DE102015208190B4 - Method for operating at least one printing unit - Google Patents

Abstract

Method for operating at least one printing unit (200; 400) of a printing press (01), wherein the at least one printing unit (200; 400) comprises at least one central cylinder (201; 401) and at least one print head aligned with a lateral surface of the central cylinder (201; 401) (212; 412) and wherein in at least one printing operation at least one printing fluid is ejected from at least one nozzle of the at least one print head (212; 412) and on a printing material (02) in contact with the lateral surface of the central cylinder (201; 401). is impinged, characterized in that a reference temperature of the central cylinder (201; 401) is controlled and / or regulated and that a thickness (d; d1; d2) of the printing material (02) to be printed as a parameter in the control and / or regulation of the reference temperature of the central cylinder (201; 401) flows in.

Description

The invention relates to an experience for operating at least one printing unit according to the features of claim 1.

In printing presses, different printing methods are used, for example rotary printing, offset printing, planographic printing, high-pressure, screen printing or gravure printing or non-impact printing methods. Non-impact printing processes (NIP = non-impact printing) are understood to mean printing processes which do not require a fixed, that is physically immutable, printing form. Such printing methods can produce different print images in each printing process. Examples of non-impact printing processes are ionographic processes, magnetographic processes, thermographic processes, and in particular inkjet printing processes or ink-jet printing processes. Such printing methods usually have at least one image-forming device, for example at least one print head. In the case of the inkjet printing method, such a printhead is designed, for example, as an inkjet printhead and has at least one and preferably several nozzles, by means of which specifically at least one printing fluid, for example in the form of ink drops, can be transferred to a printing material. The printing material should have as constant a distance as possible from the image-producing device, on the one hand in order to be able to coordinate the image formation in time and, on the other hand, to avoid damage to the image-forming device.

In ink-jet printing or ink-jet printing, individual drops of at least one printing fluid are ejected from nozzles of printing heads and transferred to a printing material in such a way that a print image results on the printing substrate. By individual control of a plurality of nozzles so different print images can be created. There is no fixed printing form and thus it is possible to design each individual print product individually. As a result, personalized printed products can be produced and / or due to the saving of the printing plates small runs of printed products can be produced at low cost.

An exact match of a print image on the front and back of a printed substrate printed on both sides is called register (DIN 16500-2). Multi-color printing is called the Passer (DIN 16500-2), when individual print images of different colors are combined exactly to a picture. Also in the context of inkjet printing, appropriate measures must be taken to maintain register and / or register.

If a printing aggregate has more than one printhead, matching printhead settings are important to achieve high-quality printing results. For example, the printheads must be correctly aligned with respect to their relative position and driven at the right time. For some expensive procedures and / or devices are used. It is equally important that an activation of the printheads takes place in such a way that nozzles of the printheads discharge printing fluid at appropriate times, so that pixels are generated in a passer-containing and / or register-containing manner under the given geometric conditions and transport speeds of the printing material and flight times of the drops of the printing fluid. The flight times depend in particular on a distance between the nozzle and the printing substrate and on a speed of the drops. It should also be noted that printheads is sometimes assigned an optimal distance to the substrate, because the drops can change geometrically during the flight and at this optimal distance have a defined state in which they should impinge on the substrate.

By the DE 10 2011 076 899 A1 a printing machine is known, wherein the printing machine has a first printing unit having at least one central cylinder and at least one print head.

By the US 2002/0166470 A1 is a printing press with printheads and central cylinder known, the central cylinder of coolant is durchströmbar.

By the DE 10 2009 000 518 A1 a method for operating a printing unit of a printing press is known, wherein the printing unit has a counter-pressure cylinder and an outer surface of the impression cylinder aligned printhead and wherein in a printing operation at least one pressurized fluid is ejected from at least one nozzle of the print head and on a with the lateral surface of the impression cylinder contacting printing material. To adapt to different thickness substrates is taught to adjust the position of the corresponding printhead to ensure a constant distance from the surface of the substrate. This can also be done coupled with the machine control.

The invention has for its object to provide a method for operating at least one printing unit, in which even with different thickness substrates Passer and register of printed products can be kept the same.

The object is achieved by the features of claim 1.

A method is preferably used to operate at least one printing unit of a printing press. The at least one printing unit preferably has at least one central cylinder and at least one print head aligned with a lateral surface of the central cylinder. More preferably, the at least one printing unit has a plurality of, in particular a plurality, with respect to a circumferential direction around the central cylinder arranged one behind the other, aligned on the lateral surface of the central cylinder print heads. The orientation in this case relates in particular to an ejection direction of one or more nozzles of the corresponding print head. The at least one printhead is preferably an inkjet printhead.

Preferably, in at least one printing operation, at least one printing fluid is ejected from at least one nozzle of the at least one printhead and strikes the at least one printing fluid, in particular after a first time of flight, on a printing material in contact with the lateral surface of the central cylinder and in particular to be printed. The pressurized fluid is preferably expelled in the form of individual drops. Preferably, the printing fluid in such a region of the printing material meets this printing material which is in contact with the lateral surface of the central cylinder on an opposite side.

Preferably, a reference temperature of the central cylinder is controlled and / or regulated. The reference temperature is preferably a temperature which represents an average temperature of all components of the central cylinder, for example identical or at least uniquely linked to it. Preferably, a thickness of the printing material in contact with the central cylinder and / or to be printed flows as parameter into the control and / or regulation of the reference temperature. In particular, a thickness of the printing material is a smallest dimension of the printing substrate.

Preferably, the method is alternatively or additionally characterized in that in a first printing process, a first substrate having a first thickness in contact with the central cylinder and is preferably transported by a rotational movement of the central cylinder along a transport path and in particular the reference temperature of the central cylinder thereby a first Value.

Preferably, the method is characterized alternatively or additionally by the fact that in a second printing process, which differs in particular from the first printing operation, a second printing material, in particular different from the first printing material, is in contact with the central cylinder with a second thickness different from the first thickness. This second printing material is preferably transported in the second printing process by a rotational movement of the central cylinder along a transport path. Preferably, during the second printing operation, the reference temperature of the central cylinder has a second value different from the first value. Preferably, the method is alternatively or additionally characterized in that the first thickness is greater than the second thickness and that the first value of the reference temperature is lower than the second value of the reference temperature.

By controlling and / or regulating the reference temperature, it can be utilized that at least one material, from which at least parts of the central cylinder are constructed, is subject to thermal expansion. Preferably, the at least one central cylinder is made of at least one material having a positive coefficient of linear expansion at least in the range between 10 ° C and 50 ° C, more preferably in the range between 0 ° C and 100 ° C. For example, aluminum has a coefficient of linear expansion of 23.1 * 10 ^ -6 per Kelvin. With a diameter of a central cylinder of 800 mm made of aluminum, it is possible to increase the radius by approx. 0.01 mm by heating the cylinder by 1 K. This increase in radius means a reduction in the distance between a lateral surface of the central cylinder and the nozzle of the printhead at the same position of a corresponding printhead. However, the sum of the radius of the central cylinder and the thickness of the printing material is decisive for the distance between the nozzle and the printing substrate. Thus, a smaller thickness of a printed in the second printing second substrate can be compensated by the fact that the radius of the central cylinder is increased accordingly. If the second printing material, for example, 0.1 mm thinner than the first substrate, the cylinder may have a reference temperature in the second printing, which is higher by 10 K, thereby keeping the same distance between the substrate surface and nozzle in both printing processes. In this way, register and register can be kept the same in both printing processes and the conditions under which the drops of the printing fluid impinge on the printing material can be kept the same in both printing processes.

The process is preferably characterized Alternatively or additionally, by a sum of a radius of the central cylinder and the thickness of the respective printing substrate in the first printing process is the same size as in the second printing operation. Preferably, the method is characterized alternatively or additionally by the fact that a maximum processible thickness of the printing material is stored in a memory and that the control and / or regulation of the reference temperature is such that this maximum processable thickness of the substrate, the actual thickness of the current to printing substrate and a standard temperature as a parameter in the control and / or regulation of the reference temperature. The standard temperature is preferably the temperature which must assume the reference temperature, so that the substrate can be properly printed with the maximum processible thickness of the substrate.

The term of a pressurized fluid in the foregoing and hereinafter ink and printing inks, but also paints and pasty materials are summarized. Preference is given to printing fluids which are transferred to a printing material by a printing machine or at least one printing unit of the printing press and preferably in a finely structured form and / or not only over a large area a preferably visible and / or perceptible by sensory impressions and / or establish machine-detectable texture on the substrate. Inks and printing inks are preferably solutions or dispersions of at least one colorant in at least one solvent. Suitable solvents include, for example, water and / or organic solvents. Alternatively or additionally, the pressure fluid may be formed as under UV light crosslinking pressure fluid. Inks are relatively low viscosity printing fluids and inks are relatively high viscosity printing fluids. Inks preferably have no binder or relatively little binder, while printing inks preferably contain a relatively large amount of binder and more preferably further auxiliaries. Colorants may be pigments and / or dyes, pigments being insoluble in the application medium, while dyes are soluble in the application medium. In particular, inks containing dyes as colorants preferably have no binder.

For the sake of simplicity, the term "printing ink" in the sense of a liquid or at least free-flowing dyeing fluid to be printed in the printing press should be understood in the preceding and following - which does not only refer to the colloquial rather with the expression - if not explicitly distinguished "Ink" brought in conjunction higher-viscosity dyeing fluid for use in rotary printing machines, but in addition to these higher viscosity dyeing fluids in particular also low-viscosity dyeing fluids such as "inks", especially inkjet inks, but also powdered dyeing fluids such. As toner includes. Thus, in the foregoing and hereinafter especially colorless paints are meant when talking of printing fluids and / or inks and / or printing inks. In the preceding and in the following, in particular, means for a pretreatment (so-called precoating) and / or a subsequent treatment (so-called post-treatment or post-coating) of the printing material are preferably meant, if printing fluids and / or inks and / or printing inks are mentioned. As an alternative to the term pressurized fluid, the term coating agent is to be understood as synonymous.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

• 1a eine schematische Darstellung einer Rollen-Druckmaschine;
• 1b eine schematische Darstellung einer Rollen-Druckmaschine mit alternativer Bahnführung;
• 2a eine schematische Darstellung eines Teils eines Druckaggregats mit einer Doppelreihe von Druckköpfen;
• 2b eine schematische Darstellung zumindest eines Düsenbalkens mit mehreren Doppelreihen von für Druckköpfe vorgesehenen Positionen;
• 3a eine schematische Darstellung eines Teils eines Zentralzylinders und eines ersten Bedruckstoffs;
• 3b eine schematische Darstellung eines Teils eines Zentralzylinders und eines zweiten Bedruckstoffs, der eine geringere Dicke aufweist als der erste Bedruckstoff in 3a, wobei der Zentralzylinder eine gleiche Ausdehnung aufweist wie in 3a;
• 3c eine schematische Darstellung eines Teils eines Zentralzylinders und des zweiten Bedruckstoffs aus 3b, der eine geringere Dicke aufweist als der erste Bedruckstoff in 3a, wobei der Zentralzylinder eine größere Ausdehnung aufweist als in 3a und 3b.

Show it:

• 1a a schematic representation of a roll printing machine;
• 1b a schematic representation of a roll printing machine with alternative web guide;
• 2a a schematic representation of a portion of a printing unit with a double row of printheads;
• 2 B a schematic representation of at least one nozzle bar having a plurality of double rows of positions provided for printing heads;
• 3a a schematic representation of a portion of a central cylinder and a first substrate;
• 3b a schematic representation of a portion of a central cylinder and a second substrate, which has a smaller thickness than the first substrate in 3a , wherein the central cylinder has a same extent as in 3a ;
• 3c a schematic representation of a portion of a central cylinder and the second printing from 3b , which has a smaller thickness than the first substrate in 3a , wherein the central cylinder has a greater extent than in 3a and 3b ,

As a printing press 01 Here is one at least a pressurized fluid on a substrate 02 to understand the application or machine capable of being applied. The printing press 01 has, for example, at least one printing material source 100 , at least a first printing unit 200 , preferably at least a first dryer 301 , preferably at least a second printing unit 400 and preferably at least a second dryer 331 and preferably at least one post-processing device 500 on. The at least one first printing unit 200 is preferred as at least a first ink jet printing unit 200 educated. The printing press 01 is also preferred as an inkjet printing machine 01 educated. The printing press is preferred 01 as a roll printing machine 01 formed, more preferably as a roller inkjet printing machine 01 , The printing press 01 is for example as a rotary printing machine 01 formed, for example, as a roller rotary printing machine 01 , in particular roll-rotary ink-jet printing machine 01 , In the case of a roll printing press 01 is the source of printing material 100 for example as Rollenabspulvorrichtung 100 educated. In the case of a sheet-fed press or sheet-fed rotary printing press, the source of printing material 100 For example, designed as a sheet feeder. In the substrate source 100 At least one printing material is preferred 02 aligned, preferably with respect to at least one edge of this printing substrate 02 , The substrate 02 is for example at least one web-shaped substrate 02 So a printing material web 02 For example, a paper web 02 or a textile web 02 or a slide 02 , For example, a plastic film 02 or a metal foil 02 ,

An axial direction A or transverse direction A is preferably one direction A , which are parallel to a rotation axis 111 a substrate roll 101 and / or to a rotation axis 207 ; 407 at least one central cylinder 201 ; 401 and / or to an axis of rotation of one in the first printing aggregate 200 arranged Bedruckstoffleitelements extending. A particular provided transport of the at least one printing substrate 02 and in particular the printing material web 02 runs after the at least one printing material source 100 preferably by the at least one first printing unit 200 where the substrate 02 and in particular the printing material web 02 preferably by means of at least one coating agent or printing fluid, in particular at least one ink and / or printing ink at least on one side and preferably in connection with the at least one second printing aggregate 400 is preferably provided on two sides with at least one printed image.

After passing the at least one first printing unit 200 the transport path of the printing material passes through 02 and in particular the printing material web 02 for example, the at least one first dryer 301 to dry the applied ink and / or ink. Ink and / or printing ink is to be understood in the preceding and hereinafter generally a coating composition, in particular also a lacquer. Preferably, the at least one first dryer 301 Part of a dryer unit 300 , The at least one post-processing device 500 is for example as at least one folding device 500 and / or as a take-up device 500 and / or as at least one planned expense 500 educated. In the at least one folding device 500 is the preferred two-sided printed substrate 02 preferably further processed to individual printed products.

The following is a roll printing machine 01 described in more detail. However, the same details can be applied to other printing presses as well 01 , for example, sheet-fed presses, provided they do not conflict. The substrate 02 preferably has a width, ie an extension in the axial direction A from 700 mm to 2000 mm, but may also have an arbitrarily smaller or preferably larger width.

A working width of the printing press 01 is a dimension which is preferably orthogonal to the intended transport path of the printing substrate 02 by the at least one first printing unit 200 extends, more preferably in the axial direction A , The working width of the printing press 01 preferably corresponds to a maximum width, which is a substrate 02 may have to still with the printing press 01 to be processed, so a maximum with the printing press 01 processable substrate width.

The at least one first printing unit 200 is preferably the Rollenabspulvorrichtung 100 with respect to the transport path of the printing material 02 downstream. The at least one first printing unit 200 has, for example, at least a first central pressure cylinder 201 or shortly central cylinder 201 on. If below from a central cylinder 201 the speech is, so is always a pressure cylinder 201 meant. The printing material web 02 preferably wraps around the first central cylinder in a printing operation 201 at least partially. In this case, a wrap angle is preferably at least 180 ° and more preferably at least 270 °. The wrap angle is the angle measured in the circumferential direction of a cylinder jacket surface of the first central cylinder 201 along which the substrate 02 and in particular the printing material web 02 with the first central cylinder 201 in contact. The printing material web 02 For example, it wraps around a part of a first deflection roller 203 and is deflected by this so that the transport path of the printing substrate 02 in a first space 204 both tangential to the first guide roller 203 as well as tangent to the first central cylinder 201 runs.

For example, at least one, as the first impression 206 trained first cylinder 206 in the at least one first printing unit 200 arranged. In one to the first central cylinder 201 Employed state forms the first impression roller 206 preferably together with the first central cylinder 201 a first impression gap 209 , By the first deflecting 203 and / or preferably by the first impression roller 206 becomes the printing material web 02 preferably flat and more preferably in a unique and known position to the first central cylinder 201 created.

The first central cylinder 201 preferably has its own, the first central cylinder 201 associated first drive motor 208 on, preferably as an electric motor 208 is formed and further preferred as a direct drive 208 and / or single drive 208 of the first central cylinder 201 is trained. Under a direct drive 208 is a drive motor 208 to understand that without interposing further with the substrate 02 in contact rotating body with the at least one first central cylinder 201 is in torque transmitting and / or transferable connection. Under a single drive 208 is a drive motor 208 to understand that as a drive motor 208 excluding the at least one first central cylinder 201 is trained.

On the first drive motor 208 of the first central cylinder 201 and / or on the first central cylinder 201 itself, a first rotational angle sensor is preferably arranged, which has a rotational angle position of the first drive motor 208 and / or the first central cylinder 201 itself measuring and / or measuring and sending to a higher-level machine control and / or is designed to transmit. The first rotation angle sensor is designed, for example, as a rotary encoder or absolute value encoder. With such a rotation angle sensor is a rotational position of the first drive motor 208 and / or preferably a rotational position of the first central cylinder 201 preferably by means of the higher-level machine control absolutely determinable.

Additionally or alternatively, the first drive motor 208 of the first central cylinder 201 For example, in terms of circuit technology connected to the machine control such that the machine control is based on the machine control of the first drive motor 208 of the first central cylinder 201 predetermined target data to a rotational position of the first drive motor 208 at any time via the rotational position of the first drive motor 208 and thus at the same time the rotational position of the first central cylinder 201 is informed. In particular, one preferred is the rotational angle position or rotational position of the first central cylinder 201 and / or the first drive motor 201 predefined area of the machine control directly with at least one print head 212 of the first printing unit 200 controlling area of the machine control connected.

Within the first printing unit 200 is at least a first printing unit 211 arranged. The at least one first printing unit 211 is preferred in the direction of rotation of the first central cylinder 201 and thus along the transport path of the printing material web 02 after the first impression 206 preferably on the at least one first central cylinder 201 acting and / or arranged and / or aligned and / or arranged alignable. The at least one first printing unit 211 is preferred as a first ink jet printing unit 211 trained and will also be the first ink-jet printing unit 211 called. The at least one first printing unit 211 preferably has at least one nozzle bar 213 and more preferably a plurality of nozzle bars 213 on. The at least one first printing unit 211 and thus the at least one first printing unit 200 preferably has the at least one first printhead 212 ; 412 preferred as an ink jet printhead 212 ; 412 is trained. Preferably, the at least one nozzle bar 213 in each case at least one print head 212 ; 412 and preferably each multiple printheads 212 ; 412 on. Every printhead 212 ; 412 preferably has a plurality of nozzles from which coating agent drops, in particular ink drops are ejected and / or ejected. A nozzle bar 213 is a component that preferably over at least 80% and more preferably at least 100% of the working width of the printing press 01 extends and that as a carrier of the at least one print head 212 ; 412 serves. An axial length of the bale of the at least one first central cylinder is preferred 201 at least as big as the working width of the printing machine 01 , There is a single or several nozzle bars 213 per printing unit 211 arranged. Each nozzle is preferably a clearly defined target area in the direction A the width of the printing material web 02 and preferably in the direction A in particular the axis of rotation 207 the at least one first central cylinder 201 related assigned. Each target area of a nozzle is preferably in particular with respect to the circumferential direction of the at least one first central cylinder 201 clearly defined at least in the printing operation. In particular, a target area of a nozzle is that, in particular, substantially rectilinear space area which extends in a direction of ejection of this nozzle from this nozzle.

The at least one first nozzle bar 213 preferably extends orthogonal to the intended transport path of the printing material 02 over the working width of the printing press 01 , The at least one nozzle bar 213 preferably has at least one row of nozzles. The at least one row of nozzles faces in the axial direction A Seen preferably over the entire working width of the printing press 01 and / or width of the bale of the at least one first central cylinder 201 For example, at regular intervals nozzle openings. Preferred are in the axial direction A side by side several print heads 212 ; 412 at the at least one nozzle bar 213 arranged. Since usually such individual printheads 212 ; 412 are not provided with nozzles up to an edge of their housing are preferably at least two and more preferably exactly two in the axial direction A extending rows of printheads 212 ; 412 in the circumferential direction of the first central cylinder 201 offset from one another, preferably so that in the axial direction A successive printheads 212 ; 412 preferably alternately one of the at least two rows of printheads 212 ; 412 always preferentially alternately a first and a second of two rows of printheads 212 ; 412 , Two such rows of printheads 212 ; 412 form a double row of printheads 212 ; 412 , Each double row of printheads 212 ; 412 For example, there are between five and twenty-five printheads 212 ; 412 and more preferably seven or fourteen printheads 212 ; 412 on. The at least one row of nozzles is preferably not formed as a single linear juxtaposition of nozzles, but results as the sum of a plurality of individual, more preferably two, circumferentially offset from each other arranged juxtaposition of nozzles.

Indicates a printhead 212 ; 412 multiple nozzles, so form all target areas of the nozzles of this printhead 212 ; 412 together a workspace of this printhead 212 ; 412 , Workspaces of Printheads 212 ; 412 a nozzle bar 213 and in particular a double row of printheads 212 ; 412 boundaries in the axial direction A seen at each other and / or overlap in the axial direction A seen. In this way is also in the axial direction A non-continuous printhead 212 ; 412 ensured that in the axial direction A seen at regular and preferably periodic distances target areas of nozzles of the at least one nozzle bar 213 and / or in particular each double row of printheads 212 ; 412 lie. In any case, an entire working area of the at least one nozzle bar extends 213 preferably over at least 90% and more preferably 100% of the working width of the printing machine 01 and / or the entire width of the bale of the at least one first central cylinder 201 in the axial direction A , On one or both sides with respect to the axial direction A can be a narrow area of the substrate web 02 and / or the bale of the first central cylinder 201 be present, which is not the working area of the nozzle bars 213 belongs. An entire working area of the at least one nozzle bar 213 is preferred from all workspaces of printheads 212 ; 412 this at least one nozzle bar 213 composed and is preferably from all target areas of nozzles of these printheads 212 ; 412 this at least one nozzle bar 213 composed. Preferably, an entire work area corresponds to a double row of print heads 212 ; 412 in the axial direction A seen the working area of the at least one nozzle bar 213 ,

Preferably, the at least one nozzle bar 213 in the circumferential direction with respect to the at least one first central cylinder 201 several rows of nozzles on. Preferably, each printhead 212 ; 412 a plurality of nozzles, more preferably in a matrix of several rows in the axial direction A and / or a plurality of columns preferably in the circumferential direction of the at least one first central cylinder 201 are arranged. Such columns are further preferably arranged running obliquely to the circumferential direction, for example, to increase a resolution of a printed image. Thus, in each case one row of nozzles and one column of nozzles preferably enclose an angle other than 90 °. Preferred are in a direction orthogonal to the axial direction A , in particular in the transport direction B along the intended transport path of the printing substrate 02 and / or in the circumferential direction relative to the at least one central cylinder 201 several rows of printheads 212 ; 412 , more preferably four double rows, and more preferably eight double rows of printheads 212 ; 412 arranged one after the other. More preferably, at least in the printing operation in the circumferential direction with respect to the at least one first central cylinder 201 several rows of printheads 212 ; 412 , more preferably four double rows, and more preferably eight double rows of printheads 212 ; 412 successively on the at least one first central cylinder 201 arranged aligned.

Here are the printheads 212 ; 412 at least in the printing operation, preferably oriented such that the nozzles of each printhead 212 ; 412 essentially in the radial direction on the cylinder jacket surface of the at least one first central cylinder 201 point. Deviations from radial directions within a tolerance range of preferably not more than 10 ° and more preferably not more than 5 ° are to be considered essentially radial directions. This means that the at least one on the lateral surface of the at least one first central cylinder 201 aligned printhead 212 ; 412 with respect to the axis of rotation 207 the at least one first central cylinder 201 in a radial direction on the lateral surface of the at least one first central cylinder 201 is aligned. This radial direction is one on the axis of rotation 207 the at least one first central cylinder 201 related radial direction. Each double row of printheads 212 ; 412 It is preferred to associate and / or assign a printing ink of a specific color, for example one of the colors black, cyan, yellow and magenta or a varnish, for example a clear varnish. The corresponding inkjet printing unit 211 is preferred as a multi-color printing unit 211 , in particular four-color printing unit 211 designed and allows a one-sided multicolor, especially four-color printing of the printing substrate 02 , It is also possible to have fewer or more different colors with a printing unit 211 to print, for example, additional spot colors. In one embodiment, at least in the printing operation, a plurality of rows of printheads 212 ; 412 , more preferably four double rows, and more preferably eight double rows of printheads 212 ; 412 arranged in succession on at least one surface of at least one transfer body, for example at least one transfer cylinder and / or at least one transfer belt aligned.

The at least one print head 212 ; 412 works for the production of coating agent drops preferably according to the drop-on-demand process in which coating agent drops are generated selectively if necessary. Preferably, at least one piezo element is used per nozzle, which can reduce a volume filled with coating agent at high speed by a certain amount when a voltage and / or change of an applied voltage. As a result, coating agent is displaced, which is ejected through a nozzle connected to the volume filled with coating agent and forms at least one coating agent drop. By applying different voltages to the piezoelectric element is on the travel of the piezoelectric element and thus the reduction of the volume and thus the size of the coating agent drops influence. In this way, color gradations in the resulting print image can be realized, for example without necessarily changing a number of drops contributing to the print image (amplitude modulation). It is also possible to use at least one heating element per nozzle, which generates a gas bubble in a volume filled with coating agent at high speed by evaporating coating agent. The additional volume of the gas bubble displaces coating agent, which in turn is ejected through the respective nozzle and forms at least one coating agent drop.

In the drop-on-demand process, it is possible to have a target position of the respective coating agent drop on the moving printing material web 02 with respect to the circumferential direction of the at least one first central cylinder 201 solely by an emission time point of the respective coating agent drop and a rotational speed of the first central cylinder 201 and / or by the rotational position of the first central cylinder 201 set. By individual control of each nozzle, coating agent drops from the at least one print head are only at selected times and at selected locations 212 ; 412 on the substrate web 02 transfer. This happens as a function of the rotational speed and / or the rotational angle position of the at least one first central cylinder 201 a distance a . a ' between the respective nozzle and the printing material web 02 and the location of the target area of the respective nozzle with respect to the circumferential angle. This results in a desired printed image, which is designed as a function of the control of all nozzles. Alternatively to the rotational angle position and the rotational speed of the first central cylinder 201 can for example also on a transport speed of the printing material 02 be resorted to.

By orientation of the printing material web 02 for example by means of a Bahnkantenausrichters and optionally through the first impression roller 206 of the first printing unit 200 and by the large wrap angle of the printing material web 02 around the at least one first central cylinder 201 and optionally by other devices such as drivers ensures that the substrate web 02 without slippage in a precisely defined position on the cylinder jacket surface of the at least one first central cylinder 201 is arranged and also remains until a selective detachment at the end of the range of the wrap angle. Through the contact of the printing material web 02 with the cylinder jacket surface of the at least one first central cylinder 201 In addition, swelling of the printing material web 02 at least in the transport direction B of the printing material web 02 and at least for the duration of a contact of a respective area of the substrate web 02 with the cylinder jacket surface of the at least one first central cylinder 201 even after contact with drops of ink prevented or at least sufficiently reduced. This will ensure that ink drops from different printheads 211 on a uniformly defined printing substrate 02 be applied. An exact and constant position of the printing material web 02 relative to the at least one first central cylinder 201 is of great importance for a passport-compatible and / or register-compatible printed image, in particular if the control of the at least one nozzle as described above with the rotational position of the first central cylinder 201 is linked.

The nozzles of the at least one printhead 212 ; 412 are arranged such that a distance a . a ' between the nozzles and on the cylinder jacket surface of the at least one first central cylinder 201 arranged printing material web 02 at least when arranged in a printing position printhead 212 ; 412 preferably between 0.5 mm and 5 mm and more preferably between 1 mm and 1.5 mm. The high angular resolution and / or the high sampling frequency of the rotation angle sensor and / or the high accuracy of the Machine control predetermined and by the first drive motor 208 of the first central cylinder 201 processed target data to the rotational position of the first drive motor 208 of the first central cylinder 201 allows a very accurate orientation and / or knowledge of the position of the substrate web 02 relative to the nozzles and their target areas. A drop flight time between the nozzles and the printing material web 02 is for example by a learning process and / or by the known distance a . a ' between the nozzles and the printing material web 02 and a known drop speed known. From the angular position of the at least one first central cylinder 201 and / or the first drive 208 the at least one first central cylinder 201 , the rotational speed of the at least one first central cylinder 201 and the drop flight time is determined an ideal time to eject a respective drop, so that a passer-sized and / or register-compliant imaging of the substrate web 02 is reached.

In particular, it is relevant for the drop flight time how large the distance a . a ' between nozzle and substrate 02 is. At a constant diameter of the central cylinder 201 and when a position of the respective nozzles is constant with respect to a radial direction, the distance depends a . a ' between the nozzle and the relevant surface of the substrate 02 of a thickness d ; d1 ; d2 of the substrate 02 from. The radial direction is on the axis of rotation 211 of the first central cylinder 201 based. The fat d ; d1 ; d2 of the substrate 02 is in particular a smallest dimension of the printing material 02 ,

Preferred is a method for operating at least one printing unit 200 ; 400 a printing press 01 , wherein the at least one printing unit 200 ; 400 at least one central cylinder 201 ; 401 and at least one on a lateral surface of the central cylinder 201 ; 401 aligned printhead 212 ; 412 and wherein in at least one printing operation at least one pressure fluid from at least one nozzle of the at least one print head 212 ; 412 is ejected and on one with the lateral surface of the central cylinder 201 ; 401 in contact printing material 02 incident.

Preferably, the method is characterized in that a reference temperature of the central cylinder 201 ; 401 controlled and / or regulated and that a thickness d ; d1 ; d2 of the substrate to be printed 02 as a parameter in the control and / or regulation of the reference temperature is included. For example, the central cylinder has at least one rotary leadthrough and at least one line system for at least one tempering fluid, in particular at least one temperature control fluid. Alternatively, at least one radiation source is arranged, by means of which electromagnetic radiation for heating the central cylinder 201 ; 401 on the central cylinder 201 ; 401 is correctable.

Preferably, the method is additionally or alternatively characterized in that in a first printing process, a first substrate 02 with a first thickness d1 with the central cylinder 201 ; 401 is in contact and the reference temperature of the central cylinder 201 ; 401 has a first value and that in a second printing a second substrate 02 with one of the first thickness d1 different second thickness d2 with the central cylinder 201 ; 401 is in contact and the reference temperature of the central cylinder 201 ; 401 a second value different from the first value. Preferably, the method is additionally or alternatively characterized in that the first thickness d1 is greater than the second thickness d2 and that the first value of the reference temperature is lower than the second value of the reference temperature. Preferably, the reference temperature is controlled and / or regulated such that a sum of a radius r ; r1 ; r2 of the central cylinder 201 ; 401 and the thickness d ; d1 ; d2 of the respective printing material 02 in the first printing process is the same size as in the second printing process. In particular, then a first sum of the first thickness d1 of the first substrate 02 and a first radius r1 of the central cylinder 201 ; 401 as large as a second sum of the second thickness d2 of the second substrate 02 and a second radius r2 of the central cylinder 201 ; 401 ,

Preferably, the method is additionally or alternatively characterized in that the reference temperature is a temperature which is an average temperature of all components of the central cylinder 201 ; 401 represents and / or that the thickness d ; d1 ; d2 of the substrate 02 a smallest dimension of the substrate 02 is and / or that the at least one printhead 212 ; 412 an ink jet print head 212 ; 412 and / or that the second substrate 02 one from the first substrate 02 different substrate 02 is. Preferably, the method is additionally or alternatively distinguished by the fact that in the first printing process, the first printing material 02 by a rotational movement of the central cylinder 201 ; 401 is transported along a transport path and / or that in the second printing process, the second substrate 02 by a rotational movement of the central cylinder 201 ; 401 is transported along the transport path.

Preferably, at least one sensor designed as a first print image sensor is arranged, more preferably at one point along the transport path of the printing material web 02 after the first printing unit 211 , By means of this at least a first Print image sensor and a corresponding evaluation, for example, the higher-level machine control, is preferably a control of all in the circumferential direction of the at least one first central cylinder 201 one behind the other and / or acting printheads 212 ; 412 and / or double rows of printheads 212 ; 412 of the first printing unit 211 monitored and / or regulated. A layer of pixels formed by coating agent drops emerging from a respective first printhead 212 ; 412 are preferably compared with a layer of pixels formed by coating agent drops, each from a second, in the circumferential direction of the at least one first central cylinder 201 and / or in the intended transport direction B of the printing substrate 02 after the first printhead 212 ; 412 arranged and / or in the axial direction A to the printhead 212 ; 412 arranged lying printhead 212 ; 412 come. This is preferably done independently of whether these each first and second, in the circumferential direction of the at least one first central cylinder 201 one behind the other and / or acting printheads 212 ; 412 process a same or a different coating agent. It will be a vote of the layers of different printheads 212 ; 412 monitored printed images. In the case of the same coating agents, register-based joining of partial images is monitored. With different coating agents, a register or color register is monitored. A quality control of the printed image is preferably also carried out with the measured values of the at least one printed image sensor. Depending on the speed with which individual nozzles can be controlled and operated, the substrate web must 02 may be printed multiple times with the same ink until the desired result can be achieved. For this purpose, each ink is preferably at least two in the circumferential direction of the first central cylinder 201 successive double rows of printheads 212 ; 412 assigned. This is for example at a transport speed of the printing material 02 of 2 m / s and a four-color print, a resolution of 600 dpi (600 pixels per inch) is reached. Preferably even higher web speeds of 150 m per minute or more are possible. Smaller resolutions and / or fewer colors allow correspondingly higher transport speeds.

In a regular printing operation, all printheads are 212 ; 412 fixedly arranged. This ensures a permanent passport-oriented and / or register-oriented alignment of all nozzles. There are different situations where a movement of the printheads 212 ; 412 necessary is. Such a situation results, for example, during installation and / or maintenance and / or replacement of at least one of the print heads 212 ; 412 , The printheads 212 ; 412 are preferably individually on the at least one nozzle bar 213 attached and individually from the at least one nozzle bar 213 solvable. This allows individual printheads 212 ; 412 serviced and / or cleaned and / or replaced. Will be a new and / or reassignable printhead 212 ; 412 on the at least one nozzle bar 213 attached to the already at least one other printhead 212 ; 412 is fixed, it does not necessarily result but at most coincidentally an exact matching orientation of this new and / or reordering printhead 212 ; 412 to the at least one already attached printhead 212 ; 412 in the circumferential direction and / or in the axial direction A with respect to the at least one first central cylinder 201 , This may result in an alignment requirement, in particular a single printhead 212 ; 412 to at least one or more other printheads 212 ; 412 the same nozzle bar 213 and / or to at least one or more other printheads 212 ; 412 other nozzle bars 213 , Are several mutually movable nozzle bars 213 arranged, so could at a return of at least one nozzle beam 213 in a printing position minimal malpositions of the nozzle bar 213 occur among each other. Align printheads 212 ; 412 is preferred per printhead 212 ; 412 arranged at least one positioning device.

At least one adjustment sensor is preferably arranged. More preferably, at least two adjustment sensors are arranged. The at least one adjustment sensor and, in particular, the at least two adjustment sensors are used for data on relative settings of a plurality of, for example at least four printheads 212 ; 412 to grasp each other. Preferably, the at least one adjustment sensor or the at least two adjustment sensors are optical sensors. Such relative settings are, for example, relative geometric positioning of the printheads 212 ; 412 and / or relative actuation times, in particular drop ejection times of the print heads 212 ; 412 , The relative settings additionally or alternatively include, for example, relative settings which relate to at least one color density and / or at least one area coverage and / or at least one point size of generated pixels. In particular, a register and / or a register or color register can also be checked by means of this at least one setting sensor.

Preference is given by appropriate temperature control of the central cylinder 201 reduces an expense that would otherwise be correspondingly large if, due to a changed thickness to a previous print job d ; d1 ; d2 of the substrate 02 one or more or all printheads 212 ; 412 would have to be repositioned.

After the printing material web 02 the at least one first printing unit 200 has happened, the printing substrate 02 transported further along their transport path and preferably the at least one first dryer 301 the at least one dryer unit 300 fed. The at least one first dryer 301 is preferred as a flow dryer 301 and / or radiation dryer 301 and / or hot air dryer 301 and / or infrared radiation dryer 301 educated.

Along the transport path of the printing material web 02 is preferably at least a second printing unit 400 arranged. The transport path of the printing material web 02 by the at least one second printing unit 400 runs analogously to the transport path through the at least one first printing unit 200 , Within the second printing unit 400 is preferably at least a second, as an inkjet printing unit 411 or ink-jet printing unit 411 trained printing unit 411 on the second central cylinder 401 arranged aligned. The at least one second printing unit 411 the at least one second printing unit 400 is preferably identical to the at least one first printing unit 211 the at least one first printing unit 200 constructed, in particular with respect to at least one nozzle beam 413 , at least one, as an ink jet printhead 412 trained printhead 412 and their arrangement in double rows, the execution and resolution of the printing process, the arrangement, alignment and control of the nozzles and the mobility and adjustability of the at least one nozzle beam 413 and the at least one printhead 412 means at least one adjustment mechanism with a corresponding electric motor. This is preferably at least a second printing unit 411 as a multi-color printing unit 411 , in particular four-color printing unit 411 educated. With regard to the transport path of the printing material web 02 is after the at least one second printing unit 400 at least a second dryer 331 the at least one dryer unit 300 arranged. The structure of the at least one second dryer 331 is preferably similar to the construction of the at least one first dryer 301 ,

LIST OF REFERENCE NUMBERS

01

Printing Machine, Inkjet Printing Machine, Rolling Printing Machine, Rolling Inkjet Printing Machine, Rotary Printing Machine, Rolling Rotary Printing Machine, Rolling Rotary Inkjet Printing Machine

02

Substrate, substrate web, paper web, textile web, film, plastic film, metal foil

100

Substrate source, roll-off device, reel splicer

101

printing material

111

Rotation axis (101, 103)

200

Printing unit, inkjet printing unit, first, rotary body

201

Central pressure cylinder, central cylinder, first; body of revolution

202

-

203

Roller, guide roller

204

Gap (201; 203)

205

-

206

Cylinder, impression roller, first

207

Rotation axis (201)

208

Drive motor, electric motor, direct drive, single drive, synchronous motor

209

Impression gap, first

210

-

211

Printing unit, ink-jet printing unit, ink-jet printing unit, multi-color printing unit, four-color printing unit, first

212

Printhead, inkjet printhead, first

213

Nozzle bar, first

300

dryer unit

301

Dryer, infrared radiation dryer, radiation dryer, flow dryer, UV radiation dryer, hot air dryer, first

331

Dryer, infrared radiation dryer, flow dryer, radiation dryer, hot air dryer, UV radiation dryer, second

400

Printing unit, second, rotary body

401

Central pressure cylinder, central cylinder, second; body of revolution

408

Drive motor, direct drive, electric motor, single drive, synchronous motor

411

Printing unit, inkjet printing unit, inkjet printing unit, multi-color printing unit, four-color printing unit, second

412

Printhead, inkjet printhead, second

413

Nozzle bar, second

500

Post-processing device, folding device, rewinder, sheet cutter, plan delivery

A

Direction, transverse direction, axial

a

distance

a '

distance

d

Thickness (02)

d1

Thickness (02), first

d2

Thickness (02), second

r

Radius (201; 401)

r1

Radius (201; 401), first

r2

Radius (201; 401), second

Claims (10)

Method for operating at least one printing unit (200; 400) of a printing press (01), wherein the at least one printing unit (200; 400) comprises at least one central cylinder (201; 401) and at least one print head aligned with a lateral surface of the central cylinder (201; 401) (212; 412) and wherein in at least one printing operation at least one printing fluid is ejected from at least one nozzle of the at least one print head (212; 412) and on a printing material (02) in contact with the lateral surface of the central cylinder (201; 401). is impinged, characterized in that a reference temperature of the central cylinder (201; 401) is controlled and / or regulated and that a thickness (d; d1; d2) of the printing material (02) to be printed as a parameter in the control and / or regulation of the reference temperature of the central cylinder (201; 401) flows in. Method according to Claim 1 , characterized in that in a first printing process, a first printing material (02) having a first thickness (d1) in contact with the central cylinder (201; 401) and the reference temperature of the central cylinder (201; 401) has a first value and that in a second printing process, a second printing material (02) having a second thickness (d2) different from the first thickness (d1) is in contact with the central cylinder (201; 401) and the reference temperature of the central cylinder (201; has different value from the first value. Method according to Claim 2 characterized in that the first thickness (d1) is greater than the second thickness (d2) and that the first value of the reference temperature is lower than the second value of the reference temperature. Method according to Claim 2 or 3 , characterized in that the reference temperature is a temperature representing an average temperature of all components of the central cylinder (201; 401). Method according to Claim 1 . 2 . 3 or 4 , characterized in that the thickness (d; d1; d2) of the printing material (02) is a smallest dimension of the printing material (02) and / or that the second printing material (02) has a printing material (02) different from the first printing material (02) ). Method according to Claim 1 . 2 . 3 . 4 or 5 characterized in that said at least one printhead (212; 412) is an ink jet printhead (212; 412) and / or said at least one central cylinder (201; 401) is made of at least one material at least in the range between 10 ° C and 50 ° C has a positive coefficient of linear expansion. Method according to Claim 2 . 3 . 4 . 5 or 6 , characterized in that in the first printing process, the first printing material (02) is transported along a transport path by a rotational movement of the central cylinder (201; 401). Method according to Claim 2 . 3 . 4 . 5 . 6 or 7 , characterized in that in the second printing process the second printing material (02) is transported along the transport path by a rotational movement of the central cylinder (201; 401). Method according to Claim 2 . 3 . 4 . 5 . 6 . 7 or 8th , characterized in that a sum of a respective radius (r; r1; r2) of the central cylinder (201; 401) and the thickness (d; d1; d2) of the respective printing material (02) in the first printing process is the same as in FIG the second printing. Method according to Claim 1 . 2 . 3 . 4 . 5 . 6 . 7 . 8th or 9 , characterized in that a maximum processable thickness (d; d1; d2) of the printing material (02) is stored in a memory and that the control and / or regulation of the reference temperature is such that this maximum processable thickness (d; d1; d2 ) of the printing material (02) and the actual thickness (d; d1; d2) of the currently printing substrate (02) and a standard temperature as parameters are included in the control and / or regulation of the reference temperature.

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