Free flow aerosol valve

Abstract

An aerosol valve having a valve stem and compression spring geometry that create shorter flow paths, have fewer changes in flow direction, and passageways with large cross-sections to reduce resistance and back pressure is disclosed. The aerosol valve minimizes agglomeration of solids in the flow paths and reduces product failures. A method of using the aerosol valve is also provided.

1 . An aerosol valve for spraying a product formulation from a container, comprising:
 a mounting cup positioned on a top portion of the container that orients the aerosol valve in the container;   a seal positioned on the mounting cup;   a dip tube connected to a reservoir of the product formulation in the container;   a valve stem housing positioned below the mounting cup and adjacent to the seal;   a valve stem comprising:   a valve stem aperture;   a center hole; and   a valve stem body,   wherein the valve stem has a bottom portion that is shaped to form a flow passageway through which the product formulation flows when the aerosol valve is actuated;   a compression spring positioned in the valve stem housing adjacent the valve stem and contacting the valve stem at a contact point, the compression spring comprising:   a spring coil;   a space between adjacent spring coils; and   a center space formed interior to and circumscribed by the spring coils with a center space diameter,   wherein when the aerosol valve is actuated by pressing on the valve stem, the product formulation in the reservoir flows upwardly under pressure through the dip tube and directly into and through the center space of the compression spring, is deflected around the outside of the valve stem body, enters the valve stem aperture and flows into the center hole to spray the product formulation outside of the container, thereby forming a primary flow path for spraying the product formulation,   wherein the primary flow path is shorter and has fewer abrupt changes in flow direction than a flow path of a conventional aerosol valve, thereby reducing resistance and back pressure to flow of the product formulation through the aerosol valve, and   wherein the primary flow path has fewer loci at which the product formulation can agglomerate and impede the flow of the product formulation before reaching the valve stem aperture as compared with a conventional aerosol valve, thereby reducing incidence of blockages in the primary flow path, and reducing a product failure rate of the aerosol valve.   
     
     
         2 . The aerosol valve according to  claim 1 , wherein the bottom portion of the valve stem is shaped to form two or more flow passageways. 
     
     
         3 . The aerosol valve according to  claim 2 , wherein the bottom portion of the valve stem is shaped to form four flow passageways, and wherein the flow passageways are oriented perpendicular to each other. 
     
     
         4 . The aerosol valve according to  claim 1 , wherein the flow passageway has a large cross-section area to further reduce resistance to flow of the product formulation through the aerosol valve, and further reduce agglomeration of the product formulation. 
     
     
         5 . The aerosol valve according to  claim 1 , wherein the cross section of the flow passageway comprises from about 44% to about 54% of the center space diameter. 
     
     
         6 . The aerosol valve according to  claim 1 , wherein the valve stem body is a thinned valve stem body having a smaller cross-section than a conventional valve stem body, and wherein the thinned valve stem body causes less deflection of the product formulation around the valve stem body than a conventional valve stem and reduces the length of the primary flow path. 
     
     
         7 . The aerosol valve according to  claim 6 , wherein the thinned valve stem body further reduces resistance to flow of the product formulation through the aerosol valve, and further reduces agglomeration of the solids in the product formulation. 
     
     
         8 . The aerosol valve according to  claim 1 , wherein the primary flow path is a non-tortuous flow path. 
     
     
         9 . The aerosol valve according to  claim 1 , further comprising a secondary flow path of the product formulation passing through the spaces between the spring coils of the compression spring. 
     
     
         10 . The aerosol valve according to  claim 9 , wherein the amount of the product formulation flowing in the primary flow path exceeds the amount of the product formulation flowing in the secondary flow path. 
     
     
         11 . The aerosol valve according to  claim 9 , wherein the amount of the product formulation flowing on the primary flow path is about 100% and the amount of the product formulation flowing on the secondary flow path is about 0% when the aerosol valve is fully-actuated. 
     
     
         12 . The aerosol valve according to  claim 1 , wherein the spring coils are fully-compressed to eliminate all spaces therebetween when the aerosol valve is fully-actuated, and all of the product formulation flows upward through the aerosol valve by the primary flow path. 
     
     
         13 . The aerosol valve according to  claim 1 , wherein the spring coils are fully-compressed to eliminate all spaces therebetween when the aerosol valve is fully-actuated, eliminating recirculation flow and reducing resistance and back pressure to the flow of the product formulation through the aerosol valve, and reducing the number of loci at which the product formulation can agglomerate and impede the flow of the product formulation. 
     
     
         14 . The aerosol valve according to  claim 9 , wherein the product formulation flows upward through the aerosol valve by both the primary flow path and the secondary flow path when the valve stem is only partially actuated. 
     
     
         15 . The aerosol valve according to  claim 1 , wherein the seal is a flexible material that is positioned between the mounting cup and the valve stem housing, and wherein the seal is slightly deformed when the valve stem pressed to actuate the aerosol valve. 
     
     
         16 . The aerosol valve according to  claim 1 , wherein the product formulation comprises a mixture of a chemical composition and a propellant. 
     
     
         17 . The aerosol valve according to  claim 16 , wherein the chemical composition comprises a powder. 
     
     
         18 . The aerosol valve according to  claim 1 , wherein the product formulation a high-solids product formulation. 
     
     
         19 . A method of using an aerosol valve for spraying a product formulation from a container, comprising:
 depressing a valve stem so that a valve stem aperture moves away from a seal positioned at a mounting cup until the product formulation flows from the container under pressure directly into and through a center space of a compression spring, passes above the compression spring and is deflected around an outside of a valve stem body, enters the valve stem aperture, flows into the valve stem, and sprays from the valve stem; and   releasing the valve stem to stop spraying the product formulation.   
     
     
         20 . An aerosol valve for spraying a product formulation from a container, comprising:
 a mounting cup positionable on the container;   a seal on the mounting cup;   a valve stem movable with respect to the seal between a sealed position and an unsealed position, the valve stem having a valve stem aperture and a dispensing hole, the dispensing hole being in fluid communication with the container via the valve stem aperture in the unsealed position, the dispensing hole not being in fluid communication with the container via the valve stem aperture in the sealed position;   a bottom portion depending from the valve stem below the valve stet aperture, the bottom portion having a spring contact point and a plurality of flow passageways; and   a coil spring having a top end in contact with the valve stem at the spring contact point so that the end is below the plurality of flow passage ways to define a primary flow path through a center of the coil spring, over the top end of the spring, and into the plurality of flow passage ways.