In the thermal printing process, the words or images are produced on the thermal paper by means of direct heat transmission.
This is done by the printer’s thermal head, which consists of numerous little heating elements. The heating elements are electronically controlled and produce thermal energy which activates a color reaction on the functional thermocoating. The numerous little dots this produces then go to make up letters, barcodes, and images.
Thermal printers have a relatively simple design and are easy to operate, which makes them considerably less susceptible to breakdowns. They are energy-saving, quiet, fast, small, and compact – and they require no other consumables, which in turn saves money and makes them highly reliable. They keep working even under extreme conditions.
Koehler thermal paper consist of a high-quality base paper which has been developed by us specially for thermal technology. While this paper is still in the paper machine, a pre-coating (Z coating) is applied which provides the foundation for high quality images, prevents heat from being conducted into the paper itself, and helps safeguard the sensitivity of the thermocoating which is applied on top of it.
The thermal coating is then applied in the coating machine. It contains the principal functional components such as the color-forming substances and color developer. The thermal printer applies points of heat to the thermocoating, thus producing a chemical reaction that makes the lettering or image appear.
Thermal paper can also be given a protective coating on the front or back. A coating on the front (topcoat) is useful if the paper is to be exposed to mechanical wear, chemical influences, or environmental influences. A coating on the back (backcoat) provides additional protection when printing, laminating, and much more.
Blue4est® is the innovative thermal paper from Koehler. It is guaranteed to be free of chemical developers and can easily be used in any conventional thermal printer. Instead of a chemical reaction to heat, the emergence of text on our new Blue4est® thermal paper is a purely physical reaction. The paper’s opaque functional layer turns transparent due to the effects of heat, and the black layer beneath it is revealed.