Sound absorbing sheet having micro resonant structure, method for manufacturing same, and sound absorption type soundproof panel using same

Patent metadata

Field	Value
Publication number	US-9447577-B2
Application number	US-201314649009-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Dec 6, 2012
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

Disclosed are a sound absorbing sheet having a micro resonant structure and capable of improving sound absorption performance up to the low frequency band by means of the micro resonance principle, a method for manufacturing same, and a sound absorption type soundproof panel using same. The sound absorbing sheet according to the present invention has multiple uneven patterns configured to have convex parts and concave parts on one surface of a porous base material, and the area ratio of the concave part determined by the following formula 1 is 40 to 99%. The area corresponding to the concave part has a lower air permeability than the area corresponding to the convex part.

Area ratio of concave portion=[area portion of concave portion]/[area portion of porous base material].  [Formula 1]

First claim

The invention claimed is:

1. A sound absorbing sheet, comprising:
a plurality of convex-concave patterns comprising protrusions and depressions on one surface of a porous substrate, wherein
the convex-concave patterns have a pitch of 1.9 mm to 15 mm,
the sound absorbing sheet has an area ratio of the depressions from 43.5% to 99%, as represented by Equation 1,
the sound absorbing sheet has an average coefficient of sound absorption of 0.4 or more in a frequency band from 200 Hz to 2000 Hz, and
a region corresponding to the depressions exhibits lower air permeability than a region corresponding to the protrusions,
Area ratio of depressions=[Area of depressions]/[Area of porous substrate].  [Equation 1]

2. The sound absorbing sheet according to claim 1 , wherein the protrusions have a width or diameter of 0.2 mm to 20 mm.

3. The sound absorbing sheet according to claim 1 , wherein the porous substrate comprises thermoplastic organic fibers.

4. The sound absorbing sheet according to claim 1 , wherein the porous substrate comprises thermoplastic organic fibers containing inorganic fibers.

5. The sound absorbing sheet according to claim 4 , wherein the thermoplastic organic fibers comprise at least one selected from the group consisting of polyethylene terephthalate, polyethylene, and polypropylene (PP).

6. The sound absorbing sheet according to claim 1 , wherein the protrusions have any shape selected from the group consisting of circles, ellipses, polygons, stripes, and combinations thereof.

7. The sound absorbing sheet according to claim 1 , wherein the porous substrate has a basis weight of 30 g/m 2 to 800 g/m 2 .

8. The sound absorbing sheet according to claim 1 , wherein the porous substrate has a thickness of 0.1 mm to 10 mm.

9. The sound absorbing sheet according to claim 1 , wherein the porous substrate has an air permeability of 20 L/m 2 /s to 1200 L/m 2 /s at a pressure of 200 Pa.

10. The sound absorbing sheet according to claim 1 , wherein the porous substrate has an original air permeability of 20 L/m 2 /s to 1200 L/m 2 /s at 100 Pa.

11. A sound absorption type soundproof panel, comprising:
a sound absorber; and
the sound absorbing sheet according to claim 1 formed on at least one surface of the sound absorber.

12. The soundproof panel according to claim 11 , wherein the sound absorber comprises at least one selected from the group consisting of porous plates, organic materials, inorganic materials, natural materials, thermoplastic resin matrices, and thermosetting resin matrices.

13. The sound absorbing sheet according to claim 4 , wherein the thermoplastic organic fibers comprise at least one selected from the group consisting of polyethylene terephthalate, polyethylene, and polypropylene (PP).

14. A method for manufacturing a sound absorbing sheet, comprising:
preparing a porous substrate; and
forming a plurality of convex-concave patterns comprising protrusions and depressions on one surface of the porous substrate through thermal transfer, wherein
the convex-concave patterns have a pitch of 1.9 mm to 15 mm,
the sound absorbing sheet has an area ratio of the depressions from 43.5% to 99%, as represented by Equation 1, the sound absorbing sheet has an average coefficient of sound absorption of 0.4 or more in a frequency band from 200 Hz to 2000 Hz,
Area ratio of depressions=[Area of depressions]/[Area of porous substrate],  [Equation 1]

and
said forming the plurality of convex-concave patterns comprises pressing the porous substrate.

15. The method according to claim 14 , wherein thermal transfer is performed by embossed roll molding or embossed press molding.

16. The method according to claim 15 , wherein said forming the plurality of convex-concave patterns comprises:
preheating the porous substrate to a temperature of 60% to 100% a melting point thereof; and
pressing an embossed roll or embossed press onto the preheated porous substrate.

Assignees

• Lg Hausys Ltd

Inventors

• Kang Gil Ho
• Jung Seong Moon
• Kang Bong Gyu

Classifications

• B29C59/022

  characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor · CPC title

• B29K2995/002

  Coloured · CPC title

• B29K2105/0854

  in the form of a non-woven mat · CPC title

• B29K2067/003

  PET, i.e. poylethylene terephthalate · CPC title

• B29K2105/04

  cellular or porous · CPC title