    characterized
    by a computer programme for the computing unit (301) for determining the amount of water fed to and removed from the dryer unit (9a, b).
23. Printing press according to any one of claims 18 to 22,
    characterized
    by at least one sensor (130b) for determining the volume flow of the supply air and of the exhaust air of the dryer device(s), respectively.
24. Printing press according to any one of claims 18 to 23,
    characterized
    by temperature sensors (120b, 130d) for determining the temperature of the flow of supply air and of the flow of exhaust air of the dryer device(s).
25. Printing press according to any one of claims 18 to 24,
    characterized
    by temperature sensors (114, 117) for determining the temperature of the printing material before and after it has passed through the dryer device(s).
26. Printing press according to any one of claims 18 to 25,
    characterized
    by a data connection (307) between the computing unit (301) and the control unit of the printing press.
27. Printing press according to any one of claims 18 to 25,
    wherein the computing unit is part of the control unit of the printing press.
28. Printing press according to any one of claims 19 to 27,
    wherein the display device is part of the control console of the printing press.
29. Printing press according to any one of claims 18 to 28,
    wherein the printing press has several dryer devices (10a, b; 11a-d) and wherein a separate sensor for measuring the moisture of the exhaust air are assigned to individual dryer units (10a, b).
30. Printing press according to claim 29,
    wherein a separate temperature sensor is assigned to each dryer unit (10, 11).
31. Printing press according to any one of claims 18 to 19,
    wherein the printing press has at least one varnishing unit (9a, 9b) for dispersion varnishes and a thermal dryer device (10a, 10b, 11a to 11d) and wherein at least one sensor for measuring the air humidity of the exhaust air is arranged in the exhaust duct of the dryer device (10, 11).
32. Printing press according to claim 18 or 31,
    wherein the sensor (130c, d) for measuring the moisture of the exhaust airstream is arranged in a cooled measurement airstream.
33. Printing press according to claim 31,
    characterized
    by a measuring cell (401) in a Peltier element (410) for cooling a measurement airstream diverted form a main airstream, the moisture sensor (408) being arranged in the measuring cell (401) together with a temperature sensor.
34. Printing press according to claim 31 including a display device for displaying the moisture or the amount of water removed by the exhaust air.

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