Ink temperatures in resistive ribbon thermal transfer printing
by T. C. Chieu, O. Sahni
A knowledge of ink temperatures is important in thermal transfer printing technologies. This paper reports on an experimental technique which uses an infrared radiometric microscope to measure the temperature of ink deposited by the resistive ribbon process on transparent substrates. A detailed examination has been made of the spatial and temporal profiles of ink temperatures as a function of input current, printing speed, substrate materials, and number of active electrodes. The results on a ®Kapton substrate permit estimation of the ink temperatures reached during printing on paper. The peak ink temperatures are observed to depend linearly on input current and inversely on an approximately linear function of writing speed from 2 to 8 inches per second. Based on a phenomenological model, these results lead to a functional relationship among speed, print current, and ink temperature during printing. The model permits projections to be made of the current required over a wide range of printing speeds.