3m Innovative Properties Company

Other

Jonathan H Alexander

Michael R Berrigan

Thomas P Hanschen

Seungkyu Lee

Ronald W Gerdes

David F Slama

Thomas Herdtle

John Stuart Bolton

Michael S Wendland

Hassan Sahouani

Akira Ito

Pingfan Peter Wu

Paul A Martinson

David A Olson

Graham M Clarke

Michelle M Mok

Daniel J Zillig

Sachin Talwar

Megan A Creighton

Liyun Ren

Georg Eichhorn

Heng-Yi Lai

Nicole D Petkovich

Thomas P Hänschen

Thomas Herdtie

Srinivas Katragadda

Jinzhang You

Taewook Yoo

Xiaojun Su

Qinrong Wu

Xiao Jun Su

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

The provided articles, assemblies, and methods use a non-woven fibrous web () having one or more layers () that are densified in situ to provide a layer that is densified relative to one or more adjacent layers, collectively within a unitary non-woven construction. The non-woven web () can be made from fibers having a composition and/or structure that resist shrinkage induced by polymer crystallization when subjected to high temperatures. Advantageously, the provided non-woven webs () can be molded to form a three-dimensional shaped article that displays dimensional stability.

Non-woven fibrous web and methods thereof

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

A multilayer damping material for damping a vibrating surface comprising: at least one constraining layer; at least one dissipating layer; and at least one kinetic spacer layer comprising multiple spacer elements. The kinetic spacer layer is arranged between the constraining layer and the vibrating surface, when used for damping the vibrating surface. Each spacer element has opposite ends. At least one end of each of the multiple spacer elements is embedded in, bonded to, in contact with, or in close proximity to the dissipating layer, such that energy is dissipated within the multilayer damping material, through movement of the at least one end of each of the multiple spacer elements.

Multilayer damping material

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

An acoustic composite comprises a flow resistive substrate having a solid acoustic barrier material bonded to at least a portion of a major surface of the flow resistive substrate; wherein the acoustic barrier material has a density greater than about 1 g/cm3 and the acoustic composite has a porosity between about 0.002% and about 50%.

Acoustic composite

Structured films having acoustical absorbance properties are disclosed. Methods of making and using the structured films are also disclosed.

Structured films having acoustical absorbance properties

New nonwoven fibrous webs are taught which comprise a collected mass of a) directly formed fibers disposed within the web in a C-shaped cross-sectional configuration and b) staple fibers having a crimp of at least 15% dispersed among the directly formed fibers in an amount of at least 5% the weight of the directly formed fibers. The web is lofty but free of macrovoids. Preferably, the web has a filling ratio of at least 50 and a light transmittance variation of about 2% or less. Typically, fibers within the web are bonded together at points of fiber intersection, preferably with autogenous bonds, to provide a compression-resistant matrix. The webs are especially useful as acoustic and thermal insulation.

Fibrous nonwoven web

A computer controlled method for predicting acoustical properties for a generally homogeneous porous material includes providing at least one prediction model for determining one or more acoustical properties of homogeneous porous materials, providing a selected prediction model for use in predicting acoustical properties for the generally homogeneous porous material, and providing an input set of at least microstructural parameters corresponding to the selection model. One or more macroscopic properties for the homogeneous porous material are determined based on the input set of the microstructural parameters and acoustical properties for the homogeneous porous material are generated as a function of the one or more macroscopic properties and the selected prediction model. Such a prediction method may be used to predict acoustical properties for a generally homogeneous limp fibrous material with use of a flow resistivity model for predicting flow resistivity of homogeneous limp fibrous materials based on an input set of microstructural parameters. Another computer controlled method for predicting acoustical properties of multiple component acoustical systems is provided which uses a transfer matrix process for determining acoustical properties of the system based at least in part on microstructural inputs provided for one or more components of the acoustical system.

Prediction and optimization method for homogeneous porous material and accoustical systems

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Roseville, MN, United States of America

Jonathan H Alexander