How a Thermal Transfer Ribbon Printer works

The thermal transfer process is accomplished in a thermal transfer printer by applying a voltage to the printhead that consists of 200 to 600 resistive heating elements per linear inch of printhead (dpi-dots per inch). The resistive material is covered by a thin coating or "glaze" that protects the heating elements from abrasion as the thermal transfer film makes contact with it.

The line of printhead elements is in direct pressure contact with the back side of the thermal film. The ink side of the thermal film is in direct contact with the receiver (ribbon). This thermal film and receiver "sandwich" is driven by a rubber-covered platen roller under the printhead print line at a speed consistent with the heating cycle time of the printhead.

Heat from the printing elements raises the ink to a temperature above its melting point. At this time the ink from the thermal film transfers to the receiver and adheres to it. Together, the thermal film and receiver continue to move from under the printhead for a short distance before separation of thermal film and receiver occurs. It is at this point that the image is formed. The text is permanent, water resistant and will not run.