Acoustic composite
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%.
1. An acoustic composite comprising:
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/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%.
2. The acoustic composite of claim 1 , wherein the flow resistive substrate having a solid acoustic barrier material is bonded to at least a portion of a major surface of the flow resistive substrate with a binder; further wherein the acoustic barrier material has a density greater than about 1 g/cm 3 and additionally wherein the barrier and the binder together cover between about 20% and about 99.998% of the major surface.
3. The acoustic composite of claim 2 , wherein the barrier and the binder together cover between about 20% and about 99.5% of the major surface.
4. The acoustic composite of claim 1 , wherein the flow resistive substrate comprises a non-woven or a microperforated film.
5. The acoustic composite of claim 4 , wherein the flow resistive substrate is a polymeric microperforated film comprising a plurality of microperforations, wherein the microperforations each have a narrowest diameter less than the film thickness and a widest diameter greater than the narrowest diameter.
6. The acoustic composite of claim 4 , wherein the flow resistive substrate is a microperforated film comprising:
a substantially planar film portion having a first major surface, a second major surface, and an average film portion thickness; and
a plurality of tubular projections extending from the substantially planar film portion, wherein one or more tubular projections comprise a hole.
7. The acoustic composite of claim 6 , wherein one or more of the tubular projections comprise:
(i) a hole extending from a first projection end above the first major surface into or through the substantially planar film portion,
(ii) a projection sidewall surrounding at least a portion of the hole, the projection sidewall having an outer projection sidewall surface, an inner projection sidewall surface, and a projection sidewall thickness, and
(iii) a projection length extending a distance from the first projection end to the first major surface, wherein a ratio of the projection length to the average film portion thickness is at least about 3.5.
8. The acoustic composite of claim 6 wherein the substantially planar film portion comprises a thermoformable material and one or more of the tubular projections comprise:
(i) a hole extending from a first projection end above the first major surface into or through the substantially planar film portion,
(ii) a projection sidewall surrounding at least a portion of the hole, the projection sidewall comprising the thermoformable material and having an outer projection sidewall surface, an inner projection sidewall surface, and a projection sidewall thickness, and
(iii) an end-to-end projection length extending a distance from the first projection end to a second projection end below the second major surface.
9. The acoustic composite of claim 6 wherein the substantially planar film portion comprises a thermoformable material and wherein at least a portion of the tubular projections comprises:
(i) a hole extending from a first projection end above the first major surface into or through the substantially planar film portion to a second projection end below the substantially planar film portion providing an opening through the structured film,
(ii) a projection sidewall surrounding at least a portion of the hole, the projection sidewall comprising the thermoformable material and having an outer projection sidewall surface, an inner projection sidewall surface, and a projection sidewall thickness, and
(iii) an end-to-end projection length extending a distance from the first projection end to the second projection end.
10. The acoustic composite of claim 6 , wherein the flow resistive substrate is liquid impermeable and vapor permeable.
11. The acoustic composite of claim 1 , wherein the acoustic barrier material comprises particles selected from the group consisting of metal particles, glass particles, and combinations thereof.
12. The acoustic composite of claim 1 , wherein the acoustic barrier material is bonded to the flow resistive substrate with a discontinuous coating of binder.
13. The acoustic composite of claim 1 , wherein the acoustic barrier material is a contiguous layer comprising holes.
14. The acoustic composite of claim 1 , wherein the acoustic barrier material comprises filler particles.
15. The acoustic composite of claim 1 , further comprising one or more layers comprising a woven or non-woven material or foam.
16. An acoustic composite system comprising:
(a) 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 solid acoustic barrier material ahs a density greater than about 1 g/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%;
(b) a layer of carpet; and
(c) a non-woven layer.
17. An acoustic composite system comprising:
(a) 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/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%; and
(b) a reflecting surface;
wherein the acoustic composite is disposed near the reflecting surface such that the acoustic composite and the reflecting surface define a cavity therebetween.
18. A method for providing acoustic absorption and transmission loss in an area comprising surrounding at least a portion of the area with an acoustic composite comprised of 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/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%, wherein for frequencies ranging from about 100 Hz to about 4000 Hz, the acoustic composite provides acoustic transmission loss ranging from about 3 dB to about 30 dB, and at least about 50% acoustic absorption.
19. A method for providing acoustic absorption and transmission loss between a sound-generating object and an area comprising providing an acoustic composite comprised of 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/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%, wherein for frequencies ranging from about 500 Hz to about 4000 Hz, the acoustic composite provides acoustic transmission loss ranging from about 3 dB to about 30 dB, and at least about 50% acoustic absorption.
20. An acoustic composite comprising a flow resistive substrate comprising solid acoustic barrier material distributed within the substrate; wherein the acoustic barrier material has a density greater than about 1 g/cm 3 and the acoustic composite has a porosity between about 0.002% and about 50%.