Title:
Baffle apparatus for a hollow structural member
Kind Code:
A1


Abstract:
A baffle apparatus mountable in a hollow structural member includes first and second sealed containers, each containing a separate reactive component. The first and second containers are formed of complementary melting point materials so as to melt and allow the reactive components to mix and react when the thermal energy is applied to the structural member. The reactive components form an expanded volume foam mass substantially filling, sealing, and/or reinforcing the cross section of the structural member.



Inventors:
Otto, David (Lake Orion, MI, US)
Application Number:
10/948906
Publication Date:
04/06/2006
Filing Date:
09/24/2004
Assignee:
JS Chamberlain & Associates, Inc. (Troy, MI, US)
Primary Class:
International Classes:
E04C2/00
View Patent Images:
Related US Applications:
20070251165Foldout Bed ModuleNovember, 2007Kern et al.
20170089067ANCHOR POSITIONING FORM WITH DRAINAGE SYSTEMMarch, 2017Blackwell
20050028451Weather screen apparatusFebruary, 2005Knoepp
20100031602Blowing Machine For Loosefil Insulation MaterialFebruary, 2010O'leary et al.
20030221387Laminated indoor flooring board and method of making sameDecember, 2003Shah
20090120026Core-Insulated Pre-Fabricated Wall Piece With Connector PinsMay, 2009Wetzel
20070227095Separated Member Wood FramingOctober, 2007Hubbe
20130019560WALLBOARD EDGE CLIP APPARATUSJanuary, 2013Marinucci
20120272592LIGHT WEIGHT MOLDED ROOF TILE WITH INTEGRATED SOLAR CAPABILITIESNovember, 2012Bellavia
20160010354Reinforcement Systems and Methods for Storage CoversJanuary, 2016Gaudet III
20050034414Hollow profile for securing objectsFebruary, 2005Unverzagt et al.



Primary Examiner:
ENGLE, PATRICIA LYNN
Attorney, Agent or Firm:
WILLIAM M HANLON, JR (TROY, MI, US)
Claims:
What is claimed is:

1. A baffle apparatus for a hollow member, the baffle apparatus comprising: a first container formed of a first melting point material mounted on the carrier; a first reactive component in the first container; a second container formed of a material having a melting point approximate the first melting point; a second reactive component in the second container; and the first and second containers disposed in proximity with each other wherein thermal energy applied to the first and second containers to raise the temperature of the first and second containers above the melting point of the materials forming the first and second containers releases the first and second components for reaction and expansion into the hollow structural member.

2. The baffle apparatus of claim 1 further comprising: means for joining the first and second containers together.

3. The baffle apparatus of claim 2 wherein the joining means comprises: complementary snap members formed on the first and second containers.

4. The baffle apparatus of claim 2 wherein the joining means comprises: adhesive.

5. The baffle apparatus of claim 1 wherein: at least one of the first and second containers is a blow molded container.

6. The baffle apparatus of claim 1 wherein: the first and second containers are formed of materials having similar melt temperatures.

7. The baffle apparatus of claim 1 wherein the material forming the first and second containers is selected from the group consisting of polypropylene, thermoplastic olefin and polyethylene.

8. The baffle apparatus of claim 1 wherein the first and second reactive components react to form a foam.

9. The baffle apparatus of claim 1 wherein the first and second reactive components react to form a polyurethane foam.

10. The baffle apparatus of claim 1 wherein: the first and second containers are sealed after the respective first and second reactive components are disposed therein.

11. The baffle apparatus of claim 1 further comprising: means for fixing one of the first and second containers to the carrier.

12. The baffle apparatus of claim 1 further comprising: a carrier mountable within a hollow member; and at least one of the first and second container disposed on the carrier.

13. The baffle apparatus of claim 12 wherein: the at least one of the first and second containers is fixed on the carrier.

14. The baffle apparatus of claim 12 wherein: at least one of the first and second containers, the carrier, and means for joining the first and second container has a catalystic effect on the reaction of the first and second reactive components during the application of thermal energy to the components and the components are mixed.

15. The baffle apparatus of claim 1 further comprising: means for enhancing mixing of the first and second reactive components after discharge of the first and second reactive components from the first and second containers.

16. The baffle apparatus of claim 15 wherein the mixing enhancing means comprises: irregular surface means disposed in the path of flow of the first and second components after the first and second components have been discharged from the first and second containers.

17. The baffle apparatus of claim 16 wherein the irregular surface means comprises: a plurality of steps of varying size.

18. The baffle apparatus of claim 17 further comprising: a carrier mountable within a hollow member; and the steps carried on the carrier.

19. The baffle apparatus of claim 18 wherein: the steps extend from the carrier.

20. The baffle apparatus of claim 18 wherein: the steps have increasing outer dimensions from a top to a bottom of the carrier.

21. The baffle apparatus of claim 16 wherein: at least one of the first and second containers has a central area substantially devoid of one of the first and second reactive components, respectively.

22. The baffle apparatus of claim 21 further comprising: a carrier mountable within a hollow member; and the central area of at least one of the first and second containers contacting the carrier.

23. The baffle apparatus of claim 22 wherein: the central area of at least one of the containers includes an aperture mountable about the carrier.

24. The baffle apparatus of claim 23 wherein: at least a portion of the carrier extends through the aperture to assist in supporting the at least one of the first and second containers on the carrier.

25. The baffle apparatus of claim 16 further comprising: a carrier mountable within a hollow member; the irregular surface means including a plurality of steps having an exposed outer surface disposed in the flow path of the first and second reactive components after the first and second reactive components have been discharged from the first and second containers, the plurality of steps having increased outer dimensions from a top to a bottom of the carrier.

Description:

BACKGROUND

Structural members, for vehicle bodies, are typically formed with hollow beams, such as pillars and rails, for weight reduction purposes while still providing structural strength. In a vehicle, the A, B and C upper and lower pillars, rocker rails, engine rails, etc., typically have a hollow cross-section. In some situations, some of the hollow rails or pillars, such as the A, B and C pillars, are used as ducts for sun roof drain tubes, wire harnesses, etc.

Due to the open nature of such rails and pillars, sound, water, dust, dirt, and gases may travel through the hollow structural members to the vehicle passenger compartment.

While it is known to place elastomeric, reactive foamable materials in vehicle hollow structural members which are activated by elevated temperatures as the vehicle passes through the paint ovens to foam to an expanded mass to provide structural rigidity to the hollow rail or beam, the designs have been complex in design thereby impeding easy application in the hollow structural members. Further, a large amount of the elastomeric material must be provided in order to fill the cross-section of the hollow structural member upon activation to a foamed or expanded state.

Another know method of providing a baffle apparatus is by pumping/mixing two part polyurethane foam in the A, B and C pillars/rails during the vehicle assembly sequence preferably after paint/oven operation. These require special dispensing equipment coupled with proper ventilation and safety equipment resulting in high risk economic feasibility for start-up. However, lesser amounts of polyurethane material are required to fill the cross section of the hollow structural member upon activation to a foam or expanded state.

It is still desirable to provide a baffle apparatus which can be easily mounted in hollow structural members, such as hollow structural members of vehicles, and is activated by the heat used in assembly operations, such as paint ovens, to a reacted, expanded, foamed state filling and sealing the cross-sectional shape of the hollow structural member from the intrusion of noise, dirt, dust, water and gas into the structural member and in turn, into the vehicle passenger compartment.

SUMMARY

The present invention is a baffle apparatus for mounting in a structural member, such as a hollow vehicle structural member, which undergoes a reaction to expand to a foamed state substantially filling the cross section of the structural member increasing the rigidity of the structural member and sealing the structural member from the intrusion of noise, dirt, dust, gas, and water through the structural member and into the passenger compartment.

In one aspect, the baffle apparatus can include a carrier mounted within a hollow structural member. A first hollow container formed of a first melting point material is disposed or mounted on the carrier. A first reactive component is sealed in the first container. A second hollow container is formed of a material having a melting point approximate the first melting point. A second reactive component is sealed in the second container. The first and second containers are disposed on the carrier in proximity with each other such that thermal energy applied to the first and second containers to raise the temperature of the first and second containers above the melting points of the materials forming the first and second containers releases the first and second components for reaction and expansion as a foam into and filling substantially the entire cross section of the hollow structural member.

The containers may alternately be disposed by themselves, in close proximity of each other, in the structural member.

In another aspect, the baffle apparatus includes means for fixedly joining the first and second containers. The joining means can include, but are not limited to, complementary snap members formed on the first and second containers or adhesive. At least one of the first and second containers is a blow molded container and formed of a similar material to the material forming the other container. The material forming the first and second containers may be selected from the group consisting of polypropylene, thermoplastic olefin and polyethylene having the described melt points.

In yet another aspect, the first and second reactive components react to form a polymeric foam such as polyurethane, polyisocyanate or the like.

In another aspect, the baffle apparatus includes irregular surface means which may be formed on the carrier supporting the first and second containers. The irregular surface means functions as a means for enhanced mixing of the first and second reactive components after release of the first and second components from the first and second containers.

In conclusion, there has been disclosed a baffle apparatus which can be mounted in a hollow structural member which automatically reacts and expands to a larger volume substantially filling and sealing the cross section of the structural member as the structural member moves through the assembly process and receives thermal energy, such as in a vehicle paint or primer operation. The baffle apparatus is easily mounted in the structural member and can be varied in cross sectional shape, expansion volume, etc., for ease of mounting, fixed retention prior to reaction, and foam expansion to any cross sectional volume or shape. The present invention uses some of the positive characteristics of known technology to provide a unique baffle apparatus and system.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features, advantages and other uses of the present invention will become more apparent by referring to the following detailed description and drawing in which:

FIG. 1 is a partial, perspective view showing the baffle apparatus of the present invention mounted in a vehicle structural member;

FIG. 2 is a cross-sectional view of the baffle apparatus taken along line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view similar to FIG. 2, but showing another aspect of the present invention;

FIG. 4 is a pictorial representation of the expanded baffle apparatus after heat activation; and

FIG. 5 is a side elevational view of another aspect of the present baffle apparatus.

DETAILED DESCRIPTION

Referring now to FIGS. 1-4, there is depicted a baffle apparatus 10 which may be used to seal the cross section of a hollow structural member found in diverse articles. It will be understood that the use of the baffle apparatus 10 in a hollow vehicle structural member, such as a upper or lower pillar or engine or rocker rail, is by way of example only as the baffle apparatus 10 of the present invention may be employed equally as well in other, non-automotive applications.

The vehicle pillar 12 is illustrated by example only as having a generally rectangular shape including four sidewalls 14, 16, 18, and 20 formed of one or a plurality of joined parts to define a hollow cross-section as shown in FIG. 1.

Prior to forming the pillar 12, the baffle 10 is mounted in the pillar 12 by means of interconnection between a carrier or support means, such as a shelf 22, forming part of the baffle apparatus 10 and complementarity shaped elements on the structural member 12, such as apertures, projections, etc., which mate with complementary shaped projections or apertures in the support shelf 22.

The interconnection of the support shelf 22 and the inner surface of the structural member 12 may also be implemented by a friction fit wherein the support shelf 22 has dimensions slightly larger than one cross-section portion of the structural member or pillar member 12; while still allowing fluid drainage required for vehicle assembly through the structural or pillar member 12.

The interconnection means enables the baffle apparatus 10 to be fixedly mounted in the structural member 12 during the assembly of the vehicle and prior to the passage of the vehicle through high temperature paint ovens. This will also enable the baffle 10 to remain in position in the structural member 12 as the vehicle is transported between an assembly plant and a different facility for the application of sealant and corrosion prevention materials, such as Electro coat or primer, or exterior paint.

The baffle apparatus 10 includes two containers 30 and 32 which, while illustrated as having the same shape, do not necessarily have to be identical in exterior dimensions and/or volume. The containers 30 and 32 are also shown as having a slight recess 34 along one edge, for example. This defines an opening between one edge of the containers 30 and 32 and the inner surface of the sidewall 20 of the structural member 12 to allow for the passage of a sunroof water drain tube, wire or wire harness through the structural member 12. Other openings for the drain tube or wires can be formed at other locations.

The containers 30 and 32 include an inlet or nozzle 36 which can be closed by a plug and/or a melted shut inlet after reactive components are introduced to the interior of the containers 30 and 32.

The baffle apparatus 10 may also include means for joining the containers 30 and 32 to each other. The joining means may include projections 38 which snap into or otherwise interlock with complementarity formed apertures in a surface of the adjacent container as shown in FIG. 3. Similarly, the projections 38 on the lowermost container 32 mounted on the support shelf 22 may also engage apertures or recesses in the support shelf 22, to fix the entire baffle apparatus 10 on the support shelf 22. Combinations of these joining features may also be used.

The joining means may also be an adhesive 33, shown in FIG. 3, having a melt point proximate the melt points of the containers 30 and 32. An adhesive 35 may also be used to fix the container 32 to the support shelf 22. The adhesive 35 may also have any melt point depending on the type of attachment. For example, the adhesive 35 may have a catalyic effect, or non-effect, on the reacting materials 50 and 52.

For example, the containers 30 and 32 may be a blow molded sheet or a blow molded hollow enclosure of suitable materials having melt points or temperatures less than the melt points or temperatures of the reactive components 50 and 52 stored in the containers 30 and 32. This suitable material should not react and/or interact with the reactive materials 50 and 52 during normal storage and operating temperatures.

For example only, the containers 30 and 32 may be formed of any suitable polymer, copolymer, or polymeric blend having a suitable melt temperature. Nonlimiting examples of suitable materials include various olefinic polyalkytenes as well as elastomers such as thermoplastic elastomers. Nonlimiting examples of suitable polymeric materials include at least one of polypropylene, thermoplastic polyolefin or polyethylene.

For example, in a vehicle application, the containers 30 and 32 are formed of a material having a similar melt temperature of about 250° F. to about 300° F. This will enable the containers 30 and 32 to melt thereby allowing interaction and mixing of the reactive components 50 and 52 initially stored in the containers 30 and 32 during automotive primer or paint operations. The containers 30 and 32 may be made of the same material or dissimilar materials having similar melt temperatures.

The material described above form the containers into a semi-rigid shape thereby allowing easy insertion and mounting of the containers 30 and 32 in the structural member 12 with or without rigid mounting shelf 22.

The containers 30 and 32 may have any suitable wall thickness, such as 0.5-1.0 mm. Further, a portion of each container 30 and 32, such as opposed, central portions of each container 30 and 32, may have a reduced thickness so as to complete melting sooner than the remaining portions of the container thereby allowing the reactive components of the container 30 and 32 to begin mixing before the entire containers 30 and 32 have melted.

The material and the wall thickness of the first and second containers 30 and 32 may be selected or tuned for complementary action such that the first and second containers 30 and 32 melt in a predefined sequence. For example, the upper or first container 30 can have a combination of a predefined wall thickness and a material selection with a melting point such that the upper disposed first container 30 begins melting to enable discharge of the first reactive component therefrom a very short time, such as one second, by example only, to ensure that a reactive component stored in the first uppermost positioned container 30 will completely flow into and mix with a reactive component stored in the second container as the second container 32 begins to melt.

The thickness and material melting point can be tuned or selected for any sequential mixing action.

It should be noted that the support shelf 22 can be formed of metal so as to support the reactive components as the containers 30 and 32 melt. If the support shelf 22 is formed of a polymeric material, the polymeric material should have a higher temperature than the melt temperature of the material used to form the containers 30 and 32 and will not melt or degrade during high temperature conditions, i.e., above 400° F.

The reactive components 50 and 52 separately stored in the containers 30 and 32, when reacting together during melting of the containers 30 and 32, create an expansive foam which results in a mass 60 shown in FIG. 4 of a large volume substantially completely filling the cross section of the structural member 12 and surrounding any drain tubes or wires extending through the structural member 12. The thermal energy applied to the structural member by the paint process through which the vehicle moves may support the reaction. The reaction of the two components 50 and 52 create a polyurethane or other foam. The volume of the components 50 and 52 can be varied to create various foam density or structural configurations depending upon the cross sectional area of the structural member to be sealed.

When the expanded foam material 60 has cured, as shown in FIG. 4, the foamed mass 60 substantially completely seals the cross section of the structural member 12 thereby minimizing and/or eliminating the intrusion of noise, dirt, dust, gas, or water through the structural member 12 and into the vehicle passenger compartment. This mass 60 may or may not enhance the structural integrity of structural member 12.

Referring now to FIG. 5, it is depicted another aspect of the present baffle apparatus in which at least one of both containers 70 and 72, which are substantially the same as container 30 and 32, respectively, are formed with a central aperture 74 and 76, respectively. This forms each container 70 and 72 into a donut-shape. The diameter of the apertures 74 and 76 are chosen to enable each container 70 and 72 to be mounted on a shelf or carrier 78 which is itself mounted within the structural member according to the methods and components described above for the shelf 22.

In this aspect, the shelf or carrier 78 forms a means for enhancing mixing of the two reactants in the container 70 and 72 during and after melting of the containers 70 and 72. The mixing enhancing means is carried on the carrier 78, and may be a series of tiers or steps 80, 82, 84, and 86 with four steps being shown and described by way of example only. When the containers 70 and 72 are mounted over an endmost portion 88 of the carrier 78, a radially inner portion of the container 70 rests on the step 80. Similarly, a radially inner portion of the container 72 rests on and is partially supported by the adjacent step 82. In this manner, the carrier 78 supports the containers 70 and 72.

When the containers 70 and 72 melt, as described above, the reactants in each container will flow by gravity toward the bottom of the carrier 78. As the reactants encounter each successive step 82, 84, and 86, the reactants form a mixing zone 90 in which the reactants tumble to enhance thorough mixing and a faster and more complete homogeneous reaction between the reactants.

The steps 80, 82, 84, and 86 may have any plan shape, so as to fit within the structural member. Thus, the steps 80, 82, 84, and 86 may have a circular plan shape, a polygonal shape formed by discrete legs, intermixed arcuate and linear portions, etc.

The steps 80, 82, 84, and 86 forming the mixing enhancing means can be broadly viewed as surface irregularities on the carrier 78. Thus, any other shaped surface irregularity, such as randomly or regularly spaced projections, etc., may also be formed on the exterior tapering side walls of the carrier 78 to enhance the mixing of the reactants initially stored in the container 70 and 72.

Reactive components 50 and 52 stored in respective containers 30 and 32, or in containers 70 and 72, may be any suitable materials that create, enhance or regulate an appropriate expansive foam. Nonlimiting examples of appropriate expansive foams include polyurethane, polyisocyanate, and polyisocyanurates. Where a suitable polyurethane foam is employed, it is contemplated that one container 30 will contain a suitable isocyanate component while the other container 32 will contain an appropriate polyol component.

The polyurethane foam may be adapted to have a relatively short cure time of between about 4 and 15 minutes. In some forms of the device as disclosed herein, the polyol and isocyanate can be selected to yield a cure time of less than about 12 minutes. It is contemplated that the polyol and isocyanate can be selected to have even shorter cure time depending upon the particular structural member and consideration regarding specific manufacture and the like.

It is contemplated that the reagents can be chosen to yield a rapid mix/cream time with a rise time of less than about 5 minutes in certain embodiments with rise times of less than 2 minutes in other embodiments. The specific rise time will be one that will permit the resulting polyurethane foam to rise and conform to the specific geometries of the structural member 12. It is to be understood that the rise time and cream/mix time can be varied to alter foam density or structural configurations depending upon the cross-sectional area of the structural member 12 to be sealed and/or reinforced. The foam is adapted to harden to a useful stiffness and to adhere to the respective surfaces of the structural member in an appropriate sealing member. The foam should not reflow or degrade after the application of additional thermal energy or heat.

The polyol component employed as one reactive component can be any known polymer polyol, polyether polyol, polyester polyol, and the like. Examples of the polyether polyol are alkaline oxide adducts of an active hydrogen compound. The active hydrogen compound includes polyhydric alcohols such as ethyleneglycol, propyleneglycol, 1,4-butanediol, 1,6-hexanediol, diethyleneglycol, triethyleneglycol, dipropyleneglycol, neopentylglycol, glycerin, trimethylolpropane, pentaerythritol, methylglycoside, sorbitol, and sucrose; polyhydric phenols such as pyrogallol, and hydroquinone; bisphenols such as bisphenol A, bisphenol S, bisphenol F, and low condensates of phenol and formaldehyde; aliphatic diamines such as propylenediamine, hexamethylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, pentamethylenehexamine, ethanolamine, diethanolamine, triethanolamine, and aminoethylethanolamine; aromatic amines, such as aniline, phenylenediamine, xylylenediamine, methylenedianiline, and diphenyl ether diamine; alicyclic amines such as isophoronediamine, and cyclohexylenediamine; heteroalicyclic amines such as aminoethypiperazine; the aforementioned polyhydric phenols, and Mannich polyols (compounds prepared by reaction of the aforementioned aliphatic amine and formalin). Such an active hydrogen compound may be a mixture of two or more thereof. The alkaline oxide to be added to the active hydrogen compound includes ethylene oxide, propylene oxide, and butylene oxide, and combination of two or more thereof. Of these, ethylene oxide, propylene oxide, and combination thereof are preferred.

The isocyanate may be any suitable isocyanate compound typically employed in polyurethane formation. Nonlimiting examples of suitable isocyanate include aromatic polyisocyanates; aliphatic polyisocyanates, and the like. Nonlimiting examples of aliphatic polyisocyanates includes isophorone diisocyanate, 1,6-hexamethylene diisocyanate, and 4,4-dicyclohexylmethane diisocyanate; aromatic polyisocyanates such as xylylene diisocyanate, tetramethylxylylene diisocyanate; modifications thereof (carbodiimide-modification, allophanate-modification, urea-modification, biuret-modification, isocyanurate-modification, oxazolidone-modification, etc.); and isocyanate-terminated prepolymers.

Nonlimiting examples of aromatic polyisocyanate include compounds such as 2,4- or 2,6-toluene diisocyanate (TDI), crude TDI, diphenylmethane 2,4′- or 4,4′-diisocyanate (MDI), and polymethylene polyphenyl polyisocyanate (crude MDI).

A polyol-isocyanate index [(equivalent number of isocyanate group in isocyanate component per equivalent number of active hydrogen in polyol component) X 100] can be in the range from about 60 to about 130 in polyurethane product production, and in the range from about 150 to 400 in polyisocyanurate ring-containing product production.

Out of the above isocyanates, mixtures of TDI and MDI are particularly preferred in the production of polyurethane foam. The isocyanate index therefor ranges from 70 to 130, but is not limited thereto.

A suitable catalyst or blowing agent can be incorporated into an appropriate container 30, 32. Examples of suitable blowing agents include, but are not limited to, hydrogen atom containing halogenated hydrocarbons, low boiling hydrocarbons, and/or water. Nonlimiting examples of hydrogen atom-containing halogenated hydrocarbon useful as the blowing agent include specifically HCFC type ones such as HCFC-123, HCFC-141b, HCFC-22, and HCFC-142b; HFC type ones such as HFC-134a, HFC-245fa, HFC-245ca, and HFC-236ea; and mixtures of two or more thereof. Of these, preferred are HCFC-141b, HFC-134a, HFC-245fa, and mixtures of two or more thereof. Suitable low-boiling hydrocarbons are typically those having a boiling point ranging from 0 to 50° C. nonlimiting examples of suitable low boiling hydrocarbons include at least one of propane, butane, pentane, cyclopentane.

The blowing agent is employed in an amount sufficient to achieve the desired level of foaming. Hydrogen atom-containing halogenated hydrocarbons employed as the blowing agent may be used in an amount ranging usually from 5 to 100 parts, preferably from 10 to 80 parts by weight, to 100 parts by weight of the polyol. The low-boiling hydrocarbon as the blowing agent may be used in an amount ranging usually from 1 to 40 parts, preferably from 1 to 30 parts by weight, to 100 parts by weight of the polyol. When water is used as the sole blowing agent, it may be employed in an amount ranging from 0.5 to 10 parts, preferably from 1 to 8 parts by weight, to 100 parts by weight of the polyol. In the combined use of a hydrogen atom-containing halogenated hydrocarbons and water as the blowing agent, the hydrogen atom-containing halogenated hydrocarbon is used in an amount ranging usually from 1 to 100 parts, preferably from 10 to 80 parts by weight, and water is used in an amount ranging usually from 0.1 to 10 parts, preferably from 0.5 to 8 parts by weight, to 100 parts by weight of the polyol. In the combined use of a low-boiling hydrocarbons and water as the blowing agent, the low-boiling hydrocarbon is used in an amount ranging usually from 1 to 40 parts, preferably from 1 to 30 parts by weight, and water is used in an amount ranging usually from 0.1 to 10 parts, preferably from 0.1 to 5 parts by weight, to 100 parts by weight of the polyol.

In the production of polyurethane foam, water is especially suitable among the aforementioned blowing agents. The amount of water to be used depends on the density of the intended foam product, and is usually not less than 2 parts by weight, preferably in the range from 3.0 to 8.0 parts by weight to 100 parts by weight of the polyol.

A suitable catalyst can be included as appropriate in containers 30, 32 or in the baffle apparatus construction as desired or required to catalyze the polyurethane reactions herein. Nonlimiting examples of suitable catalysts include tertiary amines such as dimethylethanolamine, triethylenediamine, tetramethylpropanediamine, tetramethylhexamethylethyldiamine, dimethylcyclohexylamine, and the like. Suitable catalysts can also include appropriate organo metallic compounds such as stanis octoate, dibutyltin dilaurate and the like.

It is also contemplated that suitable additional additives may be included. Such additives are typically used in the active hydrogen component (polyol component of the material). Examples of such additives include, but are not limited to, foam stabilizers, flame retardants, viscosity modifiers, pigments, and the like. Nonlimiting examples of foam stabilizers include various cyloxane, polyalcolene oxide block copolymers, and the like. Nonlimiting examples of flame retardants include, but are not limited to, materials such as tris(chloroethyl) phosphate, tris(chloropropyl) phosphate, tricresyl phossphate, fluorinated parafin, and the like. Nonlimiting examples of viscosity modifiers include dibutylphthalate, dioctyl phthalate, alcolene carbonates, and the like.

The polyesterpolyol includes condensation polyesters prepared by reaction of a polybasic acid such as succinic acid, adipic acid, sebacic acid, maleic acid, dimer acids, and trimellitic acid with a polyhydric alcohol; and polylactone polyol prepared by ring-opening polymerization of ε-caprolactone, or the like.

The polymer polyol includes, for example, those obtained by reaction of the aforementioned polyetherpolyol with an ethylenic unsaturated monomer such as butadiene, acrylonitrile, and styrene in the presence of a radical polymerization catalyst.

In conclusion, there has been disclosed a baffle apparatus that is mountable in a hollow structural member and which automatically expands to a larger volume substantially completely filling and sealing the cross section of the structural member as the structural member moves through an assembly process and undergoes the application of thermal energy, such as in a vehicle paint or primer operation. The baffle apparatus is easily mounted in the structural member and can be varied in cross sectional shape, volume, etc., for ease of mounting, fixed retention prior to reaction, and foam expansion to any cross sectional volume or shape.