Sound absorbing material, muffler using the sound absorbing material, and method for forming sound absorbing layer thereof

摘要

In order to provide a sound absorbing material superior in acid resistance, alkali resistance and sound absorbing quality and a sound absorbing layer using this sound absorbing material, multiple pieces of basalt yarn (1a) obtained by dissolving basalt to be continuous fibers are bundled by a fiber bundling agent to acquire a bundled material (1), and the bundled material (1) is fibrillated to obtain a bulky sound absorbing material (2). Moreover, the sound absorbing material (2) is arranged on the outer periphery of a perforated pipe (4) constituting a muffler to form a sound absorbing layer (6).