Utilization of alternative raw material sources from agriculture for the production of insulating materials

Abstract

Thermal insulating materials based on natural fibres currently represent a progressive direction in the area of thermal insulations, particularly from the viewpoint of sustainable development in the area of the production of building materials and construction because it concerns materials based on an easy-renewable and locally available raw material base. In existing constructions, these materials may well replace other thermal insulating materials (e.g. EPS or mineral wool), which are more demanding in terms of energy and raw materials (Zach and Hroudova 2010b). The main use of these materials is primarily in so-called healthy constructions, i.e. in constructions where traditional construction technologies and natural construction materials are used which by their thermal moisture behavior is close to the demands of the human body. From the viewpoint of utility properties, insulating materials on the basis of natural fibres have very good thermal-insulating properties, good mechanical properties and low eco-toxicity (Zach and Hroudova 2010a; Uihlein, and Ehrenberger at al. 2010). The article addresses the complex evaluation of the production of thermal insulating materials on the basis of natural fibres, mainly flax and hemp. According to implemented measurements it was find out, that insulating materials on the basis of natural flax and hemp fibres dispose of very good thermal insulating properties. Measured values of thermal conductivity of test specimens range between 0,0368 and 0,0419 W.m-1.K-1 (in dependence on bulk density and type of fibres). Next finding was that specimens with higher content of flax fibers have better thermal insulating properties comparing to samples with higher amount of hemp.