- Digital Printing System for thermoformed sheets and films
- System addresses drawbacks of conventional screen printing
- Flexible forming after printing
The German company Thieme has introduced an innovative digital printing system for the printing of sheets and films which can then thermoformed or back-injection moulded. The employed HydroGel technology combines very high printing quality with low printing costs.
System addresses drawbacks of conventional screen printing
Until now, films which were thermoformed or back-injection moulded after printing could only be printed by screen printing. However, the reproduction of colour gradients or fine fonts is possible only to a limited extent. In addition, set-up costs are higher if smaller batches are processed. The new digital printing system of Thieme addresses these drawbacks.
THIEME 505D digital printing system for thermoformed films (source: Thieme)
The new printing system employs the so-called HydroGel process which was developed in cooperation with ink manufacturer Tritron. Different from the conventional printing process where ink is fixed by means of UV light, the HydroGel process uses water-based inks which are applied “drop by drop” onto the surface using a special liquid that was applied beforehand in an inkjet process with pinpoint accuracy. The ink drop gels when it gets contact with the pre-treatment. Equipped with 7-pl printing heads, the machine allows high printing resolution at a consistently high printing speed.
Comprehensive solution of ink and technology
For the HydroGel process, the Thieme digital printing machines are equipped with special additional functions, including automatic capping of the printheads which prevents the drying of water-based printing inks. In addition, the machines feature automatic printhead cleaning, and extraction and explosion protection measures for safe processing of the alcohol-based fixing liquid.
Flexible forming after printing
Typical applications of the new digital printing process include the foil printing of buttons and control panels in medical devices and automotive. Here, the film is first printed in a flat state on the back and then brought to the desired shape by means of thermoforming. Finally, the film can be back-injected with plastic. The HydroGel print is temperature resistant, so even higher temperatures during thermoforming do not pose a problem. The technology is also suitable for other applications, such as credit card making, where laminating operations are performed at high temperatures.
After successfully using a Thieme 3020 D digital printing machine with HydroGel technology, the company has now also adapted the process for smaller print formats. The existing THIEME 500 D machine series was completely revised. Available now are Thieme 505 D (max print size 400 x 600 mm) and 510 D (630 x 730 mm), both optionally with UV or HydroGel equipment.