US20100176134A1

US20100176134A1 - Retortable Closures and Containers

Info

Publication number: US20100176134A1
Application number: US12/504,692
Authority: US
Inventors: Kenneth M. Cramer
Original assignee: Abbott Laboratories
Current assignee: Abbott Laboratories
Priority date: 2008-07-22
Filing date: 2009-07-17
Publication date: 2010-07-15
Also published as: WO2010011624A2; MX2011000873A; WO2010011624A3; CA2731743A1

Abstract

A retortable container (C) or a retortable closure (10) for use with the container (C). A receptacle (R) is included that may incorporate fasteners (F) attaching the closure (10). The closure (10) includes a retainer (20) received with a sealing barrier (100) formed from a polymeric material. The sealing barrier (100) includes a heat transfer material such as powdered metal in a volume that is between about 25% and about 65% of the closure (10) and an an oxygen barrier material such as a nanocompound or other barrier material having a relative volume of approximately between 10% and 60%. Variations of the closure (10) may incorporate seal layer of a thermoplastic elastomeric vulcanizate such as a santoprene and the heat transfer material may be an economically attractive powdered and/or oxide material such as zinc, aluminum, copper, nanotube, or similarly available material, which preferably is diffused throughout the closure (10).

Description

This application claims the benefit of U.S. Provisional Application No. 61/082,640 filed Jul. 22, 2008

BACKGROUND OF THE INVENTION

1. Field of the Invention
The invention relates to the field of retortable and/or sterilizable containers and closures that are in use for packaging pharmaceuticals, comestibles, nutraceuticals, and related liquids and powders. More particularly, the present invention relates to an improved retortable closure and container-closure combination that can be retort processed and/or heat sterilized, before and/or after filing and sealing of the contemplated container.
2. Description of Related Art
For as long as pharmaceutical, nutraceutical, beverage, and comestible products have been packaged for sale and distribution, there has been a need to ensure that the consumer or end user will receive the products in an unspoiled and uncontaminated condition. Such products may sometimes become contaminated and/or may spoil before delivery to the consumer or end-user in a variety of circumstances. A number of environmental and toxicological factors may have adverse effects on such products when the contemplated closures and containers are exposed to various airborne, vapor-borne, and other types of chemical, physical or biological agents before, during, and after the packaging process.
For an illustrative example, when a comestible, beverage, nutraceutical, and/or pharmaceutical product such as bovine milk, a liquid nutritional supplement, or another liquid and/or powdered product having a limited shelf-life is processed and packaged in a container for later use and/or consumption, a number of steps are taken to ensure a fresh, unspoiled product is delivered to the user or consumer. Most often, the closure, container, and milk are all sterilized in various steps before, during, and/or after packaging and sealing. When sterilized before packaging, and during the packaging process, the container and product are carefully maintained in their sterile condition during sealing and until the container is sealed with the closure. The sealed container of product must usually be refrigerated, delivered, and used and/or consumed before expiration of the shelf-life and within a certain period of time to ensure freshness. In the alternative, and when very high degrees of sterilization are performed, the product-filled container may have a much longer shelf-life and may not have to be refrigerated before delivery and use. With refrigeration, highly-sterilized product containers may have very long shelf-lives.
Typically, the phrase shelf-life refers to the period of time within which the highly-sterilized, unrefrigerated product must be consumed, and can often be days, weeks, or even months, in some cases. For lessor degrees of sterilization, a much shorter shelf-life is ascribed to ensure use before spoilage occurs, and such products must usually be refrigerated immediately after packaging and consumed within a far shorter period of time, which is usually within days.
In still other packaging applications, and even with the various methods of higher and/or lower degrees of sterilization, there is often a need to wash and sterilize the sealed container and closure after filling and sealing. This need sometimes arises when product inadvertently spills and/or splashes during the filling process onto an exterior portion of the container. More specifically, an upper portion of the container proximate to an opening into the interior, which is sometimes referred to as the upper finish, can become soiled with spillage of the product that may occur during the filling operation. Such spillage may spoil prematurely and may impair the cleanliness of the container and closure. Therefore, the exterior and finish portion may sometimes need to be washed and cleaned after filling and sealing.
In still other applications of comestible, beverage, nutraceutical, and pharmaceutical product packaging, there is a need to sterilize the product contents after filling the container and sealing with the closure. In these applications, the container is first sterilized, then filled with the product, sealed with the closure, and then exposed to heat and pressure or retort processing for a period of time sufficient to sterilize the packaged product and the interior of the container.
Typically, the exterior is also cleaned contemporaneously. In these post-packaging sterilization applications, the filled and sealed container may also be exposed to an exteriorly pressurized environment during heat sterilization to minimize the possibility that any heat-induced pressure buildup within the sealed container will breach the sealed container.
In other configurations, a metal disc is included as a layer or as a component of the closure to ensure sufficient strength exists in the closure to resist breach during heat sterilization and/or retort processing. Such metal disc elements also purport to enable better heat transfer to the interior surfaces of the closure, which can in some circumstances improve sterilization thereof.
In the retort processing and heat sterilization operations, retortable containers and closures are subjected to high temperature steam baths, showers, and/or hot water washes, and combinations thereof. These operations clean and wash the exterior of the filled and sealed containers and also heat the exteriorly exposed portions of the container and closure. The exterior heating also heats any exteriorly exposed and internally established interstices of the closure and container, for a period of time that is sufficient to sterilize the assembled and sealed container and its contents. The period of heating is carefully controlled so as to ensure the desired degree of sterilization occurs, but which is not so long as to spoil or degrade the product or to weaken or compromise the assembled container.
Depending upon the application and the desired level of sterilization and cleanliness, the temperature of the heat source may be increased and/or the period of time of exposure to the heat can be adjusted so that many varieties of products and containers can be accommodated and many possibly desirable levels of sterility of the containers and packaged products and resulting shelf-lives may be achieved. For higher temperatures and where otherwise indicated, the above-noted element of external pressure may also be introduced to reduce the likelihood that an increased temperature of the product inside the container will create an over pressure inside the container that could breach the seal thereof.
In one previous attempt to disclose a retortable closure, Ocha in U.S. Pat. No. 5,009,324 describes a closure that incorporates a metal disc received within a plastic ring that purports to enable improved retort processing results. However, Ocha's metal disc containing ring configuration leads those in the field to a time-intensive and more expensive means to manufacture a closure than may be desirable.
In another prior disclosure by German et al. in U.S. Pat. No. 6,276,543, a retortable closure is discussed that enables an over pressure venting capability, which purports to avoid deformation of the closure during expansion of interior gas when the container is subjected to heat sterilization. However, the German et al. closure, much like the Ocha closure, directs those skilled in the art to a metal disc or other rigid material that can withstand the pressures encountered during heat sterilization, but which necessarily must rely upon the pressure venting capability to prevent breach of the container seal. However, a significant disadvantage with any venting capability persists in that an opportunity to vent necessarily creates the opportunity for external contaminants to be communicated to the product contained in interior of the container.
In yet another prior attempt to offer a suitable, retort-processing-compatible closure, Shenkar et al. dislcose an all plastic retortable closure that incorporates an oxygen barrier. But, this retortable closure relies upon a complex and expensive to fabricate closure that includes a plethora of undesirable interstices that impede rather than improve the retortability of the closure, and which create additional, unnecessary, and undesirable sterilization challenges and obstacles.
Despite an increase in the knowledge of those skilled in the relevant arts as to how to fabricate and sterilize retortable closures and retortable containers, there remains a need for retortable closures and retortable containers that can obtain high degrees of sterility, but which can simultaneously offer lower costs and that can lessen the time and steps needed for manufacture, filling, and heat sterilization and/or retort processing. As a result of many constraints and shortcomings in the prior art, frequently cited challenges complained of by those practicing in the retort processing fields of technology include the need for lower costs and improved manufacturability and better sterilization results with a resultant lengthening of product shelf-life.

SUMMARY OF THE INVENTION

Many heretofore unmet needs are met and problems of the prior art are solved with the innovative retortable closures and retortable containers according to the principles of the invention. Such features and capabilities may preferably or optionally include, among other elements and for purposes of illustration and example but not for purposes of limitation, retortable closures that can obtain higher degrees of sterility and which cost less to manufacture and to sterilize with heat and retort processing.
In one possibly preferred embodiment of the invention, a retortable container or canister contemplates a retortable closure for use with a receptacle, vessel, bottle, and/or holder. The receptacle or vessel is formed with a side wall having one or more fastening devices or fasteners. The fastener(s) may include a friction fit, crimping, gluing, adhesive fastening, releasable welding, interlocking or snap-on type of fastener and/or may incorporate threaded portions or threads that enable affixing the closure thereto.
Although the retortable closures contemplated by the invention are depicted to be generally circular in shape, the invention is also directed to all conceivable shapes of such retortable closures and/or retortable containers, vessels, receptacles, holders, and canisters. For example, in variations of the contemplated friction-fit, interlocking, and/or snap-on retortable closures and retortable containers, a rectilinear, oval, triangular, and polygonal shape of the retortable closure and/or container are optionally preferred. In configurations that incorporate threaded fasteners, the closure and an upper portion of the receptacle or vessel may be optionally circular while the lower portion of the receptacle or vessel may be formed to have any shape or profile.
The receptacle or vessel of the container may also be formed to have an upper finish portion on which such fasteners may be formed. Preferably the upper finish portion terminates in a lip and/or rim, which defines an opening into a hollow or interior space of the receptacle, vessel, bottle, and/or holder. The retortable closure also preferably includes a polymeric, plastic, elastomeric, and/or thermoset retainer and/or crown, which also includes a fastener or fasteners that is/are arranged to fixedly and/or releasably engage the receptacle fastener. The polymeric crown or retainer is also preferably formed with a circumferential or side wall formed with a fastener arranged to releasably engage the container fastener(s).
The crown or retainer also preferably surrounds and/or is received with a substantially planar sealing disc or barrier or wall having an interior surface and that is formed from a volume of a polymeric material. Many possibly preferred polymeric materials may used to form the retainer and may include one type of material or a combination of materials, which may include, for purposes of example without limitation, a substantially polypropylene or similar polymeric and/or thermoplastic and/or thermoset resin material. The sealing disc, barrier, and/or wall may also preferably incorporate a sealing layer and one or more a heat transfer materials, which materials are preferably diffused, mixed, suspended, dispersed, and/or evenly spread throughout the three dimensions of the volume of the sealing disc, barrier, and/or wall.
In further optionally or possibly preferred modifications to any of the embodiments of the invention, the retortable closure includes the volume of polymeric material of the sealing disc or barrier to be a thermoplastic such as a substantially polypropylene material. Also optionally preferred is the sealing layer being incorporated either as a separate layer formed upon the interior surface and/or in other integrally formed arrangements, and is a polymeric material that is often referred to by those skilled in the pertinent areas of technology as a substantially thermoplastic elastomer vulcanizate or a substantially super thermoplastic elastomeric vulcanizate. Even more preferably, the thermoplastic elastomeric vulcanizate is selected to be substantially a santoprene.
Preferably, the heat transfer material is formed substantially from a volume of powdered ceramic material, metallic material, nanotube containing or nanotube material, polymeric material, oxides and reductions thereof, and/or combinations thereof, any of which preferably have substantially high-thermal conductance properties. More preferably, the heat transfer material has a volume that is preferably and approximately between about 10% and about 80%, and more preferably approximately between about 25% and about 65% of the volume of polymeric material. Even more preferably the heat transfer material has a volume that is approximately between 45% and 55% relative to the volume of the polymeric material. In any of the various preferred embodiments, other possibly preferred modifications, variations, and alternatives may incorporate the volume of heat transfer material material to be substantially a powdered zinc, aluminum, copper, ceramic, polymeric, nanotube, and/or similar material or combinations thereof, which have high thermal conductance properties and which are miscible with the polymeric material of the sealing disc or barrier in the proportions contemplated by the present invention.
In additionally preferred variations of the innovative retortable containers and retortable closures according to the invention, the contemplated retortable closures incorporate an oxygen barrier, oxygen scavenger, and/or oxygen scavenging material, which can be formed as a layer of material that is combined and/or sandwiched against the contemplated closure, or which is integrally formed with and/or diffused, mixed, dispersed, and/or suspended throughout the volume of the sealing disc, wall, and/or barrier. In optionally preferred variations wherein the oxygen barrier is integrally formed with and/or spread evenly throughout the volume of the sealing disc, wall, and/or barrier, the oxygen barrier or scavenger is selected to have a volume of a substantially oxygen scavenging material such as a nanocompound material that has a nanoclay or other substantially oxygen scavenging or barrier material therein.
More preferably, in optionally preferred embodiments that incorporate the substantially oxygen barrier, oxygen scavenger, and/or oxygen scavenging material integrally with the sealing disc, wall, and/or barrier, the material is incorporated, mixed, diffused, dispersed, suspended, and/or evenly spread throughout the volume of the sealing disc to have a volume that is approximately between about 2% and about 80% of the volume of polymeric material of the sealing disc or barrier. Even more preferably, the substantially oxygen barrier, oxygen scavenger, and/or oxygen scavenging material is included to have a volume of approximately between about 10% and about 65% of the volume of the polymeric material of the sealing disc or barrier. Most preferably, it has a volume of approximately between about 20% and about 40% of the volume of the polymeric material of the sealing disc.
In any of the contemplated and optionally preferred embodiments of the inventive retortable closures and containers or canisters of the invention, the closure is susceptible to be fabricated using various injection molding techniques that can include simultaneous injection, single injection, co-injection, and multiple shot injection molding process steps. For purposes of further example but not for purposes of limitation, an exemplary closure may be formed by first preparing a pre-melt and/or melt mixture of a substantially polymeric material that may molded into the contemplated retainer or crown. The sealing barrier or wall may be fabricated by preparing a resin pre-melt and/or melt mixture that may incorporate the contemplated heat transfer and oxygen scavenger materials, which are then molded into the desired shape of the sealing barrier, either as a separate element, or directly into position on the previously and/or contemporaneously molded retainer or crown. Next, a subsequent molding step may be effected wherein the sealing layer may be applied and/or molded onto the interior surface of the sealing barrier. Those with relevant skill and knowledge in the related fields of technology will appreciate that any combination and/or sequence of such molding operations and steps may be equally desirable.
These variations, modifications, and alterations of the various preferred and optional embodiments may be used either alone or in combination with one another and with the features and elements already known in the prior art and also herein contemplated and described, which can be better understood by those with relevant skills in the art by reference to the following detailed description of the preferred embodiments and the accompanying figures and drawings.

BRIEF DESCRIPTION OF THE DRAWING(S)

Without limiting the scope of the present invention as claimed below and referring now to the drawings and figures, wherein like reference numerals and numerals with primes across the drawings, figures, and views refer to identical, corresponding, or equivalent elements, methods, components, features, and systems:

FIG. 1 shows an elevation view of a retortable closure for use with a container, canister, vessel, or bottle and in accordance with the present invention;

FIG. 2 shows a planar or top view of the retortable closure of FIG. 1;

FIG. 3 is a section view in modified scale taken about section line 3-3 of the retortable closure of FIG. 1;

FIG. 4 is a detail view, in enlarged scale and taken about detail view line 4-4 of the retortable closure of FIG. 1;

FIG. 5 shows a variation of the retortable closure of FIG. 1 in modified scale with modified processing grip indents;

FIG. 6 is planar view in modified scale of the sealing disc or barrier or wall of the closure of FIG. 1, and with certain structure removed for purposes of further illustration; and

FIG. 7 is side view in modified scale and rotated of the sealing disc or barrier or wall of the closure according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the various figures and illustrations, those skilled in the relevant arts should appreciate that each of the preferred, optional, modified, and alternative embodiments of the inventive retortable container C and retortable closures 10 contemplate interchangeability with all of the various features, components, modifications, and variations within the scope of knowledge of those skilled in the relevant fields of technology and that are described throughout the written description, claims, and pictorial illustrations herein. Additionally, the many various alternative arrangements, optionally preferred modifications, and possible variations of the preferred embodiments of the invention may be used in part and in any conceivable combination, which may be particularly desired and/or of benefit for certain applications and uses.
With these guiding concepts in mind, and with reference now to FIGS. 1, 2, and 3, one possibly preferred embodiment of a retortable closure 10 and retortable container C is illustrated for purposes example, but not for purposes of limitation. In this optionally preferable embodiment of the invention, the retortable closure 10 is shown (FIGS. 1, 2, 3) as a component of the retortable container and/or canister C (FIG. 3).
The typically or optionally preferred container or canister C for the contemplated product is illustrated to have a generally circular profile. However, the new and novel features of the invention are susceptible for use in any number of conceivable shapes and profiles, which can be implemented in either the retortable closure 10, the retortable container C that includes the closure 10, and/or the receptacle, vessel, bottle, holder R, or combinations thereof. In any of the alternative and optionally preferable embodiments, the container or canister C is formed as a receptacle, holder, bottle, and/or vessel R with a side wall S having an upper finish portion U that terminates in a rim and/or lip L that defines an opening O into a hollow and/or interior space H.
About the upper finish portion U, the receptacle or vessel R incorporates one or more fasteners F, which may include a friction fit, crimped, releasably glued, releasably welded, interlocking, and/or snap-on type of fastener and/or may incorporate threaded portions or threads that enable fastening the closure 10 to the receptacle or vessel R. Preferably, in the circular profile alternatives of the receptacle, bottle, vessel, and/or holder R and the threaded variation of the fasteners F, the threads are formed with a thread retaining interface TR and a keyway K (FIG. 3) that together cooperate to receive and retain like elements of the closure 10, which are described in more detail elsewhere herein.
More preferably and for alternative variations of non-circular profiles of the preferred embodiments, the contemplated and optionally preferred retortable closures 10 and the receptacles R may incorporate in place of the threaded fasteners F, one or more friction-fit, interlocking, and/or snap-on elements. Such replacement fasteners can be used for circular, rectilinear, oval, triangular, polygonal, and other shapes and profiles of either or both of the retortable closure 10 and/or the entire retortable container C, or receptacle R, and/or components thereof. Preferably, the contemplated receptacle, vessel, holder, and/or bottle R optionally will be formed from a substantially polypropylene (PP), polyethylene (PE) or similar polymeric, thermoplastic material that is optionally also a high or low density polyethylene (HDPE, LDPE), and which is most preferably a Federal Department of Agriculture (FDA) approved, food and/or pharmaceutical grade material such as glass or another type of plastic or polymeric material, and/or combinations thereof.
The retortable closure 10 is preferably formed to have a substantially polymeric, plastic, elastomeric, and/or thermoset resin retainer and/or crown 20. More preferably the polymeric crown or retainer is formed from a substantially polypropylene (PP) material. The polymeric crown or retainer 20 may also incorporate one or more fasteners 25 on a side or circumferential wall 30 and about an interior side 32. The one or more fasteners 25 are selected to cooperate with the fasteners F of the receptacle or vessel R. For snap-fit, snap-on, and similarly configured variations of the receptacle or vessel R, the fasteners 25 may incorporate various cooperatively interlocking elements and features and may incorporate a rail 35 or similar component. For alternatively preferred threaded modifications, the fasteners 25 may be formed as a tooth 35 that includes an engagement interface 40 and a keyway 45, which together receive and engage the cooperatively corresponding thread elements TR and K of the fasteners F of the receptacle, bottle, or holder R.
In yet other possibly preferred variations of any of the embodiments of the invention, and with continued reference to FIGS. 1 and 2 and now also to FIGS. 4 and 5, the polymeric retainer or crown 20 may also include one or more handling enhancements or features that may take the form of grip knurls or protuberances 50, which can be formed in any number of equally suitable ways such as with ridges 55 and grooves 60. These handling features may be incorporated to improve the ability of certain users to handle, fasten, and remove the closure 10 to and from the receptacle, vessel, holder, or bottle R.
In other additionally preferable but alternative configurations of the closure 10, many types of other handling features are contemplated and can include larger grips or processing and handling indents 65 (FIGS. 1, 2) and modified indents 65′ (FIG. 5). These types of larger features 65, 65′ may be especially preferred for automated handling operations whereby automated filling and sealing process steps use machines to attach the closure 10 to the receptacle or vessel R by gripping the closure 10 about indents such as or similar to 65, 65′. When used in combination with the grip knurls or protuberances 50, the processing and handling indents may be cooperatively formed as shown in the various figures to further improve the ability of users to grip and manipulate the closure 10 and/or the assembled container or canister C.
The present invention also contemplates other possibly desirable features that can further improvement handling and manipulation characteristics and which may include about an outer wall 70 of the polymeric retainer or crown 20, one or more snap-on, snap-off release levers or thumb tabs 75 (FIGS. 1 and 3). These thumb tabs or release levers 75 may take many profiles and forms be of particular use in manipulating the closure 10 in any of the variations and modifications of the invention, and may be especially useful in the contemplated threaded as well as the snap-on, snap-off, friction-fit alternative arrangements of the container or canister C.
In further modifications to one or more of the preferred embodiments of the new and novel retortable closure 10 and/or the assembled retortable container or canister C, the retainer or crown 20 incorporates a closure seat 80 (FIG. 3) that operates to align and receive the other elements described elsewhere herein. The retainer or crown 20 also optionally includes an arcuate cantilever and/or lip 85 ending in an interiorly projecting periphery that is formed with a plurality of preferably spaced apart bonding dentils, teeth, or texture elements 95, which may improve the bond performance in cooperation with other elements as described elsewhere herein. The improvement may be accomplished as shown and/or by a mechanical crimping and/or chemical bonding effect of the arcuate cantilever and/or lip 85 and the teeth or dentils 95, 120 during fabrication.
In the various preferred embodiments of the retortable closure 10 and the retortable container or canister C, and with reference now also to FIGS. 5, 6, and 7, the crown or retainer 20 also preferably surrounds and/or is received with a substantially planar sealing disc or barrier or wall 100. The substantially planar sealing disc or barrier or wall 100 has an interior surface 107 and is typically formed from a volume of a polymeric material 105. The barrier, wall, and/or disc 100 further includes a bonding periphery 110 with an interior closure boundary 115. A plurality of texture elements or disc dentils 120 are formed on the periphery 110 exteriorly from the interior closure boundary 115 and extending approximately to the extent of the periphery 110.
The texture elements or disc dentils 120 are spaced apart to cooperate with the bonding dentils or texture elements 95 of the retainer or crown 20. During a molding operation to affix the sealing barrier, disc, and/or wall 100 to the retainer or crown 20, the additional material of the dentils 95, 120 softens and/or substantially melts and/or welds together to improve the bonding performance between the retainer or crown 20 and the barrier 100.
The preferred sealing barrier, wall, and/or disc 100 may also optionally incorporate a sealing wall 125 formed with an inclined sealing ramp 130 that terminates in a distal end 135. When the closure 10 is assembled to the receptacle or vessel R, the outwardly facing side of the ramp 130 of the sealing wall 125 rests against and is preferably flexed or biased against the inwardly facing surface of the upper finish portion U of the receptacle R. This arrangement improves the effective seal performance of the closure 10 when assembled as part of the canister or container C.
During assembly and fabrication of the closure 10, the bonding periphery 110 of the barrier 100 is aligned against and seated onto the closure seat 80 of the crown or retainer 20 to have the bonding dentils 95 of the periphery 90 of the crown 20 spaced apart from the dentils 120 of the barrier 100. Preferably, upon alignment and receipt, the barrier or wall or disc 100 is bonded with adhesive, by substantially melting, and/or by substantially welding into position upon the interiorly projecting periphery 90.
More preferably, the barrier or wall or disc 100 is bonded into position with heat and pressure to soften, substantially melt, and/or substantially weld together the peripheries 90, 110, and/or the dentils 95, 120. In the alternative or even more preferably, the barrier or wall or disc 100 is injection molded into position upon the periphery 90, and thereafter the dentils 120 of the barrier bonding periphery 110 are contemporaneously and/or subsequently subjected to heat and pressure for improved bonding performance. The softening, substantial melting, and/or substantial welding may be effected by contact or radiative heating, by ultrasonic heatings and/or welding, by radio frequency heating and/or welding, by chemically reactive heating and/or welding, and/or by any other suitably desired means of joining the contemplated elements to effect an appropriate bond.
A wide variety of possibly preferred polymeric materials may used and selection of the most desired polymeric material 105 will be dependent upon the particular requirements of the intended application. Certain types of polymeric materials have been found to work very well in applications where a product such as a comestible, nutraceutical, and/or pharmaceutical product is to be filled in the container and/or canister C, and the container and/or canister C is to be retort processed and/or otherwise sterilized before storage, distribution, and delivery to consumers and users.
Such polymeric materials that have been found to be susceptible to the uses and implementations of the present invention, including the contemplated polymeric retainer or crown 20 and/or the sealing disc, barrier, or wall 100, include a number of polymerics, thermoplastics, and thermoset resins. Preferably, but without intent to limit the possibly preferred, optional embodiments, such polymerics include a thermoplastic such as a substantially PP material and similar materials, which may include for purposes of further illustration a FDA food-grade approved PP that is available from Exxon-Mobil Chemical Corp., Houston, Tex., USA, as product no. 1024E4. This particular exemplary material is a PP homopoly that is otherwise referred to as a polypropylene homopolymer plastic material having a medium melt flow rate.
For purposes of further example without limitation, various optionally desired embodiments of the sealing disc, barrier, and/or wall 100 will incorporate one or more materials that improve the heat conductance thereof, which improves the results of the contemplated heat sterilization and/or retort processing. More specifically, the sealing disc, barrier, and/or wall 100 may preferably be formed with a separate layer and/or an integrally mixed, dispersed, suspended, diffused, and/or evenly spread heat transfer material or materials.
Preferably, the heat transfer material(s) are introduced into the pre-melted and/or melted thermoplastic resin mixture and before molding of the sealing barrier, disc, and/or wall 100 so that the heat transfer material is spread evenly throughout the three dimensions of the volume of the sealing disc, barrier, and/or wall 100. In this way, it has been found that the thermal conductivity of the barrier 100 is dramatically improved whereby unexpectedly higher degrees of cleanliness and sterility are achieved during heat sterilization and/or retort processing.
With continued reference to the various figures and especially now again to FIG. 3, those skilled in the relevant fields of art may comprehend that once the interior space or hollow H of the receptacle R has been filled with a product, and when the contemplated closure 10 is assembled onto the receptacle or vessel R, the closure 10 seals against a sealing ledge 160 of the lip or rim L of the receptacle R. Those skilled in the arts may further come to understand that the assembled container or canister C may also establish one or more interstices 165. Such interstices 165 can be the result of dimensional tolerances that while possibly minimized, can sometimes be unavoidable artifacts of the manufacturing processes.
During heat sterilization and/or retort processing of the filled and assembled container or canister C, acceptable sterilization of the packaged product must also be accomplished to establish an acceptable shelf-life. Additionally, sterilization must be similarly achieved for all such interstices 165 and sealed surfaces such as ledge 160, and the interior surfaces of the sealing wall 125 and ramps 130, the upper finish portion U, and the interior surface 107.
The unexpectedly improved thermal conductance of the sealing barrier, wall, and/or disc 100 that results from the incorporation of a heat transfer material results in the expected sterilization of the packaged product, but also has resulted in a significant, if not dramatic improvement in the degree of sterilization of the interstices 165 as well as the surfaces connoted by ledge 165, the interior surface 107, the ramps 130 of the sealing wall 125, and the interior surface of the upper finish portion U.
By way of further example, various types of post-sterilization lethality tests are sometimes conducted wherein a dimensionless unit of measure or parameter, F(0), is ascribed to certain aspects of the test results to compare the sterilization results of various types of contemplated retortable closures 10 and assembled retortable containers or canisters C. For purposes of further illustration without limitation, various FDA sterilization tests suggest or recommend that a post-sterilization F(0) of greater than about 7.0 may be acceptable in certain applications.
Those having knowledge and skill in such related fields of technology may appreciate that many manufacturers for certain applications and uses may attempt to achieve a post-sterilization result F(0) of greater than about 9.0, which may be greater that required by the FDA in certain applications, but which may be deemed to create a more desirable and enhanced margin of safety in certain applications. As described elsewhere herein, prior attempts have sometimes required the use of a metal seal disc to ensure sufficient strength for heat sterilization, and to attempt to attain sufficient heat conductance to possibly achieve post-sterilization results that may meet FDA recommended values for certain applications. Even so, such prior attempts have not seen the extraordinary results possible with the optional and preferred embodiments of the invention that have until now been unattainable without an undesirable degradation in product quality, without the need to expend higher costs, or without the need for longer sterilization times and increased numbers of processing steps, the latter of which can often result in heat-induced container or closure compromise.
The sealing barriers, discs, and/or walls 100 that are loaded with and/or that incorporate the integrally formed heat transfer materials contemplated by the instant invention have unexpectedly achieved post-sterilization F(0) results that exceed 9.0, and that have been seen to exceed an F(0) of 11.5, or higher. As a result of these unexpected results, the heat transfer material is preferably formed from a volume of a substantially high thermal conductance material such as a substantially metallic material. More preferably, the substantially metallic material has a volume that is preferably and approximately between about 10% and about 80%, and more preferably approximately between about 25% and about 65% of the volume of polymeric material of the sealing disc. Even more preferably the metallic material has a volume that is approximately between 45% and 55% relative to the volume of the polymeric material of the sealing disc or barrier or wall.
In various examples, it was discovered that in many compositions of the sealing barriers 100, a quantity of high thermal conductance material of about 10% enabled improved heat transfer benefits, but that the heat transfer properties improved substantially for greater amounts of 15%, 20%, 25%, 30%, and greater amounts. However, nanotube materials and materials and compositions containing nanotubes enabled heat transfer benefits with lesser amounts thereof, and were found to be dependent upon the quantity, quality, distribution, orientation, length, and single wall or multiple configuration of the nanotubes.
For metallic heat transfer materials, amounts exceeding approximately 65% were sometimes found to less desirable as the higher amounts can in some instances diminish the resilience, strength, and structural and mechanical properties of the sealing barriers 100. In view of the preceding nanotube parameters, greater amounts of nanotube materials and compositions thereof were in some cases found to offer greater resilience, strength, and improved structural and mechanical properties.
Additionally, these highly desirable but previously unseen post-sterilization results have been achieved with the volume of substantially metallic material being selected from the group that includes a number of substantially metallic, ceramic, nanotube, and polymeric materials, and oxides, reductions, and combinations thereof, that have high thermal conductance properties. Such materials are also economically more attractive to incorporate than the higher cost and less thermally effective and structurally efficient metal disc of the prior art attempts.
In fact, in the various prior attempts at incorporating metal disc configurations into retortable closures, the thermal conductance of the metal disc was often found to be acceptable for certain applications, but was in many aspects of thermal heat transfer performance limited to the physical extent of the actual metal disc itself and did extend to the surrounding structures as well as desired or possible. Heat energy was not transferred as efficiently as possible with the preferred and alternative variations of the embodiments of the instant invention. In contrast, the present invention incorporates the sealing disc, barrier, or wall 100 being loaded with one or more high thermal conductance, heat transfer materials, which establishes or enables the entire sealing disc, barrier, or wall 100 to be a highly efficient and very effective conductor of thermal energy to surrounding structures. In other additionally preferred and optional configurations, the contemplated heat transfer materials may also be incorporated into other elements of the contemplated closures 10, including for purposes of further example without limitation, the rim 20, the heat transfer disc 100, the oxygen barrier and seal layer 140, 145, and other elements of the container C.
Accordingly, less energy and less time is needed to achieve previous levels of sterility, and with such reduced time and energy requirements, unexpectedly higher levels of sterility are consistently achievable. Additionally, enhanced structural benefits have also been experienced such that more efficient structural configurations and arrangements are possible without the need for reinforcing metal discs or complex polymeric structural arrangements that were otherwise needed in the prior attempts.
More preferably, various substantially metal powders and oxidized and reduced metal powders have been found to be especially well-suited to the purposes of the present invention and include, among other similarly capable heat transfer materials, materials that substantially include zinc, aluminum, copper, oxides and reductions thereof, nanotube material and/or nanotube containing material, and/or similar metallic material or combinations thereof. A number of optionally preferred nanotube materials and nanotube containing materials and/or compositions are contemplated for use as and/or in combination with the heat transfer materials of the instant invention, and are described in U.S. Pat. Nos. 5,482,601, 5,753,088, 6,331,265, 6,764,628, 7,153,903, 7,244,407, 7,279,247, 7,285,591, 7,309,727, which are incorporated herein be reference as though full set forth as part of this disclosure.
Surprising heat transfer capabilities have been discovered in the context of the closures 10 of the instant invention using the various heat transfer materials contemplated herein. For example, a powdered zinc heat transfer material was incorporated having a particle size between approximately 0.1 to 100 microns in average diameter, which resulted in a range of heat transfer properties that was a function of particle size and distribution in the material of the closures 10. However, for larger particle sizes of about 100 microns, mechanical defects were sometimes observed that degraded that structural performance and capability of the closures. Further, smaller particle sizes of approximately 0.1 to about 0.8 microns often times exhibited less effective heat transfer properties in the molded closures 10.
In other examples, zinc particle sizes of between about 3 and 10 microns were found to demonstrate very effective heat transfer properties. Heat transfer performance of the molded closures 10 has been found to be dependent upon, among other parameters, the selected heat transfer material, average particle size and shape of the particle, concentration or number of such particles, and distribution of the particles throughout the volume of the material of the closures 10. Although a number of exemplary parameters have been herein disclosed as suitable or unsuitable in certain respects, many other optionally preferable ranges of these parameters are also equally desirable and may depend further upon the particular construction and applications of the contemplated closures 10.
In additionally preferred variations of the innovative retortable containers and canisters C and the retortable closures 10, the retortable closures 10 may optionally be preferred to include an oxygen barrier, oxygen scavenger, and/or oxygen scavenging material 140 (FIGS. 3, 7). This variation of any of the preferred embodiments may be particularly desirable in applications where a comestible, nutraceutical, and/or pharmaceutical product that is sensitive to exposure to oxygen is to be delivered in the innovative retortable containers and retortable canisters C.
The oxygen barrier, oxygen scavenger, and/or oxygen scavenging material 140 may preferably be formed from a layer of material that is combined and/or sandwiched against the contemplated closure on either the interior surface 107, or about the opposite exterior facing side of the sealing disc, barrier, and/or wall 100. In other possibly more preferably modifications to the various preferred embodiments, the oxygen barrier, scavenger, and/or scavenging material 140 is integrally formed with the sealing disc, wall, and/or barrier 100 in the pre-melt and/or melted resin mixture and before molding of the sealing barrier 100. In this way, the oxygen barrier, scavenger, and/or scavenging material 140 may be more evenly and efficiently distributed throughout the three dimensions of the volume of the sealing disc, barrier, or wall 100. More preferably, the oxygen barrier or scavenger 140 is selected to have a partial, substantial, and/or an entire volume of an oxygen scavenging or barrier material such as a nanocompound or other material that contains a substantial or effective quantity of, for example without limitation, a nanoclay.
Possibly preferable examples of suitable oxygen scavenging and/or barrier materials 140 include, for purposes of further example without limitation, other types of oxygen barrier or scavenging materials well-known to those skilled and knowledgeable in the relevant arts, and also the Nanoblend(™), nanoclay-containing compounds available from PolyOne Corp., Avon Lake, Ohio, USA. The noted Nanoblend(™) compounds are particularly well-suited to be incorporated in the modified and alternative variations of the preferred embodiments of the invention. More specifically, good oxygen scavenging and/or barrier results have been experienced using the PolyOne Nanoblend(™) LST 5501 and 5571 (LST averring to light, stiff, & tough) polypropylene blends and variations and mixtures thereof, which have been found to be easily mixed into the pre-melt and melted resin mix used for injection molding of the contemplated sealing barriers, walls, and/or discs 100, of the invention. It has been further found that the molded barriers 100 may be further machined for additional precise geometric and performance customization before and/or after being molded onto or being received and affixed into the retainer or crown 20.
Even more preferably, in variations of any of the preferred embodiments, the contemplated oxygen barrier, oxygen scavenger, and/or oxygen scavenging material 140 is incorporated, mixed, diffused, dispersed, and/or suspended throughout the sealing disc to have a volume that is approximately between about 2% and about 80%, and more preferably, approximately between about 10% and about 65%, and even more preferably, approximately between about 20% and about 40% of the volume of the polymeric material of the molded sealing barrier, wall, and/or disc.
In many other possibly preferred variations of any of the embodiments of the inventive retortable closures 10 and the assembled retortable containers or canisters C, a sealing layer 145 (FIGS. 3, 7) is also incorporated with the sealing barrier, disc, and/or wall 100 to effect a mechanical seal between the closure 10 and the lip or rim L of the receptacle or vessel R. Preferably, the sealing layer 145 is included as a layer affixed to the interior surface 107 of the sealing barrier 100.
More preferably, the sealing layer 145 is selected from any number of substantially thermoplastic elastomeric vulcanizates, which have exhibited excellent sealing performance characteristics in the inventive embodiments. Also preferable, the sealing barrier may be selected from a number of substantially super thermoplastic elastomeric vulcanizates, which have also demonstrated good sealing performance when applied as shown in the assembled configuration of FIG. 3, to seal against the sealing ledge 160. More preferably, a substantially thermoplastic elastomeric vulcanizate type sealing layer 145 that finds wide availability and that has application for purposes of the present invention, is any of a number of substantially santoprene materials. Many such substantially santoprene materials were first introduced in about 1975 by Monsanto Company of St. Louis, Mo., USA, and are now available from Monsanto and many other organizations including Exxon Mobil Chemical Corp.
In addition to effecting an acceptable mechanical seal, the sealing layer 145 has also established an effective barrier to reduce, minimize, and even prevent one or more of the constituents of the sealing disc, barrier, or wall 100 from leeching into the product contained in the interior space or hollow H of the receptacle, bottle, holder, or vessel R after packaging and before use of consumption. The minimization and/or elimination of such possibilities can be desirable especially in medicament and/or pharmaceutical applications where the efficacy of the packaged product could otherwise be attenuated.

INDUSTRIAL APPLICABILITY

The embodiments of the present invention are susceptible for use in many retort processing applications that involve the packaging of comestibles, nutraceuticals, and pharmaceutical products, which must be delivered in am acceptably sterilized condition fit for human use or consumption, and/or that must be delivered in a sterile condition for other specialty applications or uses, such as for research or medical uses. The many variations, modifications, and optionally preferred and innovative improvements of the inventive embodiments of retortable containers C and closures 10, contemplate a wide variety of consumer, commercial, medical, and industrial applications. Such applications include, for purposes of continued illustration, but not for purposes of limitation, the packaging, storage, distribution, and consumption of the noted comestibles, nutraceuticals, and pharmaceuticals.
The novel configurations of the invention are especially capable of use and applications wherein the contemplated product and container-closure combination C must be sterilized with heat sterilization, retort processing, or by any other suitable means, and subsequently protected from contamination and spoilage for the ascribed or recommend shelf-life, or the entire period of time spanning from manufacture and packaging, through a period of inventory storage, and until use or consumption. The various arrangements and capabilities of the inventive retortable closure 10 and assembled container C, can be modified to accommodate nearly any conceivable packaging application and/or requirement.
The capabilities and compatibility of the features, components, and elements of the novel retortable containers C and retortable closures 10 that are described herein, can be readily modified according to the principles of the invention as may be required to suit any particular industrial, commercial, research, consumer, and/or medical application. Additionally, such inventive retortable containers are suitable for use with nearly all types of liquid and powdered comestibles, nutraceuticals, and pharmaceuticals that are presently found in commerce worldwide.
Various modifications, adaptations, and alternative arrangements and configurations of any of the preferred embodiments may be further optionally desired to establish compatibility with applications and circumstances not expressly mentioned here, but that are certainly contemplated by the inventive and improved retortable containers C and closures 10. Accordingly, even though only few such embodiments, alternatives, variations, and modifications of the present invention are described and illustrated, it is to be understood that the practice of such additional modifications and variations and the equivalents thereof, are within the spirit and scope of the invention as defined in the following claims.

Claims

1. A retortable closure, for use with a container that includes a side wall formed with a container fastener about an upper finish portion proximate to a rim that defines an opening into the container, the retortable closure comprising:

a polymeric retainer formed with a fastener arranged to releasably engage the container fastener;

a sealing disc received in the retainer and formed from a volume of a polymeric material and having an interior surface;

a heat transfer material diffused throughout the sealing disc and formed from a volume that is between about 25% and about 65% of the volume of polymeric material; and

an oxygen barrier formed integrally with the sealing disc from a volume that is between about 10% and about 65% of the volume of polymeric material.

2. The retortable closure according to claim 1, wherein the volume of polymeric material is a thermoplastic and the volume of heat transfer material is substantially a powdered zinc.

3. The retortable closure according to claim 2, further comprising:

a seal layer formed from a substantially thermoplastic elastomeric vulcanizate about the interior surface; and

wherein the polymeric material is substantially a polypropylene.

4. The retortable closure according to claim 3, wherein the thermoplastic elastomeric vulcanizate is substantially a santoprene.

5. The retortable closure according to claim 3, wherein the volume of polymeric material is substantially a polypropylene and the volume of heat transfer material is substantially a powdered copper.

6. The retortable closure according to claim 5, wherein the seal layer is substantially a santoprene.

7. The retortable closure according to claim 1, wherein the volume of polymeric material is substantially a polypropylene and the volume of heat transfer material is substantially a powdered aluminum.

8. A retortable closure, for use with a container that includes a side wall formed with a container fastener about an upper finish portion proximate to a rim that defines an opening into the container, the retortable closure comprising:

a polymeric crown formed with a circumferential wall surrounding a substantially planar sealing barrier having an interior surface, the circumferential wall formed with a fastener arranged to releasably engage the container fastener, the sealing barrier including an oxygen scavenger;

a seal layer about the interior surface; and

a heat transfer material diffused throughout the sealing barrier to have a volume that is approximately between 25% and 60% of the volume of the sealing barrier.

9. The retortable closure according to claim 8, wherein the polymeric crown and the sealing barrier are formed substantially from a polypropylene and the heat transfer material is substantially a powdered zinc.

10. The retortable closure according to claim 9, wherein the seal layer is substantially a thermoplastic elastomer vulcanizate.

11. The retortable closure according to claim 9, wherein the oxygen scavenger is substantially a nanocompound having a volume that is between about 10% and about 65% of the volume of sealing barrier; and

wherein the seal layer is substantially a thermoplastic elastomeric vulcanizate.

12. The retortable closure according to claim 8, wherein the sealing barrier is substantially a polypropylene and the heat transfer material is substantially a zinc powder.

13. The retortable closure according to claim 12, wherein the seal layer is substantially a santoprene.

14. A retortable container, comprising:

a receptacle including a side wall formed with a fastener about an upper finish portion proximate to a rim defining an opening into the receptacle;

a plastic retainer formed with a fastener arranged to releasably engage the side wall fastener;

a sealing disc received in the retainer and formed from a volume of a polymeric material having an interior surface;

a heat transfer material diffused throughout the sealing disc from a volume of between about 25% and about 65% of the volume of polymeric material; and

an oxygen barrier formed integrally with the sealing disc from a volume of between about 10% and about 65% of the volume of polymeric material.

15. The retortable container according to claim 14, further comprising:

a seal layer formed about the interior surface with a substantially thermoplastic elastomeric vulcanizate; and

wherein the volume of polymeric material is substantially a polypropylene and wherein the volume of heat transfer material is substantially a powdered zinc.

16. The retortable container according to claim 15, wherein the thermoplastic elastomeric vulcanizate is substantially a santoprene.

17. The retortable container according to claim 15, wherein the thermoplastic elastomeric vulcanizate is substantially a super thermoplastic elastomer vulcanizate.

18. The retortable container according to claim 14, wherein the volume of polymeric material is a thermoplastic and the volume of heat transfer material is substantially a powdered copper.

19. The retortable container according to claim 18, further comprising:

a seal layer formed about the interior surface from a substantially thermoplastic elastomeric vulcanizate.

20. The retortable container according to claim 14, wherein the volume of polymeric material is substantially a polypropylene and the volume of heat transfer material is substantially a powdered aluminum.

21. A retortable canister, comprising:

a vessel that includes a side wall formed with a vessel fastener about an upper finish proximate to a rim defining an opening into the vessel;

a polymeric crown formed with a circumferential wall surrounding a substantially planar sealing wall having an interior surface, the circumferential wall having a fastener to releasably engage the vessel fastener, the sealing wall including an oxygen scavenger; and

a heat transfer material diffused throughout a volume of the sealing wall and having a volume of between about 25% and about 65% of the volume of the sealing wall.

22. The retortable canister according to claim 21, further comprising:

a seal layer formed about the interior surface from a substantially thermoplastic elastomeric vulcanizate; and

wherein the polymeric crown and the sealing wall are formed substantially from a polypropylene and the heat transfer material is substantially a powdered zinc.

23. The retortable canister according to claim 21, wherein the oxygen scavenger is substantially a nanocompound integrally diffused into the sealing wall to have a volume of approximately between 10% and 60% of the volume of sealing wall.

24. The retortable closure according to claim 23, further comprising:

a seal layer formed about the interior surface substantially from a thermoplastic elastomeric vulcanizate; and

wherein the heat transfer material has a volume of a powdered substantially zinc material.

25. The retortable closure according to claim 24, wherein the thermoplastic elastomer vulcanizate is substantially a santoprene.