Process to attenuate sound waves, laminate, and false-fabric sound insulation veil

摘要

A method for attenuating sound waves passing from a source area to a receiving area comprises the steps of providing a nonwoven acoustical insulation web comprising thermoplastic fibers, the web having an average effective fiber diameter of less than about 15 microns, a density of less than about 50 kg/m3, and an air pressure drop across the web of at least about 1 Mm water at a flow rate of about 32 liters/min.; and positioning the web between the source area and the receiving area such that a major face of the web intercepts and thereby attenuates sound waves passing from the source area to the receiving area. Also, a laminate adapted to be applied to the inner panel of a vehicle door comprises the web and a second layer, such as a scrim, nonwoven fabric, film, or foil, laminated thereto. The laminate can be applied to the inner panel of a vehicle door so that the second layer provides water barrier protection and the web provides acoustical insulation. Also, a nonwoven acoustical insulation web comprising thermoplastic fibers, the web having an average effective fiber diameter of less than about 15 microns, a density of less than about 20 kg/m3, and a pressure drop of at least about 1 mm water at a flow rate of about 32 liters/min. The web typically comprises melt-blown microfibers and crimped bulking fibers in a weight percent ratio of about 40:60 to about 95:5, respectively.