EP0404088A2 - Device for feeding the inking unit of a printing press - Google Patents

Abstract

The invention relates to a device for feeding the inking unit of a printing press with a mixed ink. It is mixed continuously from its basic colours and fed to the inking unit so that the step of ink mixing as a production preparation prior to a printing order is omitted. The parts filled with the mixed ink after a printing order are constructed as demountable exchange articles. By this means, the equipment can be converted to another colour with a short conversion time. <IMAGE>

Description

The invention relates to a device for loading an ink fountain on a printing press with a color which is taken from a plurality of primary colors stored in containers in the required amount, mixed and added to the ink fountain.

Up to now, printing inks for sheet-fed and web-fed printing machines have been mixed outside the printing press before the start of printing, provided they are not delivered in a mixed condition by the printing ink manufacturer. Web printing machines are often equipped with storage containers from which the printing inks are automatically fed into the ink fountains, so that the ink fountains do not have to be refilled directly during operation.

When processing orders, the required amount of paint can usually only be estimated. This often results in excess quantities or shortages before an order is finished. The excess amount of paint with the previously determined hue can no longer be used, so it must be destroyed. Manual remixing is difficult despite long experience and good color sensitivity, so that color changes are undesirable, which are undesirable. Nevertheless, the operational process is disrupted by the remixing.

Regardless of the difficulties with the correct storage of the printing ink at the end of an order, the entire ink tract within the printing machine must be completely cleaned of the color so that there is none when processing the next order with a different color Color distortions exist. Cleaning is time-consuming and hydrocarbons are used, the use of which is increasingly viewed as stressful. This work involves dirt and touching the printer with the often not completely harmless cleaning agents.

It is an object of the invention to propose a device for feeding a color box on a printing press, in which the color with an approximately arbitrary color is always continuously mixed in the required amount, including the cases in which less color or more color than originally intended is used is, the device must be designed such that it can be changed to a different color with a short changeover time.

To achieve this object, the invention proposes that at least one metering device 2 is arranged after each container 1, that at least two metering devices 2 are connected to a mixer 6, that each mixer 6 is connected to at least one ink fountain 10 for dispensing the mixed paint, and that the components of the device containing the mixed color are removable replacement articles.

The invention turns away from the preparation of the color by mixing outside the machines in the preliminary stage of the production preparation and instead proposes to mix the color from the required basic colors in the required amount, according to the consumption, continuously or in the smallest quantities.

This solves a problem that printers always face when they use colors that differ from the primary colors. The amount of ink required for an order can never be fully estimated. Often it leads different surface of the material to be printed to considerable differences in the amount of ink required. When ordering mixed color, you either have to put up with the fact that there are large quantities remaining or there is a risk that the ordered color will not be enough. The resulting residual color is stored and very often it has to be thrown away because it can no longer be used specifically for a mixed color. This is environmentally harmful and leads to a financial loss. If small quantities of a special color are required for an order, problems also arise: small quantities of such a special color are generally not supplied by the color producers and larger quantities have to be ordered, of which considerable residues remain.

These problems are solved by the device according to the invention, since the mixing of the special color from primary colors takes place relatively continuously during the printing process and this mixing process can be terminated in good time at the end of the job, so that practically no residual color is left. With skillful use of the device, even the amount of paint in the ink fountains can be kept extremely low and be used up as far as possible. The amount of mixed color is in the order of about 0 to 100 grams per minute, depending on the print format and artwork.

After the end of an order, i.e. after the printing machine has come to a standstill or when the printing machine is being prepared for another job with different colors, the cleaning effort is minimal. The parts wetted or filled with mixed paint are replaced. They are designed as exchange items so that they are thrown away, sent to an environmentally friendly separation and recycling process, or one that takes place outside the machine Can be subjected to the cleaning process, with no or only minimal amounts of cleaning agent having to be used. Replacing these parts also leads to a shorter changeover time.

Pressure inks for offset printing are paste-like substances at room temperature, the flow behavior and thus their mixing ability is significantly improved by heating. A particularly expedient embodiment of the invention therefore provides a heating zone which is connected upstream of the mixer. The containers with the basic colors, the hoses leading to the mixer or the mixer itself are heated as the heating zone or the entire device is accommodated in a housing which is heated as a whole. Warming up to 25 ° to 40 ° C brings a much better or quicker good mixing result. Since the warming up of the color can possibly lead to changes in the color, for example evaporation of volatile constituents, it is expedient to allow the heating and mixing process to take place in the absence of air. For this purpose, the areas that contain heated paint are either completely surrounded by a housing that does not let air into the paint, or the housing that surrounds these parts of the device is filled with inert gas. Such a measure makes it possible to heat the paint to 30 ° to 50 ° and to improve the mixing result even further in this way. Since the warm ink has a different viscosity than the cold ink, which can interfere with the printing process, it may be advisable to place a cooler between the mixer and the ink fountain, which cools the ink back down to room temperature.

Dosing piston pumps (e.g. Orlita, Gießen), screw dosing pumps or batch dosing devices are used to dose the primary colors. An inexpensive solution would be manual or Adjustable dosing and filling cylinders with computer control. These are cylinders with pistons that are filled via a three-way valve. After the three-way valve has been switched over, the contents can be discharged in the direction of the mixer. Here, the ejection of the filling material (color) from all cylinders can be carried out at the same time, whereby a better mixing is achieved by the mixer. It is expedient to pressurize the ink reservoir slightly with the aid of an inert gas so that no undesired evaporation occurs due to the suction effect of the metering device. Deviating from this, each container can be provided with an advancing, slightly pressurized lid. The inert cushion or the moving cover can also be used for conveying and dosing, which will be explained further below in connection with the description of exemplary embodiments.

As an exchange item, only the parts wetted with order-changing colors, such as mixers, lines and, if necessary, hoses are replaced after a color change, which may include simple check valves or valves with minimal opening pressure. The supply lines from the ink reservoir to the pump and the mixer, which are always filled with the same color, are not affected. Of course, the exchange items can be cleaned as well as recycled if they e.g. B. are made of weakly alkaline, water-soluble plastic, as it is offered on the market today.

The construction of the mixer is expediently chosen such that it discharges the paint almost without residue after mixing. A mixer designed in this way facilitates both recycling and cleaning of the exchange articles due to the small amount of paint remaining after use. Appropriate constructions are still presented in connection with the description of exemplary embodiments of the invention. Some of these are suitable for recycling, some are suitable for cleaning, but in principle they can be used for both.

It is possible to network a large number of storage containers with primary colors with metering devices, mixers and ink fountains in such a way that each inking unit of a multi-color printing press can be supplied with every possible color mixture, with controllable valves regulating the ink flow. Such a control device can be fed with a program which controls the metering and ink supply in such a way that the machine is supplied in sufficient quantity with the required special colors. After finishing the job, all you have to do is replace the parts that are dirty with mixed paint. The next job can then be printed with other spot colors in the shortest possible time.

It is also possible to arrange only one metering device for each container for a basic color and to install a branch between this metering device and the various mixers to which this metering device is connected, which branch is equipped with controllable valves which do not influence the metering. In this way it is possible to operate a large number of mixers by means of a single metering device. It can be switched from one to the other mixer, or it is possible to alternately supply a large number of mixers with the required color portions. The controllable valves must not influence the metering. Ball valves are suitable for this. The dosing devices can dose the color volumetrically or gravimetrically.

In order to promote the complete discharge of the paint from the mixer, it is expedient if the interior of the mixer comprises a variable volume that essentially starts from the value 0. For example, it can be designed as a walkable tube section, which consists of two superimposed, rectangular, welded film webs at the edges.

The mixer can also be designed as a cylinder with a piston slidingly sealing therein. In any case there are connection nozzles in the number of containers on one side, while at least one connection nozzle for connection to a mouthpiece for feeding into a paint box is arranged on the other side of the mixer. In this way, the discharge is almost complete. In the case of a cylindrical mixer, for example, the cylinder base carries the connecting nozzles for the hose lines to the containers, while the piston carries the connecting nozzle for the hose connection to the mouthpiece.

If the mixer consists of a walkable hose section, this is preferably placed in a holder which is designed in such a way that an abutment, for example in the form of a plate, is present on one side, while a walk-around roll is movably guided on the other side. The fulling roll can be moved back and forth by motor, for example with the help of a pneumatic cylinder. In deviation from this, the abutment can be designed as a circular section, in which case the flexing roller is guided in an oscillating circular movement.

In the case of such an embodiment, it is particularly easy to install a conveyor roller which, after milling, causes the mixed ink to be discharged from the mixer into the ink fountain. It is movable on the same radius as the fulling roll, e.g. B. at one above the pivot point the flexing roller extends backwards outwards, which is then pivoted through 180 ° for the discharge of the paint. The conveyor roller is located on a longer radius on the frame, or for the discharge of the paint, the pivot axis of the frame is briefly brought closer to the mixer for the engagement of the conveyor roller. In any case, in contrast to the conveying roller, the flexing roller, in order to bring about thorough mixing, must not completely press the tube section together.

Another possibility is to form the flexing roller from disks arranged at a distance from one another, so that spaces are created between the disks in which the color can flow in the opposite direction to the milling direction.

Depending on the consistency of the colors to be mixed and depending on the amount required, it may be advisable to provide the fulling roller with a helical rib, which ensures that, in addition to displacement in the direction of rotation, lateral displacement also takes place. In this embodiment, the inlet (connection nozzle 5) and the outlet (connection nozzle 7) are laterally offset. The pitch of the helix can be adapted to the length of the mixer in such a way that the frame rotates continuously and the flexing roller detects the mixer with each revolution so that the flexing roller drives the mix both in the rolling direction of the flexing roller and to the side. As a result, the mix is conveyed from the inlet to the outlet continuously, or in a small portion with every whale roll intervention. During this conveying of the color, it is thoroughly mixed by intensive milling, the screw line having to be matched to the quantity conveyed and the required mixing intensity.

Regardless of the design of the mixer or the flexing roller, it is advisable to use the spouts for the connection to be provided with the containers in the walking direction at a distance from the spout corresponding to the walking area for the connection to the mouthpiece. In this way, thorough mixing is achieved, and the emptying of the mixer is also facilitated. If a mixer designed as a hose section is used, the spouts are preferably located directly on an end face in the region of a side face, so that, despite the spouts, the two side walls with the internal volume 0 can lie completely on top of one another.

Particularly good mixing of the colors that have entered the mixer is possible if a ferromagnetic body, in particular a rod, is moved in a contactless manner with the aid of a permanent magnet, which is rotated or moved by a motor on the outside of the mixer. Then there is a strong flexing and squeezing of the colors with an excellent mixing. The stick can be easily removed from the mixer after use, for example by simply piercing the mixer skin. In this way, it is recoverable and reusable.

A mixer can also consist of two rollers arranged side by side in parallel. These rollers touch each other completely or almost, rotate in opposite directions, namely at the top of each other. If the colors to be mixed are applied to the top of the rollers, these are thoroughly mixed in the gusset formed by the rollers on the top. The top of the rollers is wetted, but the contact or the very narrow gap between the rollers prevents the ink from running through. The paint is applied to one end of the pair of rollers and z. B. promoted by an inclination of the pair of rollers to the other end, mixed and leaves the rollers at the other end as a mixed Colour. Instead of an inclination of the pair of rollers, screw-shaped, interlocking profiles can also cause conveyance to the outlet side. If such rollers are only supported at one end and the bearing is designed so that the rollers can be easily removed, the rollers can be replaced easily and without further ado. Such rollers can be subjected to cleaning after replacement, they can consist of recyclable plastic or they can be designed as disposable items. In any case, the replacement also shortens the downtime of the machine when changing from one color to another.

The rollers can also be covered with an interchangeable hose. Furthermore, it is expedient to surround the rollers with a housing which is either designed such that it fills completely with color when the color to be mixed is supplied, so that the air is completely displaced from the mixture, or the housing is filled with inert gas . This housing is also expediently interchangeable. The mixed material supplied to the rollers can be preheated beforehand, or the rollers or the housing, or both, can be heated.

The mixing can be supported by ultrasound, for which purpose an ultrasound head of relatively low power is attached to the mixer. If the paint is thin enough, mixing with ultrasound alone is sufficient; the temperature range to be used is then z. B. between 30 ° and 50 ° C.

It is not necessary that each batch be mixed first and then emptied into the ink fountain. Rather, the mixed colors are preferably metered in continuously, which is only given if the mixed section is to be emptied completely as far as possible at the end of a print job. Because the dosing units come from home apply a certain pressure, the dosing units can be set to continuous operation, which can be run with such small quantities that the basic colors to be mixed are supplied to the mixer almost continuously, which leads to a constant or approximately constant discharge of mixed color from the mixer, so that the same amount of color always comes out of the mouthpiece.

The mouthpiece can be displaced along the ink fountain, at least in the case of large machines, according to a development of the invention. As a result, almost any desired color strength can be applied over the length of the ink fountain. In this way, conditions are taken into account in which certain areas lose more color as a result of the printed image than other areas.

Continuous driving of the device is also possible in the case of a cylindrical mixer with a piston located therein, which is then held at a distance from the cylinder base and is only moved towards the cylinder base towards the end of the print job in order to completely empty the mixer. A mixer consisting of two rollers compensates for a certain discontinuity in the metering in, so that a continuous flow of mixed color leaves this mixer.

Of course, several mixers can be used for one mouthpiece or several mixers and several mouthpieces to supply a particularly long ink fountain. If several mouthpieces are supplied by a single mixer, the distribution to the individual mouthpieces and thus to individual sections of the ink fountain can in turn be controlled by an adjustable dosage.

At the start of a print job, the color of the color to be filled in is determined for each color box. It is assumed that the mixing ratio for achieving the desired color from the respective primary colors is fixed, for example with the aid of spectrophotometry or by means of stored computer programs. After checking the presence of the basic colors in sufficient quantities within the containers, the metering devices are set accordingly, or a connected microprocessor controls the speed of drive motors normally used on these metering devices. According to appropriate specifications, the color distribution over the length of the ink fountain is defined, so that the control for the position of the mouthpiece along the ink fountain is thus indirectly determined. Deviating from this, the color box can be divided into sections, and in each section there is a minimum level indicator, the exceeding signal of which is promptly filled with color.

A fresh mixer and fresh hoses must be used at the start of the order so that the system is ready for operation. Before the printing machine starts up, the ink fountain is pre-filled in the required profile, or all sections are supplied with printing ink up to the minimum height. The printing press can then be started. During operation, color is either replaced according to the program, or the minimum level switches request color depending on consumption.

At the end of the order, the ink fountains are emptied according to experience, or all remaining quantities are removed from the mixers beforehand. After the printing machine has been switched off, the ink fountains are cleaned in the customary manner, while each mixer and the hose connection to the mouthpiece are emptied and replaced. The mouthpiece may be emptied and replaced. These parts are cleaned, recycled or discarded, a mouthpiece designed as a disposable article expediently consisting of a simple valve that opens at a certain minimum pressure.

• Fig. 1 eine schematische Darstellung der Erfindung in einem ersten Ausführungsbeispiel,
• Fig. 2 eine Seitenansicht eines modifizierten Mischers,
• Fig. 3 eine schematische Draufsicht auf die Walk- und Fördereinrichtung des Ausführungsbeispiels gemäß der Figur 2,
• Fig. 4 eine Querschnittsansicht durch ein weiteres Ausführungsbeispiel eines Mischers gemäß der Erfindung,
• Fig. 5 eine schematische Querschnittsansicht einer Dosierkammer zur Dosierung von Farbe in den Mischer,
• Fig. 6 ein weiteres Ausführungsbeispiel eines Mischers ähnlich dem der Fig. 2,
• Fig. 7 einen aus zwei Walzen bestehenden Mischer und
• Fig. 8, 8a eine weitere Dosierkammer.

Exemplary embodiments of the invention which are illustrated in the drawing are explained in more detail below; show in the drawing:

• 1 is a schematic representation of the invention in a first embodiment,
• 2 is a side view of a modified mixer,
• 3 shows a schematic top view of the walking and conveying device of the exemplary embodiment according to FIG. 2,
• 4 shows a cross-sectional view through a further exemplary embodiment of a mixer according to the invention,
• 5 shows a schematic cross-sectional view of a metering chamber for metering paint into the mixer,
• 6 shows another embodiment of a mixer similar to that of FIG. 2,
• Fig. 7 is a mixer consisting of two rollers and
• 8, 8a another metering chamber.

An exemplary embodiment of the invention is shown schematically in FIG. It goes without saying that corresponding brackets are available for the individual components, but screwing surfaces on existing printing presses can also be selected, so that the illustration is limited to the components inherent in the invention and does not extend to auxiliary parts such as brackets, hose clamps and the like is.

At a suitable point, containers 1 are attached for receiving primary colors; A total of five containers are shown in FIG. The base color is also to be understood as a binder that belongs to the color formulation and must also be metered in in a predetermined amount. It can be assumed that 9 containers, including binders, are sufficient to mix any color. Dosing devices 2 are attached directly below the container 1, which are only indicated schematically. It can e.g. B. are piston metering pumps, the drive motors are infinitely adjustable or the number of strokes can be specified to bring about a certain dosage. Of course there are many types of dosing and conveying devices that are suitable. Below the metering devices 2 there are taps or valves 3 which, in the manner of main taps, allow the metering devices 2 and the container 1 to be shut off from the surroundings. The container 1 are sealed gas-tight and are slightly under pressure, which is applied by a nitrogen or CO₂ line, not shown, which opens into each container 1.

From each unit consisting of container 1, metering device 2 and valve 3, a hose 4 leads to a connecting nozzle 5 on a mixer 6. Through the hoses 4, the basic colors (including binders) are fed to the mixer 6, which is designed as a walkable hose section. Here it consists of a film lying at the bottom and a film lying thereon, which are welded together at their edges. At one end, the mixer has 6 connecting sleeves 5 on the outside, they are connected to the lower film, that is to say they point away from the viewer and lie below the image plane. The same applies to a connecting nozzle 7 at the other end of the mixer 6. A hose 8 for passing the mixed color to a mouthpiece 9 is connected to this, which supplies the ink fountain 10 with color.

The mixer 6 lies on a table (not shown) which has corresponding cutouts for the connecting sleeves 5 and 7. In order to avoid a backflow of paint from the mixer 6 back into the hoses 4, check valves (not shown) are integrated in the grommets 5 and, moreover, only open at a certain minimum pressure. A similar valve is located in the area of the mouthpiece 9.

After the color has been mixed in the mixer 6, which will be explained in more detail below, and after the color has escaped from the mouthpiece 9, the distribution within a color box 10 must still be taken care of. For this purpose, a slide 14 is provided, which is arranged displaceably on a rod guide 15 along the ink fountain 10. For the displacement, a spindle 16 can be rotated with the aid of a geared motor 17, and this rotation causes the longitudinal movement mentioned within the slide 14 via a nut (not shown). The approach to the individual positions of the carriage 14 is either controlled with the aid of a program, or the ink fountain 10 is divided into sections in which a color request can be recognized if necessary via a minimum level display. Such minimum level indicators are known per se and therefore do not require any explanation at this point.

The device is ready for operation when the container 1 is sufficiently filled, the dosing devices 2 are programmed, the valves 3 are opened for the required colors and the hoses 4 are completely filled up to the connection spouts 5. The further metering of basic colors into the mixer 6 causes it to be slowly filled, with clear color traces of the different colors being present in the area of the individual spouts 5 in the first moment. With the help of a Walk roller 20, the mixer 6 is now substantially deformed transversely to its direction of passage, which is done by a reciprocating movement as a result of a pneumatic cylinder 21 driving the walk roller 20. This results in vigorous, sufficient mixing of the individual primary colors with formation of the color to be mixed. The fulling roller 20 is set in such a way that it does not compress the two foils of the mixer 6 without a gap, but rather leaves a certain passage when it is rolled over, so that the primary colors initially metered into the mixer 6 are only mixed, but are not expelled from the mixer 6 .

Depending on the operating mode or depending on the desired operating mode, the basic colors which are gradually metered in result in the maximum expansion volume of the mixer 6 being reached. Sufficient overpressure then occurs in the hose 8 that the valve on the mouthpiece 9 opens. The mixed color then emerges at this point in the quantity of basic colors metered in. Notwithstanding this, the flexing roller 20 can be lowered after a mixing process has ended, so that it presses the two foils of the mixer 6 onto one another without a gap. The mixed ink is then almost completely squeezed out of the mixer 6. Thus, while the mixed ink continuously exits the mouthpiece 9 without lowering the flex roller 20, the lowering of the flex roller 20 effects the intermittent emptying.

The connection spout 7 for the hose 8 to the mouthpiece 9 can of course be moved to the bottom left of the mixer 6 in order to achieve the most complete possible discharge of the mixed paint from the mixer 6, but expediently a small amount of mixed paint remains prevents at the beginning of the Mixing process get unmixed paint directly into the hose 8.

A further embodiment of the device according to the invention is presented in FIGS. 2 and 3, in which the flexing roller 20 is moved in a different way. The mixer 6 in the form of the hose section described does not lie on a flat table, but nestles against an abutment 27 which is designed in the form of a circular section. In the center of the curvature, a frame 25 is rotatably mounted about a shaft 26, at one end of which the flexing roller 20 is located.

As can be clearly seen from FIG. 3, the flexing roller 20 can be formed from individual disks 28, between which areas of smaller diameter during the milling process leave channels through which the paint to be mixed can flow back against the milling direction. In FIG. 2 it is indicated that during the mixing the frame 25 is pivoted back and forth with the aid of a drive motor, not shown, so that the flexing roller 20 rolls over the mixer 6 essentially alternately over its entire length. This results in an intensive mixing of the basic colors contained in the mixer 6.

It can be clearly seen in FIG. 2 that the hoses 4 and 8 extend from the film of the mixer formed from two films, which faces the abutment 27 in the form of a circular section. For the grommets 5,7 and the hoses 4,8, 27 holes are provided for the passage through the abutment. In this way, the two foils can again be pressed together, so that the interior takes up a volume of approximately zero.

For the intermittent emptying of the mixer 6, the frame 25 is pivoted through 180 ° according to the arrow shown, so that a conveyor roller 24, which is located at the opposite end of the frame 25, rolls over the mixer 6 from the upper edge downwards. The entire mixed color contained therein is supplied to the hose 8 and thus to the ink fountain 10 via the mouthpiece 9 (see FIG. 1). As a rule, a single rollover is sufficient, the conveyor roller 24 preferably consisting of a medium-hard rubber roller. Then, for a new mixing process, the rolling roller 20 is used opposite the abutment 27, so that a new mixing process can start. A variant with a helical fulling roll was already explained at the beginning; it is not illustrated.

It goes without saying that the two functions of mixing and discharging can also be carried out by a full roller, the distance from which to the abutment 27 can be changed. If a small distance is maintained, the mixer 6 is tumbled, while the removal is carried out when the distance is eliminated. This mode of operation is thus comparable to the lowering of the flexing roller 20 in the exemplary embodiment in FIG. 1.

Another exemplary embodiment of a mixer according to the invention is shown in FIG. It consists of a cylinder 30 in which a piston 31 slides in a sealing manner. At the bottom of the cylinder, the connection sleeves 5 for the hoses 4 (see FIG. 1) are attached, while the piston 31 is provided with a corresponding connection sleeve 7 for the hose 8. Between the piston 31 and the cylinder base there is a mixing disk 33, the guide rod 36 of which is sealingly guided through the piston 31. An oscillating device, which can also be rotated in an indexed manner, is attached to the guide rod 36, while the piston 31 can be forcibly moved or supported by means of piston rods 32.

At the beginning of a color mixing, basic color is in turn applied to each connection nozzle 5 under slight pressure. The mixing disk can rest against the inside of the piston 31 without any gaps, openings 34 in the mixing disk 33 engaging over projections 35 on the piston 31 without gaps. The unit formed from the mixing disk 33 and the piston 31 can be brought into a position in which it rests on the cylinder base. As a result of the basic colors continuously metered in at the start of printing or during preparation for printing, this unit is pressed down until, for example, the position shown in FIG. 4 is reached. Now the mixing disc 33 is moved up and down with the aid of the guide rod 36, the primary colors enclosed in the cylinder space having to squeeze through the openings 34 each time. This is followed by vigorous mixing. If necessary, the mixing disc 33 can also be rotated so that an even more intensive mixing takes place, but for a mixing that covers the entire mix, the rotation can be dimensioned such that the elevations 35 always engage in the openings 34.

If paint is to be discharged from the mixer according to FIG. 4, the piston 31 is moved against the cylinder base with the aid of the piston rods 32, as a result of which the mixed paint emerges from the spout 7 into the hose 8 (see FIG. 1). A back flow through the nozzles 5 is again excluded because there is a check valve (not shown) in each nozzle 5. It is now up to the user whether the color space is completely emptied or whether a residual mixture of the color remains in the mixer 6. If a complete discharge is desired, the mixing disk 33 must be brought into the starting position beforehand in which the openings 34 coincide with the elevations 35.

Of course, this mixer can also be operated in a continuous manner, which is distinguished by the fact that the piston 31 is only supported by the piston rods 32 and is not moved. The emptying through the connection spout 7 then takes place continuously through the primary colors, the mixing disk 33 being moved back and forth continuously or at intervals.

It can be clearly seen that the mixer 6 according to FIG. 4 in particular can be cleaned particularly easily since it can be completely dismantled, and the disassembled individual parts are without complicated cavities or undercuts. As a result, cleaning by rinsing is very easy. This mixer is therefore also suitable for reuse, but this does not need to extend the changeover time because the mixer can be replaced and cleaned outside the machine.

The mixer 6, the hose 8 and the mouthpiece 9 can be equipped so that they are discarded when the color changes or after use. Then they should be made of a cheap, environmentally friendly, but color and solvent-resistant plastic, which would otherwise have no high requirements. If it turns out that 4 residual ink quantities from the previous batch remain at the end of the hoses in the area of the check valves, these hoses 4 with the check valves or flaps contained therein must also be replaced. Since the hoses are extremely thin, both the loss of color and the amount of waste are extremely low.

If it turns out that disturbing leaks occur on the seal between the guide rod 36 and the piston 31 due to a drying paint film, a roller sleeve or roller sock can be used at this point, in which these problems do not arise. The same also applies to the seal between the piston 31 and the cylinder 30.

FIG. 5 shows a metering chamber 40 of the type that can be used, for example, as metering device 2 (FIG. 1), that is to say that the number of containers 1 is present. For their function, it is necessary that the colors in the containers 1 are slightly under pressure, be it through a gas cushion of an inert gas or be it through a mechanically depressed cover with a sliding seal.

The dosing chamber 40 is divided into two chamber halves with the aid of a cutting disc 41, of which the lower chamber half is provided with an adjusting screw 42. The adjusting screw 42 is surrounded by a metallic bellows 43, which is attached on the one hand to a washer 39 resting on the adjusting screw 42 and on the other hand to the inside of the chamber 40 and, due to its metallic construction, has sufficient pressure stability.

A lead 44 leads to each chamber half, starting from a ball valve 45 with an L passage. A feed line 46 leads to the ball valve 45 and is connected, for example, directly to a container 1 (FIG. 1). In the same way, each chamber half is connected to a drain line 47, which are connected to a common ball valve 48. A hose 4 leads from this ball valve 48 to the mixer 6. This ball valve 48 also has an L passage and is connected to the one mentioned at the beginning Ball valve 45 mechanically connected for common switching, but this is not indicated in FIG. 5.

Before the colors are mixed, the individual dosing quantities are set on the adjusting screw 42. This defines the free path of the cutting disc 41 within the chamber 40, so that a certain amount of paint emerges from the chamber 40 over a single stroke over the remaining length. Both subchambers of the chamber 40 are then set in such a way that the desired color is mixed when each subchamber has delivered the amount of a stroke of the cutting disc 41.

5 shows the end of a metering stroke, in which the lower part of the chamber has been emptied, that is to say the color coming from the feed line 46 has flowed into the upper part of the chamber and the cutting disc 41 has been advanced as far as the stop against the adjusting screw 42 . The paint located in the lower sub-chamber has reached the hose 4 via the ball valve 48 and thus to the mixer 6.

For the next metering stroke, both ball valves are adjusted so that the other line 44 or 47 is connected to the other sub-chamber of the chamber 40. Paint then flows into the lower part of the chamber, while the upper part of the chamber is emptied into the hose 4 via the drain line 47. Each of these dosing chambers of the chamber 40 feeds into a mixer of almost any design, and the dosed colors are mixed in the manner described or in the manner to be described.

With reference to FIG. 6 it is illustrated how a particularly good mixing can be brought about with the aid of a ferromagnetic pin 50 within a mixer 6, which with the help of a permanent magnet 51 inside the mixer 6 is moved. The permanent magnet 51 is moved back and forth about a center point M, which is also the center point of the circular section of the abutment 27, similar to the movement of the frame 25, which has been described in connection with the exemplary embodiment according to FIGS. 2 and 3. The pin 50 moved with the help of the permanent magnet 51 causes vigorous movement, squeezing and thus mixing of the paint enclosed in the mixer 6, so that few reciprocating movements are sufficient to bring about a satisfactory mixing of the colors.

6 schematically indicates how spring-loaded check valves are accommodated in the grommets 5 and 7. Otherwise, this exemplary embodiment is similar to that which has been described with reference to FIGS. 2 and 3. There is therefore a mixer 6 which consists of foils welded to one another. Corresponding seams are indicated in FIG. 6.

The color mixing can be supported by an ultrasound head 53, which is attached to the back of the abutment. It vibrates the entire abutment 27, which is transferred to the colors. If the colors are heated to such an extent that they are very thin, even mixing with ultrasound alone is sufficient, so that the ferromagnetic pin 50 and the permanent magnet 51 are unnecessary. All that is then required is a conveyor roller 24 (FIGS. 2 and 3) to empty the mixer after mixing.

In the exemplary embodiments according to FIGS. 2 and 6, the color can of course be conveyed essentially transversely to the mixing movement, which is done by entering the colors on one side wheel of the abutment 27 and the mixed color on the other Side margin is delivered. The color then moves towards or away from the viewer.

FIG. 7 shows a mixer 6 consisting of two rollers 60 and 61. These rollers 60, 61 are arranged in parallel next to one another, touching or almost touching one another. The rollers 60, 61 rotate in opposite directions, the rotation on the top being directed towards one another. The rollers 60, 61 are connected to the drive by means of receptacles 65, 66 in such a way that they can easily be removed for replacement. A horizontal inclination around the angle ensures that the colors applied to one roller end in the area 62 flow slowly in the direction of the arrow 63 to the other roller end, mix in the process and leave the mixing device in the direction of the arrow 64. Chamfers or shoulders at this end of the rollers 60, 61 define this ink discharge and prevent the end face of the rollers from being contaminated with ink. The rotation of the rollers causes the color applied in the area 62, consisting of at least two primary colors, to be kneaded intensively between these rollers, the surface of the rollers being wetted, but the distance between the rollers at their contact line 68 being zero or so small that none Paint can drip through. The inclination of the rollers by the angle, together with the viscosity of the paint, determines the conveying speed and in this way an optimal mixing result can be determined with the appropriate roller length. The rollers can be changed during the color change and cleaned if necessary, or they can be covered with an exchangeable coating which is renewed after a color change.

The rollers 60, 61 are expediently surrounded by a housing (not shown). This housing should also be replaceable. The rollers or the housing or both can be heated in order to achieve a better mixing result. It is also possible to use the rollers to be stored horizontally and to be provided with an interlocking helical profile in the contact line, which causes the color to be conveyed to the outlet side (not shown).

FIGS. 8 and 8a show a dosing device for dosing the primary colors removed from a container and fed to the mixers. This metering device consists of a cylinder 70 with a tightly guided piston 71 running in this cylinder. The piston 71 is driven by a rod 72 leading into the cylinder 70. At the other end of the cylinder 70, a connection 77 leads to a three-way valve 76, which is connected with its two other outlets to a container 1 (line 74) and to the mixer 6 (line 75).

FIG. 8a shows the position of the three-way valve in a position in which the basic paint is drawn in by the piston 71 via the lines 74 and 77 until the piston 71 reaches a defined end position, after which the three-way valve switches over and guides the paint in this position, as shown in Figure 8, through which the line 75 to the mixer. The delivery rate can be adjusted by the stroke and the speed of the piston.

The device according to the invention can be used rationally in particular when all the repetitive movements and actuations or all movement sequences, such as, for example, the pivoting of the arm 25, the use of the conveyor roller 24 or the use of the flex roller 20, are recorded. Then all movements are z. B. can be actuated at any time by servomotors with adjustable limit switches to cover defined distances. In this way, a fully automatic mode of operation is possible, as often as required according to a predetermined program or according to an empirically recorded program, for subsequent orders is reproducible. In such a case, for example, the adjusting screw 42 in the exemplary embodiment according to FIG. 5 can be adjusted in a motorized and controllable manner and also the taps in FIG. 1 are designed as solenoid valves or the like, so that the colors are also selected according to the program can. The programmability of the dosing units 2 has already been mentioned in the preceding text. It is no problem for the person skilled in the art to provide corresponding servomotors or valves which can be controlled very precisely in time and which also allow metering while the pressure remains constant. Dosing devices of this type are commonplace, for example, on injection systems on motor vehicle engines.

Before a printing press can be run at full speed, feed devices and, if necessary, chains of printed cardboard sheets, for example, must be set up and set up. Relatively large numbers of usable specimens can be driven, which still originate from the set-up company, but still meet the quality requirements. At this stage, due to the slower running of the machine, considerably less ink is used per unit of time than later in full load operation. The metering must also take place correspondingly differently. It is therefore advisable in these special cases to be able to adapt the speed of the color mixing to the speed of the printing press. This is particularly easy when the metering devices, piston pumps or screw conveyors are used, the number of strokes or basic speed of which determines the metering. These can be adjusted to the speed of the machine, while a proportional fast to the speed adjustment of the mixing.

Claims (51)

1. Device for loading a color box on a printing press with a color which is taken from several basic colors stored in containers in a respectively predetermined quantity, mixed and added to the color box,
characterized by
that each container (1) is followed by at least one metering device (2), that at least two metering devices (2) are connected to a mixer (6), that each mixer (6) is connected to at least one ink fountain (10) for dispensing the mixed color and that the components of the device containing the mixed paint are removable replaceable items. 2. Device according to claim 1,
characterized by
that the mixer is preceded by a heating zone. 3. Device according to claim 2,
characterized by
heating to 25 to 40 ° C. 4. Device according to one of claims 1 to 3,
characterized by
that the heating zone and mixer are surrounded by a housing that keeps the paint in the absence of air. 5. The device according to claim 4,
characterized by
that the housing is filled with inert gas. 6. The device according to claim 1 and 2 with 4 or 5,
characterized by
heating to 30 to 50 ° C. 7. The device according to claim 2 with one or more of claims 3 to 6,
characterized by
that a cooler is arranged between the mixer (6) and the ink fountain (10). 8. The device according to one or more of claims 1 to 7
characterized by
that the removable replaceable items consist entirely or partially of recyclable plastic. 9. Device according to one of claims 8,
characterized by
that the recyclable plastic is soluble in an aqueous, weakly alkaline solution. 10. The device according to one or more of claims 1 to 9,
characterized by
that the removable replacement items are all or part of disposable items. 11. The device according to one or more of claims 1 to 10,
characterized by
that a mouthpiece (9) is provided for filling the paint in a paint box (10). 12. The device according to claim 11,
characterized by
that the mouthpiece (9) is movably guided along the ink fountain (10). 13. The device according to one or more of claims 1 to 12,
characterized by
that the connections of containers (1), metering devices (2), mixers (6) and ink fountains (10) are networked in such a way that each inking unit of a multi-color printing press can be supplied with every possible ink mixture, with controllable valves regulating the ink flow. 14. The device according to one or more of claims 1 to 13,
characterized by
that each container (1) is followed by only one metering device (2), and that a branching of the paint line with controllable valves which do not influence the metering is arranged between the metering device (2) and a respective mixer (6). 15. The apparatus according to claim 14,
characterized by
that the controllable valves are ball valves. 16. The device according to one or more of claims 1 to 15,
characterized by
that the dosing device doses volumetrically. 17. The device according to one or more of claims 1 to 15,
characterized by
that the dosing device doses gravimetrically. 18. The device according to one or more of claims 1 to 17,
characterized by
that the mixer (6) carries on one side connection spouts (5) in the number of containers (1) and on the other side a connection spout (7) for connection to the mouthpiece (9). 19. The device according to one or more of claims 1 to 18,
characterized by
that the mixer (6) consists of a walkable hose section. 20. The apparatus according to claim 19,
characterized by
that the hose section can be used in a holder, on one side of which an abutment and on the other side of which a motor-driven flex roller (20) is attached. 21. The apparatus according to claim 20,
characterized by
that the fulling roller (20) moves on a circular segment-shaped path, and that the abutment is designed as a circular segment-shaped plate (27). 22. The apparatus of claim 20 or 21,
characterized by
that in the direction of movement of the flex roller (20), the connection sleeves (5) for connection to the containers (1) are at a distance corresponding to the flex area to the connection sleeve (7), which leads to the ink fountain (10). 23. The device according to one of claims 20 to 22,
characterized by
that the flexing roller (20) consists of disks (28) which are at a distance from one another. 24. The device according to one of claims 20 to 23,
characterized by
that the fulling roller is provided with a helical rib and that the color feed of the mixer (6) is laterally offset from the drain. 25. The device according to claim 24,
characterized by
that the pitch of the helix is matched to the length of the mixer in such a way that the flexing roller continuously conveys the mix in the rolling direction of the flexing roller and laterally from the inlet to the outlet. 26. The device according to one of claims 20 to 25,
characterized by
that a conveyor roller (24) is provided in addition to the flex roller (20), which can be moved instead of the flex roller (20) to empty the mixer. 27. The device according to one of claims 1 to 18,
characterized by
that the mixer consists of a cylinder (30) with a sealingly sliding piston (31) and that the connecting sleeves (5, 7) are each attached to the cylinder base or to the piston (31). 28. The device according to claim 27,
characterized by
that a mixing disk (33) is movably guided between the cylinder base and the piston (31), the actuating rod (36) or rods of which are sealingly guided through the piston (31) or the cylinder base. 29. The device according to claim 27 or 28,
characterized by
that to empty the mixer, the piston (31) can be driven by a motor into the cylinder (30). 30. Device according to one of claims 1 to 19,
characterized by
that the mixer (6) contains a ferromagnetic body, in particular a rod (50), which can be moved by means of a permanent magnet (51) or electromagnet located outside the mixer (6). 31. The device according to one or more of claims 1 to 30,
characterized by
that the interior of the mixer (6) comprises a variable volume essentially starting from the value 0. 32. Device according to one or more of claims 21 to 25, 27, 28, 30 or 31,
characterized by
that the paint to the ink fountain (10) does not flow through a reduction in volume of the mixer (6), but as a result of the volume flow conveyed from the metering devices into the mixer. 33. Device according to one of the preceding claims,
characterized by
that a check valve or a valve that opens at a predetermined minimum pressure is arranged directly in front of the mixer (6) in each feed line from the associated metering device (2). 34. Device according to one of the preceding claims,
characterized by
that a valve opening at a predetermined minimum pressure is arranged directly in front of the mouthpiece (9). 35. Device according to one of claims 1 to 18,
characterized by
that the mixer (6) consists of two parallel and completely or almost touching, counter-rotating rollers (60,61), because the primary colors in the area of one end of the pair of rollers from above in the contact area (62) Applied rollers (61, 62), conveyed through to the other end of the roller (63) and there leaves the roller pair (60, 61) as a mixed color (64). 36. Device according to claim 35,
characterized by
that the rollers (60, 61) for conveying the material to the discharge side are inclined at an angle which causes a conveying speed which permits an optimal mixing result. 37. Device according to claim 35,
characterized by
that the rollers (60,61) for conveying the mixed material in the contact line have interlocking helical profiles which cause conveyance to the outlet side. 38. Device according to one of claims 35 to 37,
characterized by
that the rollers (60, 61) are only supported at one end, these bearings (65, 66) being designed in such a way that the rollers (60, 61) can be easily removed for replacement. 39. Device according to one or more of claims 35 to 38,
characterized by
that the rollers (60,61) are covered with an interchangeable coating. 40. Device according to one or more of claims 35 to 39
characterized by
that the rollers (60,61) are surrounded by a housing. 41. Device according to one or more of claims 35 to 40,
characterized by
that the housing is interchangeable. 42. Device according to one or more of claims 35 to 41,
characterized by
that the rollers (60,61) are heated. 43. Device according to claim 42,
characterized by
that the feed lines to the mixer (6) can be heated. 44. Device according to one of the preceding claims,
characterized by
that the metering device consists of a chamber (40) with a movable separating disc (41) adjustable in the length of movement, the two partial chambers separated by the separating disc (41) are each provided with a paint feed line (44) and a drain line (47). 45. Device according to claim 44,
characterized by
that an adjusting screw (42) is provided to limit the displacement of the cutting disc (41). 46. Device according to claim 45,
characterized by
that the adjusting screw (42) is separated from the paint by means of a bellows (43). 47. Device according to one of the preceding claims,
characterized by
that the mixer (6) is mounted in the area of influence of an ultrasound generator. 48. Device according to one of the preceding claims,
characterized by
that the mixer (6) can be heated separately to an elevated temperature. 49. Device according to one of the preceding claims,
characterized by
that the adjustment values of the metering devices and, if appropriate, also the respective mouthpiece positions and all other settings and movement sequences can be stored and called up for a repetition of an order. 50. Device according to one of the preceding claims,
characterized by
that the mixing speed and all other movements are adjustable in relation to the speed of the printing press. 51. Device according to one or more of claims 1 to 44 or 47 to 50,
characterized by
that the metering device consists of a cylinder (70) with piston (71) and a three-way valve (76), that the three-way valve (76) with the cylinder (70), one Container (1) and a mixer (6) is connected so that the three-way valve (76) for sucking in the piston (71) opens and then closes the line to the container (1) and that the metered quantity is determined by the stroke and speed of the piston (71) is adjustable.

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