Investigation of thermal conductivity of natural fibres processed by different mechanical methods

The article presents the results obtained during investigation of thermal conductivity at mean temperature of 10°C, macro- and microstructures of differently processed natural fibres. Natural fibres were processed into various types of fibres: long and short flax, long and short hemp, long and short combed flax, long and short combed hemp, chopped flax, chopped hemp, chopped peat. Samples of natural fibres with varying density from 39,6 kg/m 3 to 102,5 kg/m 3 , thermal conductivity, respectively, varies from 0.0599 W/(m·K) to 0.0341 W/(m·K). Measurements of thermal conductivity were performed in conformity with requirements of EN 12667, EN 12939 by use of device Fox-304 (Laser Comp. USA). Macro- and microstructures investigations were carried out by optical and scanning electron microscopes. The empirical equations were suggested for determination of density of natural fibres. The paper describes the manufacturing possibilities with regard to thermal insulating materials based on natural fibres from easily renewable material resources provided by the agriculture.