3m Innovative Properties Company

Seungkyu Lee

Jonathan H Alexander

Michael R Berrigan

Thomas P Hanschen

Ronald W Gerdes

Thomas Herdtle

Michael S Wendland

Hassan Sahouani

Paul A Martinson

Michelle M Mok

Megan A Creighton

John Stuart Bolton

Nicole D Petkovich

Thomas P Hänschen

Provided are acoustic articles, and related methods, that include a porous layer and heterogeneous filler received in the porous layer. The heterogeneous filler can include clay, diatomaceous earth, graphite, glass bubbles, polymeric filler, non-layered silicate, plant-based filler, or a combination thereof, and can have a median particle size of from 1 micrometer to 1000 micrometers and a specific surface area of from 0.1 m/g to 800 m/g. The acoustic article can have an overall flow resistance of from 100 MKS Rayls to 8000 MKS Rayls. The acoustic articles can serve as acoustic absorbers, vibration dampers, and/or acoustic and thermal insulators.

Acoustic articles and methods thereof

Provided are acoustic articles having a porous layer () placed in contact with a heterogeneous filler comprising porous carbon and having an average surface area of from 0.1 m/g to 10,000 m/g. The acoustic articles can have a flow resistance of from 10 MKS Rayls to 5000 MKS Rayls. Optionally, the porous layer includes a non-woven fibrous layer or a perforated film having a plurality of apertures with an average narrowest diameter of from 30 micrometers to 5000 micrometers. The heterogeneous filler can enhance low frequency performance without significantly compromising high frequency performance, thickness or weight.

Acoustic article and related methods

Provided are conduits for air flow that are capable of reducing noise and related methods. The provided conduits include a first section that is tubular and substantially non-perforated and a second section with at least a portion having a multiplicity of microperforations that provide an average flow resistance of from 50 MKS Rayls to 8000 MKS Rayls therethrough. The second section is either (a) tubular and connected in series with the first section, with an outer surface of the second section being in fluid communication with an outer surface of the conduit, or (b) disposed within the first section.

Microperforated conduit

Provided acoustic devices include an external housing defining an expansion chamber and a wall extending through and partitioning the expansion chamber into a central chamber and a peripheral chamber adjacent the central chamber, wherein an inlet and outlet communicate with the central chamber, and wherein the wall includes a plurality of apertures formed therethrough to allow air movement to and from the central and expansion chambers, the plurality of apertures sized to provide an average flow resistance ranging from 100 MKS Rayls to 5000 MKS Rayls. The acoustic devices advantageously show significant sound attenuation while streamlining air flow to reduce pressure drop across the expansion chamber.

Acoustic device

Growing community of inventors

Woodbury, MN, United States of America

Seungkyu Lee