Topic of your interest

Mackle and CO2 savings through paper-dependent pre-adjustment of sheet-fed offset presses

Short name: Mackle savings in sheet-fed offset presses

Fogra no. 34.022
Project leader: J. Gemeinhardt
Funding: BMWi (IGF) via AiF

 

Timescale: 01.09.2020 - 31.08.2022

Objective and relevance

The individual behaviour of the papers to be printed is not known to the printer in advance. Consequently, the required setting must be determined on the running printing machine. This requires a certain number of prints. This so-called mackle cannot be sold and increases production costs as well as CO2 emissions due to the additional material consumption.

Within the scope of the research project, a new paper characteristic value is to be established with which predictions can be made about the solid tone densities and tone value increases to be expected in the sheet-fed offset process. Furthermore, a method is to be specified with which reproducible and comparable results can be achieved in different paper laboratories.

Jürgen Gemeinhardt

Head of Printing Techniques

+49 89 431 82 - 256

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I would be pleased to answer your questions about the project and look forward to exchanging ideas with you.

Solution steps

The basis for the paper characteristic value to be established is the solid tone densities of laboratory prints with a special test ink at a specific ink film thickness. In order to compensate for fluctuations in the measured values, inking series must be carried out from which the characteristic values are to be derived by means of a polynomial fit.

Furthermore, a procedure is to be developed how the characteristic value can be adapted to different ink-paper systems in practice. Extensive print tests on a sheet-fed offset press are planned to determine correlations with the solid tone densities and tone value increases.

Targeted results

The research results are to be incorporated both in international standardization and in the daily practice of sheet-fed offset printing. The incorporation of the research results into standardization is to be achieved by supplementing the already existing ISO 15397 in the form of an additional paper characteristic value.

A concrete implementation in practice can happen as follows: Paper manufacturers determine the new characteristic value to be established and specify it in addition to the otherwise usual paper specifications. Printers store this characteristic value in their workflow system, where it is used for automatic presetting of the printing units. In order to achieve the desired printing results, a one-off calibration to the ink series used must take place in advance.