Patent ID: 7677359
Filing Date: 2010-03-16
Classification: E04B,G10K

Abstract:
1. Sound absorbent of a hard material for absorption of acoustic waves by friction of viscous flow, essentially in the frequency range between 100 and 4000 Hz, comprising a panel element constructed and arranged for mounting at a predetermined distance from a rear surface, creating a space therebetween, the panel element having a predetermined thickness (t), and having microslits therethrough, each said microslit having a predetermined length (L) and width (b), the width (b) being substantially uniform throughout the length (L) thereof and throughout the thickness (t) of the panel, and each said microslit having a width (b)≦0.45 mm, wherein each said microslit has a ratio (L):(b) between the length (L) and the width (b) of at least 50.