Sound absorption properties of composites made of discarded duck feathers

A novel composite with good sound absorption properties was prepared by discarded duck feathers and ethylene vinyl acetate copolymer (eva) non-woven fabrics by using lay-up and hot-pressing method. the effects of discarded duck feather concentration,composite density,composite thickness and air cavity depth on sound absorption performance were studied. when the composites with proportion (w/w) of the discarded duck feathers to eva non-woven fabrics of 300/100,density of 1400g/m2,thickness of 20mm,the noise reduction coefficient (nrc) was 0.54. by adding the 30mm air cavity depth,the nrc of the composite increased from 0.54 to 0.76. theoretical models for the prediction of sound absorption coefficients of composites made of discarded duck feathers were presented. the good agreement was obtained by the comparison of measured and calculated absorption coefficient curves. the theoretical models were therefore suitable for the design of discarded duck feather composites with an excellent sound absorption performance.