Classifications

• • 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
  • B05B7/02—Spray pistols; Apparatus for discharge
  • B05B7/04—Spray pistols; Apparatus for discharge with arrangements for mixing liquids or other fluent materials before discharge
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7404—Mixing devices specially adapted for foamable substances
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/002—Manually-actuated controlling means, e.g. push buttons, levers or triggers
  • B05B12/0022—Manually-actuated controlling means, e.g. push buttons, levers or triggers associated with means for restricting their movement
  • B05B12/0024—Manually-actuated controlling means, e.g. push buttons, levers or triggers associated with means for restricting their movement to a single position
  • B05B12/0026—Manually-actuated controlling means, e.g. push buttons, levers or triggers associated with means for restricting their movement to a single position to inhibit delivery
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/7438—Mixing guns, i.e. hand-held mixing units having dispensing means
  • B29B7/7447—Mixing guns, i.e. hand-held mixing units having dispensing means including means for feeding the components
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B7/00—Mixing; Kneading
  • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
  • B29B7/76—Mixers with stream-impingement mixing head
  • B29B7/761—Mixers with stream-impingement mixing head of gun-type, i.e. hand-held units having dispensing means

Definitions

• the present invention relates generally to dispensing systems for chemical reactants, and in particular, to the combination of a self-contained, self-regulating pressure generating system and an apparatus for mixing and dispensing the individual reactive components. More particularly, in a preferred embodiment, the invention relates to a system for dispensing two separately contained, reactive liquids and causing them to flow into a mixing nozzle wherein a cross linking reaction- will take place, wherein a blowing agent will cause the resins comprising the material to begin forming a chemical foam.
• the present invention utilizes the same gas that is used to dispense one or more liquids under pressure to entrain the foam being formed and propel it to the point of application.
• the invention relates to a system for generating carbon dioxide which serves the multiple purposes of causing a liquid hydroxyl-rich resin from one flexible walled container and an isocyanate material from a second flexible walled container, to flow to a dispensing gun having a removable mixing and dispensing nozzle. At the same time, part of the generated gas is directed through the same gun, impinging on and serving to propel the materials being mixed to the point of application.
• mixture of the isocyanate or "A” component and the resin or "B” component is normally a thermosetting reaction which can also be made to generate a gas for the purpose of "blowing" the constituents into a foam.
• Such a foam when being mixed with a swirling action inside a mixing and dispensing nozzle, can be directed to the outlet of a tube from which the same gas used to urge the components into the mixing chamber is discharged at atmospheric pressure. As the mix just beginning to foam impinges upon the gas stream, the being-formed foam will be picked up and propelled to a surface to which it is being applied.
• successful systems for dispensing urethane foam have been produced. These include those described in U.S. Patent No. 3,784,110 and U.S. Patent No. 4,676,437, for example.
• propellants of the kind in question include butane and propane, for example, which are highly flammable, and which require special protection against fire and/or explosion hazards, particularly during shipment and storage.
• One very advantageous propellant for example, is carbon dioxide.
• carbon dioxide Such a gas can be made to serve both the blowing or expansion requirements of foam-forming and the role of propellant.
• carbon dioxide because of the nature of carbon dioxide, it requires extremely high pressures to be liquified.
• liquid or highly compressed carbon dioxide confined under great pressures for some dispensing application, such as for dispensing carbonated beverages, for example, this requires using high pressure containers and accurate pressure regulation systems.
• Another object of the invention is to provide a container system which includes a chemical reagents which are isolated from each other for shipment but which may thereafter be activated so as to begin generating gas for the purpose of mixing and dispensing chemical foams.
• a further object of the invention is to provide a simplified, low cost system for generating propellant gases, including carbon dioxide, in which the reagents used to create the propellant gas are held separate from each other until it is desired to initiate the mixing reaction.
• a still further object of the invention is to provide a gas-generating system which is inherently able to regulate the pressure of gas being generated over a significant period of time.
• Yet another object of the invention is to provide a gas-generating arrangement which provides essentially self- regulated pressure in a selected range.
• Another object of the invention is to provide an inherently self-regulating pressure control arrangeme .- wherein gas pressure results from mixing two or more reactants, and wherein the system includes separate containers for each of the reactants and an arrangement of containers, passages, and fittings or the like whereby a decrease in pressure caused by using the gas causes additional gas forming chemicals to be supplied for mixing with each other so as to again increase the system pressure to a controlled level.
• a further object of the invention is to provide a packaged dispensing system which includes a dispensing gun having a removable mixing and dispensing nozzle including at least two liquid inlet passages and a separate gas passage for dispensing the foam product, with the system further including sealed containers with gas-generating components and an arrangement of passage tubes and seals permitting the reactants to be mixed when desired by the user.
• a still further object of the invention is to provide a combination dispensing gun and gas-generating apparatus wherein the entire package contains relatively non-toxic, non-corrosive chemicals able to be shipped at minimum expense while unpressurized, and yet being activatable upon demand to supply a regulated dispensing pressure.
• the invention also achieves its objects by providing a gas-generating and dispensing system that includes a master container that in turn includes one or more containers of dispensible fluent materials and is able to be pressurized by a generated gas, a generator having at least two containers with gas producing reactants separately contained therein, an arrangement of passages between the containers whereby controlled mixing of the gas-generating materials can be achieved in practice, and a dispensing gun with valves for controlling liquid and gas flow therethrough.
• FIG. 1 is a perspective view of a portable package containing the gas-generating and product dispensing apparatus of the invention
• FIG. 2 is an exploded view, showing the principal elements of the generating and dispensing apparatus of the invention and the manner in which the packaged apparatus operates in use; and
• FIG. 3 is an enlarged side view, partly in elevation and partly in section, showing the elements of the gas- generating and liquid dispensing apparatus in greater detail.
• the concept of the invention is adaptable to dispensing other products, using somewhat varied forms of guns or like dispensers and that the chemistry of the gas-generating system and the arrangement of certain of its components may also change considerably and still lie within the spirit of the present invention.
• the generator and dispenser of the invention is adapted to dispense one or more reactive components under a elevated, comparatively regulated pressure generated by a chemical reaction. More particu- larly, in the form shown, the apparatus is adapted to form and dispense urethane foams made from a pair of separately packaged, reactive components.
• the carbon dioxide or (“C0 2 ") gas is generated by the reaction of citric acid and potassium carbonate.
• the exterior or master containers are made from semi-rigid plastic, and the inner containers, for either liquids or gas, include flexible sidewalls.
• a chemical trigger is described, and it may be made from rigid or flexible materials. Non-chemical triggers may also be used, as will appear.
• the dispensing gun preferably, but not necessarily, includes a mixing nozzle removably secured to a valve body, a handle, a trigger, and attachment points for connection to two liquid hoses and a gas hose.
• the principles of the invention are not limited, however, to dispensing such foams or even limited to foams at all, but are primarily directed to the concept of providing a self-contained, largely self-regulating pressure source for a gas which serves at least the purpose of dispensing the contents of certain containers.
• the gun and pressure system may also be used, by way of example only, to dispense "pour" foams that are not literally sprayed through the air but emerge from the gun as an expanding liquid stream.
• the reactive chemical components include a hydroxyl-rich resin and a isocyanate portion, respectively, which, when combined, create a urethane foam; a finite amount of water is present in the resin for reaction with the isocyanate to generate the auxiliary amount of CO- actually used in "blowing" the foam.
• This CO- is to be distinguished from the CO- generated by the generator for providing liquid dispensing and propellant functions.
• FIGS. 1 and 2 show one form of package generally designated 8 for a combination gas-generating and dispensing apparatus generally designated 10.
• the package 8 is shown to include a relatively rigid outer box generally designated 12 having a handle 14 extending through a top cover flap 16.
• the generating and dispensing system 8 of the invention is able to be stored and shipped in the box 12 and the components, except for the chemical trigger and the actual dispensing gun, remain in place in the container throughout the period of use. With slight, non-inventive design modifications, the trigger could remain in the carton or box 12 in use.
• the box 12 when opened, includes closure flaps 18, 20, and 21, in addition to the top flap 16 and that a combination divider/container neck locator generally designated 22 is provided.
• the principal components of this embodiment of the invention include a chemical trigger generally designated 24, a gas-generating master container generally designated 25, and a product- retaining master container generally designated 26.
• Container tops generally designated 28, 30 cover the containers and include various hoses and fittings including a composite hose generally designated 32 leading to a dispensing gun generally designated 34.
• the first gas-generating master container 25 includes an outer wall 37, and that its neck portion 38 is secured to the closure generally designated 28.
• an inner liquid container generally designated 42 and having flexible sidewalls 43.
• This container 42 also includes a neck portion 44 secured to a portion of the closure 28 and kept isolated from the headspace or pressurizable area 46 lying between the flexible walls 43 of the inside container 42 and the walls 37 of the outside container 25.
• the wall portions 37 of the outer container 25 define an interior area for reception of a charge 50 of a mild acid solution. In the preferred form, this is 2 liters of a 50% citric acid in water solution.
• the inner bag 42 with the flexible sidewalls 43 preferably includes 1.5 liters of a liquid 54, in this case a 50% solution of potassium carbonate in water.
• the potassium carbonate or salt solution should occupy 25% or less of the total volume of the bag 42, the remainder being available for headspaces 68.
• the master container 25 is an acid container and the inner container 42 is a salt bag.
• a dip tube 56 with a hollow center and an open lower end portion 58 lying near the bottom wall 60 of the inner container 42 is provided.
• the upper end 62 of the dip tube 56 is fitted with a rupturable, low pressure seal 64 in the form of an adhesively affixed cover secured to a margin 66 of the inner or salt bag outer sidewall 43.
• the dip tube 56 thus provides a path of communication between the headspace 46 and the interior or headspace 68 of the inner bag 42, through the liquid 54.
• the trigger 24 includes end caps 78, 80 and a cylindrical body 82, defining an interior space 84 in which a predetermined volume of liquid trigger acid 86, typically citric acid, is disposed.
• the tube 76 operates as a vent tube and consequently, when the trigger is in the position shown in FIG. 3, the upper end 88 of the tube 76 will lie above the level of the liquid 86, while the upper end 90 of the supply tube 74 lies beneath the level of the liquid 86.
• the trigger includes its own headspace 91 and a portion 86 devoted to liquid, as do the other liquid containers 25, 42.
• the chemical trigger includes a spring-loaded ball check pressure relief valve 40 in the upper end cap 78.
• the supply and return hoses 74, 76 are capable of being crimped or folded over so as to close them off, and that such hoses may be retained in this position by a clamp such as the simple clamping 92.
• a clamp such as the simple clamping 92.
• this unit is preferably comprised of an at least semi-rigid sidewall portion 94, and an upper margin or collar 96 to which the closure fitting 30 is secured.
• a pressurizable interior headspace 100 lies within the container 26 and outside the space occupied by first and second liquid product bags or pouches generally designated 102, 104, respectively.
• Pouch 102 has an upper margin 106 surrounding an outlet tube 108 which extends through a fitting 110, and to an exterior hose 112.
• the other bag or pouch 104 which includes an outlet tube 114 extending into it from the end of a fitting 116, positioned on the closure 30.
• the headspace 100 is pressurized by gas passing from the headspace 46 of the container 25 through the tube 118, the fitting 120, the transfer tube 122, and the fitting 124, and the gas inlet tube 126.
• the pressure in the headspace 100 acts on and tends to collapse the interiors 128, 130 of the bags 100, 102, causing the products in them to flow through the tubes as aforesaid and into the composite hose 32.
• the far or gun end 134 of the composite hose 32 ends in fittings 136, 138, each secured to the valve body 140 of the gun generally designated 34.
• the transfer tube 122 for the gas is also in communication, through line 142, to the composite hose 32.
• An end portion 144 of the gas tube 142 terminates in a fitting 146 which is also secured in gas-tight relation to the valve body 140 of the gun 34.
• the gun includes a removable nozzle generally designated 148 and held in place by a mechanism 150 acting as a combined nozzle latch and ejector.
• the gun 34 typically further includes a handle 152, a trigger 154 and a trigger safety 156.
• Operation of the gun is generally conventional and, with the exception of the provision of the gas fitting, may operate in the same manner as the gun described and claimed in U.S. Patent No. 4,676,437, for example.
• dispensing gun is not a critical portion of the present invention, but is preferably a form of gun which is advantageously used with the invention.
• the gas is used not only to pressurize the headspace of one or more master containers for dispensing liquid components, but is also used as a part of the propellant for the product to be dispensed.
• a two or three component gun one or two liquid passages and one gas passage — has proven to be very advantageous.
• the product is packaged as illustrated, except for the position of the chemical trigger.
• the supply hoses 74, 76 are folded over and secured by the cylindrical clamp 92.
• the trigger is preferably inverted with respect to its position in FIG. 3, so as to lie in the portion of the container below the divider 22 and adjacent the individual containers 25, 26.
• the chemical trigger 24 contains the citric acid solution as described, but is isolated from the other contents because its supply is crimped. This solution exhibits no measurable gas pressure and requires no particular shipping precautions.
• the respective interiors 46, 68 of the master and salt containers 25, 42 each also contains a liquid.
• the liquid 54 is a salt such as potassium carbonate and the liquid acid 50 is a citric acid, by way of example only.
• the cap 64 is rupturable by pressure, but is secured against leakage during any time the pressure in the headspace 68 is modest. Accordingly, the two liquid just discussed will not mix with each other and the pressure in all headspaces is substantially atmospheric.
• this container simply accommodates individual, non- pressurized but reactive components which are kept separate from each other by the walls of their containers.
• the bags may be single or multi-layer plastic bags, with or without a metalized finish. At any rate, the bag materials are selected so as to be substantially impermeable with respect to the products contained therein, so the products can be kept separate and protected from moisture or other contamination during storage and shipment.
• the interior or headspace 100 of the container 26 is likewise not subject to pressure during shipment and storage.
• a throw-away type nozzle 148 is inserted into the gun 34.
• the chemical trigger assembly 24 is removed from the divider in the box and positioned as shown in FIG. 2. Thereupon, the clamp 92 is removed and the chemical trigger 24 is raised sufficiently to release the crimp in the supply and return hoses 74, 76. Gravity then causes the liquid acid 86 in the interior 84 of the chemical trigger to begin flowing through the tube 74 into the headspace 68 of the container 42. The initial reaction rapidly begins generating carbon dioxide, which inflates the bag 42 and also passes through the return tube 76 to the headspace 84.
• the equalized headspace pressures permit the remaining liquid 86 to empty rapidly into the interior of the inner bag 42, generating a pressure determined by the amounts of chemicals, and the size of the containers and their headspaces.
• the chemical trigger contains only a small part of the total available acid.
• the bag 42 continues to expand, forcing liquid 54 upwards in the dip tube 56 towards the seal 64.
• the seal 64 ruptures and permits liquid salt solution 54 to flow out the opening in the dip tube, along the bag sidewalls and finally down into the reservoir of acid 50.
• This reaction immediately begins generating more CO-, which appears as a positive pressure in the headspace 46.
• a significant differential pressure between the containers 25 and 42 a significant portion of the liquid dosing salt 54 is immediately supplied into the acid 50, causing a volume of gas to be generated that is proportional to the amount of dosing liquid 54 supplied at that time.
• a reference or initial operating pressure which is important to the operation of the mechanism as a whole, has been set.
• the trigger caused initial dosing to occur and the amount of dosing was determined by initial pressurization of the inner bag 42. This pressure dosed until such pressure was equalized by the headspace pressure in the two master containers, whereupon dosing stopped and the reference pressure was set.
• the gun is not manipulated, so that all conditions are in a preset equilibrium.
• the trigger 154 is manipulated to dispense products from the containers 128, 130.
• the referenced pressure in the headspace causes the contents 128, 130 of the bags to be emptied.
• the gun manipulation also discharges additional CO- from one or both headspaces 64, 100 through the gas hose, initially lowering the system pressure.
• a compact gas-generating system is provided which is sufficient to dispense approximately 10 lbs each of reactive liquid ingredients. These materials, when applied to a substrate and permitted to achieve a free rise density of 1.1 to 3 lbs per cubic foot, for example, will produce some 80 to 200 board feet of finished foam. Calculations and tests have indicated that, using 11 lbs. of isocyanate and 8 to 9 lbs. of resin, these amounts of liquid can be mixed and dispensed by approximately 90 liters of gas, measured at or just above atmospheric pressure. This corresponds to some 18 to 20 liters of gas at 70 - 80 psi. Bearing in mind that each atmosphere is just less than 15 psi, gas at some 72 - 75 psi will expand to five times that volume as the pressure drops to 1 atmosphere.
• the trigger may be made from components such as polyvinyl chloride (PVC) pipe in a two to three inch diameter.
• PVC polyvinyl chloride
• Plastic and/or rubber hoses of the type conventionally used in throwaway urethane-forming kits may be used and a similar, substantially all plastic throwaway gun may be utilized, suitably modified to use a generated gas supply as the propellant.
• PVC polyvinyl chloride
• One such form of gun is described in co- pending U.S. Patent Application Serial No. 08/264,640 filed June 23, 1994.
• the foam products dispensed using the apparatus of the invention have proven fully the equal of prior art products dispensed using environmentally objectionable materials such as freon, which requires all metal, expensive, pressure-resistant containers.
• the invention advantageously uses an essentially self-regulating mechanism for pressure control, i.e., controlling dosing and reaction to the difference between the interior and the exterior pressures of two interconnected, flexible walled containers. This provides relatively constant dispensing rates, also.
• a number of different products may be advantageously mixed and dispensed using this system.
• the system is very advantageous in that the generated gas may serve the dual function of pressurizing the dispensing container and also serving as the propellant when supplied through separate hoses and fittings.
• the master container 26 includes two interior liquid product bags. Naturally, three or more product bags could be placed in such master container if this were desired for some reason.
• two or more master separate containers could be provided, each with one or more separate, individual bags for liquid or fluent products.
• the headspace in each of two containers could be pressurized by the gas-generator and the products respectively would be dispensed from each master container. It is normally desired to simply use one master container for two or more separately bagged dispensable ingredients, however.
• the gas-generating chemicals could be arranged differently, or other chemicals altogether could be used.
• a chemical trigger has been described.
• the function of the trigger is merely to set a reference pressure in the dosing container, this might be achieved by other means.
• a small C0 2 cartridge of a conventional type could be pierced and the CO- used to provide initial pressurization of the inner bag and an initial dosing action to take place.
• a trigger could be made simply utilizing an air supply tube with a check valve or the like, initially using a compressed air or other gas source to initiate dosing and supply a predetermined pressure and the dosing bag.
• a headspace of at least 75% of the container volume be provided.
• a moderate pressure which decreases only slightly during the time the dosing liquid is being exhausted is preferred, generous headspace should be provided in the bag 42.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Nozzles (AREA)
• Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23006982

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (62)

Citations (5)

Family Cites Families (5)

• 1994
  • 1994-06-23 US US08/264,643 patent/US5526957A/en not_active Expired - Fee Related
  • 1994-08-15 TW TW083107453A patent/TW269644B/zh active
• 1995
  • 1995-06-22 JP JP8503251A patent/JPH10506317A/ja active Pending
  • 1995-06-22 AU AU29038/95A patent/AU682974B2/en not_active Ceased
  • 1995-06-22 CA CA002193737A patent/CA2193737A1/en not_active Abandoned
  • 1995-06-22 EP EP95924606A patent/EP0762975A4/en not_active Ceased
  • 1995-06-22 WO PCT/US1995/007704 patent/WO1996000170A1/en not_active Application Discontinuation

Patent Citations (6)

Non-Patent Citations (1)

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