Dispensing multi-component products

Abstract

Pressurized dispensing systems are provided, for dispensing multi-component products. Some dispensing systems include (a) an outer body defining a first chamber constructed to contain a first component of the product; (b) an inner container, disposed within said body, defining a second chamber constructed to contain a second component of the product and maintain the second component separate from the first component; (c) a dispensing head, in fluid communication with the first and second chambers, through which the product is dispensed; and (d) a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from the first and second chambers to said dispensing head, a valve body surrounding at least a portion of the valve stem. The dispensing systems may include, for example, a sealing member constructed to provide a seal between the valve stem and an inner wall of the valve body, the sealing member including two portions having different outer diameters.

Description

TECHNICAL FIELD

The present invention relates to dispensing multi-component products, and to valves for use in dispensing such products.

BACKGROUND

It is often necessary, or desirable, to maintain one component of a multi-component product, e.g., a shaving cream, separate from other components of the product or from some part of the container in which the product is stored.

For example, the components of the product may react with each other when mixed, and it may be desired to prevent this reaction from occurring until the product is dispensed.

Moreover, in some cases it is important to keep one component of a multi-component product from contacting the container holding the product due to the reactive nature of the particular component, e.g., if the component reacts with metals and the container is metal or includes metal parts such as springs.

Other reasons for maintaining one component separate from other components include aesthetic reasons, e.g., to provide a “stripe” of one color against a background of another color when the product is dispensed.

Various systems have been used in the past to package and dispense products containing two components so that the components are separated during storage and mixed during or just prior to dispensing. One type of system includes an outer canister, a pair of nested bags within the container, defining first and second chambers for the components, and a valve constructed to allow metered dispensing of the components from the chambers by a user.

Systems of this type are described, for example, in U.S. Ser. No. 10/283,033, filed Oct. 29, 2002, the disclosure of which is incorporated herein by reference. An example of a valve assembly that may be included in the systems described in U.S. Ser. No. 10/283,033 is shown in FIG. 1. In use, this valve assembly is crimped into a container, and is in fluid communication with a pair of nested bags (not shown) that contain first and second components of a composition and with a dispensing head (not shown) through which the components are dispensed. Valve assembly 17 includes a valve stem 74 mounted within a spring 72. Spring 72 biases first valve portion 76 against first valve seal 78 and second valve portion 80 against second valve seal 82, so that both valve portions are biased towards a closed position. Generally valve seals 78 and 82 are resilient gaskets, e.g., stamped flat gaskets. Valve stem 74 also includes a central bore 79, in fluid communication with a first passage in the dispensing head, and a passage 154, in fluid communication with a second passage in the dispensing head. The dispensing head includes an actuating stem (not shown), which extends into and seats in a cup-shaped area 86 of the valve stem 74. When an actuator is depressed, the actuating stem presses valve stem 74 down, against the biasing force of spring 72. This movement simultaneously moves both valve portions away from the corresponding valve seals, moving the dispensing system to its open position, shown in FIG. 1. When the valve opens, openings 81 in the valve stem allow the first component to flow from the inner bag into bore 79, while openings 64 allow the second component to flow from the outer bag into passage 154.

In these systems, the components can also be filled into the container through the valve assembly, by pressing the valve stem down and injecting the components through the openings 64 and 81. It is generally important that, during filling, there be little or no cross-contamination between the two components. This is particularly important, for example, if the two components will react with each other when mixed.

SUMMARY

The invention features pressurized dispensing systems for dispensing multi-component products. The dispensing systems include (a) an outer body defining a first chamber constructed to contain a first component of said product; (b) an inner container, disposed within said body, defining a second chamber constructed to contain a second component of said product and maintain said second component separate from said first component; (c) a dispensing head, in fluid communication with said first and second chambers, through which the product is dispensed; and (d) a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from said first and second chambers to said dispensing head, and a valve body surrounding at least a portion of the valve stem.

In one aspect, the dispensing system includes a sealing member constructed to provide a seal between the valve stem and an inner wall of the valve body. The sealing member may include two portions having different outer diameters, and/or may include a portion that seals against an inner wall of the valve body.

In another aspect, the valve body includes a threaded portion configured to receive a corresponding threaded portion of the inner container.

In a further aspect, the outer body includes a flexible bag, and the valve body includes a raised region configured to maintain a flow path to openings in the valve body as the contents of the outer body are exhausted causing the flexible bag to collapse against the valve stem.

In some implementations, the dispensing systems described herein may exhibit one or more of the following advantages. Unintentional mixing of the components during filling of the container is minimized or eliminated. The container may be filled at a relatively low filling pressure, e.g., less than 100 psi and, in some implementations, less than 75 psi. The filling pressure can be selected to suit the rheology of the components being filled and may range, for example, from about 60 to 600 psi. The ratio of the components dispensed from the container during use can be readily and precisely controlled. The product may be filled and dispensed under relatively low shear conditions. For example, the shear rate of flow to the inner bag 202 may be less than about 3×10⁵ s⁻¹, and the shear rate of flow to the outer bag can range from about 1×10⁴ s⁻¹ to about 2×10⁴ s⁻¹. The system may allow product to be dispensed at a predetermined ratio even when the contents of the container are almost exhausted.

Generally, the products described herein are pressurized, i.e., the contents of the container are under pressure, for example pressure applied by a propellant or by a mechanical force such as a spring.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a valve used in a prior art dispensing system.

FIG. 2 is a side plan view of a valve according to one embodiment of the invention in place in the neck of a container. FIG. 2A is a cross-sectional view of the valve, taken along line A-A in FIG. 2. FIG. 2B is an exploded perspective view showing the components of the valve.

FIG. 3 is a perspective view of the valve of FIG. 2, taken from below.

FIG. 4 is a cross-sectional view of a dispensing system including the valve of FIG. 2; FIG. 4A is an enlarged detail view of area A of FIG. 4 with the valve in an open position; FIG. 4B is an enlarged detail view of area A of FIG. 4 with the valve in a closed position.

FIG. 5 is a cross-sectional view of a valve according to an alternative embodiment of the invention.

FIG. 6 is an enlarged cross-sectional view of a spring seat used in the valve of FIG. 2.

DETAILED DESCRIPTION

Referring again to FIG. 1, the inventor has found that the flat gasket seal 82 in the prior art valve assembly may allow “cross-over” between the two components, i.e., one component may enter the chamber that is reserved for the other component, especially when the components are being filled into the container through the valve. This cross-over effect is generally the result of the seal 82 bending or otherwise distorting during filling. As a result, cross-over may be exacerbated by high filling pressures and by the location of openings 64 adjacent to seal 82. Bending of seal 82 may also occur during dispensing, which may cause the two components to exit the valve at different times.

In the valve assembly 98 shown in FIG. 2, seal 82 is replaced by a molded sealing member 100 that is dimensioned to be press-fitted into the valve body. Sealing member 100 includes an upper portion 102, dimensioned to sealingly seat against a shoulder 106 of valve body 108. Upper portion 102 also seals against the valve stem. Sealing member 100 also includes a smaller diameter lower portion 104, which engages the inner wall of the valve body below the shoulder 106. The lower portion 104 has an inner diameter that is greater than that of the upper portion, so that the inner wall of lower portion 104 is spaced from and does not seal against the valve stem 105. Thus, the sealing member contacts the inner wall of the valve body over a length sufficient to prevent the sealing member from bending, deforming or being dislodged, while allowing the valve to open without excessive axial movement of the valve stem. Preferably, the surface area of the portion of the sealing member that contacts the inner wall is at least about 0.065 in², more preferably at least about 0.140 in².

The geometry of sealing member 100 prevents bending or other distortion of the sealing member, ensuring a secure seal even when the seal is subjected to a load, e.g., during filling of the container. The stability of the sealing member generally prevents cross-over and ensures that the two components will begin dispensing simultaneously each time the valve is opened.

Additionally, openings 64 of the prior art valve have been replaced by openings 110, which are spaced from upper portion 102 a sufficient distance to minimize (and preferably to eliminate) the potential for a cross-over path between the sealing member 100 and the openings 110. Thus, even if the sealing member were to distort under pressure, it would be unlikely that cross-over would occur. Preferably, openings 110 are at least 0.055 inch from the upper surface 112 of sealing member 100, more preferably at least 0.110 inch.

Advantageously, the openings 110 in the valve body and the openings 114 in the valve stem are large, preferably as large as can be accommodated by the design constraints of the valve body and valve stem. Importantly, not only are the openings large, they are also unobstructed, so that the effective area through which flow can occur is substantially equal to (within 5% of) the actual area of the openings. The large valve openings allow a high flow rate into the nozzle during filling of the dispensing system, and minimize shear on the first and second components during filling and dispensing. Preferably, the total area of openings 110 is at least about 0.004 in², more preferably at least about 0.016 in², and the total area of openings 114 is at least about 0.001 in², more preferably at least about 0.002 in². These areas are the theoretical design measurements; the actual areas of the openings are subject to tolerances and distortion of the valve during installation into the container. The area of the openings is selected to allow the two components to be delivered into the container through the valve during a high-speed manufacturing process. It is desirable to fill through the valve because doing so facilitates high-speed in-line processing. The large size of the openings also tends to reduce the filling pressure and thereby minimize shear on the composition during filling. Moreover, the larger the openings, the less influence the valve design will have on the ratio of the two components delivered during dispensing. As a result, the large openings allow fine adjustments to the ratio to be made by adjusting the design of the actuator. As a result, in some cases the same valve design can be used for a variety of products having different rheologies, with adjustments being made, to compensate for rheology, by changing the actuator design.

The use of a female valve stem allows design room to provide these relatively large openings. Using a female valve stem also allows the flow rate of the components out of the container to be finely controlled by the actuator, rather than by the valve. It is generally easier to accurately control the flow at the last point of exit (the actuator), rather than at the valve openings.

Preferably, the valve stem is a single, unitary part, for ease of manufacturing and economy. It is also generally preferred that the lower end of the valve stem have an outer diameter that equal to or slightly greater than the inner diameter of the sealing member, so that the valve can be easily assembled by press fitting the valve stem into the valve body.

Referring to FIGS. 2A and 2B, in the new design spring 72 is supported by a spring seat 101. Spring seat 101, shown in detail in FIG. 6, includes an aperture 103 that has an inner diameter ID that is only slightly larger, e.g., 5 to 20% larger, than the outer diameter of the valve stem. As a result, the spring seat inhibits radial movement and bending of the valve stem. Reducing the radial movement and bending of the valve stem will tend to improve the efficiency of the valve and make it more robust.

Still referring to FIG. 2, in the finished product the valve assembly 98 is crimped onto a valve cup 13. Referring to FIG. 5, an outer bag 200 and an inner bag 202 are attached to the lower end of the valve assembly, as will be discussed below, and a dispensing head 50 is mounted over the valve cup 13. Dispensing head 50 includes an actuator 52 that may be depressed by a user to actuate valve assembly 98. Dispensing head 50 defines a first channel 54, for flow of the first component, and a coaxially disposed second channel 56, for flow of the second component. Channels 54 and 56 are in fluid communication with nozzle 58, through which the product is dispensed.

Referring to FIGS. 2-2B and 3, it is generally preferred that the valve assembly include a skirt 204 mounted on the outer surface of the valve body 108. Skirt 204 includes a generally cylindrical or dome-shaped main portion 203 having an outer surface 206 configured to prevent the neck of the outer bag 200 from collapsing around the valve body (which could choke off flow to the openings 110). Preferably, the outer surface 206 is spaced from the outer wall of valve body 108 by at least about 0.135 inch, and the skirt extends axially along the length of the valve body at least about 0.625 inch from the bottom of the valve body towards the valve cup. The skirt 204 defines a pair of channels 207 that provide a fluid path to the openings 110 even when the outer bag 200 collapses against the outer surface 206. It is generally preferred that the skirt extend to the top of openings 110. The entire skirt may extend to the top of openings 110, or the skirt may include ribs 205 that extend upwardly from the main portion 203, as shown. Including ribs 205, rather than extending the main portion 203 to openings 110, will reduce the amount of plastic required to mold the valve body while still maintaining a flow path to openings 110. The ribs 205 preferably extend radially outward from the valve body the same distance as the outer surface 206 where the ribs 205 intersect with outer surface 206. At the centerline of openings 110, the ribs 205 extend outwardly at least about 0.040 inch.

Alternatively, instead of providing a skirt 204 having a cylindrical main portion, the valve body 108 may include only a pair of raised ribs 209, as shown in FIG. 5. In this case, the ribs 209 extend axially along the valve body 108 over the same length covered by the skirt 204 discussed above.

Skirt 204 also includes a threaded inner surface 208 configured to receive a corresponding threaded neck 209 of the inner bag 202 (FIG. 4A). The threaded connection provides a positive compression on bag gasket 201 (FIGS. 4A and 4B) and prevents the component in outer bag 200 from being sucked into inner bag 202. Without the threaded connection, this may tend to occur if there is a pressure differential between the inner and outer bags when the outer bag is filled. The threaded connection also provides a tortuous path from the bag gasket 201 to the inner bag 202, and thus inhibits flow of material into the inner bag even if the seal provided by bag gasket 201 is broken. The threaded connection is particularly advantageous when the two components react with each other, and thus cross-over must be minimized or eliminated altogether. In products that can tolerate some cross-over, the threaded connection can often be omitted, if desired. For example, the valve may include a snap-on connection rather than a threaded connection, as shown in FIG. 5.

It may be preferred to use a bag-in-bag arrangement such as that shown in FIG. 4, in which a lower portion 210 of the outer bag 200 is contoured to match the contour of the inner bag 202. In particular, the lower portion 210 tapers inwardly in the same manner as the corresponding lower portion of the inner bag, so that the walls of the two bags are generally parallel in this area. This configuration tends to prevent material from getting trapped on the bottom of the outer bag, which reduces residue and allows more product to be delivered to the consumer rather than wasted. Because less material is trapped in the bottom of the outer bag, the ratio of the two components generally remains constant as the contents of the container are dispensed. This bag-in-bag arrangement is discussed in U.S.Ser. No. ______, filed ______, the complete disclosure of which is incorporated by reference herein.

Other embodiments are within the scope of the following claims.

Claims

1. A pressurized dispensing system for dispensing a multi-component product, comprising:

an outer body defining a first chamber constructed to contain a first component of said product;

an inner container, disposed within said body, defining a second chamber constructed to contain a second component of said product and maintain said second component separate from said first component;

a dispensing head, in fluid communication with said first and second chambers, through which the product is dispensed; and

a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from said first and second chambers to said dispensing head, a valve body surrounding at least a portion of the valve stem, and a sealing member constructed to provide a seal between the valve stem and an inner wall of the valve body, the sealing member including two portions having different outer diameters.

2. The dispensing system of claim 1 wherein the sealing member is constructed to be press fitted into the valve body.

3. The dispensing system of claim 1 wherein the sealing member includes an upper portion that seals against the valve stem, and a lower portion that does not seal against the valve stem.

4. The dispensing system of claim 3 wherein both the upper and lower portions seal against the valve body.

5. The dispensing system of claim 1 wherein the valve body includes a plurality of upper openings and the valve stem includes a plurality of lower openings.

6. The dispensing system of claim 5 wherein the sealing member is positioned to seal the lower openings when the valve is in its closed position.

7. The dispensing system of claim 1 wherein the valve stem is a female valve stem.

8. The dispensing system of claim 6 wherein the sealing member is spaced from the upper openings.

9. The dispensing system of claim 8 wherein an upper surface of the sealing member is at least 0.055 inch below the center of the lowest of the upper openings.

10. The dispensing system of claim 5 wherein the upper openings have an unobstructed open area of at least about 0.004 in2 and the lower openings have an unobstructed open area of at least about 0.001 in2.

11. The dispensing system of claim 1 wherein the outer body and inner container comprise flexible bags.

12. The dispensing system of claim 11 wherein the inner container has a threaded neck and the valve assembly includes a threaded bore constructed to receive the neck of the inner container in threaded engagement.

13. The dispensing system of claim 1 wherein the outer body comprises a flexible bag and the valve body includes a raised region configured to prevent the outer body from collapsing against an outer surface of the valve body.

14. The dispensing system of claim 13 wherein the valve body includes raised ridges extending from an outer surface of the valve body to prevent the outer body from collapsing against the outer surface of the valve body.

15. The dispensing system of claim 14 wherein the valve body includes upper openings, and the ridges extend longitudinally along at least a portion the length of the valve body adjacent the upper openings.

16. The dispensing system of claim 13 wherein the raised region comprises a skirt extending radially from a side wall of the valve body.

17. The dispensing system of claim 11 wherein corresponding lower portions of the bags have substantially parallel, tapered sides.

18. The dispensing system of claim 17 wherein each bag has a lower portion that tapers from a relatively larger cross-section, nearer to the middle of the length of the bag, to a relatively smaller cross-section at the bottom of the bag.

19. The dispensing system of claim 1 further comprising a spring seat configured to provide radial support to the valve stem.

20. A pressurized dispensing system for dispensing a multi-component product, comprising:

an outer body defining a first chamber constructed to contain a first component of said product;

an inner container, disposed within said body, defining a second chamber constructed to contain a second component of said product and maintain said second component separate from said first component;

a dispensing head, in fluid communication with said first and second chambers, through which the product is dispensed; and

a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from said first and second chambers to said dispensing head, a valve body surrounding at least a portion of the valve stem, and a sealing member constructed to provide a seal between the valve stem and an inner wall of the valve body, the sealing member including a portion that seals against an inner wall of the valve body.

21. The dispensing system of claim 20 wherein the portion that seals against the inner wall of the valve body has a surface area of at least about 0.065 in2.

22. The dispensing system of claim 21 wherein the portion that seals against the inner wall of the valve body has a surface area of at least about 0.140 in2.

23. A pressurized dispensing system for dispensing a multi-component product, comprising:

an outer body defining a first chamber constructed to contain a first component of said product;

an inner container, disposed within said body, defining a second chamber constructed to contain a second component of said product and maintain said second component separate from said first component;

a dispensing head, in fluid communication with said first and second chambers, through which the product is dispensed; and

a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from said first and second chambers to said dispensing head, and a valve body surrounding at least a portion of the valve stem, the valve body including a threaded portion configured to receive a corresponding threaded portion of the inner container.

24. A pressurized dispensing system for dispensing a multi-component product, comprising:

an outer body, comprising a flexible bag, defining a first chamber constructed to contain a first component of said product;

an inner container, disposed within said body, defining a second chamber constructed to contain a second component of said product and maintain said second component separate from said first component;

a dispensing head, in fluid communication with said first and second chambers, through which the product is dispensed; and

a valve assembly, including a valve stem constructed to move between a closed position, in which said first and second chambers are sealed, and an open position, in which said first and second components flow simultaneously from said first and second chambers to said dispensing head, and a valve body surrounding at least a portion of the valve stem and including openings providing fluid communication between the first chamber and the dispensing head;

wherein the valve body includes a raised region configured to maintain a flow path to the openings in the valve stem as the contents of the outer body are exhausted causing the flexible bag to collapse against the valve stem.

25. The dispensing system of claim 24 wherein the valve body includes raised ridges extending from an outer surface of the valve body to prevent the outer body from collapsing against the outer surface of the valve body.

26. The dispensing system of claim 25 wherein the valve body includes upper openings, and the ridges extend longitudinally along at least a portion the length of the valve body adjacent the upper openings.

27. The dispensing system of claim 24 wherein the raised region comprises a skirt extending radially from a side wall of the valve body.