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

Sound-absorbing plasters have had a relative advantage over panels due to their economic efficiency and ease of application, especially on curved surfaces. In this research, a production of plaster was investigating which was consisting of water-based acrylic resin along with Typha natural fiber absorbent and some additives such as foaming agent, which had mixing ratio of 90/10 by weight between binder and absorbent. The effect of length of 0.5, 1 and 2 cm in Typha was measured as a variable factor by static wave impedance tube device with finding the maximum and minimum pressure and calculating the absorption coefficient at four frequencies of 250, 500, 1000 and 2000 Hz. The results obtained illustrated that with the increase in the length of Typha fibers, the absorption coefficients at three frequencies of 250, 500 and 1000 Hz increases visibly, as far as at the frequency of 500 Hz, the use of 2 cm Typha fibers caused about a 60% sharp increase in the absorption coefficient. At the same situation, the effect of length of Typha fibers did not lead to any difference in the frequency of 2000 Hz.