2022 Volume 30 Issue 2 Pages 45-59
Although thermal insulation paper has attracted attention from various industrial fields, there are very few reports on its thermal conductivity at present. Especially, there are few examples of measuring the thermal conductivity with single sheet of thermal insulation paper, and there are no reports on the thermal conductivity in the in-plane direction where fibers are extremely strongly oriented. Therefore, a method for simultaneously measuring the thermal conductivity in the thickness and the in-plane directions using the heat flow separated method which have been developed in the preceding research was examined. The measurement apparatuses for large size (300 mm × 300 mm) and for small size (150 mm ×150 mm) have been developed based on our principle. And, the dependence of the size of the specimen and the measurement accuracy were examined by comparing the results of both. Furthermore, the obtained results were compared with those by Guarded Hot Plate (GHP) method. In addition, the uncertainty analysis of the proposed measurement method was carried out, and it was shown that both the measurement uncertainty of thickness and in-plane directions were about 6 % and 13 %, respectively.
