AEROSOL VALVE WITH DEFINED FLOW PATHS
An aerosol valve having a valve stem, valve stem housing, compression spring, and a hard stop formed by the interaction of valve stem and valve stem housing is provided. The hard stop prevents the compression spring from becoming fully compressed, or coil-bound, when the valve stem is pressed to dispense a product formulation from the container, thereby creating open spaces between coils of the compression spring and providing a defined flow path for the product formulation. The aerosol valve increases mixing and turbulence of the product formulation that reduce agglomerations of solids that might otherwise block the flow paths. The additional defined flow path also directs more of the product to the valve stem aperture, further increasing dispensing of the product formulation from the container. A method of using the aerosol valve is provided.
1. Field of the Disclosure
The present disclosure relates to the field of aerosol valves for delivery of product formulations having solids. More particularly, the present disclosure relates to an aerosol valve having a valve stem, compression spring, and a hard stop that prevents full compression of the compression spring when the valve stem is pressed by the consumer to dispense the product formulations having solids, creating defined flow paths.
2. Description of Related Art
Aerosol valve structures for product formulations that contain solids can fail because of agglomeration (clumping) of solids in the flow passages in the internal space of the valve stem housing. Conventional designs of aerosol valves often employ flow paths that have long, narrow channels, abrupt changes in flow direction, and areas of recirculation—any or all of which can cause solids in the product formulation to clump and clog the flow paths.
Also, conventional aerosol valves have a compression spring that is fully compressed (i.e., the individual spring coils are pressed tightly together) when the valve stem is fully pressed by a consumer to dispense or spray the product. However, the compressed spring coils form a barrier to the product formulation that is flowing upward, and so forces the product and propellant to follow a flow path that is nearly entirely along the outside of the fully-compressed spring coils, since there is little or no space between the spring coils to permit the product formulation and propellant to flow in between the spring coils or access the volume in the center of the compression spring. A fully-compressed (i.e., coil-bound) compression spring in the conventional aerosol valve, therefore, provides little or no product mixing, or little surface to break up clumps of solids that may accumulate and clog flow paths.
Also, because the coil-bound compression spring coils form a barrier that keeps the majority of product flow on the outside, the aperture (vapor tap) only impinges a small portion of the product flow path and so does not take in the maximum potential amount of product or propellant.
SUMMARY OF THE DISCLOSUREThe present disclosure provides an aerosol valve that provides an additional flow path for the product and propellant that improves mixing of the product formulation.
The present disclosure also provides such an aerosol valve that provides an additional flow path for the product and propellant that improves mixing of the product formulation, reduces agglomeration of solids in the product that might otherwise clog the flow paths in the aerosol valve, increases turbulence of the product formulation as it flows through the aerosol valve, and feeds more of the product directly to the aperture for better dispensing of the product.
The present disclosure further provides an aerosol valve having a valve stem, housing, compression spring, and a hard stop between the valve stem and housing. The hard stop prevents the compression spring from becoming fully-compressed (coil-bound) when the consumer presses on the valve stem to dispense a product, so that there are open spaces between adjacent coils of the compression spring.
The present disclosure still further provides that the resulting open spaces between the coils of the compression spring create an additional flow path for the product formulation and propellant that provides access to the product and propellant into the center space circumscribed by the compression spring.
The present disclosure also provides that the compression spring has these open spaces that can function as a baffle and a static mixer for the product formulation to improve the mixing of the solids in the product formulation as they flow through the aerosol valve.
The present disclosure further provides that the spaces between the coils of the compression spring also increase turbulence in the flow path, and can break up agglomerations of solids in the product formulation that might otherwise clog the flow path.
The present disclosure still further provides that the aerosol valve structure directs the ingress of the product to preferentially flow through the center of the spring diameter, and to exit as a cascade through the open coils over the upper end of the compression spring.
The present disclosure yet further provides that the aperture (vapor tap) is positioned adjacent to the open spring coils to maximize impingement of the product and propellant into the center of the fluid flow in the interior space formed by the compression spring.
The present disclosure also provides that the aerosol valve has a valve stem with large cross-section passageways that allow the product formulation to flow directly from the dip-tube through the center of the compression spring. This configuration allows the product flow to be gently deflected around the valve stem, which reduces back pressure (resistance).
Referring to the drawings and, in particular,
Aerosol valve 10 includes a dip tube 12, compression spring 14, valve stem 16, valve stem housing 18, mounting cup 20, and seal 22. Valve stem 16 is enclosed in valve stem housing 18. Valve stem 16 has a pair of apertures (not shown in
Compression spring 14 exerts an upward pressure on valve stem housing 18, which is pressed against seal 22 that is located on the inner aspect of mounting cup 20. Valve stem 16 has an upper portion that protrudes through seal 22 and mounting cup 20, and which is pressed by the consumer to spray the product formulation.
When valve stem 16 is pressed down by the consumer to spray the product, the product formulation flows upward through the internal space of valve stem housing 18 in a flow path 30.
As shown in
Aerosol valve 40 has fewer abrupt changes in flow direction, as compared with the flow paths of aerosol valves in the prior art. This reduces the propensity of the solids in the product formulation to agglomerate in the flow paths, by providing fewer loci at which the particles may accumulate, and thereby reduces product failures.
An embodiment of valve stem 46 has four (4) passageways (not shown) that are large in cross-section, to minimize drag and thereby reduce agglomeration of the solids in the product formulation as the product passes through, reducing the incidence of product failure.
The passageways readily allow the product formulation to flow directly from dip tube 42 through the center space inside compression spring 44, and to be gently deflected around valve stem 46. Valve stem 46 is preferably a thinned valve stem body. These structures and configuration reduce back pressure (resistance) to the flow of the product formulation before it reaches valve stem aperture(s) 58. This is an advantage over conventional valve flow paths, which require abrupt changes in flow direction and passage through long, narrow channels prior to arriving at the valve stem apertures.
As shown in
Spaces 45 between the individual coils in compression spring 44 increase turbulence along the flow paths of the product and propellant. This turbulence can break up agglomerations of solids in the product formulation as it moves along the flow path, thereby reducing the likelihood that solids will agglomerate and clog any of the flow paths. In this way, the coils of compression spring 44 can “atomize” the solids in the product formulation; i.e., maintain the solids at their smallest individual particle size, on average, with few or zero “clumps” of solids.
Spaces 45 between the coils of compression spring 44 also improve the mixing of the product formulation as the solids flow through aerosol valve 40.
Spaces 45 between the coils of compression spring 44 (when open for spraying) also direct the ingress of the product formulation to preferentially flow through the center of compression spring 44 and exit as a cascade through the open coils and over the upper end of compression spring 44.
Spaces 45 between the coils of the compression spring 44 create an additional defined flow path for the product and propellant that improves mixing of the product formulation, reduces agglomeration of solids that might otherwise block the flow path, increases turbulence of the product formulation as it flows through the aerosol valve, and feeds more of the product directly to the aperture for better dispensing of the product.
Seal 52 is a flexible material that seals the space between mounting cup 50 and valve stem housing 48. Seal 52 is preferably made of rubber or similar flexible material. Seal 52 is preferably shaped as a gasket. A seal between seal 52, valve stem housing 48 and mounting cup 50 occurs by compression during crimping of cup 50. Pressing on valve stem 46 can somewhat deform the gasket-like seal between seal 52 and valve stem housing 48 as well as between seal 52 and mounting cup 50.
Dip tube 42 is the access point for the stored product formulation in the container (not shown) to aerosol valve 40.
Aerosol valve 40 preferentially forms the largest possible flow path cross-sections that are viable, given the constraints of the valve stem housing, compression spring geometry, and valve stem molding capability (for strength and moldability).
Similarly,
In another embodiment, the product formulation of the present disclosure is a mixture of two types of media, such as a mixture of a powder (solids) and propellant.
A method of using the aerosol valve described above for delivery of a product formulation is also provided. The method uses the aerosol valve having a hard stop that prevents full compression of the compression spring when the valve stem is pressed by the consumer to dispense the product. The resulting spaces between the coils of the compression spring create an additional flow path for the product and propellant and can act as a baffle and/or static mixer. The method improves mixing of the product formulation, reduces agglomeration of solids that might otherwise block the flow path, increases turbulence of the product formulation as it flows through the aerosol valve, and feeds more of the product directly to the aperture for better dispensing of the product. The aerosol valve structure also permits loading the product and propellant into the aerosol container in a single production line, increasing the manufacturing rate, and reducing material usage.
EXPERIMENTALTesting the proposed aerosol valve with high-solids product formulations has resulted in no recordable instances of failure of the product to dispense throughout full-life testing. This is in contrast to laboratory testing with known, existing aerosol valve designs that failed due to agglomeration with a high-solids formulation that showed a propensity to agglomerate.
As used in this application, the word “about” for dimensions, weights, and other measures means a range that is ±10% of the stated value, more preferably ±5% of the stated value, and most preferably ±1% of the stated value, including all subranges therebetween.
It should be understood that the foregoing description is only illustrative of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the present disclosure. Accordingly, the present disclosure is intended to embrace all such alternatives, modifications, and variances that fall within the scope of the present disclosure.
Claims
1. An aerosol valve for dispensing a product formulation from a container, comprising:
- a mounting cup on the container for orientating the aerosol valve on the container;
- a seal positioned on the mounting cup;
- a valve stem housing positioned below the mounting cup and adjacent the seal, the valve stem housing having an interior surface;
- a dip tube positioned below the valve stem housing, the dip tube being connected to a reservoir of the product formulation in the container;
- a valve stem in the valve stem housing, the valve stem having a top portion that protrudes through and above the seal and a bottom portion in the valve stem housing, the valve stem further comprising a valve stem aperture and a center hole; and
- a compression spring positioned in the valve stem housing contacting the valve stem, the compression spring comprising: a spring coil that, in a first position, forms a plurality of spaces with each space between adjacent spring coils; and a center space circumscribed by the spring coil with a center space diameter,
- wherein the valve stem is movable from a top position when the aerosol valve is in an unactuated, closed position, to a bottom position when the aerosol valve is fully actuated,
- wherein the interior surface interacts with the valve stem to form a hard stop that prevents the downward-moving valve stem from fully compressing the spring coils when the aerosol valve is fully-actuated,
- wherein when the aerosol valve is actuated, the product formulation in the reservoir flows upwardly under pressure through the dip tube, with a first portion of the product formulation flowing into and through the center space of the compression spring, around the outside of the valve stem body, enters the valve stem aperture, and into the center hole to dispense the product formulation from the container, forming a first flow path, and a second portion of the product formulation flowing into and through the spring coils and the spaces therebetween, forming a second flow path.
2. The aerosol valve according to claim 1, wherein the interaction of the product formulation with the spring coils in the second flow path increases mixing of the product formulation and breaks up agglomerations of solids in the product formulation.
3. The aerosol valve according to claim 1, wherein the increased mixing of the product formulation and breaking up of agglomerations of solids in the second flow path reduces the incidence of blockages and thereby decreases a product failure rate of the aerosol valve.
4. The aerosol valve according to claim 1, wherein the valve stem housing further comprises:
- an interior surface having an area that inclines inward to form the hard stop that is a physical barrier to further downward movement of the valve stem.
5. The aerosol valve according to claim 4, wherein the position of the hard stop allows the valve stem to attain the bottom position that partially, but not completely, compresses the spring coils of the compression spring.
6. The aerosol valve according to claim 1, wherein the first flow path is a short path that has few abrupt changes in flow direction to decrease resistance and back pressure of the product formulation as it flows through the aerosol valve.
7. The aerosol valve according to claim 1, wherein the first flow path has few loci at which the product formulation can agglomerate and impede the flow of the product formulation.
8. The aerosol valve according to claim 1, wherein the flow of the product formulation through the spring coils and in the spaces therebetween increases turbulence of the product formulation to maintain a small average particle size for the solids therein.
9. The aerosol valve according to claim 1, wherein the spring coils and the spaces therebetween direct the product formulation to flow into and upward through the center space of the compression spring, so that the product formulation exits as a cascade through an upper end of the compression spring where it enters the valve stem aperture and flows into the center hole,
- thereby increasing the amount of the product formulation entering into the valve stem aperture and center hole.
10. The aerosol valve according to claim 1, wherein the first flow path and the second flow path form a single flow path before entering the valve stem aperture.
11. The aerosol valve according to claim 1, wherein all, or substantially all, of the product formulation flows in and through the spaces between the spring coils of the compression spring before entering the valve stem aperture.
12. The aerosol valve according to claim 1, wherein bottom portion of the valve stem is shaped to form a flow passageway through which the product formulation flows when the aerosol valve is actuated.
13. The aerosol valve according to claim 1, wherein the product formulation comprises a mixture of a chemical composition and a propellant.
14. The aerosol valve according to claim 13, wherein the chemical composition comprises a powder.
15. The aerosol valve according to claim 14, wherein the product formulation is a high-solids product formulation.
16. An aerosol valve for dispensing a product formulation from a container, comprising:
- a mounting cup on a top portion of the container that orientates the aerosol valve in a position perpendicular to the mounting cup;
- a seal positioned on the mounting cup;
- a valve stem housing positioned below the mounting cup and adjacent the seal, the valve stem having an interior surface;
- a dip tube positioned below the valve stem housing, the dip tube being connected to a reservoir of the product formulation in the container;
- a valve stem being in the valve stem housing, the valve stem having a top portion that protrudes through and above the seal and a bottom portion in the valve stem housing, the valve stem further comprising a valve stem aperture and a center hole; and
- a compression spring positioned in the valve stem housing and contacting the valve stem, the compression spring comprising: a spring coil that, in a first position, forms a plurality of spaces with each space between adjacent spring coils; and a center space circumscribed by the spring coil with a center space diameter,
- wherein the valve stem is in a vertical position prior to actuation, and is tilted away from the vertical position by pressing sideways on the valve stem to form a tilted valve stem that can actuate the aerosol valve,
- wherein the interior surface has an area that inclines inward and interacts with the tilted valve stem to form a hard stop so that the tilted valve stem partially, but not completely, compresses the spring coil when the aerosol valve is actuated,
- wherein when the aerosol valve is actuated, the product formulation in the reservoir flows upwardly under pressure through the dip tube,
- wherein the product formulation has a first portion that flows 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 dispense the product formulation from the container, forming a first flow path,
- wherein the product formulation has a second portion that flows into and through the spring coils and the spaces therebetween, forming a second flow path,
- wherein the interaction of the product formulation with the spring coils of the second flow path increases mixing of the product formulation and breaks up agglomerations of solids in the product formulation.
17. The aerosol valve according to claim 16, wherein the increased mixing of the product formulation and breaking up of agglomerations of solids in the second flow path reduce the incidence of blockages to decrease a product failure rate of the aerosol valve.
18. The aerosol valve according to claim 16, wherein the valve stem is tilted between about 5% and about 10% from the vertical position to actuate the aerosol valve.
19. A method for using an aerosol valve for dispensing a product formulation from a container, comprising:
- actuating the aerosol valve to dispense the product formulation, wherein the aerosol valve comprises: a mounting cup on the container that orientates the aerosol valve on the container; a seal positioned on the mounting cup; a valve stem housing positioned below the mounting cup and adjacent the seal, the valve stem having an interior surface; a dip tube positioned below the valve stem housing, the dip tube being connected to a reservoir of the product formulation in the container; a valve stem positioned in the valve stem housing, the valve stem having a top portion that protrudes through and above the seal and a bottom portion in the valve stem housing, the valve stem having a valve stem aperture and a center hole; and a compression spring positioned in the valve stem housing and contacting the valve stem, the compression spring comprising: a spring coil that, in a first position, forms a plurality of spaces with each space between adjacent spring coils; and a center space circumscribed by the spring coil with a center space diameter, wherein the valve stem is movable from a top position when the aerosol valve is in an unactuated, closed position, to a bottom position when the aerosol valve is actuated, wherein the interior surface has an area that interacts with the valve stem to form a hard stop that prevents the valve stem from fully compressing the spring coils when the aerosol valve is actuated, wherein when the aerosol valve is actuated, the product formulation in the reservoir flows upwardly under pressure through the dip tube, wherein the product formulation has a first portion that flows 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 dispense the product formulation from the container, forming a first flow path, wherein the product formulation has a second portion that flows into and through the spring coils and the spaces therebetween, forming a second flow path, and wherein the interaction of the product formulation with the spring coils on the second flow path increases mixing of the product formulation and breaks up agglomerations of solids in the product formulation, and
- releasing the valve stem to stop dispensing the product formulation.
20. The method according to claim 19, wherein the increased mixing of the product formulation and breaking up of agglomerations of solids in the second flow path reduces the incidence of blockages and thereby decreases a product failure rate of the aerosol valve.
Type: Application
Filed: Mar 14, 2014
Publication Date: Jan 14, 2016
Inventors: John B. FORE (Travelers Rest, SC), Michael Paul DOWNEY (Greer, SC), Geoffrey BRACE (Columbus, NC)
Application Number: 14/777,128