TH89681A - Composite material structure for sound absorption - Google Patents

Abstract

DC60 This invention presents a sound-absorbing material structure that improves the broad-range sound absorption properties of the primary porous sound-absorbing material without increasing density and thickness. Specifically, it uses a porous or foam-type material as the primary sound-absorbing material, and employs a composite sound-absorbing material structure with a single or multiple layers of non-woven fabric attached to a hotmelt material that does not hinder air permeability to the surface of the primary sound-absorbing material, at least on the side where sound waves strike. This allows for efficient absorption of mid-low frequency sounds without compromising high-frequency sound absorption properties. 1,4 ... Non-woven fabric 2,5 ... Hotmelt 3 ... Primary sound-absorbing material 102 ... Composite sound-absorbing material structure Figure 2 This invention presents a sound-absorbing material structure that improves the broad-range sound absorption properties of the primary porous sound-absorbing material without increasing density and thickness. Specifically, it uses a porous or foam-type material as the primary sound-absorbing material, and employs a composite sound-absorbing material structure with a single or multiple layers of non-woven fabric attached to a hotmelt material that does not hinder air permeability to the surface of the primary sound-absorbing material. By using hot melt material that does not hinder air permeability to the surface of the primary sound-absorbing material mentioned above, at least on the side where sound waves strike, it is possible to achieve good sound absorption efficiency in the mid-low frequency range without reducing the sound absorption properties in the high frequency range. 1,4 ... Non-woven fabric 2,5 ... Hot melt 3 ... Primary sound-absorbing material 102 ... Composite sound-absorbing material structure Figure used: Figure 2

Claims (13)

1. A characteristic composite sound-absorbing material structure uses porous or foam materials as the primary sound-absorbing material, with a non-woven fabric in contact with the surface where the sound-absorbing waves strike the primary material in a manner that does not hinder air resistance. 2. A composite sound-absorbing material structure as specified in Reputation 1, in which a hot-melt material, without obstructing air permeability, is bonded to the surface of the primary sound-absorbing material mentioned above. 3. Composite sound-absorbing material structures as specified in Claim 1 or Claim 2, where the primary sound-absorbing material is a high-molecular-weighted material such as polyester, etc.; an inorganic fiber material such as glass fiber or asbestos, etc.; a porous material material such as metallic fibers, etc.; a high-molecular-weighted foam material such as soft polyurethane foam, etc.; or a metallic foam material such as aluminum, etc. 4. It is a composite sound-absorbing material structure as specified in claims 1-3, where one of the primary sound-absorbing materials has an air resistance of 0.3-7 x 10⁴ Nsec/m⁴. 5. A composite sound-absorbing material structure as specified in Claim 1, containing one or more layers of non-woven fabric. 6. A composite sound-absorbing material structure as specified in Claim 2, consisting of one or more layers of non-woven fabric fused together through a hot-melt process. 7. In any of the composite sound-absorbing material structures specified in Reputations 1-6, the single or multiple layers of non-woven fabric on the incident side are a high-molecular-weight non-woven fabric or a paper-like fabric. 8. The composite sound-absorbing material structure specified in claim 7, where the non-woven fabric is a high molecular weight material such as polyester, polyethylene, nylon, etc. 9. Composite sound-absorbing material structure as specified in claim 7, which includes non-woven fabrics such as paper, Japanese paper, or wallpaper. 10. Any of the composite sound-absorbing material structures specified in claims 1-9 that have a non-woven fabric weight per unit area between 20-200 g/m2 and an air resistance between 0.5-5 x 10⁴ Nsec/m4. 11. One or more of the composite sound-absorbing material structures specified in claims 1-10 shall have at least one layer of the first layer on the incident surface treated to be waterproof, flame-retardant, weather and sunlight resistant, dirt-resistant, etc. 12. Composite sound-absorbing material structures as specified in claims 2 or 6, where the hot-melt material is in a high molecular weight powder form, such as polyester, nylon, polypropylene, olefin, etc., or in a mesh form, or in a fibrous form, with a melting point of 70-180 °C. 13. Any of the composite sound-absorbing material structures specified in claims 1-12 that use a layer of air as the primary sound-absorbing material.