تاثیر طول الیاف استبرق بر ویژگی جذب صوت پلاستر با رزین پایه آبی

Today, there is a tendency to make a type of wall covering called plaster in order to reduce noise pollution, which is applied in the form of a paste and has a lower cost. The formulation of theses plasters is based on industrial resins. In the current research, a type of water-based resin was used in the plaster as binder and adhesive as well as some natural fiber filler called Stabragh. The resin used here also caused damping affect in effective frequencies due to its viscoelastic properties. Due to having hollow channels and a porous structure, the fibers of Stabargh were able to further reduce the sound energy. In this research, the effect of changing the length of dried natural fibers was investigated on increasing the sound absorption coefficient. The results obtained from impedance tube illustrated a noticeable increase in the absorption coefficient with enlarging the size of fiber length. Therefore by changing the length of the fiber from 1 cm to 2 cm in the frequency of 500 and 2000 Hz, the absorption coefficient increased by about 10%.