DD226839A1 - DEVICE FOR REMOVING THE OVERALL WATER IN THE COLORING WORKS - Google Patents

Abstract

The invention relates to a device for removing the excess dampening solution in the inking unit of sheet-fed offset printing machines, wherein the inking unit can be connected to the dampening unit via an intermediate roller. The object to provide a device for removing the excess dampening solution in the inking, with the aid of the color dampening solution dissolved and then the excess dampening solution can be reliably removed, is achieved by a hydrophilic roller is arranged on a paint roller, the the blowing device is assigned. figure

Description

-3- 662 72

The mode of action is the following.

By the rotational movement of the ductor 2 ink passes from the ink fountain 1. The ink lifter 3 accepts a color strip from the ductor 2 and then oscillates against the distribution cylinder 4. About the remaining ink rollers 17; 18; 5; 4.1; 4.2; 4.3; 8 of the inking unit passes the ink as a uniform color film on the spanned on the plate cylinder 9 printing plate. Also on the printing plate passes, by the rotational movement of the Feuchtduktorwalze 14 and subsequent transfer to the rollers 13 and 12, dampening liquid to wet the non-printing surface portions of the printing plate.

Moist liquid is also transported into the inking unit via the connecting roller 11 and / or the printing plate, where it can emulsify with the color film present there.

This emulsion is dissolved by the hydrophilic roller 6 and the fountain solution collects on its surface in the form of a fountain solution film. By the blowing device 7, the dampening solution is evaporated on the surface of the hydrophilic roller 6 and thus removed from the inking unit.

The invention is not limited to this embodiment, since if necessary, a second hydrophilic and further roller with blowing device 7 can be arranged on the ink roller 10 or the hydrophilic roller is incorporated directly into the color strand of the inking unit.

For local dampening dosing the blowing device 7 is provided with rotatable covers 16 which cover or release the blower stream locally as needed.

Claims (4)

1. An apparatus for removing the excess dampening solution in the inking unit of printing machines by means of a blowing device, wherein the inking unit can be connected via an intermediate roll with the dampening unit, characterized in that on a paint roller (5) a hydrophilic roller (6) is arranged, which Blowing device (7) is assigned. 2. Device according to item 1, characterized in that the hydrophilic roller (6) is placed as a rider roll on a paint roller or arranged as a connecting roller in the roll association. -2- 662 Invention claims: 3. Device according to item 1, characterized in that on the blowing device (7) rotatable covers (16) are provided. 4. The device according to item 1, characterized in that the blown air is heatable. For this 1 page drawing Field of application of the invention The invention relates to a device for removing the excess dampening solution in the inking unit of sheet-fed offset printing machines, wherein the inking unit can be connected to the dampening unit via an intermediate roller. Characteristic of the known technical solutions In offset printing, special attention must be given to the damp during the printing process. Equally next to the inking unit for rolling in the printing plate and for later transfer of the printing ink from the printing plate on the blanket on the paper is the dampening unit. Offset printing as a planographic printing process is based on the contrast of printing ink (grease) and water. So that actually only the printed image printed on the printing plate assumes the color, the surface of the printing plate must be moistened before each rolling in with printing ink. This is not to be understood as a fleeting wetting, but rather as evenly as possible, properly dosed wetting with a moisture curtain. Care must be taken to bring only so much moisture on the plate that the non-printing areas assume no color. If there is too little moisture, the plate starts to "tarnish." It becomes dry in places, the image becomes "full" and color transfer takes place at non-printing areas. If too much moisture, the ink absorbs excess dampening solution and emulsifies. The print quality is negatively affected because the color strength is lost, so-called "water flags" arise and drying difficulties can occur. In order to avoid this disadvantage of emulsification, blowing devices that act directly on the dyeing and / or dampening rollers have become known. Such devices have the disadvantage that process disturbances can be caused by the direct blowing on the dampening rollers and on the other hand, these devices have a low efficiency when blowing on the ink rollers, since water and color are mixed together. Object of the invention The aim of the invention is to provide a device for removing the excess dampening solution in the inking unit in order to achieve the color-moisture balance faster and thereby to contribute to reducing the waste content. Object of the invention The object of the invention is to provide a device for removing the excess dampening solution in the inking unit, with the aid of the color dampening solution emulsion dissolved and then the excess dampening solution can be reliably removed. Essence of the invention According to the invention, the object is achieved by a device for removing the excess dampening solution in the inking unit of printing machines by means of a blowing device, wherein the inking unit can be connected to the dampening unit via an intermediate roller, characterized in that a hydrophilic roller is arranged on an inking roller and associated with the blowing device is. The hydrophilic roller is placed as a rider roll on a paint roller or arranged as a connecting roller in the roll association and on the blower rotatable covers are provided.
In addition, the blown air is heatable. The invention advantageously utilizes the principle that hydrophilic rollers (for example chrome rollers), placed on ink rollers or arranged in the ink path between ink rollers, dissolve the emulsion ink / fountain solution. The excess dampening solution is collected on the surface of the hydrophilic roller and can evaporate, whereby the evaporation process is effectively supported by the blowing device. embodiment The invention will be explained in more detail with reference to an embodiment. In the accompanying drawing of the superstructure of a printing unit is shown schematically. The inking unit consists essentially of an ink fountain 1 with the printing ink therein, a ductor 2 and a between ink ductor 2 and a Farbreibzylinder 4 movably arranged ink lifter 3. Up to an inking roller 5 are the Farbreibzylinder4eine first and second ink roller 17; 18 subordinate. The ink roller 5 is associated with a hydrophilic roller 6 in the form of a chrome roller. Above the hydrophilic roller 6, a blowing device 7, which may be connected to the central air supply system of the machine, is arranged. If necessary, the air can be heated by a commercial heater. The ink roller 5 are further Farbreibzylinder 4.1; Subordinated 4.2 and 4.3, via the applicator rollers 8; 8.1; 8.2 and 8.3 are connected to the plate cylinder 9. About two more ink rollers 10 and 10.1 are the Farbreibzylinder 4.1; 4.2 and 4.3 in conjunction. Via a connecting roller 11, the contact with the applicator roller 8.3 and the dampening roller 12 is produced. Below the dampening roller 12, a transfer roller 13 is arranged, which is connected to a dipping roller 15 immersed in a fountain solution box 15.