Optimization of Acoustical Properties Polyurethane (PU) Wood Fibres Foam Composites

In this study, an optimization approach was proposed to improve acoustical behaviours of PU foams. The important parameters of PU foams: content of the combination of renewable monomer and epoxy as polyol, methylene diphenyl diisocyanate (MDI) as crosslinker. Their effects on sound absorption coefficient of PU foams were studied by using Taguchi methods. In addition, wood fibres were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Three controlled factors: the monomers, wood fibres and sample thickness with three levels for each factor were chosen and Taguchi method based on orthogonal array L9 (33) was employed to conduct the experiments. Based on the results of Taguchi's orthogonal array L9 (33), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU wood fibres foam composites. The results showed that the noise reduction coefficient (NRC) had showed an increased value from 0.4850 to 0.5550 positively improved the acoustic property and the best combination values of variables were monomer mixture of 25 gram, filler ratio of 3% wt and sample thickness of 30mm.