Estimating the Thermal Properties of Flat Products by a New Non-contact Method

A new non-contact method dedicated to identifying the mechanisms of heat transfer through a flat sample is described. The method consists in measuring the infrared radiation emitted from both sides of a flat sample at the same time using two infrared mirrors and a thermovison camera. The temperature - time characteristics recorded are analysed and by their shape and mutual position, the existence of thermal conduction, convection and infrared radiation is identified. A measuring stand as well as standard samples of specific structure special design for the purpose of this investigation are described The method can be used for flat samples of every kind but is especially devoted to textile applications. Temperature - time dependencies characteristic for a standard sample as well as a hemp-fibre stitched nonwoven are presented and discussed Criteria for determining the heat transfer mechanisms are listed, and directions for further development of this method are proposed.