Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B31/00—Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers
  • B65B31/003—Adding propellants in fluid form to aerosol containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B3/00—Packaging plastic material, semiliquids, liquids or mixed solids and liquids, in individual containers or receptacles, e.g. bags, sacks, boxes, cartons, cans, or jars
  • B65B3/04—Methods of, or means for, filling the material into the containers or receptacles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D83/00—Containers or packages with special means for dispensing contents
  • B65D83/14—Containers or packages with special means for dispensing contents for delivery of liquid or semi-liquid contents by internal gaseous pressure, i.e. aerosol containers comprising propellant for a product delivered by a propellant
  • B65D83/75—Aerosol containers not provided for in groups B65D83/16 - B65D83/74
  • B65D83/752—Aerosol containers not provided for in groups B65D83/16 - B65D83/74 characterised by the use of specific products or propellants

Definitions

• This invention relates to a method of manufacturing an aerosol container, specifically a pressurized paint formulation.
• the invention also relates to the final composition of the manufactured aerosol container.
• my invention involves significantly reducing or eliminating the amount hydrocarbon propellant typically used in the manufacturing process and to use compressed ambient air to achieved the desired pressure for product discharge.
• Aerosol containers are ubiquitous and are used to deliver of great number of products from paint to air fresheners by delivering such products in a convenient spray or atomized stream. Regardless of the specific product to be delivered, one common ingredient of these aerosol containers is a propellant that acts as a carrier to dispense the product. Because the propellants are highly volatile, the container is pressurized to keep the propellant as a liquid. In the case of a spray paint container, these propellants are typically hydrocarbons that must be injected into the container under high pressure during manufacturing. The liquid propellant is typically mixed with the liquid product to be dispensed, such as a paint formulation.
• the liquid propellant When the user pushes or activates the container valve, the liquid propellant is flashed (vaporized) through a spray nozzle or tip carrying with it the liquid product as atomized droplets.
• hydrocarbon propellants provide a convenient delivery vehicle for dispensing spray products, they add a significant cost to the manufacture of aerosol containers and the flashed gaseous hydrocarbons can potentially have a negative impact on the environment. Accordingly, reducing the amount of hydrocarbon propellant required for a given product formulation is cost effective and good for the environment.
• the present invention provides a method of preparing an aerosol container where the amount of hydrocarbon propellant is significantly reduced or eliminated by substituting compressed ambient air.
• my invention could also be adapted to for any type of aerosol product where oxygen would not have a deleterious effect on the product to be dispensed.
• my invention concerns a method of filling an aerosol container where an empty container at ambient pressure is supplied to a filling line and a liquid paint mixture and an appropriate agitator device are added to the interior of the container. An aerosol one way check valve is then added to the top of the container and crimped into place using methods well known in the art of manufacturing aerosol containers.
• reduced amount of propellant I mean that the normal volume of propellant typically added to a specific product formulation is reduced by about 1 vol.% to about 99 vol.%, and in some cases all of the propellant is replaced by compressed air.
• the container is then injected with compressed ambient air through the check valve in an amount equal to the difference between the reduced amount of propellant and the normal amount of propellant or an amount that is sufficient to deliver substantially all of the product initially contained within the container.
• normal amount of propellant I mean the volumetric amount of propellant typically used for a given product formulation.
• the amount of compressed air added to the container results in a volumetric ratio of compressed air to propellant is approximately 50:50 and more preferably in the range of from about 20 to 80. Since typical aerosol containers can only be pressurized to about 70 psig to about 120 psig, the added compressed air will not liquefy and will remain as a gas. Because commonly used propellants act as a solvent they will reduce the viscosity of the paint formulation.
• a spray tip or nozzle is attached to the valve followed by a cap and the container is ready for use.
• Any filling equipment known to the art of aerosol container manufacturing can be used to practice my invention provided a charge head assembly is available to add the compressed ambient air to the container after the addition of the reduced amount of hydrocarbon propellant.
• the goal of my invention is to significantly reduce the amount of hydrocarbon propellant that is typically used in the manufacture of aerosol spray containers.
• the particular propellant used in manufacturing aerosol containers will depend on the properties of the liquid product to be dispensed.
• the type of solvent is dependent on whether the paint formulation is water base or solvent based.
• solvent based refers to a paint formulation soluble in one or more hydrocarbons.
• DME dimethyl ether
• DME is a commercially available liquefiable gas having a boiling point of -23°C. at one atmosphere, and is soluble in water to the extent of about 35% by weight at 24°C. at about 5 atmospheres of pressure.
• any commercially available DME can be used in the present invention, one commercial supplier of DME is DuPont®.
• DME is one preferred type of propellant, other propellants may be used alone or in addition to DME, for example, propane, 152a, carbon dioxide, and nitrous oxide. In those circumstances where the initial paint formulation is solvent based, then an acceptable propellant is propane, however, any known propellant compatible with a solvent based paint formulation will work.
• the propellant must be able to pressurize the initial paint formulation for delivery to the substrate or surface to be coated once the container is filled and crimped at the point of manufacture of the container.
• Each particular paint product formulation or recipe will specify a type and quantity of the propellant to be added to the container.
• My invention is aimed at reducing this "normal" quantity of propellant by any where from about 1 vol.% to about 99 vol.%, in some cases completely replacing allof the propellant, and substituting compressed air as the carrier gas for the product to be dispensed.
• compressed air is added to the container in an amount equal to about 20 psig.
• the ambient air is compressed by any known means and is preferably delivered to the check value at a pressure in the range of from about 80 psig to about 120 psig.
• the amount of compressed air that can be added is also a function of product quality or spray performance. In other words, if too much compressed air is substituted for the propellant there can be a tendency for the paint not to dispense in an acceptable spray pattern.
• An acceptable spray pattern is one where a 1 inch to 4 inch line can be sprayed with sharp edges and no overspray.
• a paint formulation is added to the container along with an agitator device prior to adding the check valve and pressure sealing the container.
• the paint formulation can be any known to those skilled in the art and preferably includes a clear non-pigmented base or a clear pigmented base or a white/off-white or neutral base.
• the type or design of aerosol container that can benefit from my invention is not critical to my invention.
• a conventional upright spray paint can be used as well as an inverted spray container that is used to mark horizontal surfaces, such as athletic fields, roadways, yards, and the like.
• a aerosol paint product was made in accordance with the above mentioned recipe by taking a standard 20 ounce aerosol can, placing 353 grams of a paint formulation into the can and crimping the valve onto the can.
• the valve used was a typical inverted tip valve used for spraying lines on the ground. After the valve was crimped, 137 grams of propellant was added. When this composition was sprayed on the ground, a 1 to 1 1 ⁇ 2 inch line was produced.
• a second can was prepared, identical to the first can, except instead of adding the propellant the can was pressurized with 90-100 psi of air. When tested, the resulting line was only a 1 ⁇ 2 inch in width and the paint splattered, yielding a line that did not have crisp edges.
• a third can was prepared, again using the same procedure as for the first can, except this time the propellant was replaced by acetone.
• the viscosity of the paint formulation, after adding the acetone, was reduced from 85 seconds to 26 seconds as measured using a Zahn #2 cup. Once this paint formulation was added to the can and the valve was crimped on the can, the can was pressurized with 90-100 psi of air.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Paints Or Removers (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (5)

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Family Cites Families (6)

• 2010
  • 2010-09-29 MX MX2012002377A patent/MX2012002377A/es not_active Application Discontinuation
  • 2010-09-29 CA CA2774394A patent/CA2774394A1/en not_active Abandoned
  • 2010-09-29 EP EP10770661A patent/EP2483156A1/de not_active Withdrawn
  • 2010-09-29 WO PCT/US2010/050679 patent/WO2011041382A1/en active Application Filing
  • 2010-09-29 CN CN2010800434157A patent/CN102574587A/zh active Pending

Non-Patent Citations (1)

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