Physical properties of glass fiber felt: role of multi-layer morphology

In this work, glass fiber felt (GFF) was prepared via wet beating method to explore the correlation between the physical properties (air permeability, thermal conductivity and acoustic property) and microstructure. The consequence presents that increasing the layers of GFF could enlarge the average pore size, but almost have no effect on air permeability. It also finds that the thermal insulation property and acoustic property could be enhanced via the increase layers of GFF. More the layers leads to a superior sound insulation property. This is because that layered structure can avoid thermal bridge to reduce thermal conductivity. Besides, the comparatively big mismatching among characteristic acoustic impedances (CAIs) of layered structure result in multi-reflection, which will causing the increasing of acoustic property.