Analysis of Sheep Wool-Based Composites for Building Insulation

Abstract

The aim of this paper is to propose ecological thermal insulation materials that meet the goals of sustainability but also fulfill the imposed thermal performance requirements. This paper studies new composite materials based on sheep wool from the perspective of thermal conductivity. The composites were prepared using two types of binder: acrylic-polyurethane resin and natural rubber latex, which were applied to the wool fibres through different methods and percentages. Based on the obtained results of thermal conductivity, two types of samples were selected for further analysis, which aimed to determine the microstructure, chemical composition, water absorption, attack of microorganisms, water vapour permeability, hygrothermal adsorption characteristics and sound absorption of the samples. In order to analyse the variation of thermal conductivity, the following parameters were taken into account: thickness, density, type of binder and percentage of binder. Following the obtained results, it was observed that the value of the thermal conductivity of the samples varies between 0.0324 and 0.0436 W/mK. It was found that all the samples prepared and analysed in this study fulfil the national criteria for the thermal performance of thermal insulation material. After conducting the in-depth analysis of the two selected sample types, it was concluded that both materials have good sound absorption characteristics over the considered frequency range. In addition, as it was expected from the natural fibres, the samples had low resistance against the attack of microorganisms and water-related tests.

Mechanical and radar absorption properties of sheep wool/epoxy composites

“…In addition, the formation of subsurface critical cracks is another factor that the material used should withstand. E-Glass, carbon and Kevlar are the main laminated polymeric composite materials used for the radome (Danzer et al, 2008).…”

“…Nevertheless, some articles of other investigators show us that wool could effectively be used with that aim (Goncalves et al, 2004) Thermal insulation properties of sheep wool were also studied as a renewable resource in building construction. As well as its insulation properties, economics and the scale production were also considered (Bosia et al, 2015;Corscadden et al, 2014;D enes et al, 2022;D enes et al, 2017). Some patented commercial products are currently available.…”

“…Recently, there has been a significant increase in the amount of studies in this field (Fiore et al , 2020). Among natural fibers, sheep wool has several advantages over other fibers such as hydroscopic, neutralizing pollutant and high temperature of ignition (Dénes et al , 2022). Thanks to their specific properties, sheep wool fibers receive increased attention nowadays, especially as reinforcement for cementitious or plastic matrices.…”

The Application of Sheep Wool in the Building Industry and in the Removal of Pollutants from the Environment

“…The conclusion was that wool can replace, to some extent, the hydrocarbon-based products. In a follow-up work, the authors, Dénes et al [29], investigated the thermal and acoustic conductivity of two types of composites made of wool, on which they applied an acrylicpolyurethane resin and a natural rubber latex as a binder using different methods and in different quantities. The following analysis included the determination of the following parameters: the microstructure, chemical composition, water absorption, attack of microorganisms, water vapor permeability, hygrothermal adsorption characteristics and sound absorption (125-2000 Hz) of the samples.…”

Investigation of Physical Properties of Polymer Composites Filled with Sheep Wool

“…Conversely, these panels demonstrated higher sound absorption coefficients than the GW samples, only at lower excitation frequencies (from 250 to 500 Hz). Dénes et al [ 34 ] studied the sound absorption properties of polymer–sheep wool composites that were prepared using two types of binders (i.e., acrylic–polyurethane resin and natural rubber latex). The composites were produced with uniform wool concentration across the binders.…”