Research Institute of Forests and Rangelands Iranian Journal of Wood and Paper Science Research 1735-0913 29 Fall 3 2014 09 23 Investigation of the sound absorption properties of gypsum particleboard produced with kenaf stalks and nano clay Investigation of the sound absorption properties of gypsum particleboard produced with kenaf stalks and nano clay 434 442 8481 10.22092/ijwpr.2014.8481 FA Hossein Rangavar Assistant Prof., Wood Science and Technology Department, Shahid Rajaee Teacher Training University, Lavizan, Tehran, Iran Mohammad Hassan Payan M.Sc., Wood Science and Technology Department , Shahid Rajaee Teacher Training University, Lavizan, Tehran, Iran Journal Article 2014 09 29    In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based on dried mass of wooden particles. Sound absorption coefficient determined according to ISO 10534-1 and hardness was measured in accordance with the ASTM D-1037 standards. The sound absorption coefficient was measured at four frequencies of 250, 500, 1000, and 2000 Hz. The obtained results showed that with increasing frequencies, sound absorption coefficient increased. With increasing ratio of kenaf stalk in boards, hardness decreased, but sound absorption increased. Furthermore, increase in percentage of nano clay used in the boards increased the hardness and reduced the sound absorption in coefficient in gypsum particleboard. Generally, the highest sound absorption coefficient was shown the boards produced with 60% kenaf and without nano clay in frequencies of 2000 Hz.    In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based on dried mass of wooden particles. Sound absorption coefficient determined according to ISO 10534-1 and hardness was measured in accordance with the ASTM D-1037 standards. The sound absorption coefficient was measured at four frequencies of 250, 500, 1000, and 2000 Hz. The obtained results showed that with increasing frequencies, sound absorption coefficient increased. With increasing ratio of kenaf stalk in boards, hardness decreased, but sound absorption increased. Furthermore, increase in percentage of nano clay used in the boards increased the hardness and reduced the sound absorption in coefficient in gypsum particleboard. Generally, the highest sound absorption coefficient was shown the boards produced with 60% kenaf and without nano clay in frequencies of 2000 Hz. https://ijwpr.areeo.ac.ir/article_8481_d8feaa0df77788c5b419dc940f5ba701.pdf