Drop-on-Demand technology

High speed and high resolution

We distinguish between three inkjet technologies:

1. The oldest of these technologies is continuous inkjet. It is characterized by high jet frequencies and correspondingly elevated printing speeds. Print resolution is up to approx. 300 dpi, while nozzle diameters vary between 5 and 42 micron. Non-conductive water or MEK inks are used; the inks are usually dye-based.

2. The most widespread D-D technology, and one that dominates the desktop sector, is thermal inkjet. Drops are generated by the rapid heating and expulsion of drops (of volume 3 to 50 pl) from a nozzle. Water and solvent-based inks can be used in principle, but dye-based inks predominate, some of them pigmented, particularly black. At low speeds photorealistic prints of one to two DIN A4 pages can be achieved on special inkjet paper.

3. The third process is piezo inkjet. In this case the drops are generated from a chamber by means of the piezoelectric effect. Piezo technologies are used primarily in the industrial sector. Fast-drying UV inks are the main ones used, as these are essential for rapid finishing processes. Two variations in particular are distinguished: the ‘shared wall’ process and the ‘roof shooter’ process. Shared wall technologies are characterized by printing speeds of up to 30 m/min at a resolution of up to 360 dpi, while some roof shooter technologies allow much higher speeds that could reach 150 m/min at 600 dpi.
Both technologies can handle a variety of ink systems (water or solvent-based inks, UV inks), depending on the manufacturer and product type. It is normally pigmented inks that are used. Piezo inkjet is the only process that can handle any ink system and even other liquids.

Depending on the customer’s requirements, Linoprint systems employ technologies from Konica Minolta, Xaar, Panasonic, TOSHIBA TEC or Dimatix. Linoprint integrates the individual modules into complete printing systems that can be adapted to the particular application in printing width, resolution and speed.

The Linoprint printing system comprises the DoD printing unit itself, a cleaning unit, a UV dryer, the data and drive electronics, the ink supply, the operating and workflow software and the mechanical-electrical integration into the packaging machine.