Cattail- luffa fibre reinforced and rice stubble ash filled composites for acoustic applications

Abstract

The possibility of using fibro-granular acoustic composites for the sound absorption of a wide range of
frequencies through an experimental approach has been explored. The fibrous materials (cattail and luffa fibre) and
granular materials (rice stubble ash) are used for the manufacturing of acoustic boards. The use of toxic binders,
such as phenol-formaldehyde, polyester foams and polyurethane, has been eliminated in this modified method to
manufacture acoustic panels through a sustainable development route. The extraordinary free space available in the
network of luffa fibres has been utilized to hold the rice stubble ash particles binder and still left free space are
used for effective sound absorption. The prepared samples are tested mainly for density, pore size and sound absorption
coefficient. The findings show that the developed panels have a density of 80 kg/m3 and pore size of 110 μm, which
are effective in absorbing both low and high-frequency sound waves within the acoustic frequency range 63 −6300 Hz.
The sound absorption coefficient of these panels is found more than 0.8, which is comparable with commercially
available acoustic boards. These eco-friendly acoustic panels, made of agricultural residues such as cattail fibre, luffa
fibre and rice stubble waste, do not require significant capital to make a green utilization of waste materials for
product development.