CA1054869A - Method and apparatus for forming multiple-component composite structures - Google Patents
Method and apparatus for forming multiple-component composite structuresInfo
- Publication number
- CA1054869A CA1054869A CA224,425A CA224425A CA1054869A CA 1054869 A CA1054869 A CA 1054869A CA 224425 A CA224425 A CA 224425A CA 1054869 A CA1054869 A CA 1054869A
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- Canada
- Prior art keywords
- spray
- granular
- resin
- liquid
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- 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.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
- B29C41/34—Component parts, details or accessories; Auxiliary operations
- B29C41/36—Feeding the material on to the mould, core or other substrate
- B29C41/365—Construction of spray-up equipment, e.g. spray-up guns
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
- B05B7/1481—Spray pistols or apparatus for discharging particulate material
- B05B7/149—Spray pistols or apparatus for discharging particulate material with separate inlets for a particulate material and a liquid to be sprayed
- B05B7/1495—Spray pistols or apparatus for discharging particulate material with separate inlets for a particulate material and a liquid to be sprayed and with separate outlets for the particulate material and the liquid
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Reinforced Plastic Materials (AREA)
- Nozzles (AREA)
- Moulding By Coating Moulds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method and apparatus can be used to form complex laminates and other such structures with economical use of resins. This apparatus and method provides a mixed spray of a plural component liquid resin and curing agent with granular and fiber material entrained in the mixed spray. The apparatus includes a plurality of resin and curing agent spray means and granular and fibrous material dispensing means associated with the curing agent and resin spray means. The plurality of sprays are adapted to intersect and mix externally of the apparatus prior to deposition upon a surface. One or more mixed with the liquid spray so as to provide a mixed spray of multiple component materials. Reinforcing chopped fibers such as glass may be introduced into this mixed spray from a chopper located above the array of powder and liquid sprays.
A method and apparatus can be used to form complex laminates and other such structures with economical use of resins. This apparatus and method provides a mixed spray of a plural component liquid resin and curing agent with granular and fiber material entrained in the mixed spray. The apparatus includes a plurality of resin and curing agent spray means and granular and fibrous material dispensing means associated with the curing agent and resin spray means. The plurality of sprays are adapted to intersect and mix externally of the apparatus prior to deposition upon a surface. One or more mixed with the liquid spray so as to provide a mixed spray of multiple component materials. Reinforcing chopped fibers such as glass may be introduced into this mixed spray from a chopper located above the array of powder and liquid sprays.
Description
The present inventi.on xelates to a method of and an appa-ratus for foxming multiple~co~ponent composite str.uctures, :Such stxuctures may include lam~nates having a plurality of distinct layers~ each layer beàng composed to have different physical properties, In addition~ such structures may be made having no distinct interface, but having gradually changing material con-stituents, or gradually changing material prOpQrtions. Particulate and fibrous materials are mixed into catalyzed resin and the use of particulate and fibrous material provides special physical and chemical properties and sa~es expensive resins while imparting such properties. This invention includes a method of and an appa-ratus for providing a spray, including a plural component material with a multiplicity of entrained filler and reinforcing materials, and more particularly, includes an apparatus for and a method of providing a commingled spray, including a plural component material with granular material and with chopped fiber glass wetted by the li~uid component prior to deposition.
Multiple~component composite structures which may be formed with this invention include, for example, rigid laminates including outer layers of one composite material and a central layer or layers of other composite materials. The outer layer can be composed to have one set of physical characteristics, such as resistance to oxidation and ultraviolet light, high gloss and color retention, hardness and other characteristics associated ~ith exterior surfaces. The central layer or layers can be com-posed to have an entirely different set of physic~l characteristics, such as lo~ dens~ity~ low. thermal conductivity, rigidity, low ther-mal expansion, and good adhesion with the outer layers. With this lOS486~
method and apparatus~ a rig~d structure can be economically and quickly made haYin~ speci~ic physical properties not othexwise available.
It is also feasible to use this method and apparatus to pro~ide coatings upon a myriad of surfaces such as wood, paperboard, plasterboard, polyester~based materials~ cement-based or cement~impregnated paper materials and masonry exterior sur-faces, including but not limited to brick, cement and stone. This method and apparatus can reduce the cost of the coating, reduce the weight of the coating, provide a surface with a coating having a variable surface contour and various colors, and provide an ad-herent coating with which mechanical fasteners may be easily used.
Plural component li~uid materials which may be sprayed concurrently with granular and fibrous materials include polyester resins, epoxy resins, urethane resins, silicone rubber and the like.
Generally, the plural component liquid material is converted, at ambient atmospheric temperature, from a liquid to a solid by the addition of an appropriate curing agent, which includes catalyst materials. Polyester resins may be cured by the addition of an or-ganic peroxide catalyst and a naphthenate or aniline promoter.Epoxies may be cured by the addition of a suitable amine or anhy-dride curing agent. Urethanes may be obtained by the addition of a suitable isocyanate ester to a polyol resin. Silicone rubber may be obtained by the addition of a suitable tin soap to a silicone elastomer.
The addition of the curing agent to the other plural com-ponent liquid material is usually made just prior to use to thereby initiate curing Gf the plural component material. Generally, the
Multiple~component composite structures which may be formed with this invention include, for example, rigid laminates including outer layers of one composite material and a central layer or layers of other composite materials. The outer layer can be composed to have one set of physical characteristics, such as resistance to oxidation and ultraviolet light, high gloss and color retention, hardness and other characteristics associated ~ith exterior surfaces. The central layer or layers can be com-posed to have an entirely different set of physic~l characteristics, such as lo~ dens~ity~ low. thermal conductivity, rigidity, low ther-mal expansion, and good adhesion with the outer layers. With this lOS486~
method and apparatus~ a rig~d structure can be economically and quickly made haYin~ speci~ic physical properties not othexwise available.
It is also feasible to use this method and apparatus to pro~ide coatings upon a myriad of surfaces such as wood, paperboard, plasterboard, polyester~based materials~ cement-based or cement~impregnated paper materials and masonry exterior sur-faces, including but not limited to brick, cement and stone. This method and apparatus can reduce the cost of the coating, reduce the weight of the coating, provide a surface with a coating having a variable surface contour and various colors, and provide an ad-herent coating with which mechanical fasteners may be easily used.
Plural component li~uid materials which may be sprayed concurrently with granular and fibrous materials include polyester resins, epoxy resins, urethane resins, silicone rubber and the like.
Generally, the plural component liquid material is converted, at ambient atmospheric temperature, from a liquid to a solid by the addition of an appropriate curing agent, which includes catalyst materials. Polyester resins may be cured by the addition of an or-ganic peroxide catalyst and a naphthenate or aniline promoter.Epoxies may be cured by the addition of a suitable amine or anhy-dride curing agent. Urethanes may be obtained by the addition of a suitable isocyanate ester to a polyol resin. Silicone rubber may be obtained by the addition of a suitable tin soap to a silicone elastomer.
The addition of the curing agent to the other plural com-ponent liquid material is usually made just prior to use to thereby initiate curing Gf the plural component material. Generally, the
- 2 ~
curing cycle of the plural component material is of short duration.
For example, upon the addition of bot~ a catalyst and a promoter, pol~ester resin may solidify ~n a matte~ of 45 minutes or less.
The plural component materiaI can be mixed with granular materials such as perlite, clay~ sand~ talc~ mica, aluminum hy~
drate, calcium carbonate, calcium silicate~ glass beads~ plastic spheres, fire retardants and the like~ and with reinforcing fiber glass or other fibrous materials. Such particulate and fibrous fillers may provide any one or more of the following properties:
reinforcement of the resin rigidity, reduced shrinkage, economy in the use of resin, low density and special properties such as fire retardancy.
With the method and apparatus of this invention, higher concentrations, as well as different combinations, of such materials can be obtained in such structures than with other methods and apparatus. The difficulty of wetting a high concentration of fillers in attempting to pre-mix it with the resin, as well as the difficulty in pumping and atomizing the viscous mixture, has limited concentration of filler material to typically about 17% by volume.
This invention permits significantly higher mixed concentrations because of the increased wetting of particulate and fibrous mater-ials that is achieved by this new method and apparatus.
Among older methods U.S. Patent 3,399,834 shows an appa-ratus for and a method of depositing commingled sprays of promoted polyester and catal~st wherein a spray of the catalyst is mixed with sprays of promoted polyester externally of the spray apparatus usin~ a plurality -of converging sprays. Prior to deposition upon a surface to be coated, t~e mixed spray has chopped lengths of glass ~054869 fibers mixed therewith. The chopped length of glass fibers are used to enhance the physical properties of the polyester resin. In addition, U.S. Patent 3,676,197 shows an apparatus or and a method of mixing granular material entrained in a fluid medium with sprays of a plural component material and a curing agent and depositing the resultant mixture upon a surface of an article.
The method and apparatus of this invention is capable of forming multiple-component composite structures that were not possible with prior existing methods and apparatus.
The present invention provides an apparatus for and a method of wetting and,substantially uniformly mixing granular and fiber material in large concentrations with a plural component material exteriorly of a spray apparatus and prior to engagement of such materials with and deposition,on a mold surface.
The invention in one aspect provides a method of forming a multi,-component composite structure. This method includeq atomizing a liquid resin material and directing same from a plurality of spaced apart sites in such a way that the sprays converge. The method also includes atomizing a liquid resin curing agent and projecting the resulting spray into the converging resin sprays from a site intermediate the sites of atomization of the resin. Gas entrained granular material is also projected from a site located closely adjacent one of the sites of atomization of the resin material while a second gas entrained granular material is directed from a site closely adjacent the other site of atomization of the resin material so that the two sprays of liquid and granular materials intersect.
In a further feature of the invention, fiber material is cut to form a plurality of cut fibers having a 1~
_ 4 f~
` 1054869 predetermined length and the cut fibers are directed into the liquid and granular sprays from a location above the latter thereby to prov~de a mixed spray of resin and curing agent with entrained granular and fiber material mixed with and wetted by the liquid resin and curing agent. This mixed spray of resin, curing agent and granular and fiber materials is deposited on a suitable surface.
In accordance with a further aspect of the invention there is provided apparatus for forming multiple-component composite structures. One form of the apparatusincludes a plurality of spray-forming means carried by a housing at spaced apart locations. Each of the spray forming means may be connected with a source of plural component material including separate sources of resin and curing agent. A
granular emitting means is carried by the housing and preferably each such means being closely adjacent a respective one of the plurality of spray forming means. Means are provided to entrain the granular material in a flow of gas and deliver it to the granular emitting means. The apparatus is also provided with a cutter to form fibrous material into fibers of pre-determined length and means are carried by the housing to effect operation of the plurality of spray forming means, the granular emitting means and the cutter.
In a preferred form of the invention there is provided a fluidized bed source of the granular material, a hose being connected with the fluidized bed source and terminating adjacent to the granular emitting means. The means for entraining the granular material serve to entrain such material in a flow of gas in the hose thereby to deliver such granular material to the granular emitting means.
The invention, in a further aspect, provides a ~,k - 4a -novel method of providing a mixture of liquid and solid particulate materials. This aspect of the invention involves atomizing the liquid material airlessly by delivering it at high hydraulic pressure to a site of atomization and projecting it at high velocity as a thin expanding film to-form the liquid material into spray particles. A solid particulate material is fluidized to form a fluidized bed and the fluidized solid particles are entrained in a flow of compressed air. A uniform flow of entrained solid particulate material and air is delivered to a site of emission located closely adjacent the site of atomization of the liquid particles. The uniform flow of solid particles is emitted closely adjacent the high velocity projecting liquid film so that the solid particulate material is captured in the induced flow of air adjacent the sited atomization of the liquid component and thoroughly mixed and wetted therewith.
Further features and advantages of the present in-vention will become apparent from the following description of preferred embodiments of same taken in conjunction with the appended claims.
FIGURE 1 is a perspective view of one embodiment of the present invention;
FIGURE 2 is a diagrammatic view showing spray patterns of the embodiment of FIGURE l; and FIGURE 3 is a partial cross-sectional view of the embodiment of FIGURE 1 through the particulate passageways in its housing.
Referring now to FIGURE L of the drawing, a spray apparatus of the present invention is indicated by the reference numeral 10. The spray apparatus 10 includes housing or support means 11, outboard plural component spray means 12 and 13 and centrally located curing agent spray means 14 positioned between the outboard spray means 12 and 13. The housing 11 serves as the A t~ _ m~in suppoxt member for the outboaxd spray means 12 and 13 and for the curing agent spray means 14. The curing agent spray means 14 may provide a spray o~ organic peroxide catalyst whexe the outboard spray means 12 and 13 may be spraying a promoted polyester resin or a spray of suitable amine or anhydride where the outboard spray means are spraying an epoxy resin. Urethanes may be obtained by the addition of a su~table isoc~anate ester to a polyester resin.
Silicone rubber may be obtained by the addition of a suitable tin soap to a silicone elastomer.
Each of the outboard spray means 12 and 13 are suitably connected through plural component material manifold 15 and con-duit 16 to a source (not shown) of a plural component material.
The plural component material may be supplied under pressures of about 300 to 3000 p.s.i. to the outboard spray means 12 and 13 by an air-operated hydraulic pump (not shown). Using the apparatus 10 shown in FIGURE 1, the plural component material is atomized by interaction with the surrounding air upon emerging from the ori-fices of the outboard spray means 12 and 13. The plural component material, of course, may be atomized by any other suitable means such as by compressed air. The outboard spray means 12 and 13 are illustrated as including nozzles which hydraulically atomize the plural component material, and the curing agent spray means 14 is illustrated as being a compressed air spray means. The outboard spra~ means 12 and 13 are angled or inclined toward each other as shown in FIGURE 2 in such a manner that the spray patterns 19 and 20 pro~ided by each of the outboard spray means converge and intersect at a Iocus spaced a~out five inches from the front of the spray apparatus 10, ~054869 The centrally Iocated curing agent spra~ means 14 is flanked by and on substant~all~ the same horizontal plane with the outboard spra~ means 12 and 13~ The curing agent spra~ means 14 is connected to a source ~n~t shown~ of curing agent through curing agent man~fold 17 and conduit 18. The curing agent spray means 14 is positioned to provide a spray 21 of curing agent that intersects the con~erging sprays o~ the outboard means at the locus of their intersection. The vertical width o~ the spray pattern of the curing agent as it intersects the sprays of the outboard spray means 12 and 13 is preferably substantially the same as the ver-tical width of the sprays of the plural component material to assure substantially uniform mixing of the curing agent with the plural component material.
In order to provide a spray of substantially uniformly mixed plural component material and curing agent, the curing agent spray means 14 is desirably centrally located between the outboard spray means 12 and 13. The outboard spray means 12 and 13, when dispensing a polyester resin, dispense up to about 99 weight per-cent of the total weight of the fluid component of the spray issuing from apparatus 10. The outboard spray means 12 and 13 dis-pense approximately 50 weight percent of the total weight of the fluid component when dispensing a urethane. The remainder of the liquid component of the spray issuing from the spray means 10 is dispensed by the curing agent spray means 14. The relative ratios of other resins and cur~ng agents, of course, may vary, depending upon the plural component material used, Locations of the curing agent spray means 14 at a posit~on other than centrally between the outboard spray means 12 and 13 may not yield as thorough a mixing ~ 6 -lOS4869 of the. cuxing agent wi.th the othex p.lural component.and may result in an undesixable'defl:ect~on in the resulting spra~
Spaced fxom but positioned closel~ ad~'acent each of the outboard spxay means are gxanula~ material emitting means 22 and 23. The'granular emittin~ means ma~ include spray-forming no:zzles pivotally mounted upon housing 11 to direct the granular material emitted toward the sprays from the outboard spray means 12 and 13 as desired.
The'granular material may be any suitable material which, by using a suitable fluidized bed and immexsed venturi pump, may be entrained in a flowing stream of compressed air, or may be con-veyed using any other suitable granular material conveying means.
Such granular material may include perlite, clay, sand, talc, mica, aluminum hydrate, calcium carbonate, calcium silicate, glass beads, plastic spheres, fire retardants and the like.
A suitable source of granular material is shown in FIGURE 1. The source includes an open container 24 with a porous plate 25 ad;acent its bottom to form an air chamber 26 at its bottom. The granular material is supported by the porous plate 25, which is made from a material like sintered polyethylene. Compressed air from an air source is supplied .
through hose 27 to an immersed venturi pump 28 and through a sealed tube 29 to the air chamber 26. The slow and uniform flow of air through porous plate 25 fluidizes the granular material in the container 24, and the flow of compressed air thxough the. venturi pump 2~ dxaws. the fluidized ~ranular material into an openin~ (not shown] in the. ven.turi pump, entrains it in the mo~ing air stream and deIi~ers it through hose 30 to a smooth passageway or passageways in housing 11 (sho~n more'particularly in FIGURE 3~ that dixect the'air-entrained granular material to granular spray-,forming nozzles 22 and 23 that are mounted on and carried by housing 11.
FIGURE 3 shows in gXeater detail the portion of appa~
ratus 10 that is associated with'the emission o~ granular filler materials, The'passageways lla ~only one of which is shown in FIGURE 3) in housing 11 through which granular and particulate material are directed are straight throughout the housing. The granular spray~forming nozzles 22 and 23 are mounted at the forward end of passageways lla. The hose 30 conveying the granular material from the fluidized bed is inserted into and held within the passageways lla by a hose retainer 30a. Hose 30 extends thus from the source of powder 24 up to the granular nozzle means 22 and 23 and provides an uninterrupted and smooth-walled passageway for the air-entrained granular material to provide an even delivery of granular particles to the spray-forming means.
The granular nozzles may be designed to form the air-entrained granular material into any pattern desired for association with the liquid plural component material sprays from nozzles 12, 13 and 14. The outputs of the granular nozzles 22 and 23 are located closely adjacent to the outboard spray means 12 and 13.
The creation of spray by these liquid spray means forms an area of lo~ pressure closel~ adjacent the means 12 and 13. Locating the granular~emitting nozzles closely ad;acent this area of low pres-sure, as for example~ within an inch or so, results in entrapment of the 'granular material in the liquid spray with the assistance of the 'air ~low adj'acent the front of the apparatus 10. The ~ 8 ~
1054~369 nozzles 22 and 23 shown in FIGURE 1 and FIGURE 2, for example, include orifices that are generally elliptical with'a ma~or dia meter o~ about 0.5 inches and a m~nor diameter of about 0.25 inches. The nozzles include inner surfaces adjacent to orifices that are 'cun7ed to direct the air~entrained granular material into the area adjacent thé means forming the liquid spra~s.
The granular material from nozzles 22 and 23 should in~
tersect the sprays of the pluraI component material so that the granular material is adequately wetted by and substantially uni-10 formly mixed with the plural component material prior to depositionupon surface 31. ~ocating the granular~-emitting means 22 and 23 about one inch above the 'orifices of the outboard spray means 12 and 13 and curing agent spray means 14 so the granular material is brought into the spray of plural component material within several inches of the front of the spray apparatus 10 appears to result in good wetting and substantially uniform mixing of the granular material with the sprays of the liquid plural component material.
A cutter means 32 is used to spray and deposit cut fibers with the plural component material and granular material. The cut-20 ter means 32 cuts fibers into various lengths by changing the spacingbetween blades in a cutting wheel within the cutter. Such a cutter means 32, described in U.S. Patent 3,399,834, preferably includes a housing 33, an adjustable attaching means 34, and a directional opening 35.
In this type of cutter means, the attaching means 34 provides for m~3vable mounting of the housiny 33 upon the housing 11, pre~erablx~ ahove 'the granular emitting means and so that the open-ing 35 through which the 'cut roving is ej'ected may be angularly _ 9 _ Yaried with xespect to the spray~ issuing from spray means 12, 13, 14, 22 and 23. Th~s pro~des for directlng the cut roving in the spray streams so that the roving ~ill be "pre~et" and will not ride on top of ox fall through the spray stream.
Cutter means 32 is positioned to receive roving strand 36 and to cut the continuous strands into short filaments, which are then e;ected through opening 35 into the spray streams of spray means 12, 13, 14, 22 and 23, as shown in FIGURE 2. Fiber material most frequently used is a roving of glass fibers. The ¢ut lengths of fiber glass can be~ used to provide reinforcement throughout the body of the composite material.
Operation of the apparatus can be effected by actuation of trigger means 38 carried by housing 11. Actuation of trigger means 38 can provide in the proper sequence, operation of valve m~ans controlling the flow of liquid to spray means 12, 13 and 14, the flow of atomizing air to spray means 14, and the flow of compressed air to air motor 37. The flow of compressed air to the apparatus 10 through hose 39 can be detected by an air flow switch (not shown) whose output can be used to effect a flow of air to the granular material source through hose 27 and de-liYery of granular material to apparatus 10 through hose 30.
Release of the trigger 38 will substantially simultane-ously terminate the flow of plural component material from spray means 12 and 13, the flow o~ curing agent and atomizing air from spray means 14 of apparatus 10 and the flow of granular material and fibers from granular emitting means 22 and 23 and cutter means 32.
As shown in FIGURE 2a, the con~erging spray streams 19 ~ 10 ``
and 20 issuing from outboaxd spxa~ means 12 and l3 may have a sub-stantially oval ox ~elliptical~shaped trans~erse cross s~ection.
The liquid spra~s are formed bel~w the means to emit granular material and films and form a base for ~such materials. As shown in FIGURE 2b, emission of the particulate material closely adja-cent thé sites of formation of the liquid sprays results in the granular material being quic~ly urged into the liquid sprays. The intersection of the converging liquid and granular sprays issuing from the outboard liquid and granular spray means and the fibers from cutter means 32, as shown in FIGURE 2c, causes a resultant mixed homogeneous spray with the granular and fiber material substantially uniformly wetted by the liquid and distributed in the spray.
As illustrated in FIGURE 2a, the array of liquid and solid sprays form a pyramid-like arrangement before intersecting.
The outboard liquid sprays 19 and 20 carry almost all the liquid material sprayed and form a spray pattern base with the curing agent spray 21. They capture the granular materials emitted from nozzles 22 and 23 and the fibers ejected from orifice 35 and inter-secting, uniformly mix and wet the granular materials and fibers.Where cut fibers are used, they form a significant percentage of the weight of the composite spray material, typically 25 to 35 per-cent in glass~reinforced polyester structures; however, lower percentages may be used, if desirable.
Where two different granular materials are used, such as ~lass beads and aluminum hydrate~ the apparatus lO can be ar-ranged to intermingle the two paxticulate materials prior to, or at about the locus of intersection with the liquid sprays.
~ 11 -The apparatus of this invention thus ~orms a superior means to mix a plurality of materials. The liquid components are at~mized by the use of a high h~dxaulic pressure'of from 300 to 300~ p s.i. and with specially shaped nozzles', for example~
adapted to form the li~uid into a thin, expanding fan~shaped form.
The liquid is e~'ected at a very high'velocit~ from the nozzles and atomized by interaction with'the atmosphere. An area of low pressure is created ad~acent the nozzles b~ operation of the noz~
zles in forming the spray. Particulate, or granular, material to be mixed with the liquid component is uni~ormly delivered to and released closely adjacent the liquid nozzles in the low pressure area where it is captured by the air flow at the front of the appa-ratus. With two liquid nozzles in use, two particulate components may be used, one located closely adjacent each liquid nozzle so that each particulate material is captured by a spray of liquid material. By directing the two liquid nozzles so that they inter-sect, the liquid and granular spra~s are uniformly mixed and the particulate material is wetted. Plural component material may be formed with an unusually high percentage of particulate material using this method and apparatus. In addition, fibers can be added to this material by cutting and ejecting the fibers into the air ``
flow forwardly of the apparatus. Where a catalyzed resin liquid ~ jnt1~oJ.u c ed ~ I material is used, curing agent is desirably lntroducted- into the L J~i spray from between the two liquid nozzles.
Suitable additives may be introduced into the plural component material for color, ultraviolet absorption, flame-proofing and the like.' Pi~ments ma~ be used to achieve'the desired color of the plural component material. Antimony oxide, aluminum ~ 12 -trih~.drate.~. chlorinated ~axes. and the like may. be. us.ed to assist in flame~proofing the:plural component material.
The. ~olume of granular material to plural component material may. vary considerabl~, Using perlite, the volume of perlite ma~ be'about 30 to 65 percent b~. volume of perlite with the remaining percentage of polyester resin. Using glass beads, the percentage of total volume'that may be glass beads is most gener-ally 20 to 40 percent; howe~er, smaller percentages may be used, if desirable.
The thickness of a coating of plural component material and granular material. using this method and apparatus may be as desired. The lower limit on thickness of the coating is about 15 to 20 mils with the upper limit only limited by the economics of the situation. Generally, for coatings having good weathering char-acteristics and strength, the thickness of a coating including a binder of polyester and perlite granular material should approach about 0.125 to about 0.25 of an inch or more.
Cut fiber glass provides reinforcement and may be used in percentages of 10 to 30 percent, to be determined by the diffi-culty of roll-out. Thick coatings of material, including cut fiber glass and particulate, must be "rolled out"; that is, the deposited coating must be worked with a roller to eliminate air trapped in the interstices of the fibers. Where these composite coatings are too thick, it is not possible to roll out such entrapped air. The coating is instead pushed about by the roller and entrapped air is not xemoved. Thus such mixed coatings on the order of one inch thick are'not practical ~ith :cut glass fibers.
The spxay apparatus 10 may be hand held or carried by any ~ 13 suitable b~om (not sho~n~ and mo~ahle base (not shown) to facili-ta1:e thé movement of the spra~ appara*us.
The following examples axe intended to illustrate the formation of multiple component composite structures using the apparatus and method of this invention~
EXAMPLE I
A laminated multicomponent structure can be manufactured using the method and apparatus of this invention by the follow~
ing prGceaures. A mold surface is spaced about l8~36 inches in front of the spray apparatus lO. Polyester resin is supplied to the outboard spray means at a pressure of about 2000 p.s.i. at a rate of about l900 cubic centimeters per minute through the airless spray nozzles forming the polyester resin into an elongated, fan-shaped spray pattern having an acute angle of 25 degrees. The sprays from the outboard spray means converge about 5 inches in front of the spray apparatus. Undiluted methyl ethyl ketone per-oxide catalyst is atomized from the central nozzle at a rate of about 30 cubic centimeters per minute, using atomizing air pressure of 20 p.s.i. from a compressed air spray nozzle of more or less standard confi~uration, such as the Spraying Systems' No. El8B. A
spray of catalyst intersects the outboard spray means about 5 inches in front of the spray apparatus at the locus of their intersection.
Aluminum trihydrate, the granular material, is supplied to the gran-ular emitting nozzles associated with the outboard spray means at a rate of about 2050 grams per minute. The granular emitting spray means are Iocated closel~ adjacent the sites of atomization of the polyester resin to direct the aluminum trihydrate into the liquid spray. The aluminum trihydrate is manufactured by Aluminum Company ~A of America and sold under the trade ~m ~ALCOA C3II'. Chopped fiber glass is directed into the spray of liquid and granular mat:erial at a rate of about 1.5 pounds per minute. The cut fibers have an average length o~ about one inch. This composite laminate is deposited on the mold surface to a thickness of about .1 of an inch. Entrapped air is rolled out of this coating. This layer is allowed to cure at room temperature of 70 degrees Fahrenheit for one hour.
A central core is then deposited upon the resulting laminate structure. As before, the apparatus is spaced 18~36 inches away from the laminate. Polyester resin is supplied to the outboard spray means under a pressure of 2000 p.s.i. at the pump at a rate of about 1900 cubic centimeters per minute. The outboard spray means are nozzles which form the polyester resin material into aan elongated spray pattern having an acute angle of about 25 degrees.
As before, the outboard sprays converge about five inches in front of the spray apparatus. Undiluted methyl ethyl ketone peroxide catalyst is delivered to a compressed air atomizing nozzle at a rate of about 40 cubic centimeters per minute and atomized by com-pressed air supplied to the atomizing nozzle at 20 p.s.i. A spray of peroxide catalyst intersects the resin sprays about 5 inches in front of the spray apparatus. From the central core, the aluminum trihydrate is supplied to only one of the granular emitting means - at a rate of about 400 grams per minute. The other spray emitting means is connected wit~ the source of Minnesota Mining and Manufac-turing Company glass beads. These glass beads have an average dia-meter of about three mils. Thé Minnesota Mining and Manufacturing ~ 15 -105~869 Compan~ glass beads are su~plied to the other ~ranular emitting means at a rate of abDut 8QQ ~rams per minute. Thè two granular emitting means are 'Ioc~ted closel~ adjacent the 'resin atomiz-ers and direct the''glass bubbles and alumin'um, trihydrate 'into the liquid sprays in front of the appa~atus. The commingled~ catalyzed poly-ester resin, the 'glass beads and aluminum trihydrate are carried and deposited on the first layer to a thickness of about .1 of an inch. The central core is then allowed to cure at ambient tempera-ture of 70 degrees Fahrenheit for about 60 minutes.
After the central core has had an opportunity to cure, a top layer like the bottom layer is added to the central core.
The apparatus and method of operation are exactly like those used in making the first layer and the materials in this top layer are deposited to a thickness of .1 of an inch and rolled out as before.
The top layer is then allowed to cure for about 60 minutes at 70 degrees Fahrenheit.
The resulting three-layered laminate is a rigid, composite structure of .3 of an inch thick, having glass reinforced outer layers and a low density central layer to increase its rigidity.
Because of the use of the aluminum trihydrate and the glass beads, approximately 25 percent less resin is used to form this structure than would otherwise have been required with a resulting saving in weight and cost.
EXAMPLE II
A composite structure is manufactured using the apparatus and method of this invention with the benefits of a substantial sa~ing in res'in and weight and ~ith little, if any loss of rigidity and strength. The surface of a mQld is spaced a~Qut 18 to 36 inches in front of the'spra~ apparatus 10. Pol~ester resin is supplied to the outboard spra~ means under a pressure of 2000 p.s.i. at the pump at the rate of about 1900 cubic centimeters per minute through air-less nozzles' forming the pol~es'tex res'in into an elongated fan-like spray pattern having an acute angle o~ about 25 degrees. Undiluted methyl ethyl ket'one'peroxide'is supplled to the atomizing nozzle at a rate'of 40 cubic centimeters per minute and atomized by com~
pressed air supplied to the Spraying System No. E18B atomizing nozzle at 20 p.s.i. The liquid sprays of resin and catalyst inter-sect about 5 inches forwardly of the apparatus. Particulate aluminum trihydrate, sold by Aluminum Company of America under the trade name i'ALC~A C31", is supplied to the two granular emitting means at a combined rate o~ 2000 grams per minute. The granular emitting means are arranged to direct the aluminum trihydrate into the liquid sprays forwardly of the site of formation of the liquid sprays. Fiber glass roving is cut and expelled into the liquid and granular sprays at a rate of 400 grams per minute. Standard fiber glass gun roving is cut into fibers having an average length of about 3/4 of an inch. The composite material is sprayed onto the mold form to a thickness of about .1 of an inch and is allowed to cure at room temperature of 70 degrees Fahxenheit. The resulting composite material structure was a rigid, translucent, glass-reinforced polyester sheet having low density and good strength.
~;,,, ~rk ~A "Suzorite", a particulate mica sold under this ~ by Marietta Resources International Ltd., can be substituted for the aluminum trihydrate.' 1~5~869 `EXAMPL'~'I`II
A composite material structure was prepared that is suitable'for thé hull of a boat. Pure pigmented catalyst poly-ester resin is spxa~ed onto a polished mold surface to a thickness of about .005 inches. The' piymented polyes'ter resin is a high quality type of the'type normally used as gel coat in the manufac-ture of polyes'ter resin particles and in spra~ing, the apparatus is operated in a manner known to those 'skilled in the art. Then glass beads are added to the gel coat and anothe'r .010 inches of coating is applied. The geI coat resin is allowed to cure for 60 minutes at 70 degrees Fahrenheit. When the gel coat has cured, the procedure as set forth in Example I above was repeated, but with glass bubbles substituted for ALCOA C31 in the central core.
The resulting composite material structure was ideally suited for the hull of a boat.
The method and apparatus of this invention can thus be used to manufacture many different composite material structures.
Such a device is particularly applicablé in the manufacture of boats, bathroom fixtures, counter tops, and many other such 20'' 'items.
curing cycle of the plural component material is of short duration.
For example, upon the addition of bot~ a catalyst and a promoter, pol~ester resin may solidify ~n a matte~ of 45 minutes or less.
The plural component materiaI can be mixed with granular materials such as perlite, clay~ sand~ talc~ mica, aluminum hy~
drate, calcium carbonate, calcium silicate~ glass beads~ plastic spheres, fire retardants and the like~ and with reinforcing fiber glass or other fibrous materials. Such particulate and fibrous fillers may provide any one or more of the following properties:
reinforcement of the resin rigidity, reduced shrinkage, economy in the use of resin, low density and special properties such as fire retardancy.
With the method and apparatus of this invention, higher concentrations, as well as different combinations, of such materials can be obtained in such structures than with other methods and apparatus. The difficulty of wetting a high concentration of fillers in attempting to pre-mix it with the resin, as well as the difficulty in pumping and atomizing the viscous mixture, has limited concentration of filler material to typically about 17% by volume.
This invention permits significantly higher mixed concentrations because of the increased wetting of particulate and fibrous mater-ials that is achieved by this new method and apparatus.
Among older methods U.S. Patent 3,399,834 shows an appa-ratus for and a method of depositing commingled sprays of promoted polyester and catal~st wherein a spray of the catalyst is mixed with sprays of promoted polyester externally of the spray apparatus usin~ a plurality -of converging sprays. Prior to deposition upon a surface to be coated, t~e mixed spray has chopped lengths of glass ~054869 fibers mixed therewith. The chopped length of glass fibers are used to enhance the physical properties of the polyester resin. In addition, U.S. Patent 3,676,197 shows an apparatus or and a method of mixing granular material entrained in a fluid medium with sprays of a plural component material and a curing agent and depositing the resultant mixture upon a surface of an article.
The method and apparatus of this invention is capable of forming multiple-component composite structures that were not possible with prior existing methods and apparatus.
The present invention provides an apparatus for and a method of wetting and,substantially uniformly mixing granular and fiber material in large concentrations with a plural component material exteriorly of a spray apparatus and prior to engagement of such materials with and deposition,on a mold surface.
The invention in one aspect provides a method of forming a multi,-component composite structure. This method includeq atomizing a liquid resin material and directing same from a plurality of spaced apart sites in such a way that the sprays converge. The method also includes atomizing a liquid resin curing agent and projecting the resulting spray into the converging resin sprays from a site intermediate the sites of atomization of the resin. Gas entrained granular material is also projected from a site located closely adjacent one of the sites of atomization of the resin material while a second gas entrained granular material is directed from a site closely adjacent the other site of atomization of the resin material so that the two sprays of liquid and granular materials intersect.
In a further feature of the invention, fiber material is cut to form a plurality of cut fibers having a 1~
_ 4 f~
` 1054869 predetermined length and the cut fibers are directed into the liquid and granular sprays from a location above the latter thereby to prov~de a mixed spray of resin and curing agent with entrained granular and fiber material mixed with and wetted by the liquid resin and curing agent. This mixed spray of resin, curing agent and granular and fiber materials is deposited on a suitable surface.
In accordance with a further aspect of the invention there is provided apparatus for forming multiple-component composite structures. One form of the apparatusincludes a plurality of spray-forming means carried by a housing at spaced apart locations. Each of the spray forming means may be connected with a source of plural component material including separate sources of resin and curing agent. A
granular emitting means is carried by the housing and preferably each such means being closely adjacent a respective one of the plurality of spray forming means. Means are provided to entrain the granular material in a flow of gas and deliver it to the granular emitting means. The apparatus is also provided with a cutter to form fibrous material into fibers of pre-determined length and means are carried by the housing to effect operation of the plurality of spray forming means, the granular emitting means and the cutter.
In a preferred form of the invention there is provided a fluidized bed source of the granular material, a hose being connected with the fluidized bed source and terminating adjacent to the granular emitting means. The means for entraining the granular material serve to entrain such material in a flow of gas in the hose thereby to deliver such granular material to the granular emitting means.
The invention, in a further aspect, provides a ~,k - 4a -novel method of providing a mixture of liquid and solid particulate materials. This aspect of the invention involves atomizing the liquid material airlessly by delivering it at high hydraulic pressure to a site of atomization and projecting it at high velocity as a thin expanding film to-form the liquid material into spray particles. A solid particulate material is fluidized to form a fluidized bed and the fluidized solid particles are entrained in a flow of compressed air. A uniform flow of entrained solid particulate material and air is delivered to a site of emission located closely adjacent the site of atomization of the liquid particles. The uniform flow of solid particles is emitted closely adjacent the high velocity projecting liquid film so that the solid particulate material is captured in the induced flow of air adjacent the sited atomization of the liquid component and thoroughly mixed and wetted therewith.
Further features and advantages of the present in-vention will become apparent from the following description of preferred embodiments of same taken in conjunction with the appended claims.
FIGURE 1 is a perspective view of one embodiment of the present invention;
FIGURE 2 is a diagrammatic view showing spray patterns of the embodiment of FIGURE l; and FIGURE 3 is a partial cross-sectional view of the embodiment of FIGURE 1 through the particulate passageways in its housing.
Referring now to FIGURE L of the drawing, a spray apparatus of the present invention is indicated by the reference numeral 10. The spray apparatus 10 includes housing or support means 11, outboard plural component spray means 12 and 13 and centrally located curing agent spray means 14 positioned between the outboard spray means 12 and 13. The housing 11 serves as the A t~ _ m~in suppoxt member for the outboaxd spray means 12 and 13 and for the curing agent spray means 14. The curing agent spray means 14 may provide a spray o~ organic peroxide catalyst whexe the outboard spray means 12 and 13 may be spraying a promoted polyester resin or a spray of suitable amine or anhydride where the outboard spray means are spraying an epoxy resin. Urethanes may be obtained by the addition of a su~table isoc~anate ester to a polyester resin.
Silicone rubber may be obtained by the addition of a suitable tin soap to a silicone elastomer.
Each of the outboard spray means 12 and 13 are suitably connected through plural component material manifold 15 and con-duit 16 to a source (not shown) of a plural component material.
The plural component material may be supplied under pressures of about 300 to 3000 p.s.i. to the outboard spray means 12 and 13 by an air-operated hydraulic pump (not shown). Using the apparatus 10 shown in FIGURE 1, the plural component material is atomized by interaction with the surrounding air upon emerging from the ori-fices of the outboard spray means 12 and 13. The plural component material, of course, may be atomized by any other suitable means such as by compressed air. The outboard spray means 12 and 13 are illustrated as including nozzles which hydraulically atomize the plural component material, and the curing agent spray means 14 is illustrated as being a compressed air spray means. The outboard spra~ means 12 and 13 are angled or inclined toward each other as shown in FIGURE 2 in such a manner that the spray patterns 19 and 20 pro~ided by each of the outboard spray means converge and intersect at a Iocus spaced a~out five inches from the front of the spray apparatus 10, ~054869 The centrally Iocated curing agent spra~ means 14 is flanked by and on substant~all~ the same horizontal plane with the outboard spra~ means 12 and 13~ The curing agent spra~ means 14 is connected to a source ~n~t shown~ of curing agent through curing agent man~fold 17 and conduit 18. The curing agent spray means 14 is positioned to provide a spray 21 of curing agent that intersects the con~erging sprays o~ the outboard means at the locus of their intersection. The vertical width o~ the spray pattern of the curing agent as it intersects the sprays of the outboard spray means 12 and 13 is preferably substantially the same as the ver-tical width of the sprays of the plural component material to assure substantially uniform mixing of the curing agent with the plural component material.
In order to provide a spray of substantially uniformly mixed plural component material and curing agent, the curing agent spray means 14 is desirably centrally located between the outboard spray means 12 and 13. The outboard spray means 12 and 13, when dispensing a polyester resin, dispense up to about 99 weight per-cent of the total weight of the fluid component of the spray issuing from apparatus 10. The outboard spray means 12 and 13 dis-pense approximately 50 weight percent of the total weight of the fluid component when dispensing a urethane. The remainder of the liquid component of the spray issuing from the spray means 10 is dispensed by the curing agent spray means 14. The relative ratios of other resins and cur~ng agents, of course, may vary, depending upon the plural component material used, Locations of the curing agent spray means 14 at a posit~on other than centrally between the outboard spray means 12 and 13 may not yield as thorough a mixing ~ 6 -lOS4869 of the. cuxing agent wi.th the othex p.lural component.and may result in an undesixable'defl:ect~on in the resulting spra~
Spaced fxom but positioned closel~ ad~'acent each of the outboard spxay means are gxanula~ material emitting means 22 and 23. The'granular emittin~ means ma~ include spray-forming no:zzles pivotally mounted upon housing 11 to direct the granular material emitted toward the sprays from the outboard spray means 12 and 13 as desired.
The'granular material may be any suitable material which, by using a suitable fluidized bed and immexsed venturi pump, may be entrained in a flowing stream of compressed air, or may be con-veyed using any other suitable granular material conveying means.
Such granular material may include perlite, clay, sand, talc, mica, aluminum hydrate, calcium carbonate, calcium silicate, glass beads, plastic spheres, fire retardants and the like.
A suitable source of granular material is shown in FIGURE 1. The source includes an open container 24 with a porous plate 25 ad;acent its bottom to form an air chamber 26 at its bottom. The granular material is supported by the porous plate 25, which is made from a material like sintered polyethylene. Compressed air from an air source is supplied .
through hose 27 to an immersed venturi pump 28 and through a sealed tube 29 to the air chamber 26. The slow and uniform flow of air through porous plate 25 fluidizes the granular material in the container 24, and the flow of compressed air thxough the. venturi pump 2~ dxaws. the fluidized ~ranular material into an openin~ (not shown] in the. ven.turi pump, entrains it in the mo~ing air stream and deIi~ers it through hose 30 to a smooth passageway or passageways in housing 11 (sho~n more'particularly in FIGURE 3~ that dixect the'air-entrained granular material to granular spray-,forming nozzles 22 and 23 that are mounted on and carried by housing 11.
FIGURE 3 shows in gXeater detail the portion of appa~
ratus 10 that is associated with'the emission o~ granular filler materials, The'passageways lla ~only one of which is shown in FIGURE 3) in housing 11 through which granular and particulate material are directed are straight throughout the housing. The granular spray~forming nozzles 22 and 23 are mounted at the forward end of passageways lla. The hose 30 conveying the granular material from the fluidized bed is inserted into and held within the passageways lla by a hose retainer 30a. Hose 30 extends thus from the source of powder 24 up to the granular nozzle means 22 and 23 and provides an uninterrupted and smooth-walled passageway for the air-entrained granular material to provide an even delivery of granular particles to the spray-forming means.
The granular nozzles may be designed to form the air-entrained granular material into any pattern desired for association with the liquid plural component material sprays from nozzles 12, 13 and 14. The outputs of the granular nozzles 22 and 23 are located closely adjacent to the outboard spray means 12 and 13.
The creation of spray by these liquid spray means forms an area of lo~ pressure closel~ adjacent the means 12 and 13. Locating the granular~emitting nozzles closely ad;acent this area of low pres-sure, as for example~ within an inch or so, results in entrapment of the 'granular material in the liquid spray with the assistance of the 'air ~low adj'acent the front of the apparatus 10. The ~ 8 ~
1054~369 nozzles 22 and 23 shown in FIGURE 1 and FIGURE 2, for example, include orifices that are generally elliptical with'a ma~or dia meter o~ about 0.5 inches and a m~nor diameter of about 0.25 inches. The nozzles include inner surfaces adjacent to orifices that are 'cun7ed to direct the air~entrained granular material into the area adjacent thé means forming the liquid spra~s.
The granular material from nozzles 22 and 23 should in~
tersect the sprays of the pluraI component material so that the granular material is adequately wetted by and substantially uni-10 formly mixed with the plural component material prior to depositionupon surface 31. ~ocating the granular~-emitting means 22 and 23 about one inch above the 'orifices of the outboard spray means 12 and 13 and curing agent spray means 14 so the granular material is brought into the spray of plural component material within several inches of the front of the spray apparatus 10 appears to result in good wetting and substantially uniform mixing of the granular material with the sprays of the liquid plural component material.
A cutter means 32 is used to spray and deposit cut fibers with the plural component material and granular material. The cut-20 ter means 32 cuts fibers into various lengths by changing the spacingbetween blades in a cutting wheel within the cutter. Such a cutter means 32, described in U.S. Patent 3,399,834, preferably includes a housing 33, an adjustable attaching means 34, and a directional opening 35.
In this type of cutter means, the attaching means 34 provides for m~3vable mounting of the housiny 33 upon the housing 11, pre~erablx~ ahove 'the granular emitting means and so that the open-ing 35 through which the 'cut roving is ej'ected may be angularly _ 9 _ Yaried with xespect to the spray~ issuing from spray means 12, 13, 14, 22 and 23. Th~s pro~des for directlng the cut roving in the spray streams so that the roving ~ill be "pre~et" and will not ride on top of ox fall through the spray stream.
Cutter means 32 is positioned to receive roving strand 36 and to cut the continuous strands into short filaments, which are then e;ected through opening 35 into the spray streams of spray means 12, 13, 14, 22 and 23, as shown in FIGURE 2. Fiber material most frequently used is a roving of glass fibers. The ¢ut lengths of fiber glass can be~ used to provide reinforcement throughout the body of the composite material.
Operation of the apparatus can be effected by actuation of trigger means 38 carried by housing 11. Actuation of trigger means 38 can provide in the proper sequence, operation of valve m~ans controlling the flow of liquid to spray means 12, 13 and 14, the flow of atomizing air to spray means 14, and the flow of compressed air to air motor 37. The flow of compressed air to the apparatus 10 through hose 39 can be detected by an air flow switch (not shown) whose output can be used to effect a flow of air to the granular material source through hose 27 and de-liYery of granular material to apparatus 10 through hose 30.
Release of the trigger 38 will substantially simultane-ously terminate the flow of plural component material from spray means 12 and 13, the flow o~ curing agent and atomizing air from spray means 14 of apparatus 10 and the flow of granular material and fibers from granular emitting means 22 and 23 and cutter means 32.
As shown in FIGURE 2a, the con~erging spray streams 19 ~ 10 ``
and 20 issuing from outboaxd spxa~ means 12 and l3 may have a sub-stantially oval ox ~elliptical~shaped trans~erse cross s~ection.
The liquid spra~s are formed bel~w the means to emit granular material and films and form a base for ~such materials. As shown in FIGURE 2b, emission of the particulate material closely adja-cent thé sites of formation of the liquid sprays results in the granular material being quic~ly urged into the liquid sprays. The intersection of the converging liquid and granular sprays issuing from the outboard liquid and granular spray means and the fibers from cutter means 32, as shown in FIGURE 2c, causes a resultant mixed homogeneous spray with the granular and fiber material substantially uniformly wetted by the liquid and distributed in the spray.
As illustrated in FIGURE 2a, the array of liquid and solid sprays form a pyramid-like arrangement before intersecting.
The outboard liquid sprays 19 and 20 carry almost all the liquid material sprayed and form a spray pattern base with the curing agent spray 21. They capture the granular materials emitted from nozzles 22 and 23 and the fibers ejected from orifice 35 and inter-secting, uniformly mix and wet the granular materials and fibers.Where cut fibers are used, they form a significant percentage of the weight of the composite spray material, typically 25 to 35 per-cent in glass~reinforced polyester structures; however, lower percentages may be used, if desirable.
Where two different granular materials are used, such as ~lass beads and aluminum hydrate~ the apparatus lO can be ar-ranged to intermingle the two paxticulate materials prior to, or at about the locus of intersection with the liquid sprays.
~ 11 -The apparatus of this invention thus ~orms a superior means to mix a plurality of materials. The liquid components are at~mized by the use of a high h~dxaulic pressure'of from 300 to 300~ p s.i. and with specially shaped nozzles', for example~
adapted to form the li~uid into a thin, expanding fan~shaped form.
The liquid is e~'ected at a very high'velocit~ from the nozzles and atomized by interaction with'the atmosphere. An area of low pressure is created ad~acent the nozzles b~ operation of the noz~
zles in forming the spray. Particulate, or granular, material to be mixed with the liquid component is uni~ormly delivered to and released closely adjacent the liquid nozzles in the low pressure area where it is captured by the air flow at the front of the appa-ratus. With two liquid nozzles in use, two particulate components may be used, one located closely adjacent each liquid nozzle so that each particulate material is captured by a spray of liquid material. By directing the two liquid nozzles so that they inter-sect, the liquid and granular spra~s are uniformly mixed and the particulate material is wetted. Plural component material may be formed with an unusually high percentage of particulate material using this method and apparatus. In addition, fibers can be added to this material by cutting and ejecting the fibers into the air ``
flow forwardly of the apparatus. Where a catalyzed resin liquid ~ jnt1~oJ.u c ed ~ I material is used, curing agent is desirably lntroducted- into the L J~i spray from between the two liquid nozzles.
Suitable additives may be introduced into the plural component material for color, ultraviolet absorption, flame-proofing and the like.' Pi~ments ma~ be used to achieve'the desired color of the plural component material. Antimony oxide, aluminum ~ 12 -trih~.drate.~. chlorinated ~axes. and the like may. be. us.ed to assist in flame~proofing the:plural component material.
The. ~olume of granular material to plural component material may. vary considerabl~, Using perlite, the volume of perlite ma~ be'about 30 to 65 percent b~. volume of perlite with the remaining percentage of polyester resin. Using glass beads, the percentage of total volume'that may be glass beads is most gener-ally 20 to 40 percent; howe~er, smaller percentages may be used, if desirable.
The thickness of a coating of plural component material and granular material. using this method and apparatus may be as desired. The lower limit on thickness of the coating is about 15 to 20 mils with the upper limit only limited by the economics of the situation. Generally, for coatings having good weathering char-acteristics and strength, the thickness of a coating including a binder of polyester and perlite granular material should approach about 0.125 to about 0.25 of an inch or more.
Cut fiber glass provides reinforcement and may be used in percentages of 10 to 30 percent, to be determined by the diffi-culty of roll-out. Thick coatings of material, including cut fiber glass and particulate, must be "rolled out"; that is, the deposited coating must be worked with a roller to eliminate air trapped in the interstices of the fibers. Where these composite coatings are too thick, it is not possible to roll out such entrapped air. The coating is instead pushed about by the roller and entrapped air is not xemoved. Thus such mixed coatings on the order of one inch thick are'not practical ~ith :cut glass fibers.
The spxay apparatus 10 may be hand held or carried by any ~ 13 suitable b~om (not sho~n~ and mo~ahle base (not shown) to facili-ta1:e thé movement of the spra~ appara*us.
The following examples axe intended to illustrate the formation of multiple component composite structures using the apparatus and method of this invention~
EXAMPLE I
A laminated multicomponent structure can be manufactured using the method and apparatus of this invention by the follow~
ing prGceaures. A mold surface is spaced about l8~36 inches in front of the spray apparatus lO. Polyester resin is supplied to the outboard spray means at a pressure of about 2000 p.s.i. at a rate of about l900 cubic centimeters per minute through the airless spray nozzles forming the polyester resin into an elongated, fan-shaped spray pattern having an acute angle of 25 degrees. The sprays from the outboard spray means converge about 5 inches in front of the spray apparatus. Undiluted methyl ethyl ketone per-oxide catalyst is atomized from the central nozzle at a rate of about 30 cubic centimeters per minute, using atomizing air pressure of 20 p.s.i. from a compressed air spray nozzle of more or less standard confi~uration, such as the Spraying Systems' No. El8B. A
spray of catalyst intersects the outboard spray means about 5 inches in front of the spray apparatus at the locus of their intersection.
Aluminum trihydrate, the granular material, is supplied to the gran-ular emitting nozzles associated with the outboard spray means at a rate of about 2050 grams per minute. The granular emitting spray means are Iocated closel~ adjacent the sites of atomization of the polyester resin to direct the aluminum trihydrate into the liquid spray. The aluminum trihydrate is manufactured by Aluminum Company ~A of America and sold under the trade ~m ~ALCOA C3II'. Chopped fiber glass is directed into the spray of liquid and granular mat:erial at a rate of about 1.5 pounds per minute. The cut fibers have an average length o~ about one inch. This composite laminate is deposited on the mold surface to a thickness of about .1 of an inch. Entrapped air is rolled out of this coating. This layer is allowed to cure at room temperature of 70 degrees Fahrenheit for one hour.
A central core is then deposited upon the resulting laminate structure. As before, the apparatus is spaced 18~36 inches away from the laminate. Polyester resin is supplied to the outboard spray means under a pressure of 2000 p.s.i. at the pump at a rate of about 1900 cubic centimeters per minute. The outboard spray means are nozzles which form the polyester resin material into aan elongated spray pattern having an acute angle of about 25 degrees.
As before, the outboard sprays converge about five inches in front of the spray apparatus. Undiluted methyl ethyl ketone peroxide catalyst is delivered to a compressed air atomizing nozzle at a rate of about 40 cubic centimeters per minute and atomized by com-pressed air supplied to the atomizing nozzle at 20 p.s.i. A spray of peroxide catalyst intersects the resin sprays about 5 inches in front of the spray apparatus. From the central core, the aluminum trihydrate is supplied to only one of the granular emitting means - at a rate of about 400 grams per minute. The other spray emitting means is connected wit~ the source of Minnesota Mining and Manufac-turing Company glass beads. These glass beads have an average dia-meter of about three mils. Thé Minnesota Mining and Manufacturing ~ 15 -105~869 Compan~ glass beads are su~plied to the other ~ranular emitting means at a rate of abDut 8QQ ~rams per minute. Thè two granular emitting means are 'Ioc~ted closel~ adjacent the 'resin atomiz-ers and direct the''glass bubbles and alumin'um, trihydrate 'into the liquid sprays in front of the appa~atus. The commingled~ catalyzed poly-ester resin, the 'glass beads and aluminum trihydrate are carried and deposited on the first layer to a thickness of about .1 of an inch. The central core is then allowed to cure at ambient tempera-ture of 70 degrees Fahrenheit for about 60 minutes.
After the central core has had an opportunity to cure, a top layer like the bottom layer is added to the central core.
The apparatus and method of operation are exactly like those used in making the first layer and the materials in this top layer are deposited to a thickness of .1 of an inch and rolled out as before.
The top layer is then allowed to cure for about 60 minutes at 70 degrees Fahrenheit.
The resulting three-layered laminate is a rigid, composite structure of .3 of an inch thick, having glass reinforced outer layers and a low density central layer to increase its rigidity.
Because of the use of the aluminum trihydrate and the glass beads, approximately 25 percent less resin is used to form this structure than would otherwise have been required with a resulting saving in weight and cost.
EXAMPLE II
A composite structure is manufactured using the apparatus and method of this invention with the benefits of a substantial sa~ing in res'in and weight and ~ith little, if any loss of rigidity and strength. The surface of a mQld is spaced a~Qut 18 to 36 inches in front of the'spra~ apparatus 10. Pol~ester resin is supplied to the outboard spra~ means under a pressure of 2000 p.s.i. at the pump at the rate of about 1900 cubic centimeters per minute through air-less nozzles' forming the pol~es'tex res'in into an elongated fan-like spray pattern having an acute angle o~ about 25 degrees. Undiluted methyl ethyl ket'one'peroxide'is supplled to the atomizing nozzle at a rate'of 40 cubic centimeters per minute and atomized by com~
pressed air supplied to the Spraying System No. E18B atomizing nozzle at 20 p.s.i. The liquid sprays of resin and catalyst inter-sect about 5 inches forwardly of the apparatus. Particulate aluminum trihydrate, sold by Aluminum Company of America under the trade name i'ALC~A C31", is supplied to the two granular emitting means at a combined rate o~ 2000 grams per minute. The granular emitting means are arranged to direct the aluminum trihydrate into the liquid sprays forwardly of the site of formation of the liquid sprays. Fiber glass roving is cut and expelled into the liquid and granular sprays at a rate of 400 grams per minute. Standard fiber glass gun roving is cut into fibers having an average length of about 3/4 of an inch. The composite material is sprayed onto the mold form to a thickness of about .1 of an inch and is allowed to cure at room temperature of 70 degrees Fahxenheit. The resulting composite material structure was a rigid, translucent, glass-reinforced polyester sheet having low density and good strength.
~;,,, ~rk ~A "Suzorite", a particulate mica sold under this ~ by Marietta Resources International Ltd., can be substituted for the aluminum trihydrate.' 1~5~869 `EXAMPL'~'I`II
A composite material structure was prepared that is suitable'for thé hull of a boat. Pure pigmented catalyst poly-ester resin is spxa~ed onto a polished mold surface to a thickness of about .005 inches. The' piymented polyes'ter resin is a high quality type of the'type normally used as gel coat in the manufac-ture of polyes'ter resin particles and in spra~ing, the apparatus is operated in a manner known to those 'skilled in the art. Then glass beads are added to the gel coat and anothe'r .010 inches of coating is applied. The geI coat resin is allowed to cure for 60 minutes at 70 degrees Fahrenheit. When the gel coat has cured, the procedure as set forth in Example I above was repeated, but with glass bubbles substituted for ALCOA C31 in the central core.
The resulting composite material structure was ideally suited for the hull of a boat.
The method and apparatus of this invention can thus be used to manufacture many different composite material structures.
Such a device is particularly applicablé in the manufacture of boats, bathroom fixtures, counter tops, and many other such 20'' 'items.
Claims (15)
1. A method of forming a multicomponent composite structure comprising the steps of atomizing a liquid resin material from a plurality of spaced-apart sites, and directing the resulting plurality of sprays to converge, atomizing a liquid resin curing agent and projecting the resulting spray into the converging resin sprays from a site between the sites of atomization of the resin, projecting gas-entrained granular material from a plurality of sites each of which is located closely adjacent a respective one of the sites of atomization of the resin material, cutting a fiber material to form a plurality of cut fibers having a predetermined length and directing the cut fibers into the liquid and granular sprays from a location above said liquid and granular sprays to provide a mixed spray of resin and curing agents with entrained granular and fiber material substantially mixed with and wetted by liquid resin and curing agent, and depositing the mixed spray of resin and curing agent and granular and fiber materials on a surface.
2. The method of claim 1, wherein the resin materials are atomized at sites separated about 3 inches, the curing agent is directed from a site midway between the sites of atomization of the resin material, and granular materials are projected from sites about one inch above the sites of atomization of the resin material, and the cut glass fibers are projected from a location about 3 inches above and midway between the sites of atomization of the resin material and the plurality of sprays are directed to converge about 5 inches forwardly of the apparatus.
3. The method of claim 1, including the steps of pro-jecting one granular material from one location and a second and different granular material from a second location to achieve combined characteristics of the two granular materials in a composite structure.
4. A method of forming a multicomponent composite structure comprising the steps of atomizing a liquid resin material from a plurality of spaced-apart sites, and directing the resulting plurality of sprays to converge, atomizing a liquid resin curing agent and projecting the resulting spray into the converging resin sprays from a site between the sites of atomization of the resin, projecting one gas-entrained granular material from a site located closely adjacent one of the sites of atomization of the resin material, and directing a second gas-entrained granular material from a site located closely adjacent the other site of atomization of the resin material so that the two sprays of liquid and granular materials intersect.
5. The method of claim 4, wherein the resin materials are atomized at sires separated about 3 inches, the curing agent is directed from a site midway between the sires of atomization of the resin material, and granular materials are projected from sites about one inch above the sites of atomization of the resin material.
6. The method of claim 4 with the additional step of directing the mixed spray of liquid resin and curing agents with the two entrained granular materials substantially mixed with and wetted by the resin and curing agent for deposition on a mold surface.
7. The method of forming a multicomponent composite structure comprising the steps of atomizing a liquid resin material to provide a resin spray pattern base, atomizing a resin curing agent and projecting the resulting spray into the resin spray pattern base, projecting gas-entrained granular material from above and closely adjacent the sites of atomization of the resin material and directing the granular material into the resin spray pattern base, cutting a fiber material to form a plu-rality of cut fibers and directing the cut fibers into the resin spray pattern base from a location above said liquid and granular sprays to provide a mixed composite spray, and depositing the composite spray of resin, curing agent, granular and fiber materials on a surface and wherein the resin materials are atomized at spaced-apart sites, the curing agent is directed from a site between the spaced-apart sites of atomization of the resin material, and granular materials are projected from spaced-apart sites above the sites of atomization of the resin material, and the cut glass fibers are projected from a location between the sites of atomization of the resin material and be-tween the sites of projection of granular material, and the plurality of sprays of liquid, granular, fiber material are directed to converge several inches forwardly of the apparatus.
8. A spray gun for forming multiple-component composite structures comprising a housing forming a handle and carrying a trigger, a pair of spray-forming means carried at the forward portion of the housing at spaced-apart locations, each of said spray-forming means being adapted for connection with a source of plural component material, an atomizing nozzle carried by the housing at a location centrally located between the pair of spray-forming means and adapted for connection with a source of curing agent, a pair of granular emitting means carried by the forward portion of the housing, each of said granular emitting means being located closely adjacent a respective one of said pair of spray-forming means, a pair of passageways formed by the housing and connected at the rear with the source of granular material, cutter means for cutting fibrous materials adjustably carried by the housing having an orifice for the ejection of cut fibers located above the granular emitting means and centrally located therebetween, a valve means within the housing operated by the trigger simultaneously causing the operation of the spray-forming means, the curing agent atomizing nozzle, and the cut-ter means.
9. The apparatus of claim 8 wherein each of the granu-lar emitting means is located about one inch above its associated spray-forming means for resinous material.
10. The apparatus of claim 8 wherein the orifice for ejection of cut fibers is located about 3 inches above the pair of spray-forming means for resinous material and centrally lo-cated therebetween.
11. Apparatus for forming multiple-component composite structures comprising a housing forming a handle and carrying a trigger;
a plurality of spray-forming means carried at the forward portion of the housing at spaced-apart locations, said plurality of spray-forming means being connected with separate sources of resin material and curing agent;
granular emitting means carried by the forward portion of the housing;
a fluidized bed source of granular material;
a hose connected with said fluidized bed source, carried by-said housing and terminating adjacent to said granular emitting means;
means to entrain granular material in a flow of gas in said hose to deliver the granular material to said granular emitting means;
cutter means for cutting fibrous materials carried by the housing above the granular emitting means; and means to cause the operation of the plurality of spray-forming means, the source of granular material and the cut-ter means.
a plurality of spray-forming means carried at the forward portion of the housing at spaced-apart locations, said plurality of spray-forming means being connected with separate sources of resin material and curing agent;
granular emitting means carried by the forward portion of the housing;
a fluidized bed source of granular material;
a hose connected with said fluidized bed source, carried by-said housing and terminating adjacent to said granular emitting means;
means to entrain granular material in a flow of gas in said hose to deliver the granular material to said granular emitting means;
cutter means for cutting fibrous materials carried by the housing above the granular emitting means; and means to cause the operation of the plurality of spray-forming means, the source of granular material and the cut-ter means.
12. Apparatus for forming multiple-component composite structures comprising a plurality of spray-forming means carried by a housing at spaced-apart locations, each of said plurality of spray-forming means being connected with a source of plural component material including separate sources of resin and curing agent and at least one of the plurality of spray-forming means emitting resin at high velocity under the action of high hydraulic pressure;
a granular emitting means carried by the housing and each being located closely adjacent a respective one of the plurality of spray-forming means;
a means to entrain granular material in a flow of gas and deliver it to the granular emitting means, including smooth, uninterrupted walls from the source of granular material to said granular emitting means;
a cutter to form fibrous material into fibers of predetermined length; and means carried by the housing to operate simultane-ously,said plurality of spray-forming means, the curing agent and said cutter.
a granular emitting means carried by the housing and each being located closely adjacent a respective one of the plurality of spray-forming means;
a means to entrain granular material in a flow of gas and deliver it to the granular emitting means, including smooth, uninterrupted walls from the source of granular material to said granular emitting means;
a cutter to form fibrous material into fibers of predetermined length; and means carried by the housing to operate simultane-ously,said plurality of spray-forming means, the curing agent and said cutter.
13. A method of forming a multicomponent composite structure comprising the steps-of atomizing a liquid resin mate-rial and a curing agent from a plurality of spaced-apart sites, and directing the resulting plurality of sprays to form a cata-lyzed resin spray pattern base, projecting gas-entrained granular material from a plurality of sites each located above and closely adjacent to a respective one of the sites of atomization of the resin material and directing the granular material into the catalyzed resin spray pattern base while varying the quantity of granular material projected, cutting a fiber material to form a plurality of cut fibers having a pre-determined length and directing the cut fibers into the catalyzed spray pattern base to provide a mixed spray of resins and curing agents with varying amounts of entrained granular and fiber material sub-stantially mixed with and wetted by liquid resin and curing agent, and depositing the mixed spray of resin and curing agent and granular and fiber materials on a surface.
14. A method of providing a mixture of liquid and solid particulate materials comprising.
atomizing the liquid material airlessly by deliver-ing it at high hydraulic pressure to a site of atomization and projecting it at high velocity as a thin expanding film to form the liquid material into spray particles;
fluidizing a solid particulate material to form a fluidized bed and entraining the fluidized solid particulate material in a flow of compressed air;
delivering a uniform flow of entrained solid par-ticulate material and air to a site of emission located closely adjacent the site of atomization of the liquid particles; and emitting the uniform flow of solid particles closely adjacent the high velocity, projecting liquid film so that the solid particulate material is captured in the induced flow of air adjacent the site of atomization of the liquid component and mixed and wetted therewith.
atomizing the liquid material airlessly by deliver-ing it at high hydraulic pressure to a site of atomization and projecting it at high velocity as a thin expanding film to form the liquid material into spray particles;
fluidizing a solid particulate material to form a fluidized bed and entraining the fluidized solid particulate material in a flow of compressed air;
delivering a uniform flow of entrained solid par-ticulate material and air to a site of emission located closely adjacent the site of atomization of the liquid particles; and emitting the uniform flow of solid particles closely adjacent the high velocity, projecting liquid film so that the solid particulate material is captured in the induced flow of air adjacent the site of atomization of the liquid component and mixed and wetted therewith.
15. The method of claim 14 wherein liquid material is atomized at two spaced-apart sites and solid, particles are emitted from two nozzles, each closely adjacent a site of atomization, and the liquid material is directed from each site of atomization to form two intersecting sprays.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US46499474A | 1974-04-29 | 1974-04-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1054869A true CA1054869A (en) | 1979-05-22 |
Family
ID=23846108
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA224,425A Expired CA1054869A (en) | 1974-04-29 | 1975-04-11 | Method and apparatus for forming multiple-component composite structures |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1054869A (en) |
-
1975
- 1975-04-11 CA CA224,425A patent/CA1054869A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2517864A1 (en) | 1975-11-06 |
| DE2517864B2 (en) | 1976-10-14 |
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