US20020179367A1 - Sound-absorbing polymer foam molded article - Google Patents

Sound-absorbing polymer foam molded article Download PDF

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Publication number
US20020179367A1
US20020179367A1 US10/168,419 US16841902A US2002179367A1 US 20020179367 A1 US20020179367 A1 US 20020179367A1 US 16841902 A US16841902 A US 16841902A US 2002179367 A1 US2002179367 A1 US 2002179367A1
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US
United States
Prior art keywords
moulded part
foam
polymer foam
sound absorption
sound
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/168,419
Inventor
Arno Becker
Dirk Sagemuhl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bayer AG
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19962865A external-priority patent/DE19962865C1/en
Application filed by Individual filed Critical Individual
Priority to US10/168,419 priority Critical patent/US20020179367A1/en
Assigned to BAYER AKTIENGESELLSCHAFT reassignment BAYER AKTIENGESELLSCHAFT ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SAGEMUEHL, DIRK, BECKER, ARNO
Publication of US20020179367A1 publication Critical patent/US20020179367A1/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/162—Selection of materials
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2110/00—Foam properties
    • C08G2110/0041—Foam properties having specified density
    • C08G2110/0058—≥50 and <150kg/m3
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2350/00—Acoustic or vibration damping material

Definitions

  • the invention relates to polymer foam moulded parts with improved sound absorption capacity.
  • Polymer foam moulded parts are frequently used for insulating equipment housings, especially also in the automotive sector, for example as vehicle boot coverings, longitudinal pillar coverings, etc.
  • the foam moulded parts are generally produced as a two-dimensional extended sheet with a foam moulded part thickness of 0.5 to 5 cm.
  • the two-dimensional extended sheet may be curved in the third dimension.
  • Such foam moulded parts have an external layer that is compacted relative to its volume, this layer also being termed the skin.
  • the compaction of the surface is effected during the production of the moulded foam by contact of the still unhardened foam composition with the mould surface, whereby foam bubbles present on the surface are destroyed.
  • the surface skin is an inherent feature of moulded foam. Attempts by the use of special foaming agents or by chemical modification of the foam-forming composition to reduce the tendency to form a surface skin have been only partially successful.
  • film-foam laminates may consist of an open-cell polyurethane foam and a deformable, perforated film joined to the latter that may for example be a plastics or metal sheet.
  • Foam moulded parts are used in the automotive sector and in the equipment insulation sector to absorb sound, especially in the range above 1,000 Hz, in particular above 5,000 Hz.
  • the present invention accordingly provides polymer foam moulded parts with improved sound absorption capacity in the frequency range above 1,500 Hz, that are characterised by a perforation of the surface compacted layer.
  • the perforation consists of holes of 0.1 to 10 mm diameter, particularly preferably 0.3 to 3 mm diameter.
  • the perforation according to the invention is however not restricted to holes of circular diameter.
  • Oval or slit-shaped perforations may advantageously be used.
  • Particularly preferred are slit-shaped perforations with a cross-section ratio of 1:5 to 1:100. In the case of slit-shaped perforations these are preferably arranged in at least 2 directions on the surface.
  • the smaller cross-section dimension should preferably be 0.1 to 3 mm, particularly preferably 0.5 to 2 mm.
  • the total area of the perforations may account for up to 50% of the compacted surface. In general a total area of the perforations of between 0.1 and 10% of the compacted surface is sufficient. Particularly preferably the total area of the perforations is between 1.5 and 4% of the surface.
  • polyurethane foam moulded parts with a density of 60 to 120 kg/m 3 are used.
  • the invention is not however restricted to the preferred moulded foam densities that are normal for terrestrial applications. It is also employed for the much lower densities of down to less than 10 kg/m 3 that are normally used in aircraft construction.
  • the perforations are advantageously formed at the same time as the normally executed rolling of the polymer foam moulded part in order to increase the open-pore structure of the foam.
  • the rollers are preferably provided with needles or cylindrical burls that drill through the compacted surface layer of the polymer foam moulded part during the rolling process.
  • cylindrical hollow burls are used that are open at their front face and have a cutting surface on their external edge.
  • a polyurethane foam moulded part of density 80 kg/m 3 and thickness 25 mm is used. Test pieces of 20 mm diameter are cut from the flat, two-dimensional moulded part, perpendicular to the surface of the moulded part. The frequency-dependent sound absorption is measured according to ASTM E 1050-90 in a sound absorption tube of 20 mm diameter. Curve a) of the accompanying FIG. 1 shows the measured sound absorption of the test body with non-perforated surface skin.
  • test body produced according to Example 1 is provided on its surface with ca. 1 mm size holes whose total area makes up 1% of the overall surface.
  • the corresponding sound absorption curve is curve b) of FIG. 1.
  • test body is prepared corresponding to Example 1, but in this case the total area of the perforations makes up 2% of the surface.
  • the corresponding sound absorption curve is curve c) of FIG. 2.

Abstract

A polymer foam moulded part is described with an improved sound absorption capacity in the frequency range above 1,500 Hz, in which the improved sound absorption capacity is produced by perforating the surface compacted layer of the moulded part.

Description

  • The invention relates to polymer foam moulded parts with improved sound absorption capacity. [0001]
  • Polymer foam moulded parts, in particular also polyurethane foam moulded parts, are frequently used for insulating equipment housings, especially also in the automotive sector, for example as vehicle boot coverings, longitudinal pillar coverings, etc. In this connection the foam moulded parts are generally produced as a two-dimensional extended sheet with a foam moulded part thickness of 0.5 to 5 cm. The two-dimensional extended sheet may be curved in the third dimension. [0002]
  • Such foam moulded parts have an external layer that is compacted relative to its volume, this layer also being termed the skin. The compaction of the surface is effected during the production of the moulded foam by contact of the still unhardened foam composition with the mould surface, whereby foam bubbles present on the surface are destroyed. The surface skin is an inherent feature of moulded foam. Attempts by the use of special foaming agents or by chemical modification of the foam-forming composition to reduce the tendency to form a surface skin have been only partially successful. [0003]
  • In DE-OS 25 25 051 film-foam laminates are described that may consist of an open-cell polyurethane foam and a deformable, perforated film joined to the latter that may for example be a plastics or metal sheet. [0004]
  • Foam moulded parts are used in the automotive sector and in the equipment insulation sector to absorb sound, especially in the range above 1,000 Hz, in particular above 5,000 Hz. [0005]
  • It has now been found that the sound absorption in the range of the aforementioned higher frequencies can be improved if the moulded foam skin is perforated. [0006]
  • The present invention accordingly provides polymer foam moulded parts with improved sound absorption capacity in the frequency range above 1,500 Hz, that are characterised by a perforation of the surface compacted layer. [0007]
  • Preferably the perforation consists of holes of 0.1 to 10 mm diameter, particularly preferably 0.3 to 3 mm diameter. The perforation according to the invention is however not restricted to holes of circular diameter. Oval or slit-shaped perforations may advantageously be used. Particularly preferred are slit-shaped perforations with a cross-section ratio of 1:5 to 1:100. In the case of slit-shaped perforations these are preferably arranged in at least 2 directions on the surface. [0008]
  • Furthermore, circular slits in the shape of closed or broken circles are also suitable. [0009]
  • In the case of non-circular, hole-like perforations the smaller cross-section dimension should preferably be 0.1 to 3 mm, particularly preferably 0.5 to 2 mm. [0010]
  • The total area of the perforations may account for up to 50% of the compacted surface. In general a total area of the perforations of between 0.1 and 10% of the compacted surface is sufficient. Particularly preferably the total area of the perforations is between 1.5 and 4% of the surface. [0011]
  • Preferably polyurethane foam moulded parts with a density of 60 to 120 kg/m[0012] 3 are used. The invention is not however restricted to the preferred moulded foam densities that are normal for terrestrial applications. It is also employed for the much lower densities of down to less than 10 kg/m3 that are normally used in aircraft construction.
  • The perforation should obviously not penetrate the moulded foam part itself, but simply the compacted layer of the surface. [0013]
  • The perforations are advantageously formed at the same time as the normally executed rolling of the polymer foam moulded part in order to increase the open-pore structure of the foam. For this purpose the rollers are preferably provided with needles or cylindrical burls that drill through the compacted surface layer of the polymer foam moulded part during the rolling process. Preferably cylindrical hollow burls are used that are open at their front face and have a cutting surface on their external edge. [0014]
  • The invention is illustrated hereinafter with the aid of Examples 1 to 3. [0015]
    • EXAMPLES Example 1
  • A polyurethane foam moulded part of density 80 kg/m[0016] 3 and thickness 25 mm is used. Test pieces of 20 mm diameter are cut from the flat, two-dimensional moulded part, perpendicular to the surface of the moulded part. The frequency-dependent sound absorption is measured according to ASTM E 1050-90 in a sound absorption tube of 20 mm diameter. Curve a) of the accompanying FIG. 1 shows the measured sound absorption of the test body with non-perforated surface skin.
    • Example 2
  • The test body produced according to Example 1 is provided on its surface with ca. 1 mm size holes whose total area makes up 1% of the overall surface. The corresponding sound absorption curve is curve b) of FIG. 1. [0017]
    • Example 3
  • The test body is prepared corresponding to Example 1, but in this case the total area of the perforations makes up 2% of the surface. The corresponding sound absorption curve is curve c) of FIG. 2. [0018]

Claims (6)

1. Polymer foam moulded part with improved sound absorption capacity in the frequency range above 1,500 Hz, characterised by a perforation of the surface compacted layer.
2. Moulded part according to claim 1, characterised in that the perforation consists of holes of diameter from 0.1 to 10 mm.
3. Moulded part according to claim 1 or 2, characterised in that the perforation consists of holes of diameter from 0.3 to 3 mm.
4. Moulded part according to any one of claims 1 to 3, characterised in that the total area of the perforations amounts to between 0.1 and 10% of the surface.
5. Moulded part according to any one of claims 1 to 4, characterized in that the total area of the perforations amounts to between 1.5 and 4% of the surface.
6. Moulded part according to any one of claims 1 to 5 of polyurethane foam with a density of 60 to 120 kg/m3.
US10/168,419 1999-12-24 2000-12-12 Sound-absorbing polymer foam molded article Abandoned US20020179367A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/168,419 US20020179367A1 (en) 1999-12-24 2000-12-12 Sound-absorbing polymer foam molded article

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19962865A DE19962865C1 (en) 1999-12-24 1999-12-24 Shaped polymer foam component for sound absorption purposes in automobiles is provided with perforations in its compacted surface layer
US10/168,419 US20020179367A1 (en) 1999-12-24 2000-12-12 Sound-absorbing polymer foam molded article
PCT/EP2000/012565 WO2001048069A1 (en) 1999-12-24 2000-12-12 Sound-absorbing polymer foam molded article

Publications (1)

Publication Number Publication Date
US20020179367A1 true US20020179367A1 (en) 2002-12-05

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040180978A1 (en) * 2003-03-13 2004-09-16 Thorsten Dreier Soundproofing and thermally insulating structural element

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770560A (en) * 1971-10-21 1973-11-06 American Cyanamid Co Composite laminate with a thin, perforated outer layer and cavitated bonded backing member
US3966526A (en) * 1973-03-26 1976-06-29 Detroit Gasket & Manufacturing Company Process for making resilient laminar panel
US4097633A (en) * 1975-06-04 1978-06-27 Scott Paper Company Perforated, embossed film to foam laminates having good acoustical properties and the process for forming said
US4271219A (en) * 1979-10-02 1981-06-02 Rohr Industries, Inc. Method of manufacturing an adhesive bonded acoustical attenuation structure and the resulting structure
US4615411A (en) * 1982-05-27 1986-10-07 Dynamit Nobel Ag Sound-insulated flow duct and process for the manufacture thereof
US4715473A (en) * 1984-12-14 1987-12-29 Irbit Research & Consulting Ag Foam acoustic absorption member
US4863791A (en) * 1987-04-06 1989-09-05 United Technologies Automotive, Inc. Sound absorption in foam core panels
US5633067A (en) * 1991-08-26 1997-05-27 Illbruck Production S.A. Engine compartment casing element with perforated foam layer
US5962107A (en) * 1997-10-29 1999-10-05 Johns Manville International, Inc. Perforated cellular sound absorption material
US6033756A (en) * 1996-12-04 2000-03-07 Pritex Limited Apparatus for and method of attenuating acoustic energy
US6290022B1 (en) * 1998-02-05 2001-09-18 Woco Franz-Josef Wolf & Co. Sound absorber for sound waves
US6334280B1 (en) * 1996-02-08 2002-01-01 Bpb Plc Sound absorbing cementitious tile

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770560A (en) * 1971-10-21 1973-11-06 American Cyanamid Co Composite laminate with a thin, perforated outer layer and cavitated bonded backing member
US3966526A (en) * 1973-03-26 1976-06-29 Detroit Gasket & Manufacturing Company Process for making resilient laminar panel
US4097633A (en) * 1975-06-04 1978-06-27 Scott Paper Company Perforated, embossed film to foam laminates having good acoustical properties and the process for forming said
US4271219A (en) * 1979-10-02 1981-06-02 Rohr Industries, Inc. Method of manufacturing an adhesive bonded acoustical attenuation structure and the resulting structure
US4615411A (en) * 1982-05-27 1986-10-07 Dynamit Nobel Ag Sound-insulated flow duct and process for the manufacture thereof
US4715473A (en) * 1984-12-14 1987-12-29 Irbit Research & Consulting Ag Foam acoustic absorption member
US4863791A (en) * 1987-04-06 1989-09-05 United Technologies Automotive, Inc. Sound absorption in foam core panels
US5633067A (en) * 1991-08-26 1997-05-27 Illbruck Production S.A. Engine compartment casing element with perforated foam layer
US6334280B1 (en) * 1996-02-08 2002-01-01 Bpb Plc Sound absorbing cementitious tile
US6033756A (en) * 1996-12-04 2000-03-07 Pritex Limited Apparatus for and method of attenuating acoustic energy
US5962107A (en) * 1997-10-29 1999-10-05 Johns Manville International, Inc. Perforated cellular sound absorption material
US6290022B1 (en) * 1998-02-05 2001-09-18 Woco Franz-Josef Wolf & Co. Sound absorber for sound waves

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040180978A1 (en) * 2003-03-13 2004-09-16 Thorsten Dreier Soundproofing and thermally insulating structural element
US7179846B2 (en) 2003-03-13 2007-02-20 Bayer Materialscience Ag Soundproofing and thermally insulating structural element

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Owner name: BAYER AKTIENGESELLSCHAFT, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BECKER, ARNO;SAGEMUEHL, DIRK;REEL/FRAME:013186/0848;SIGNING DATES FROM 20020517 TO 20020523

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION