WO2012143305A1 - Perfectionnements apportés à des écrans acoustiques ou s'y rapportant - Google Patents

Perfectionnements apportés à des écrans acoustiques ou s'y rapportant Download PDF

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Publication number
WO2012143305A1
WO2012143305A1 PCT/EP2012/056848 EP2012056848W WO2012143305A1 WO 2012143305 A1 WO2012143305 A1 WO 2012143305A1 EP 2012056848 W EP2012056848 W EP 2012056848W WO 2012143305 A1 WO2012143305 A1 WO 2012143305A1
Authority
WO
WIPO (PCT)
Prior art keywords
plate
baffle according
baffle
foamable material
ribs
Prior art date
Application number
PCT/EP2012/056848
Other languages
English (en)
Inventor
Jean-Michel Coulon
Jörn KAGEMANN
Philippe FARHNER
Original Assignee
Zephyros Inc
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
Application filed by Zephyros Inc filed Critical Zephyros Inc
Publication of WO2012143305A1 publication Critical patent/WO2012143305A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D29/00—Superstructures, understructures, or sub-units thereof, characterised by the material thereof
    • B62D29/001—Superstructures, understructures, or sub-units thereof, characterised by the material thereof characterised by combining metal and synthetic material
    • B62D29/002—Superstructures, understructures, or sub-units thereof, characterised by the material thereof characterised by combining metal and synthetic material a foamable synthetic material or metal being added in situ

Definitions

  • the present invention relates to baffles and particularly baffles that are employed in cavities in automobile structures to provide seals and/or sound insulation in particular improved sound insulation.
  • baffles within cavities in automobile structures and various forms of baffles are known. Initially metal components were located within the cavities which are typically within tubular metal structures. Previously as a general guideline the sound barrier properties that are required should be similar to those of the vehicle metal panels which are typically from 0.7 to 0.8 millimetre thick steel. It was then proposed to provide foamed inserts within the cavity, typically made of foamed polymeric material. Such inserts posed the problem of how best to locate the insert within the cavity and furthermore the foamed polymeric material can be very expensive and substantial quantities were required in order to provide adequate sealing and/or sound insulation in the various positions in the vehicle where it may be required.
  • a vehicle frame typically consists of a frame comprising a main frame comprising rails and cross members and subframes which support the working components of the vehicle.
  • the frame also supports pillars such as the A, B and C pillars which are the vertical support components of the vehicle. These pillars in turn support roof structures, doors, windows etc. Sound insulation and/or seals may be required in many of these locations and accordingly a large number of seals or baffles may be required at different locations within a single vehicle.
  • the size and shape of each baffle will be determined by the size and shape of the cavity in which the sealing or sound alternation are required.
  • baffles were developed and sold comprising a plate of material surrounded by a ribbon of foamable material.
  • the plate may be integrally formed with a fastener such as a clip which would enable the baffle to be located at the desired position within the vehicle cavity.
  • the foamable material could be formulated so that it would foam at temperatures experienced during automobile manufacture such as the temperatures experienced in the anticorrosion coating (sometimes known as e-coat) process such as the coating bake ovens or the paint bake ovens.
  • e-coat anticorrosion coating
  • the plate may be of metal or moulded plastic, whatever the material the plate needed to be of a thickness that would provide the desired sound barrier properties.
  • the commercial baffles of this type consisted of a plastic plate carrying a ribbon of foamable material around its extremity.
  • the plastic plate could be formed by injection moulding and the means of attachment within the vehicle cavity (such as a clip) could be integrally moulded with the plate.
  • the ribbon of foamable material could be provided on the perimeter of the plate by overmoulding of the foamable material providing the overmoulding took place at a temperature below that at which the foaming would take place.
  • baffles could be mounted within the vehicle cavity whilst leaving a gap between the exterior of the ribbon of foamable material and the internal surface of the cavity of the vehicle.
  • the presence of the gap enabled the internal surface of the metal defined cavity to be coated with the anticorrosion material in the immersion of the vehicle structure (body in white) in the bath of anticorrosion material for deposition of the anticorrosion coating on the metal.
  • the coated structure would be heated in an oven to bake the anticorrosion coating and the foamable material was formulated to foam at that temperature to bridge the gap previously formed between the exterior of the foamable material and the interior of the vehicle and to some extent cover the plate in this way providing the desired sound insulation and sealing.
  • the plate of the baffle was usually formed from a thermoplastic material by injection moulding and strong materials such as polyamide and rigid polyolefins were preferred. Typical examples include fibre reinforced nylon and polypropylene. Glass fibre reinforced nylon being preferred.
  • the foamable material was also based on a thermoplastic containing formulation and is preferably one that will also develop adhesive properties as it foams so that it will bond to the interior surface of the metal cavity upon foaming.
  • baffles Whilst these baffles have enjoyed commercial success in order for them to satisfy the sound insulation requirements of the vehicle in which they are used, there is now a need to improve the acoustic properties of such baffles.
  • improved acoustic performance of baffles such as those described in Japanese Patent Publications Kokai 10-71628 it would be necessary to increase the thickness of the central plate. This will however undesirably increase the moulding cycle time with attendant manufacturing disadvantages. Furthermore it may require the use of undesirably large amounts of material. We have found that these disadvantages may be overcome whilst allowing the desired acoustic properties to be achieved if upstanding ribs are formed on the plate.
  • WO 2010/015645 is concerned with how the weight and thickness of the carrier (plate) impacts the manufacturing process and the ability to tailor a baffle.
  • the solution provided by WO 2010/015645 is to modify the baffle by providing an insert within the carrier to increase weight, density and structural rigidity of the baffle without altering the exterior dimensions.
  • the present invention therefore provides a baffle suitable for sealing and/or providing sound insulation within a cavity of a vehicle comprising an internal plate provided with a band of foamable material around its perimeter wherein the plate is formed with upstanding ribs.
  • the plate component of the baffle of the present invention may be formed from any suitable material and formed in any particular manner. It is particularly preferred that it be formed by injection moulding from a strengthened thermoplastic material such as fibre reinforced polyamide or polyolefine such as polypropylene or rigid ethylene homo or copolymers.
  • a strengthened thermoplastic material such as fibre reinforced polyamide or polyolefine such as polypropylene or rigid ethylene homo or copolymers.
  • the preferred ribbed structure that is upstanding from the plate will depend upon the location of the baffle within the automobile and also the performance required of the baffle. Ribs may be provided on one or both sides of the plate and can conveniently be integral with the plate and formed during the injection moulding process. We have found that the provision of the upstanding ribs on the plate enables the desired improvement in acoustic barrier properties to be obtained with a plate below 5 millimetres in particular below 4 millimetres thickness.
  • the preferred height of the ribs will also depend upon the location of the baffle within the vehicle and the properties it is required to provide. However ribs having a height of from 1 to 60 millimetres preferably 3 to 10 millimetres and a thickness of 1 to 4 millimetres has been found to be particularly useful.
  • the moulding cycle times required for the same mass of material with a ribbed structure is significantly less than the time required for a moulding of uniform thickness.
  • the plate can also be provided with means of attachment to enable it to be assembled within the vehicle cavity.
  • a clip may be integrally moulded with the plate.
  • the perimeter of the plate may be provided with structures that will operate to secure the foamable material to the perimeter of the plate. For example grooves, attachment studs and the like may be provided. These embodiments may also be formed during the injection moulding process.
  • the foamable material is preferably overmoulded around the perimeter of the injection moulded plate.
  • the foamable material will be selected according to the properties the foam is required to impart to the cavity.
  • a high expansion typically 100%-3000% preferably 400- 2500% expansion foamable material may be used to produce a soft foam.
  • the foamable material is preferably such as to produce a highly expanded soft foam typically from polymers such as ethylene unsaturated ester copolymers typically ethylene vinyl acetate copolymers and/or ethylene acrylate copolymers.
  • a particularly preferred material is an olefinic polymer-based acoustic foam, and more particularly an ethylene based polymer.
  • the foamable material may be based on an ethylene copolymer or terpolymer that may contain a C 3 to C 8 alpha-olefin comonomer.
  • particularly preferred polymers include ethylene vinyl acetate copolymers, ethylene acrylate copolymers, EPDM, or mixtures thereof.
  • foam formulations that are commercially available include polymer-based materials commercially available from L & L Products, Europe, under the designations as L-2704, L-2806, L-2811 , L-2820, L-2821 , L-1066, L-2105, L-2106, L-2115, L-2308, L-241 1 , L-2412, L-2663, L-2664, L-2700, L-2703, L-4161 , L-4200, L-4300, L-4315, L-4316, L7102, L7107 and L7220. These materials may be readily injection moulded around the ribbed plate to produce a baffle of this invention.
  • foams for noise attenuation and/or vibration damping include an open-cell polymeric base material, such as an ethylene-based polymer which, when compounded with appropriate ingredients (typically a blowing and curing agent), expands and cures in a reliable and predictable manner upon the application of heat or the occurrence of a particular ambient condition.
  • an acoustic foam is usually initially processed as a flowable thermoplastic material before curing. It will preferably cross-link upon curing, which makes the material resistant to further flow or change of final shape.
  • the material can be formed of other materials (e.g., foams regarded in the art as structural foams) provided that the material selected is heat-activated or otherwise activated by an ambient condition (e.g. moisture, pressure, time or the like) and cures in a predictable and reliable manner under appropriate conditions for the selected application.
  • foams regarded in the art as structural foams
  • an ambient condition e.g. moisture, pressure, time or the like
  • Some other possible materials include, but are not limited to, polyolefin materials, copolymers and terpolymers, phenol/formaldehyde materials, phenoxy materials, and polyurethanes.
  • the desired characteristics of the resulting foam include relatively low glass transition point, and good corrosion resistance properties. In this manner, the material does not generally interfere with the materials systems employed by automobile manufacturers. Moreover, it will withstand the processing conditions typically encountered in the manufacture of a vehicle, such as the e-coat priming, cleaning and degreasing and other coating processes.
  • One or more curing agents may be included in the foamable material used in this invention. Optionally curing agent accelerators may also be included.
  • the amounts of curing agents and curing agent accelerators used can vary widely depending upon the type of structure desired, the desired properties of the foamed material and the desired amount of expansion of the foamable material and the desired rate of expansion. Exemplary ranges for the curing agents or curing agent accelerators present in the foamable material range from about 0.001 % by weight to about 7% by weight.
  • the foamed material may include one or more additional polymers or copolymers, which can include a variety of different polymers, such as thermoplastics, elastomers, plastomers and combinations thereof.
  • polymers that might be appropriately incorporated into the foamable material include halogenated polymers, polycarbonates, polyketones, polyurethanes, polyesters, and polymers derived from silanes, sulfones, allyls, olefins, styrenes, acrylates, methacrylates, epoxies, silicones, phenolics, rubbers, polyphenylene oxides, terphthalates, acetates (e.g., EVA), acrylates, methacrylates (e.g., ethylene methyl acrylate polymer) or mixtures thereof.
  • EVA acrylates, methacrylates (e.g., ethylene methyl acrylate polymer) or mixtures thereof.
  • polystyrene may be or may include, without limitation, polyolefin (e.g., polyethylene, polypropylene) polystyrene, polyacrylate, poly(ethylene oxide), poly(ethyleneimine), polyester, polyurethane, polysiloxane, polyether, polyphosphazine, polyamide, polyimide, polyisobutylene, polyacrylonitrile, polyvinyl chloride), poly(methyl methacrylate), polyvinyl acetate), poly(vinylidene chloride), polytetrafluoroethylene, polyisoprene, polyacrylamide, polyacrylic acid, polymethacrylate.
  • these polymers can comprise a small portion or a more substantial portion of the material.
  • the one or more additional polymers preferably comprises about 0.1 % to about 50%, more preferably about 1 % to about 20% and even more preferably about 2% to about 10% by weight of the foamable material.
  • the formulation may include one or more ethylene polymers or copolymers such as ethylene acrylate, copolymers and ethylene acetate copolymers. Ethylene methacrylate and ethylene vinyl acetate are two preferred ethylene copolymers. It may also be desirable to include a reactive polyethylene resin that is modified with one or more reactive groups such as glycidyl methacrylate or maleic anhydride. Examples of such polyethylene resins are sold under the tradename LOTADER ® (e.g., LOTADER AX 8900) and are commercially available from Arkema Group. One or more blowing agents may be used to cause the material to be foamable by producing inert gasses that form, as desired, an open and/or closed cellular structure of the foamed material.
  • LOTADER ® e.g., LOTADER AX 8900
  • One or more blowing agents may be used to cause the material to be foamable by producing inert gasses that form, as desired, an open and/or closed
  • the blowing agent may include one or more nitrogen containing groups such as amides, amines and the like.
  • suitable blowing agents include azodicarbonamide, dinitrosopentamethylenetetramine, azodicarbonamide, initrosopentamethylenetetramine, 4,4 r oxy-bis-(benzenesulphonylhydrazide), trihydrazinotriazine and N, N r dimethyl-N,Ni- dinitrosoterephthalamide.
  • An accelerator for the blowing agents may also be provided. Various accelerators may be used to increase the rate at which the blowing agents form inert gasses.
  • One preferred blowing agent accelerator is a metal salt, such as an oxide, for example zinc oxide.
  • blowing agents and blowing agent accelerators include modified and unmodified thiazoles or imidazoles.
  • the amounts of blowing agents and blowing agent accelerators that should be used can vary widely depending upon the type of cellular structure desired, the desired amount of expansion the desired rate of expansion and the like. Exemplary ranges for the amounts of blowing agents and blowing agent accelerators in the activatable material range from about 0.001 % by weight to about 5% by weight.
  • the foamable material may also include one or more fillers, including but not limited to particulate materials (e.g., powder), beads, microspheres such as Zeospheres available from Zeelan Industries, or the like.
  • the filler includes a material that is generally non- reactive with the other components present in the activatable material. While the fillers may generally be present to take up space at a relatively low weight, it is contemplated that the fillers may also impart properties such as strength and impact resistance.
  • fillers examples include silica, diatomaceous earth, glass, clay (e.g., including nanoclay), talc, pigments, colorants, glass beads or bubbles, glass, carbon or ceramic fibers, nylon or polyamide fibers (e.g., Kevlar), antioxidants, and the like.
  • Such fillers, particularly clays can assist in leveling itself during flow of the foamable material.
  • the clays that may be used as fillers may include clays from the kaolinite, illite, chloritem, smecitite or sepiolite groups, which may be calcined.
  • suitable fillers include, without limitation, talc, vermiculite, pyrophyllite, sauconite, saponite, nontronite, montmorillonite or mixtures thereof.
  • the clays may also include minor amounts of other ingredients such as carbonates, feldspars, micas and quartz.
  • the fillers may also include ammonium chlorides such as dimethyl ammonium chloride and dimethyl benzyl ammonium chloride. Titanium dioxide might also be employed.
  • one or more mineral or stone type fillers such as calcium carbonate, sodium carbonate or the like may be used as fillers.
  • silicate minerals such as mica may be used as fillers.
  • the fillers can range from 10 % or less to 90 % or greater by weight of the foamable material, but more typical from about 20 to 55 % by weight of the foamable material.
  • the foamable material may include from about 0 % to about 3 % by weight, and more preferably slightly less that 1 % by weight clays or similar fillers.
  • Powdered (e.g. about 0.01 to about 50, and more preferably about 1 to 25 micron mean particle diameter) mineral type filler can comprise between about 5 % and 70 % by weight, more preferably about 10 % to about 50% by weight.
  • foamable material may contain an antioxidant, a UV resistant agent, a flame retardant, an impact modifier, a heat stabilizer, a colorant, a processing aid, a lubricant, a reinforcement (e.g., chopped or continuous glass, ceramic, aramid, or carbon fiber, particulates or the like).
  • Liquid polysufides may be used to improve the environmental exposure such as exposure to humidity and salt water.
  • the foamable material contains an adhesion promoting material such as a petroleum resin or a synthetic or naturally occurring rosin ester tackifier. The use of these materials can improve the adhesion of the foamable material to the interior walls of the cavity. It is preferred to include from 0.5 to 10 wt % of such an adhesion promoting material
  • the material should flow and foam at higher processing temperatures.
  • temperatures such as those encountered in an automobile assembly plant may be appropriate, especially when the foamable material is processed along with the other components at elevated temperatures or at higher applied energy levels, e.g., during painting preparation steps.
  • the foamable material be non-tacky to the touch at ambient temperature to reduce the pick up of dirt and dust and to facilitate storage and transportation of the baffles.
  • the amount of foamable material employed around the plate will be determined by the size of the cavity in which the foam is to be provided and the desired degree of expansion. However for most vehicles a layer of foamable material from 1.5 mm to 10 mm thick has been found to be appropriate particularly for the production of a sound absorption and/or vibration damping foam.
  • Figure 1 shows a conventional baffle with a standard thickness plate (1) located within a cavity defined by metal plates based on plates (2) and (3) and having foam (4) around it's perimeter.
  • Figure 2 is a cross section taken along AA 1 of Figure 1.
  • Figure 3 is a cross section similar to Figure 2 but showing the use of a plate provided with ribs (5).
  • Figure 4 shows diagrammatic cross sections of baffles provided with various rib structures.
  • Figure 5 is a plot showing the acoustic performance (decibels transmitted at various frequencies) of

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Structural Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Vehicle Interior And Exterior Ornaments, Soundproofing, And Insulation (AREA)
  • Body Structure For Vehicles (AREA)

Abstract

L'invention concerne des écrans acoustiques comportant une plaque centrale (1) comportant un ruban de matériau expansible (4) autour de son périmètre. La plaque centrale comporte des nervures qui permettent d'utiliser une plaque plus mince pour une isolation acoustique comparable permettant un cycle de moulage plus rapide.
PCT/EP2012/056848 2011-04-21 2012-04-13 Perfectionnements apportés à des écrans acoustiques ou s'y rapportant WO2012143305A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1106813.7 2011-04-21
GBGB1106813.7A GB201106813D0 (en) 2011-04-21 2011-04-21 Improvements in or relating to baffles

Publications (1)

Publication Number Publication Date
WO2012143305A1 true WO2012143305A1 (fr) 2012-10-26

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WO (1) WO2012143305A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3967579A1 (fr) * 2020-09-14 2022-03-16 Sika Technology Ag Élément isolant

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5266133A (en) 1993-02-17 1993-11-30 Sika Corporation Dry expansible sealant and baffle composition and product
US5575526A (en) 1994-05-19 1996-11-19 Novamax Technologies, Inc. Composite laminate beam for radiator support
JPH1071628A (ja) 1996-08-30 1998-03-17 Neox Lab:Kk 中空構造物における中空室遮断具とその製造方法
US5755486A (en) 1995-05-23 1998-05-26 Novamax Technologies Holdings, Inc. Composite structural reinforcement member
US5766719A (en) 1994-03-14 1998-06-16 Magna Exterior Systems Gmbh Composite material
US5932680A (en) 1993-11-16 1999-08-03 Henkel Kommanditgesellschaft Auf Aktien Moisture-curing polyurethane hot-melt adhesive
WO2000027920A1 (fr) 1998-11-05 2000-05-18 Sika Corporation Compositions conçues pour le renforcement structural et la reduction du bruit et procedes pour leur utilisation
JP2001030252A (ja) 1999-07-26 2001-02-06 Neoex Lab Inc 中空構造物における中空室遮断具とその製造方法
EP1593588A2 (fr) * 2004-05-06 2005-11-09 Nitto Denko Corporation Élément comportant une mousse de remplissage
EP1607204A2 (fr) * 2004-06-15 2005-12-21 L & L Products, Inc. Fabrication de pièces moulées laminaires
WO2010015645A1 (fr) 2008-08-05 2010-02-11 Sika Technology Ag Écran acoustique

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5266133A (en) 1993-02-17 1993-11-30 Sika Corporation Dry expansible sealant and baffle composition and product
US5932680A (en) 1993-11-16 1999-08-03 Henkel Kommanditgesellschaft Auf Aktien Moisture-curing polyurethane hot-melt adhesive
US5766719A (en) 1994-03-14 1998-06-16 Magna Exterior Systems Gmbh Composite material
US5575526A (en) 1994-05-19 1996-11-19 Novamax Technologies, Inc. Composite laminate beam for radiator support
US5755486A (en) 1995-05-23 1998-05-26 Novamax Technologies Holdings, Inc. Composite structural reinforcement member
JPH1071628A (ja) 1996-08-30 1998-03-17 Neox Lab:Kk 中空構造物における中空室遮断具とその製造方法
WO2000027920A1 (fr) 1998-11-05 2000-05-18 Sika Corporation Compositions conçues pour le renforcement structural et la reduction du bruit et procedes pour leur utilisation
JP2001030252A (ja) 1999-07-26 2001-02-06 Neoex Lab Inc 中空構造物における中空室遮断具とその製造方法
EP1593588A2 (fr) * 2004-05-06 2005-11-09 Nitto Denko Corporation Élément comportant une mousse de remplissage
EP1607204A2 (fr) * 2004-06-15 2005-12-21 L & L Products, Inc. Fabrication de pièces moulées laminaires
WO2010015645A1 (fr) 2008-08-05 2010-02-11 Sika Technology Ag Écran acoustique

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3967579A1 (fr) * 2020-09-14 2022-03-16 Sika Technology Ag Élément isolant
WO2022053433A1 (fr) * 2020-09-14 2022-03-17 Sika Technology Ag Élément isolant

Also Published As

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