Sheet-fed UV Printing Small Experience: Use of Cleaners

Different inks require different cleaning solvents. Cleaners and chemicals for rolls, blankets, and coating plates require:

Chemically compatible

Meets environmental and toxic standards

Effective cleaning

For traditionally-printed mineral oil based cleaners, the removal of UV inks requires polar solvents (glycol ethers). For mixed-mode applications, there are other combinations of cleaning agents (for use with UV and traditional inks) - it is also possible to use two separate systems, one for UV and one for conventional cleaning agents. Non-classical UV (hybrid) requires a specific cleaning agent.

1 Use only tested and approved cleaning agents

2 Make sure that the correct cleaning agent is used in the ink system (such as traditional ink, UV ink, UV mixed ink)

3 Check the questions in accordance with compatibility before use

For all print applications, it is of utmost importance to use only cleaning agents that have been audited by the printing press manufacturer; audited and Fogra certified cleaning agents for various sheetfed presses. Fogra tested the compatibility of cleaners with rubber rollers, blankets, cleaning devices and other parts of the press.

Depending on the combination of materials used (substrates, inks, blankets and roller covers), the cleaning system (brush roller or cloth type) and the type of cleaning agent, it is also important to select the correct cleaning procedure and cycle time.

Printers who use the standard four-color ink set and rarely make changes often find it necessary to use a cleaning agent for the combination process. However, for a wide range of inks and often changing conditions, some printers have two containers - one for blanket cleaners and one for roller cleaners. These two additional containers are useful in a half-to-half combination process that separates UV from conventional blankets and roller cleaning solutions.

Cleaner efficiency comparison

From the comparative test of the efficiency of the cleaning agent, it can be seen that the cleaning agent of the oil ink has an excellent effect and the effect on the classic UV ink is also satisfactory. Tests of non-classical UV (mixed) cleaners can only achieve poorly-justified results - however, the cleaning agents being developed for these inks will improve performance.

Expansion test

This simple experience shows that aggressive cleaning agents can swell rubber compounds. Three rubber samples were immersed in the three detergents and the sharpness increased from left to right. After a soaking time of 10 hours, the sample in the right tube swelled considerably, while the left one remained almost unchanged.

The test results are summarized as follows:

Traditional Ink: Using a cleaning device with the most commonly used cleaning agent is generally sufficient for achieving good results.

Classic UV ink: Use a suitable UV cleaning agent to quickly and effectively clean; use a cleaning device to clean the UV ink with a combination of cleaning agents, and only get a good cleaning effect once.

Non-classic UV (hybrid) inks: Conventional cleaning agents or cleaning agents for classic UV inks are not suitable for removing these inks from blankets or rollers. There are also specialized UV UV cleaning agents, most of which are based on vegetable oils and have a high flash point.