Patent ID: 9190046
Filing Date: 2015-11-17
Classification: D21H,G10K

Abstract:
1. A sound absorbing sheet comprising a base material, and having a noise reduction coefficient of 0.4 or higher in a frequency range from 200hertz (Hz) to 2000 Hz obtained by Pipe Method (KS F 2814), wherein the base material comprises 30 weight percent (wt %) to 60 wt % glass fibers, 40 wt % to 70 wt % cellulose fibers and 2 wt % to 10 wt % synthetic organic fibers, wherein 90 wt % or more of the cellulose fibers have a diameter from 5 μm to 100 μm and a length from 1 mm to 50 mm, wherein the base material has a thickness from 0.1 mm to 0.7 mm, and wherein the sound absorbing sheet further comprises pores having an average pore diameter size from 10 μm to 50 μm.