Topic of your interest

Edge angle injection

Modelling of colour rendering properties for highspeed inkjet printing and establishment of suitable characteristic values for paper

Short name: Papers for highspeed inkjet

Fogra no. 42.031
Project leader: J. Gemeinhardt
Funding: BMWK (IGF) via AiF
 

Timescale: 01.03.2019 - 31.05.2021

Forschungsbericht

Objective and relevance

In the interests of efficient print production, it is not possible with highspeed inkjet to readjust the printing machine or create an individual media profile every time the paper is changed. This would take up many times the actual production time and make the job unprofitable.

Therefore, within one paper category, printing is usually done with the same settings, although the solid tone colouration and tone value increases achieved can differ significantly. If corresponding changes occur with a new paper, the desired colour appearance of the print product will be missed even with identical paper colour.

Jürgen Gemeinhardt

Head of Printing Techniques

+49 89 431 82 - 256

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Contact

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

Solution steps

In order to reduce the time required to set up the inkjet machine and at the same time ensure colour reliable print production, the research project aims to establish suitable paper parameters. For this purpose, a large variety of paper is to be printed with different highspeed inkjet machines. The print results will be compared to extensive laboratory tests and examined for correlations.

In addition to the standard paper characteristics, the paper tests to be performed include numerous additional properties. These include drying time, local colour fluctuations, surface geometry, spreading, penetration and lateral light scattering.

stack of paper

Achieved results

The correlations determined are different for all the presses examined. In addition to the presence or absence of a coating, the most relevant paper properties were gloss, print-surf roughness, roughness values, light scattering and light absorption coefficients, oil absorption, contact angle parameters along the grain direction and specific pore volume.

These variables alone often allow a rough prediction of the printing result. An improvement of the correlations can additionally be achieved by including the thickness, the grammage, the specific volume or the sheet density, the ash content, the water absorption, the absolute water content as well as the contact angle parameters perpendicular to the grain direction.