Basic Study on Evaluation Method of Thermal Conduction through Printing Papers using 1-Dimensional Thermal Conductivity Measurement

This study targets to develop a 1-dimensional evaluation method of thermal conduction process around printing papers in DTP (Direct Thermal Printing) process. Our special attention was paid to investigate an evaluation method of thermal conductivity and contact thermal resistance of the printing papers. The evaluation of thermal conductivity of the printing papers is generally difficult because thermal conductivity of the papers is small like insulation. In addition, contact thermal resistance between the thermal head and the papers cannot be measured directly. Therefore, in this report, the clarification of the level of the thermal conductivity and the contact thermal resistance were targeted by using 1-dimensional thermal conductivity measurement system. From the measurement of the equivalent thermal conductivity, the level of the difference of the thermal conductivity and the contact resistance of the paper was investigated. In addition, the optimum pressing pressure of the platen roller in order to minimize thermal contact resistance is clarified.