An optical light reflectance measurement system above an imaging member surface measures fountain solution surface light reflectance interference on reflective substrate portions of the imaging member surface in real-time during a printing operation. The measured light reflectance interference corresponds to a thickness of the fountain solution layer and may be used in a feedback loop to actively control fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during a printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

According to aspects of the embodiments, there is provided a method of determining the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is determined by examining optical density of some halftone or solid patch versus laser current level. The apparatus and method uses a variable current signal to dither or perturb the laser imaging system to irradiate a fountain solution layer to create patches at different laser current levels. An aptly programmed controller then process optical density measurements to indirectly estimate fountain solution level.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured using a glass roll at a lower temperature than the fountain solution. The lower temperature causes the fountain solution to undergo a change in state and in a solid state the fountain solution crystalizes and changes roll opacity with the thickness of the film. When radiated with a light source the opacity is continuously measured through the surface of the roller. The thickness of the crystallized fountain solution can then be determined via the opacity level increase by the crystallization and the impact to the opacity on the glass roll.

In some examples, an ink feed system for providing and feeding printing ink to an inking unit of an intaglio printing unit includes an inking device in the inking unit for inking a first inking unit cylinder. A provision device includes a storage receptacle with an ink reservoir of printing ink that is fed via an outlet and a line to the inking device. Furthermore, a wall of the storage receptacle encompassing the outlet can be heated and/or a metering device may be provided in the line path to support and/or effectuate delivery of the printing ink from the storage receptacle. On an output side, the metering device may provide a mass flow or volume flow that correlates with a working speed of the metering device via a defined relationship, and the metering device may be connected to a control device to control the working speed of the metering device.

A method for operating a printing material processing machine by using a computer includes acquiring print job parameters from print jobs for the printing material processing machine and machine parameters by using the computer, evaluating the acquired parameters to determine the machine state by using the computer, and requesting and providing fluid consumable materials for optimizing the operation of the machine on the basis of the determined machine state by using the computer. Maintenance measures carried out on the machine are optimized on the basis of the determined machine state, by using the computer.

A method is provided for setting a layer thickness of a covering coating material to be applied to a substrate by an application device. The coating material is applied to the substrate in a printing machine or in a paper-processing machine. The coating material is applied at various points on the substrate by the use of the application device in a machine process. At each of at least one first point on the substrate, the coating material is applied in a grid having a plurality of grid points, and at each of at least one other second point on the substrate, the coating material is applied over the full area. Each first point on the substrate forms a grid zone and each second point on the substrate forms a solid zone. A control unit connected to a sensing device determines respective values of the optical density of the layer of the coating material applied on the points on the substrate using data captured by the sensing device at the first and second points on the substrate. The control unit defines the layer thickness of the coating material currently applied to the substrate by the application device in an ongoing machine process. At the defined thickness, the value of the optical density determined in a grid zone corresponds to the value of the optical density determined in a solid zone, as the layer thickness of the coating material having an opacity of 100%.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is measured using a glass roll at a lower temperature than the fountain solution. The lower temperature causes the fountain solution to undergo a change in state and in a solid state the fountain solution crystalizes and changes roll opacity with the thickness of the film. When radiated with a light source the opacity is continuously measured through the surface of the roller. The thickness of the crystallized fountain solution can then be determined via the opacity level increase by the crystallization and the impact to the opacity on the glass roll.

According to aspects of the embodiments, there is provided a method of determining the amount of fountain solution employed in a digital offset lithography printing system. Fountain solution thickness is determined by examining optical density of some halftone or solid patch versus laser current level. The apparatus and method uses a variable current signal to dither or perturb the laser imaging system to irradiate a fountain solution layer to create patches at different laser current levels. An aptly programmed controller then process optical density measurements to indirectly estimate fountain solution level.

An optical light reflectance measurement system above an imaging member surface measures fountain solution surface light reflectance interference on reflective substrate portions of the imaging member surface in real-time during a printing operation. The measured light reflectance interference corresponds to a thickness of the fountain solution layer and may be used in a feedback loop to actively control fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during a printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

A method is provided for setting a layer thickness of a covering coating material to be applied to a substrate by an application device. The coating material is applied to the substrate in a printing machine or in a paper-processing machine. The coating material is applied at various points on the substrate by the use of the application device in a machine process. At each of at least one first point on the substrate, the coating material is applied in a grid having a plurality of grid points, and at each of at least one other second point on the substrate, the coating material is applied over the full area. Each first point on the substrate forms a grid zone and each second point on the substrate forms a solid zone. A control unit connected to a sensing device determines respective values of the optical density of the layer of the coating material applied on the points on the substrate using data captured by the sensing device at the first and second points on the substrate. The control unit defines the layer thickness of the coating material currently applied to the substrate by the application device in an ongoing machine process. At the defined thickness, the value of the optical density determined in a grid zone corresponds to the value of the optical density determined in a solid zone, as the layer thickness of the coating material having an opacity of 100%.