Thermal Conductivity Improvement of Fiber Orientation Control By Sheet Folding Method

Abstract

In this study, a method improving the thermal conductivity in the sample thickness direction by secondary processing of an intermediate sheet in which carbon fibers were oriented in one direction was proposed. Moreover, the effectiveness of the proposed method was experimentally investigated. When fillers having a large aspect ratio such as carbon fibers are added to the polymer matrix, the thermal conductivity of the composites is largely influenced by the filler orientation. Therefore, it is necessary to orient the filler in the out-plane direction to effectively improve the thermal conductivity in the thickness direction of thermal conductive film or sheet. In the experiment, a zigzag shape was given to the intermediate sheet, and a sample with a thickness of 1 mm was obtained by folding the intermediate sheet. As a result, the thermal conductivity in the sheet thickness direction measured by the laser flash method became five times larger than that of the initial sample, the intermediate sheet.