Low pressure non-barrier type, valved dispensing can

Abstract

A low pressure aerosol dispensing can which is distinguished from existing high pressure aerosol dispensing cans. The generally cylindrical can has a thin wall thickness, like that of a carbonated beverage can, which can be distorted by finger pressure but whose shape is maintained by internal gas pressure. The liquid contents to be dispensed and the propellant gas are mixed in the can. The dispensing valve at the top of the can dispenses the liquid contents and propellant in a controlled manner. The valve may include an additional narrow bore vapor tap between the gaseous propellant head space in the can and the valve chamber for delivering extra gas for atomizing the liquid and propelling it from the nozzle. The gas pressure in the can is coordinated with the can wall and bottom thickness so that the can will have sufficient distortion resistance and burst resistance at elevated temperature. Yet the can has side walls of a thickness low enough to permit the can to be easily crushed by hand pressure when the can is empty.

What is claimed is: 
     
       1. A low pressure, non-barrier type, valved dispensing can for containing and dispensing fluent materials by compressed and/or liquified gas the can comprising: a generally cylindrical can having a wall of such a material and with such a thickness that when the can is unpressurized, the can wall is easily distortable by normal finger pressure and is easily crushable by normal hand pressure, but when the can is pressurized, the can is rigid enough to not be easily distortable and crushable by normal finger and hand pressure;   the can being adapted for containing propellant and fluent material to be dispensed, the propellant and fluent material not being separated by a barrier in the can between them;   a dispensing valve on the can with a valve orifice adapted to be opened to dispense a desired quantity and rate of flow of fluent material and propellant in selected spray, foam or stream form in a manner such that the can will retain enough propellant pressure to expel substantially all of the dispensable fluent material in the can.   
     
     
       2. The can of claim 1, wherein the can side wall thickness is such that an internal pressure in the can is required to give the can its rigidity, and this internal pressure prevents normal finger pressure from distorting the side wall and normal hand pressure from crushing the can. 
     
     
       3. The can of claim 2, including the fluent material and the propellant in the can, wherein the type and amount of the propellant are selected so that the pressure of the propellant which is used to dispense controlled amounts of the fluent material is the same pressure which gives the can wall the required rigidity for preventing normal finger and hand pressure from distorting and crushing the can. 
     
     
       4. The can of claim 2, including the fluent material and the propellant in the can, wherein the propellant is both for generating the pressure which dispenses the fluent material in a controlled manner and is for giving the can wall the required rigidity. 
     
     
       5. The can of claim 2, where the thickness of the can wall is such that the can, when pressurized to 100 psig or 689.5 kPa, expands across the diameter by at least one and one half thousands of the diameter. 
     
     
       6. The can of claim 4, where the valve can be easily and repeatedly opened and closed. 
     
     
       7. The can of claim 4, wherein the can also has a top and a bottom which are joined to the can wall and close the can; the amount and type of propellant is selected to give the can rigidity and is sufficient to dispense substantially all of the fluent material but the can is of such side wall, top and bottom construction that the pressure of the selected propellant does not cause the can to exceed the regulatory distortion and burst requirements. 
     
     
       8. The can of claim 7, where the can side wall, bottom and top are of such thickness and the type and quantity of propellant are selected so that the can will not permanently distort at 130° F. or 54.4° C. and will not burst at one and one half times the pressure generated by the propellant at 130° F. or 54.4° C. 
     
     
       9. The can of claim 8, where the can is a metal can with a wall thickness of at most 0.0065 inches or 0.165 mm in a can of approximately 21/16 inches or 52.4 mm in diameter. 
     
     
       10. The can of claim 8, where the can is a metal can with a wall thickness of 0.0075 inches or 0.191 mm or less in a can of approximately 25/8 inches or 66 m in diameter. 
     
     
       11. The can of claim 8, where the can is a metal can with a wall thickness of 0.008 inch or 0.216 mm or less in a can of approximately 3 inches or 76 mm in diameter. 
     
     
       12. The can of claim 9, wherein the wall thickness for the 21/16 inch or 52.4 mm diameter can is 0.0034-0.0055 inch or 0.086-0.139 mm. 
     
     
       13. The can of claim 10, where the wall thickness for the 25/8 inch or 66 mm diameter can is 0.005-0.007 inch or 0.127-0.178 mm. 
     
     
       14. The can of claim 11, where the wall thickness for the 3 inch or 76 mm diameter can is 0.006-0.008 inch or 0.152-0.203 mm. 
     
     
       15. The can of claim 8, the side walls of which will not withstand an internal vacuum of more than 18 inches or 46 cm of mercury without collapsing. 
     
     
       16. The can of claim 1, wherein the valve includes a valve body with a chamber inside the valve body communicating with the atmosphere, a valve body orifice communicating between the interior of the can and the valve chamber, the orifice being of a cross sectional size sufficient to permit the fluent material and the mixed propellant to pass through the valve chamber and be expelled to the atmosphere in an aerosol spray, stream or foam while they are being transmitted into the valve chamber at a slow enough rate that all of the fluent dispensable material in the can be dispensed under pressure by and with the propellant. 
     
     
       17. The can of claim 16, wherein the valve body further includes a vapor tap of narrower cross-section than the cross-section of the valve body orifice and the vapor tap communicating into the can for receiving pressurized propellant therefrom and communicating into the valve chamber before the exit to the atmosphere for providing extra propellant to help atomize and disperse the fluent material. 
     
     
       18. The can of claim 17, wherein the vapor tap is of a narrow bore of about 0.005-0.007 inch or 0.127-0.178 mm. 
     
     
       19. A process for dispensing fluent material in an aerosol spray, the process comprising: filling a can with a fluent dispensable material and a gaseous propellant which are mixed together to a pressure of at most about 105 psig or 724 kPa at about normal room temperature, wherein the can has the following characteristics:   a generally cylindrical can having a wall and bottom of a thickness such that it will permanently distort at an internal pressure in excess of 120-130 psig or 827-896 kPa and that the wall and bottom will not burst at an internal pressure one and one half times that of permanent distortion said generally cylindrical can having a wall of such a material and with such a thickness that when the can is unpressurized, the can wall is easily distortable by normal finger pressure and is easily crushable by normal hand pressure, but when the can is pressurized, the can is rigid enough to not be easily distortable and crushable by normal hand and finger pressure;   the can being adapted for containing propellant and fluent material to be dispensed, the propellant and fluent material being mixed and the can being without internal barrier between the propellant and the material to be dispensed;   placing propellant in the can to an amount such that when the can is pressurized sufficiently to provide propellant to expel all of the dispensable fluent material in the spray, stream or foam form, the can will not permanently distort at temperatures below 130° F. or 54.4° C. and the pressurized can cannot be deformed inwardly by normal finger pressure on the can wall;   the method further comprising applying a valve to the can for closing the can, the valve having the ability to dispense a mixed quantity of dispensable fluent material and propellant in a manner such that the can will retain enough propellant pressure to expel substantially all of the fluent dispensable material in an acceptable spray, stream or foam form. .Iadd.   
     
     
       20.  A low pressure, non-barrier type, aerosol spray valved dispensing can for containing and dispensing fluent materials in aerosol spray form by compressed and/or liquified gas the can comprising: a generally cylindrical can having a wall of such a material and with such a thickness that when the can is unpressurized, the can wall is easily distortable by normal finger pressure and is easily crushable by normal hand pressure, but when the can is pressurized, the can is rigid enough to not be easily distortable and crushable by normal finger and hand pressure;   the can being adapted for containing propellant and fluent material to be dispensed, the propellant and fluent material not be separated by a barrier in the can between them;   an aerosol spray dispensing valve on the can with a valve orifice adapted to be opened to dispense a desired quantity and rate of flow of fluent material and propellant in an aerosol spray form and in a manner such that the can will retain enough propellant pressure to expel substantially all of the dispensable fluent material in the can. .Iaddend..Iadd.   
     
     
       21.  The can of claim 20, wherein the can side wall thickness is such than an internal pressure in the can is required to give the can its rigidity, and this internal pressure prevents normal finger pressure from distorting the side wall and normal hand pressure from crushing the can. .Iaddend..Iadd.22. The can of claim 20, including the fluent material and the propellant in the can, wherein the type and amount of the propellant are selected so that the pressure of the propellant which is used to dispense controlled amounts of the fluent material is the same pressure which gives the can wall the required rigidity for preventing normal finger and hand pressure from distorting and crushing the can. .Iaddend..Iadd.23. The can of claim 20, including the fluent material and the propellant in the can, wherein the propellant is both for generating the pressure which dispenses the fluent material in a controlled manner and is for giving the can wall the required rigidity. .Iaddend..Iadd.24. The can of claim 20, where the thickness of the can wall is such that the can, when pressurized to 100 psig or 689.5 kPa, expands across the diameter by at least one and one half thousands of the diameter. .Iaddend..Iadd.25. The can of claim 23, wherein the can also has a top and a bottom which are joined to the can wall and close the can; the amount and type of propellant is selected to give the can rigidity and is sufficient to dispense substantially all of the fluent material but the can is of such side wall, top and bottom construction that the pressure of the selected propellant does not cause the can to exceed the regulatory distortion and burst requirements. .Iaddend..Iadd.26. The can of claim 20, wherein the aerosol spray dispensing valve includes a valve body with a chamber inside the valve body communicating with the atmosphere, a valve body orifice communicating between the interior of the can and the valve chamber, the orifice being of a cross sectional size sufficient to permit the fluent material and the mixed propellant to pass through the valve chamber and be expelled to the atmosphere in an aerosol spray while they are being transmitted into the valve chamber at a slow enough rate that all of the fluent dispensable material in the can be dispensed under pressure by and with the propellant. .Iaddend.