The disclosure relates to acoustic panels and methods for preparing them. The disclosure relates more particularly to panels having a porous facing and to methods for making such panels. One aspect of the disclosure is an acoustic panel comprising a base structure. The base structure has one or more edges, an outward major surface having a total area, and an inward major surface opposing the outward major surface. The base structure has a noise reduction coefficient (NRC) of at least about 0.3. The panel includes a coating layer directly disposed on the outward major surface of the base structure, the coating layer being formed of an open-cell foam. The coating layer has an exterior major surface opposing the outward major surface of the base structure. The coating layer is substantially scattering for light in the wavelength range of 380 nm to 780 nm, and has an absorption coefficient of less than 0.5 for acoustic frequencies in the range of 100 Hz to 10,000 Hz.

Described herein are noise-resistant assemblies pursuant to various commercial and industrial applications. The noise-resistant assemblies can include duct assemblies, pool assemblies, motor assemblies, carpet flooring assemblies, and roofing assemblies. These assemblies incorporate an acoustic article containing a porous layer and a heterogeneous filler having a median particle size of from 1 micrometer to 1000 micrometers and a specific surface area of from 0.1 m.sup.2/g to 10,000 m.sup.2/g received in the porous layer.

An aerospace component, for example, used in a gas turbine engine, includes the following structurally-integrated layers: a metallic layer and a composite layer having reinforcing fibers embedded in a matrix material. The aerospace component can also include an insulating layer disposed between the metallic layer and the composite layer where the insulating layer has a thermal conductivity that is lower than a thermal conductivity of the composite layer.

A polymer matrix composite includes a porous polymeric network structure; and a plurality of acoustically active particles distributed within the polymeric network structure. The weight fraction of acoustically active particles is between 0.80 and 0.99, based on the total weight of the polymer matrix composite. The polymer matrix composite has an air flow resistance of less than 100 seconds/50 mL/500 μm.

A polymer matrix composite includes a porous polymeric network structure; and a plurality of acoustically active particles distributed within the polymeric network structure. The weight fraction of acoustically active particles is between 0.80 and 0.99, based on the total weight of the polymer matrix composite. The polymer matrix composite has an air flow resistance of less than 100 seconds/50 mL/500 μm.

Embodiments of the invention include sound suppressors, and/or sleeves for sound suppressors and/or barrels of firearms, incorporating mats, sheets, and/or powders of silica fibers and methods for producing such sound suppressors and sleeves. The silica fibers may be formed via electrospinning of a sol gel produced with a silicon alkoxide reagent, such as tetraethyl ortho silicate, alcohol solvent, and an acid catalyst.

A sound absorbing body comprises a non-woven fabric or a non-woven fabric laminate, the non-woven fabric or the non-woven fabric laminate comprises a fiber that has an average fiber diameter of less than 3,000 nm, the non-woven fabric or the non-woven fabric laminate has a thickness of less than 10 mm, the non-woven fabric or the non-woven fabric laminate has a unit thickness flow resistance of greater than 4.0 E+06 Ns/m.sup.4 and less than 5.0 E+08 Ns/m.sup.4, and the non-woven fabric or the non-woven fabric laminate has a bulk density of greater than 70 kg/m.sup.3 and less than 750 kg/m.sup.3.

Aspects are disclosed of a filler for occupying a volume. The filler includes an expandable filler positioned in the volume so that it occupies a percentage of the volume. The expandable filler can permanently expand from a first dimension to a second dimension upon the application of an expansion trigger. The filler also includes an acoustic filler made up of a plurality of acoustically active beads positioned with the expandable filler in the volume so that the acoustic filler can adsorb gas flowing into the volume. Other embodiments are disclosed and claimed.

An acoustic matching material supply device includes a frame portion that may be attachable to an ultrasonic probe that includes an ultrasonic sensor surface. The frame portion ejects an acoustic matching material. The frame portion includes an inner peripheral surface, an ejection port, an introduction port, and a flow passage. The ejection port is provided on the inner peripheral surface or in a region including the inner peripheral surface, and ejects the acoustic matching material. The introduction port receives the acoustic matching material from a device external of the frame portion. The flow passage extends between the ejection port and the introduction port, and the ejection port and the introduction port communicate with each other via the flow passage.

An acoustic matching material supply device includes a frame portion that may be attachable to an ultrasonic probe that includes an ultrasonic sensor surface. The frame portion ejects an acoustic matching material. The frame portion includes an inner peripheral surface, an ejection port, an introduction port, and a flow passage. The ejection port is provided on the inner peripheral surface or in a region including the inner peripheral surface, and ejects the acoustic matching material. The introduction port receives the acoustic matching material from a device external of the frame portion. The flow passage extends between the ejection port and the introduction port, and the ejection port and the introduction port communicate with each other via the flow passage.