Patent ID: 8387747

Claim:
A soundproof panel comprising a first nonwoven structural member in the form of a board comprising a plurality of thermal adhesive fibers melt bonded under moisture with a thermal adhesive resin forming a continuous area of the surface of the fibers in a longitudinal direction thereof, wherein the thermal adhesive fibers are arranged in a direction approximately parallel to a surface direction of the first nonwoven structural member, and a honeycomb member having a honeycomb structure, wherein the first nonwoven structural member has a bonded fiber ratio of 3 to 85% and an apparent density 0.05 to 0.7 g/cm 3 , wherein the bonded fiber ratio is 3 to 85% in each of three areas and the proportion of the minimum value relative to the maximum value among the bonded fiber ratios in each of the three areas is not less than 50%, providing that the three areas are obtained by cutting the first nonwoven structural member in the thickness direction for giving a cross section, and dividing the cross section in a direction perpendicular to the thickness direction equally into three, wherein the first nonwoven structural member has a maximum bending stress of not less than 0.05 MPa in at least one direction, and a bending stress of not less than 1/5 of the maximum bending stress at 1.5 times as large as a bending deflection at the maximum bending stress, wherein the soundproof panel has a coefficient of sound absorption from 500 to 5000 Hz that is greater than the cumulative coefficient of sound absorption of the first nonwoven structural member and the honeycomb member.