Relief Vent for a Hot Fill Fluid Container
Caps having porous elements that act as a vent to facilitate cooling of hot fluids stored in containers. Certain embodiments comprise a cap that may be affixed to a container filled with a hot fluid. The cap may include a porous element that allows air to enter the container during the cooling process, but also prevents the introduction of microbes and bacteria into the container. The cap may include a through hole, chamber, or recessed area to receive and secure the porous element. In certain embodiments the porous element may comprise a sintered composite material with thermoplastic particles and either metal particles and/or metal powder. In other embodiments, the porous element may comprise a layered structure. The layers may include a combination of the sintered composite material, a metallic layer, or various porous layers.
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/245,166, entitled “Relief vent for a hot fill beverage container,” filed on Sep. 23, 2009, and to U.S. Provisional Patent Application Ser. No. 61/204,756, entitled “Relief vent for a hot fill beverage container,” filed on Jan. 9, 2009, the entire contents of which are incorporated by reference.
FIELD OF THE INVENTIONEmbodiments of the present invention relate to vents and/or barriers for fluid containers, for example beverage containers.
BACKGROUND OF THE INVENTIONWhen a container is filled with some type of hot fluid and the fluid cools, any gas that is inside the container contracts. This contraction of internal gasses causes a pressure differential between the inside of the container and outside of the container (the ambient conditions), which may cause the sidewalls of the container to collapse inward. The food processing industry is one example of an industry that might encounter such problems. For example, in order to maintain product quality and consumer safety, most foodstuffs are packaged in a hot-fill operation in which the foodstuffs are placed in the containers while hot (for example 82° C. or higher), and then a cap is affixed to the container. But such caps seal the contents of the container to ambient conditions. Thus, when the foodstuffs cool, air cannot enter the container to alleviate the pressure differential, and the sidewalls of the container may collapse. It should be understood that the food industry is but one non-limiting example, and other industries may also experience problems with allowing containers to cool.
One solution is to provide collapsing panels (or vacuum panels) in the sidewalls to alleviate the pressure differential, but such panels have disadvantages. For example, containers must have thick sidewalls to accommodate panels, which increases material cost and assembly cost. Additionally, the panels may allow the fluid to leak out of the container and may allow airborne microbes to enter the container.
Another solution is to provide an aperture in one or both of the container or cap, and to provide a hydrophobic membranes to cover the aperture. A hydrophobic membrane is one that allows air but not liquid to pass. Although such membranes may relieve the pressure differential, but they are typically very thin (for example 100 microns) and very delicate, and thus may become damaged during the manufacturing or cooling process. The membranes increase manufacturing costs because lamination and/or adhesives are required to secure the membranes.
Thus, there is a need for a structure that can more effectively ventilate containers filled with hot fluid.
There is a need for a structure to allow ambient air to enter containers filled with hot fluids to equalize pressures during the cooling process, thus preventing the sidewalls of the container from collapsing.
There is a need for a structure that ventilates containers filled with hot fluids while blocking liquid flow out of the container.
There is a need for a structure that ventilates containers filled with hot fluids without causing the introduction of airborne microbes and bacteria into the container.
There is a need for a sturdy structure that ventilates containers that will not become damaged during the manufacturing or cooling process.
There is a need to reduce the material cost and assembly cost of such containers for hot fluids.
SUMMARY OF THE INVENTIONCertain embodiments of the invention comprise a cap that may be affixed to a container that is preferably at least partially filled with a hot fluid. For example, in the food processing industry, containers may be filled with hot foodstuffs or fluids, and it may be desirable to allow the containers to cool using embodiments of the invention. The cap may include a porous element that facilitates cooling of the hot fluid. Specifically, the porous element may allow air to enter the container during the cooling process, thus equalizing pressure on either side of the container walls and preventing or minimizing the sidewalls of the container from collapsing. The porous element may also preferably prevent the introduction of microbes and bacteria into the container. The porous element may be secured to the cap in any number of ways. For example, the cap may include a through hole, chamber, or recessed area to receive the porous element. The porous element may be provided in any desired shape. The porous element is stronger than previously used membranes and less susceptible to damage. Additionally, in certain embodiments it is not necessary to use adhesive or lamination to secure the porous element to the cap, thus reducing manufacturing time and expenses.
According to certain embodiments the porous element may comprise a sintered porous plastic. In other embodiments, the porous element may comprise a sintered composite material with sintered porous plastic and either metal particles and/or metal powder. In still other embodiments, the porous element may comprise a layered structure with at least one porous plastic layer and at least one metallic layer.
Regardless of the composition of the porous element, in certain embodiments the porous element contains pores that allow for the passage of air into and out of the container during the cooling process, but that also prevent the passage of microbes and bacteria. Upon sufficient cooling, heat may be applied to the porous element if desired, thus sealing the porous element and the cap.
According to certain embodiments of the invention, caps are provided with porous elements that function as a vent to allow air to pass into or out of a container during the cooling process, and also act as a bacterial barrier to prevent microbial and bacterial contamination.
The embodiment of cap 10 shown in
In other embodiments, the cap 40 in
According to certain embodiments, such as cap 50 shown in
In yet other embodiments, such as those shown in
In certain other embodiments there may be provided a plug-shaped porous element 82, such as shown in
Although the embodiments have been described as having separate caps and porous elements that are subsequently assembled together, it should be understood that in certain embodiments the porous elements may be manufactured into the caps by insertion molding. For example, in
Once the porous element is secured within the cap, the cap may be affixed to the container, as shown in
When sufficient time for cooling has passed, the cap may be sealed in order to minimize or prohibit any further flow of air into or out of the container.
Yet another embodiment of a cap 88 having a porous element 96 is shown in
According to certain embodiments, the porous elements described herein are sintered and may be made from a variety of materials. Certain materials for the porous elements are described in
In its initial state, the second layered structure 130 is porous to allow the passage of air. The metallic layer 132 does not obstruct the passage of air due to the perforations 134 in the metallic layer 132. Additionally, the pores 108 in the porous layer 144 are sized to allow air to pass, but also act as a bacterial barrier. In some embodiments, the porous layer 144 has a bacterial filtration efficiency of over 99.9% based on the ASTM 1200 test. Upon sufficient heating, the porous layer 144 may become non-porous. Specifically, the pores 108 in the porous layer 144 may melt, thus sealing the second layered structure 130 and preventing air from entering or exiting the container.
Upon sufficient heating the third layered structure 140 may become sealed. Specifically, it may be desirable to provide a first porous layer 142 that melts more readily than the second porous layer 144, so that the first porous layer 142 may become non-porous. Thus, the first porous layer 142 may have a higher melt index, lower melting temperature, and/or a lower viscosity than the second porous layer 144. Materials with a high melt flow index and low viscosity tend to minimize or eliminate any pores 108 that may be formed therein. And if the first porous layer 142 has a lower melting temperature than the second porous layer 144, then it will melt first. Thus, upon sufficient heating the first porous layer 142 may be non-porous to seal the container.
According to certain embodiments, the first porous layer 142 may comprise a colored polymer screen and the metallic layer 132 may comprise a metal screen. Upon heating, the colored polymer screen and the metal screen melt together to seal the third layered structure 140. In other embodiments, the first porous layer 142 may comprise a colored polymer open-celled foam, the metallic layer 132 may comprise a metal screen, and the second porous layer 144 may comprise a bacterial barrier membrane, which may then be non-contact heated with an air jet to melt the colored polymer open-celled foam and thus seal the third layered structure 140.
Certain methods of making layered structures are illustrated in
In embodiments comprising metal (such as the sintered composite material 100 or any of the layered structures), induction heating may be used to sinter and/or seal the material. Induction heating is generally known to one of skill in the art as a process of heating an electrically conducting object by electromagnetic induction, where a high-frequency alternating current (AC) is generated within the metal and resistance leads to heating of the metal. For example, when the sintered composite material 100 is induction heated, the temperature of the metal particles 104 may increase, because metal is a good conductor. The radiant heat from the metal particles 104 melts the surrounding thermoplastic particles 102. Upon sufficient heating the material may become non-porous, thus sealing the cap.
In certain embodiments, the materials described herein—such as sintered porous plastic 122, sintered composite material 100, and/or the layered structures—may have specific shapes or sizes to facilitate their as porous elements. For example, they may be cylindrically shaped (like porous elements 30 or 56), disc-shaped (like porous elements 46, 64 67), or shaped like the plug 82 shown in
Caps having porous elements as described herein may be prone to tampering. For example, if the porous element is exposed or visible then people may tend to pick at the porous element. Such tampering may cause injury to the person and may sacrifice the seal of the cap. Thus, it may be desirable to provide tamper-resistant properties to caps and/or porous elements. In one embodiment, the head 84 of the plug 82 described above may melt to and become fused with the rest of the cap 80, which reduces tampering. In embodiments having a metallic layer 132, the strength of the metallic layer 132 may make it exceedingly difficult to tamper with the porous element and/or cap. Thus, the sealing and strength of certain embodiments provide tamper-resistant properties.
If desired, any of the layered structures described herein may contain one or more additional layers. In embodiments where the porous layer 142 is not itself non-porous or sealed, a separate hydrophobic layer may be provided, including but not limited to wax, an adhesive sealant, or polyethylene. Similarly, although in some embodiments the first porous layer 142 and/or the metallic layer 132 may be tamper-resistant, in other embodiments a separate tamper-resistant layer may be provided. Finally, the layered structures may be provided with oxygen scavenger properties. When air enters the container during the cooling process, a certain amount of air (and oxygen) may remain in the container even after cooling and sealing of the porous element. The remaining oxygen may cause unpleasant properties, such as distaste of the contents in the container. Thus, one or all of the layers in the various layered structures (120, 130, 140) may contain iron powder, which reacts with and eliminates oxygen in the container.
The foregoing is provided for purposes of illustration and disclosure of embodiments of the invention. It will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.
Claims
1. A cap for a container, the cap comprising:
- a. a top surface having an outer edge, a first side, and a second side opposite the first side, wherein the second side faces towards the container;
- b. at least one sidewall extending from the outer edge of the top surface and towards the second side, wherein the at least one sidewall is at least partially threaded to engage with a neck of the container;
- c. at least one through hole defined by the top surface and passing between the first side and the second side; and
- c. a porous element adjacent to the top surface and generally aligned with the through hole, wherein the porous element comprises a plurality of pores that allow air to enter the container but prohibit bacteria from entering the container.
2. The cap as in claim 1, further comprising at least one chamber wall extending from the second side of the top surface of the cap, wherein the chamber wall defines a chamber that receives the porous element.
3. The cap as in claim 1, further comprising at least one chamber wall extending from the first side of the top surface of the cap, wherein the chamber wall defines a chamber that receives the porous element.
4. The cap as in claim 1, wherein the second side of the top surface of the cap defines a recessed area, and the porous element is secured within the recessed area.
5. The cap as in claim 4, further comprising a lip extending around at least a portion of the recessed area, wherein the lip secures the porous element within the recessed area.
6. The cap as in claim 4, wherein the porous element is disc-shaped.
7. The cap as in claim 1, further comprising a protrusion extending from the first side of the top surface of the cap, and wherein the through hole is defined by the protrusion.
8. The cap as in claim 1, further comprising a layered structure comprising the porous element and at least one substrate, wherein the layered structure contacts the second side of the top surface of the cap.
9. The cap as in claim 1, wherein the porous element covers substantially all of the second side of the top surface of the cap.
10. The cap as in claim 1, wherein the porous element has a head and a body, and wherein the body is inserted into the through hole and the head contacts the first side of the top surface of the cap.
11. A device for facilitating the cooling of fluids within a container, the device comprising:
- a. a cap, the cap comprising:
- a top surface having an outer edge and at least one sidewall extending from the outer edge of the top surface, wherein the at least one sidewall is at least partially threaded to engage with a neck of the container;
- at least one through hole defined by the top surface; and
- b. a porous element adjacent to the top surface and generally aligned with the through hole, the porous element comprising:
- a metallic layer comprising a plurality of perforations;
- a porous layer comprising a plurality of pores that allow air to enter the container but prohibit bacteria from entering the container.
12. The device as in claim 11, wherein the porous layer comprises at least one of sintered porous plastic, sintered composite material, porous polyethylene, porous polypropylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, porous polyvinylidene fluoride, porous polyethersulfone, or porous nylon.
13. The device as in claim 11, wherein the metallic layer comprises at least one of metal mesh, metal foil with holes, or a metal screen.
14. The device as in claim 11, wherein the metallic layer comprises at least one of steel, stainless steel, aluminum, copper, zinc, tin, iron, or their alloys.
15. The device as in claim 11, wherein the porous layer is a second porous layer, and wherein the device further comprises a first porous layer.
16. The device as in claim 15, wherein the first porous layer comprises a material having at least one of a higher melt index, lower melting temperature, and/or a lower viscosity than the material comprising the second porous layer.
17. The device as in claim 15, wherein the first porous layer becomes non-porous after melting.
18. The device as in claim 15, wherein the first porous layer is adjacent to the top surface of the cap, and the metallic layer is positioned between the first porous layer and the second porous layer.
19. The device as in claim 15, wherein the first porous layer comprises at least one of polymer screen, polymer non-woven material, polymer woven material, or a polymer open cell foam.
20. The device as in claim 11, wherein the porous element comprises a head and a body, and wherein at least a portion of the head comprises the metallic layer and at least a portion of the body comprises the porous layer.
21. A device for facilitating the cooling of fluids within a container, the device comprising:
- a. a cap, the cap comprising:
- an outer surface having an outer edge and at least one sidewall extending from the outer edge of the outer surface, wherein the at least one sidewall is at least partially threaded to engage with a neck of the container;
- at least one aperture defined by the outer surface; and
- b. an insert secured within the aperture of the cap, the insert comprising:
- an outer surface having an outer edge and at least one sidewall extending from the outer edge of the outer surface, wherein the at least one sidewall defines at least one through hole;
- a porous element secured within the insert and generally aligned with the through hole, the porous element comprising a plurality of pores that allow air to enter the container but prohibit bacteria from entering the container,
- wherein in a first position the through hole of the insert is above the outer surface of the cap, and in a second position the through hole of the insert is below the outer surface of the cap.
22. A method of cooling fluid within a container, the method comprising:
- a. providing a container at least partially filled with fluid;
- b. providing a device comprising:
- i. a cap, the cap comprising a top surface having an outer edge and at least one sidewall extending from the outer edge of the top surface, wherein at least a portion of the sidewall comprises structure to engage with a neck of the container, and wherein the top surface defines at least one through hole;
- ii. a porous element adjacent to the top surface and generally aligned with the through hole, wherein the porous element comprises a plurality of pores that allow air to enter the container but prohibit bacteria from entering the container;
- c. engaging the device to the neck of the container;
- d. allowing the fluid to cool, wherein during cooling air enters or exits the container through the porous element; and
- e. applying heat to at least one of the through hole or the porous element to thereby seal the device.
Type: Application
Filed: Jan 11, 2010
Publication Date: Jul 15, 2010
Inventors: Edward M. Kaucic (Newnan, GA), James P. Wingo (Peachtree City, GA), Bryan Thompson (Sharpsburg, GA), Trevor Waghorn (Peachtree City, GA), Yuet-Yuen Chan Cushing (Atlanta, GA), Tim Meredith (Peachtree City, GA), Michael John Flater (Mableton, GA), Timothy Allen Martin (Newnan, GA), Guoqiang Mao (Smyrna, GA)
Application Number: 12/685,174
International Classification: F24F 7/00 (20060101); B65D 51/16 (20060101);