WO2005032964A2

WO2005032964A2 - Container and sealing system

Info

Publication number: WO2005032964A2
Application number: PCT/US2004/032377
Authority: WO
Inventors: Marc Velmer
Original assignee: Bristol Myers Squibb Company; Herman, Susan Lynn; Mcdonald, Billy David
Priority date: 2003-10-03
Filing date: 2004-10-01
Publication date: 2005-04-14
Also published as: WO2005032964A3

Abstract

The present invention includes a container (10) having a hermetic multilayer polymeric seal (102) fused to a land (48) formed at one end of the container. The container also includes a closure (100) having a multilayer polymeric liner (104). The hermetic seal can withstand a high temperature retort process and is releasably fused to the container land so that it can later be removed to expose the container's contents.

Description

CONTAINER AND SEALING SYSTEM FIELD OF THE INVENTION [0001] The present invention relates to the field of container constructions in general, and more particularly to a container and sealing system for sealing and resealing containers and retaining the seal during and after a sterilization process.

BACKGROUND OF THE INVENTION [0002] Nutritional products such as soy and milk-based liquid foods have been developed for adults and children. Such products are presently marketed in non-resealable metal cans or in plastic containers.

Typically, once opened and the seal on the container is compromised, the contained product must be refrigerated to prevent spoilage.

[0003] Prior to the opening of such containers, it is desirable that the products have a prolonged shelf life. Typically, such nutritional products are packaged in plastic or metal containers and then closed with a hermetic seal to provide for that prolonged shelf life. A hermetic seal is a seal that is impervious to microbiological intrusion and external effects.

Hermetic sealing may be accomplished through either the use of (1) a glass container to which a stamped steel cap having a rubber or vinyl gasket is secured by vacuum , (2) a plastic container having a foil seal permanently fused to the land of the container under vacuum pressure or

(3) a composite metal/plastic vacuum closure. After filling the container, the contents and the container itself are sterilized by subjecting the filled container to retort conditions during which the seal must survive. [0004] Because the glass container and the stamped-steel cap expand by similar amounts, the hermetic seal on glass containers will withstand the sterilization process. Moreover, permanently fused foil seals on plastic containers also generally withstand the harsh retort conditions.

[0005] Manufacturers of liquid nutritional products prefer to use plastic containers because of lower material costs and container weights and because such plastic containers do not suffer from breakage as do glass containers. Various plastics, such as polypropylene, may be used in making such containers to overcome the disadvantages of using metal or glass containers.

[0006] Plastic containers, like their glass counterparts, must be able to withstand heating without significant distortion to allow for the proper sterilization and heat treatment required to obtained prolonged shelf- stable liquid products. The ability to "hotfill" packages or to retort cold- filled foods and liquids after they have been packaged permits the foods to be stored without refrigeration until opened. Commercial sterilization by hotfilling or retorting imposes several additional restrictions on the choice of materials for the package. First, the heat seal must survive commercial sterilization temperatures of over 180° F or typical retort conditions of steam or water at 250° F or more under pressure for one half hour or more. Secondly, the structure must not delaminate, unduly shrink or wrinkle as a result of the sterilization conditions. The oxygen and water barrier properties of the container must not be permanently adversely affected by the conditions of commercial sterilization. ,,Finally, the container structure must be adequately strong to permit handling of the container while still hot.

[0007] A problem arises in attempting to provide a sealable cap for a plastic container. The cap, even on a plastic container, must maintain a hermetic seal until opened by the consumer. During heat application, the plastic containers may expand or contract. These changes cause severe problems in maintaining a conventional metal cap on a plastic bottle and also prevent the use of a conventional plastic cap on a plastic bottle when pre-attached prior to heating. In addition, since it is difficult to maintain a vacuum in a plastic container, and conventional metal caps and plastic containers are affected differently by heating, metal caps cannot maintain a hermetic seal on plastic containers when subjected to retort conditions. [0008] One approach to overcome these problems would be to apply a substantial amount of torque when initially capping a plastic bottle with a plastic cap. However, the amount of torque necessary to maintain a conventional cap on a plastic bottle is so high that a person would not be able to easily twist off the cap following retort. Another possible approach would be to fabricate a bottle from a plastic which does not shrink at retort temperatures and can maintain an internal vacuum without distortion, however, the cost of providing such a plastic bottle would likely be prohibitive.

[0009] Other closing systems have employed composite metal/plastic vacuum closures that require the filled container to have a vacuum. Such plastic containers must be fabricated to maintain an internal vacuum without distortion. Therefore, these plastic containers are more expensive to manufacture than containers used with closing systems that do not require a vacuum. [0010] Yet another possible approach to the providing of a hermetic seal to a plastic container would be to utilize a barrier membrane, such as aluminum foil, such that the integrity of the seal is independent of the closure or cap. The metal foil is permanently sealed to the rim of the container opening and is protected from accidental or premature puncture by an overcap of conventional design. A permanent heat-fused foil membrane seal does not require a container with internal vacuum. However, to open such seals, the consumer must pierce the foil membrane with a pair of scissors, a knife, one's finger, or some other object, and then tear away the foil. When the seal on such permanently fused closing systems is pierced, the contained product may be accidentally contaminated with bacteria residing on the puncturing object. [0011] Another type of foil seal is the type which is peelable.

However, in dealing with nutritional products subject to spoilage, peelable seals have thus far not been optimal for maintaining confidence that the product has not been tampered with and or for ensuring against spoilage.

Additionally, many known peelable foils often encounter difficulty surviving sterilization and retorting conditions without encountering problems in their removal. [0012] It is thus apparent that a need exists for an improved closure for a retortable plastic container that has been filled and then membrane- sealed prior to sterilization without the need for a vacuum. Such container and closing system should provide hermetic system seal integrity during retort, as well as the sanitary opening of the container in a single action motion. The present container and method of packaging are particularly pertinent to milk based products that are subject to bacterial growth such as baby formula manufactured by Mead Johnson Nutritional Products under the trade names ENFAMIL^® and PROSOBEE^® or adult nutritional products sold under the trade name BOOST^®. SUMMARY OF THE INVENTION [0013] The present invention recognizes and addresses disadvantages of prior art constructions and methods, and it is an object of the present invention to provide an improved container and seal. This and other objects may be achieved by a container and sealing system wherein a releasable hermetic seal and bottle are capable of withstanding retort conditions and comprise a generally cylindrical container spout having a first end and a second end, and a first inner circumference and a first outer circumference. The first inner and said first outer circumferences define a land at the first end of the generally cylindrical container spout. A generally cylindrical closure has an open third end and a closed fourth end and a second inner circumference and a second outer circumference. A multilayer polymeric seal contains a first polymer layer, a first copolymer layer, and at least one gas impermeable barrier layer intermediate and bonded to the first polymer layer and the first copolymer layer. The multilayer polymeric seal is releasably fused to the land. [0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0015] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which:

[0016] Figure 1 is an exploded perspective view of a container and sealing system embodying one design of the present invention;

[0017] Figure 1 A is an exploded perspective view of a container and sealing system embodying another design of the present invention where the sealing system employs a pull tab;

[0018] Figure 1 B is an exploded perspective view of a container and sealing system embodying another design of the present invention where the sealing system employs a pull flap; [0019] Figure 2 is a front elevation view of the container shown in

Figure 1 , the back elevation view being a mirror image of the front;

[0020] Figure 3 is a right side elevation view of the container shown in Figure 1 , the left side elevation view being a mirror image of the right; [0021] Figure 4 is a front cross-sectional view along line 4 - 4 of the container in Figure 2, the back cross-sectional view being a mirror image of the front;

[0022] Figure 4A is a detailed cross-sectional view of a portion of the container wall of Figure 4;

[0023] Figure 4B is a cross-sectional view of the closure of the container shown in Figure 1 ;

[0024] Figure 5 is a detail cross-sectional view of a threaded spout and closure of the container shown in Figure 1 ; [0025] Figure 6 is a cross-sectional view of a releasable seal usable in the present invention;

[0026] Figure 7 is a cross-sectional view of a liner usable in the present invention;

[0027] Figure 8A is a flow chart of a process embodying a method for providing a releasable seal as the sealing system on a container according to the present invention;

[0028] Figure 8B is a continuation of the block diagram shown in

Figure 8A; and

[0029] Figure 8C is a continuation of the block diagram shown in Figure 8B.

[0030] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. DETAILED DESCRIPTION OF THE INVENTION [0031] Reference will now be made in detail to presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope and spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0032] With reference to the drawings, and in particular to Figures 1 to 5, an embodiment of the new and improved container and sealing system generally designated by the reference numeral 10 will be described. The container and sealing system 10 includes a generally rectangular body 12 as part of container 11 , and a closure 100, releasable seal 102 and closure liner 104 which form part of the sealing system 13. [0033] Body 12 has front and rear walls 14 and 16, respectively, and respective side walls 18 and 20. Side walls 18 and 20 are connected to the front and back walls by rounded corners generally designated by the numeral 22. Rounded circumferential corner 26 connects a bottom wall 24 to the front, back and side walls. Front and back walls 14 and 16 include discontinuous horizontal channels 28 that aid in preventing container deformation during the retort process.

[0034] A generally recessed body portion 30 is located intermediate body 12 and a threaded spout 32, and connects to body 12 by an inwardly sloping edge 34 and to threaded spout 32 by an inwardly sloping shoulder

36. A generally rectangular recessed body portion 30 contains multiple horizontal circumferential ribs 38 of various diameters that provide stability to the container 11 during the retort process and also that act as a gripping surface for the consumer. [0035] Still referring to Figures 1 to 4, threaded spout 32 includes a cylindrical portion 40 having an outer circumference 42 and an inner circumference 44. Referring specifically to Figures 1 and 4, a mouth 46 is defined by inner circumference 44, and a land 48 is defined by the thickness of cylindrical portion 40 between the inner and outer circumferences. In one embodiment, land 48 may be at least 0.080 inches thick but not thicker than 0.140 inches, and in one embodiment, land 48 is 0.110 inches.

[0036] Threaded spout 32 defines mouth 46 which opens into chamber 50 that is in fluid communication with chamber 52 defined by body 12. The open end of threaded spout 32 is adapted for the removable receipt of closure 100, which can be a conventional plastic cap. A helical thread 54 is integrally formed on outer circumference 42 of cylindrical portion 40 for removably securing closure 100 to threaded spout 32. Helical thread 54 begins proximate to mouth 46 and terminates proximate a flange 57. The thread includes one and one-quarter full turns and has a pitch of six threads per inch. Flange 57 is an annular discontinuous flange that may have several gaps 59 that allow moisture created during the retort process to drain from between threaded spout 32 and closure 100. A second continuous flange 56, which is sometimes referred to in the industry as a transfer bead, is located intermediate discontinuous flange 57 and shoulder 36. Flange 56 allows the container to be grasped, for example, during the molding process. The height of threaded spout 32, measured between land 48 and flange 56, may, in one embodiment, be approximately one inch and, more specifically, 0.917 inches.

[0037] Body 12, recessed body portion 30 and threaded spout 32 may be integrally molded from a multilayered polymeric structure, which may be blow molded, by extrusion or injection, so that it is a unitary member. Referring to Figure 4A, the multilayer polymeric structure may include a six layer design: a first polymer layer 33a, second polymer layer 33b, a first adhesive layer 33c, a third polymer layer 33d, a second adhesive layer 33e and a fourth polymer layer 33f. Suitable polymers for forming the container 11 include, but are not limited to, polypropylene, ethylene vinyl alcohol copolymer (EVOH) and blends thereof. The multilayer polymeric structure should generally be able to withstand a high temperature retort process in the range of approximately 265°F. [0038] The retort process may be carried out through a rotary continuous water cascading hydrostat retort apparatus where the containers are subjected to water baths and moist heat. The pressure in the retort chamber is maintained at a level approximately equal to the internal container pressure during retort to minimize the pressure differential between the containers and retort chamber. However, some pressure differential exists during the retort process, thus causing the container to slightly expand during heating and contract during cooling. [0039] In one embodiment, the polymeric structure forming the container 11 may contain, in aggregate, 59.89% virgin polypropylene, 31.02% reground or recycled polypropylene, 2.67% EVOH, 3.756% adhesive, and 2.67% colorant. For example, first polymer layer 33a may be a 0.0060 inch polypropylene layer having a 4% coloring, for example product number 150749, red coloring, manufactured by Ampacet, Inc. of White Plains, NY. Second polymer layer 33b may be formed from a 0.0200 inch combination of reground, recycled and/or virgin polypropylene having a 2% coloring, for example product number 190600, black coloring, manufactured by Ampacet, Inc. of White Plains, NY. Colored polypropylene layers 33a and 33b provide a light barrier to the container to protect the container's contents from degradation due to light intrusion. [0040] Adhesive layers 33c and 33e may be formed from a 0.0007 inch layer of a suitable adhesive resin such as, TYMOR^® extrudable adhesive resin. TYMOR^® is a modified polymer developed for use as a tie-layer in co-extrusions and extrusion coating applications and is manufactured by Morton Chemical. Other suitable adhesives may be used provided the adhesive exhibits high bond strength, can survive retort temperatures in the range of 265°F and exhibits flexibility in response to both in-plane and out-of-plane stretching due to expansion and contraction of the multilayer polymeric structure during the retort process. [0041 ] Third polymer layer 33d may be formed from a 0.0010 inch EVOH copolymer layer, for example a product sold under the trade name

SOARNOL^® and manufactured by The Nippon Synthetic Chemical Industry Co., Ltd. of Osaka, Japan. The EVOH polymer layer provides an oxygen barrier and prevents degradation of the container's contents from oxidation. The inclusion of an oxygen barrier layer extends the product's shelf life. In addition to the oxygen barrier properties, EVOH is tough, resistant to heat and highly wear resistant. Strength and toughness are a function of the material and the geometry of the particular material chosen. Adhesive layer 33c bonds second polymer layer 33b to third polymer layer 33d. [0042] Fourth polymer layer 33f may be formed from a 0.0090 inch virgin polypropylene layer having a 4% coloring, for example product number 150749, red coloring, manufactured by Ampacet, Inc. of White Plains, NY. Fourth polymer layer 33f provides a functional barrier between the adhesive layer and the packaged product so as not to contaminate the container's contents. The coloring also helps to prevent light from penetrating through the multilayer polymeric structure. Adhesive layer 33e bonds third polymer layer 33d to fourth polymer layer 33f. [0043] While the container 11 may be formed into various sizes for example a 32 oz. container, one commercially viable container size will hold approximately 8 ounces of liquid product. In one embodiment of this 8 ounce container, container 11 has a height of approximately 5.715 inches, a width from side wall to side wall of body 12 of approximately

2.333 inches and a depth of approximately 1.893 inches. The total polymer material used to form container 11 is equal to 23 grams ± 4 grams for the 8 ounce container design. This overall container design allows for 8.12 fluid ounces of product to be packaged in container 11 with an overflow capacity of approximately 8.83 fluid ounces. That is, container 11 may include a maximum headspace of about 9 percent that may receive the fluid overflow.

[0044] Internal wall balance and thickness throughout the container provide the necessary structural stability to withstand the high temperature retort process while maintaining dimensional stability. Thus, using small geometry vacuum panels (discontinuous horizontal channels 28), the wall thickness may be designed to permit the container to be thermally retorted. The following table provides the wall thicknesses for one embodiment of an 8 ounce container 11 at thirteen locations as indicated by reference letters A - M in Figures 2 and 3: Container Wall Thickness at Various Locations

Reference M is shown in Figure 4 and is located at approximately 2 o'clock looking down from the top of the container in Figure 2 toward the bottom wall. [0045] As should be understood, the reference letters for C, F, I and L shown in Figure 3 are located at the same location on the container as those for A, E, G and K, but on the opposite side of the container. The same is true for reference letters D and J, which are not shown in the drawings. [0046] With reference to Figures 5 - 7, and in particular to Figure

4B and 5, the sealing system includes closure 100 having an annular cap 106 which has a continuous type helical thread 108 on its inner circumference for removably securing cap 106 to the externally threaded cylindrical spout 32. Closure 100 may be molded of a suitable polymer material, which may be molded by compression or injection. Suitable plastics for forming the closure include, but are not limited to, polypropylenes and other thermoplastic and thermoset materials and blends thereof that can withstand the retort process. [0047] Outer circumference 110 of annular cap 106 may contain ribs or knurling 112 (Figure 1 ). Ribs 112 allow the consumer to more easily grip closure 100 to remove it from, or fit it onto, container 11. In addition to its internally threaded cylindrical wall, annular cap 106 includes an annular end wall 114. End wall 114 receives closure liner 104 and includes a retention groove 105 that retains liner 104 in closure 100. Closure 100 is dimensioned to seat on land 48 of mouth 46 where an outermost edge portion 103 of closure liner 104 is in abutting contact with the inner circumference of annular cap 106. Thus, threadably securing closure 100 onto threaded spout 32 causes the under surface of annular end wall 114 to compress closure liner 104 against land 48 to form a seal. Closure liner 104 also assists in keeping releasable seal 102 on land 48 during the retort process. That is, because closure liner 104 is formed from a thermoplastic material, the liner will mold to mouth 46 and land 48 of container 11 during the retort process, thereby forming a seat 107 for land 48. Seat 107 is a recessed area on closure liner 104 that receives land 48. In addition to seat 107, portion 109 of closure liner 104 that is radially inward of land 48 bulges axially downward to exert pressure against releasable seal 102. Thus, closure liner 104 aids in keeping releasable seal 102 intact during the retort process by squeezing the seal between closure liner 104 and land 48. Moreover, because closure liner 104 includes a thermoplastic material, it molds to land 48 and mouth 46 during the retort process and retains its shape after cooling. As a result, closure liner 104 acts as a secondary seal once releasable seal 102 is removed. This allows for later sealing of the container while it is being stored or refrigerated after some of the product has been used. [0048] Referring to Figure 7, closure liner 104 may be formed from a multilayer polymer structure having a first polymer layer 116 and a second polymer layer 118. In one embodiment, second polymer layer 118 is formed from a thermoplastic elastomer such as SANTOPRENE^® or VYRAM^®, which are manufactured and marketed by Advanced Elastomer Systems of Akron, OH, or KRATON^®, manufactured by Kraton Polymers of Houston, Texas. Thermoplastic elastomers such as those mentioned above are all pliable and "spring back" into shape after being compressed.

That is, once annular cap 106 is removed from the container 11 , thereby releasing the compression forces exerted on the liner by the cap end wall and the container land, closure liner 104 generally returns to its uncompressed state. In one embodiment, second polymer layer 118 is a 0.041 inch SANTOPRENE^® layer.

[0049] First polymer layer 116 may be formed from a 0.004 inch layer of polypropylene thermoplastic and may also contain a pigment, for example 2% titanium dioxide to provide a white coloring to the liner. Polypropylene layer 116 provides a low coefficient of friction between the underside of end wall 114 and closure liner 104 so that the liner spins freely in the closure. Thus, as closure 100 is tightened onto threaded spout 32, closure liner 104 becomes rotationally fixed to releasable seal 102 as closure 100 clamps the liner between the cap end wall and land 48. As a result, closure liner 104 exerts axial downward force against releasable seal 102 but not torsional force. Consequently, during the packaging process, releasable seal 102 is properly seated on land 48 prior to being fused to the land.

[0050] Releasable seal 102 is generally circular in shape and attaches to land 48 over mouth 46 to allow for hermetic packaging of the container's contents. As shown in Figure 6, releasable seal 102 may be formed from a multilayer composite material as well. In one particular embodiment, a first polymer layer 120 is adhesively attached to a gas impermeable barrier layer 122 by an adhesive layer 124. A second coextruded polymer layer 126 may be adhesively attached to the other side of barrier layer 122 by an adhesive layer 128. Each polymer layer is chosen by its performance characteristics. For example, polymer layer 120 should exhibit high tear strength so that it provides structural rigidity and strength to releasable seal 102, and coextruded polymer layer 126 should provide a good bond with land 48 but also allow for releasable seal

102 to be fractured from land 48.

[0051] One suitable adhesive to bond the polymer layers to the barrier layer, for example, is a two component adhesive consisting ofaromatic diisocyanate, diphenylmethane diisocyanate, and non-aromatic polyester (polyol) sold under the name TYCEL^® and manufactured by

Henkel Technology Industrial Adhesives, Gary, N.C. Other suitable adhesives may be used to bond the polymer layers to the barrier layer. For example, other solventless and solvent-based adhesive systems may be used so long as they exhibit high bond strength, bond the barrier layer to the polymer layer and can withstand the high temperature retort process.

[0052] One suitable barrier layer 122 is a 0.0015 inch aluminum foil layer, but other suitable metal foils may be used. In addition to foil layers, metallized polymer layers may be used provided the layer results in a gas impermeable barrier to maintain the necessary hermetic seal. [0053] Polymer layer 120 may be formed from 0.002 inch polyethylene terephthalate (PET) or other suitable polymers that provide a low coefficient of friction, can survive the heat of the retort process and exhibit high tear strength characteristics.

[0054] The coextruded polymer layer 126 is extruded as a multiple of polymer layers. In one particular embodiment, the coextruded polymer layer 126 is comprised of two layers 126a and 126b. Polymers are chosen for layers 126a and 126b so that the interface that is formed between layers 126a and 126b as the layers are extruded may be fractured when the releasable seal 102 is peeled away from the mouth of the container and the land upon which it is fused. Suitable polymer materials for layer 126a include, but are not limited to, polyethylenes, such as linear medium density polyethylene. Suitable polymer materials for layer 126b include, but are not limited to, propylene/ethylene copolymers, polypropylene and other suitable thermoplastic and thermoset polymers and copolymers. The selection of the particular polymers for layers 126a and 126b will depend on the employment of polymers that allow fusing of the outside polymer layer (when part of the releasable seal 102) to the plastic container spout while allowing fracturing of 126a and 126b at the interface therebetween when the releasable seal 102 is removed from the container spout. In addition, such polymers should be chosen so that the retort conditions of the presently described process do not affect their operability.

[0055] In one particular embodiment, coextruded 0.0015 inch polymer layer 126 includes a first polymer layer 126a of a linear medium density polyethylene that has a thickness of 0.00135 inches, and second polymer layer 126b of a propylene/ethylene copolymer that has a thickness of 0.0015 inches. The polypropylene/ethylene copolymer in layer 126b assures a sufficient bond with container land 48 to form the hermetic seal. Additionally, because polyethylene does not completely bond with the propylene/ethylene copolymer, the polyethylene in layer 126a allows releasable seal 102 to fracture at the layer 126a/layer 126b interface and peel away from land 48.

[0056] Releasable seal 102 is bonded on land 48 over container mouth 46 in such a manner that it maintains an airtight seal during and after the container is subjected to retort conditions - yet the bond allows a consumer to peel the seal from the container mouth. Thus, releasable seal 102 may be oversized whereby the diameter of seal 102 is larger than the diameter of threaded spout 32 so that the consumer can grab the edge of the seal to pull it away from the threaded spout, as shown in Figure 1. Additionally, the seal may include a tab 130 (Figures 1 A and 1 B) that allows the consumer to grip a portion of the releasable seal to pull it away from the container's mouth, or the seal. Tab 130 may be formed as a uniform bulge at a specified edge of releasable seal 102, as shown in Figure 1 A, or it may be a partial layer connected to polymer layer 120 along a cord 132 that bisects generally circular releasable seal 102, as shown in Figure 1 B. Moreover, any other variation of tab 130 may be connected to releasable seal 102, provided that it allows a consumer to peel releasable seal 102 away from container mouth 46 to allow access to the container's contents. [0057] In addition to the releasably attached seal, container and sealing system 10 may also include an anti-tamper ring 131. Anti-tamper ring 131 connects to a lower edge 133 of annular cap 106 by a plurality of relatively thin and frangible breakaway tongues or webs 134. Internally, radially inwardly projecting and angularly extending ridges 135 (Figure 5) are formed on an inner circumference of anti-tamper ring 131 and engage an under surface 136 of radially outwardly projecting flange 57. Thus, tensile forces rotationally fix anti-tamper ring 131 to flange 57 as annular cap 106 is unthreaded off container 11. As annular cap 106 is rotationally removed, both tensile and torsional forces acting on webs 134 cause the webs to sever, thus allowing annular cap 106 to be completely removed. Removal of annular cap 106 will not disturb the hermetic seal.

[0058] An exemplary process of packaging food products in container and sealing system 10 is represented by the flow chart shown in Figures 8A - 8C and described in detail below. In general, the containers are cleaned, filled, capped, hermetically sealed, retorted, labeled and packaged for shipment. Referring particularly to Figure 8A, containers are input into the packaging process at 200. At 202, the containers are cleaned in a two-zone cleaning process. In zone 1 , deionized air is flushed into chamber 52 through mouth 46 to dislodge particulates that accumulate during and after the container molding process. Deionized air is used since it reduces the amount of static electricity created during the flushing process so that most if not all of the particulates are airborne in the container. In zone 2, the deionized air is vacuumed out of the containers along with any airborne particulates. After cleaning, the containers are moved to a coding station 204 where the date, time and filing valve identification is stamped onto the container. [0059] After coding, the containers are moved to a filling station 206 where the containers are filled with product. A volumetric fill process is used whereby liquid product is pumped into the container while air is vented out. That is, the amount of product pumped into the container is controlled by the amount of air that is vented out of the container. After filling, the containers are moved to a nitrogen flush station 208 where nitrogen is pumped into the head space of the containers prior to being capped. [0060] After the containers are flushed and filled with nitrogen, they are capped at capping station 210. Closures 100, including closure liner 104 and releasable seal 102, are fed from a closure bin 212 to capper 210 where the closures are screwed on threaded spout 32. Because the liner in the closure spins freely behind the retention groove, the seal is seated on the container land and remains flat and centered as the closure is tightened. Optionally, if breakaway anti-tamper ring 131 is used, the closures are passed through a heater 214 prior to being secured on the container's threaded spout. The purpose of heating the closures is to soften the anti-tamper ring so that it slides over flange 56 and does not break-way during the capping process.

[0061] After capping, the containers are moved to a fill monitor station 216. At fill monitor station 216, a small percentage of containers are diverted to a quality control process 218 and another group of containers are diverted to a weigh station 220. The remaining containers move through fill monitor station 216, which checks the height of the product in the container to ensure that the fill valves are operating correctly. Quality control station 218 examines the closure removal torque of the containers to ensure that it is no less than 7 inch pounds and not more than 36 inch pounds from the threaded spout. The containers passed to weigh station 220 have their physical weight checked as a cross-check to fill monitor 216 to ensure that the containers have the proper amount of product. If the weight is correct, these containers are merged back into the packaging line. [0062] Once the containers are filled and examined, the capped containers move to an induction foil seal station 222 as shown in Figure 8B. Induction foil seal station 222 subjects the closures and releasable seal to a source of electromagnetic energy induced by an induction coil. The electromagnetic current is of sufficient strength so as to heat metallic barrier layer 124 in the releasable seal 102 which causes the polypropylene in the co-extruded polymer layer 126 to melt and fuse to container land 48. The fusing of land 48 and seal 102 forms the hermetic seal, which is capable of surviving retort conditions. In one embodiment, the induction process utilizes a dwell time of not less than 0.7 seconds and not more than 1.1 seconds for the releasable seal to be properly fused to land 48. It should be understood that the hermetically sealed container does not contain a vacuum but, instead, the head space of the container is at the same pressure as the outside atmosphere. If a container is capped by a closure missing seal 102, that container is rejected at 223.

[0063] After fusing the releasable seal to the container land, the container fill level is once again checked at fill level inspection station 224. Under filled containers are rejected at 226, and the remaining containers are passed to the hydrostat station 228. Hydrostat station 228 performs the retort process where the containers are heated to between approximately 257°F to 265°F. The retort process sterilizes the contents of the container by heating the contents to a sufficient temperature to kill off any bacteria contained in the product. After heating, the product is allowed to cool to room temperature. Releasable seal 102 must withstand the heating process and the ensuing pressure differentials created during the retort process.

[0064] After retort, the containers are passed to air knife/drying stations 230 and 232 where air is directed between the closure and the threaded spout. Any moisture created between the closure and the container is allowed to exit through the discontinuous flange and drains away from the closure. Once dried, the container is passed to a seal integrity inspection station 234 where the containers are gently squeezed to test the integrity of the hermetic seal by exerting a pressure to the container's body of approximately 7 - 15 lbs/in². Sensors at the beginning and end of the compressing process record any changes in pressure to determine if a leak exists between the land and the releasable seal. If a leak is detected, the container is rejected at 236. Otherwise, the containers are passed to a label station 238.

[0065] As shown now in Figure 8C, labeler 238 wraps a label around each container by gluing the first end of the label to the container, wrapping the label around container body and gluing the second end of the label to the first end. The label may be formed from any suitable material including a heat shrink polymer. Should a heat shrink polymer material be used, the labeled containers are passed through optional heat tunnel 244 to shrink the labels tightly around the container's body. Other suitable labels may be used, such as thermoplastic polymers and paper. [0066] Once labeled, the containers move to a carton packer and coding station 246 where multiple containers are wrapped together using a paperboard sleeve. Inferior paperboard sleeves are rejected at 248. After wrapping, the containers are coded with a batch number and packaging date and are moved to a casing station. Casing station 250 wraps a corrugated cardboard case around several carton packs. Once wrapped in a case, a case coder 252 stamps the expiration date and batch code onto the case and the coded case is moved to a case accumulator 254. Case accumulator 254 collects cases onto a pallet for shipping. [0067] A consumer opens container and sealing system 10 by first unscrewing closure 100 from the container 11 (and breaking the anti- tamper ring 131 , if one is provided). Once the closure is removed, seal 102 is grasped and pulled up and away from threaded spout 32. Seal 102 should fracture from land 48 and peel away in a single piece so that the consumer can drink or pour from the spout without interference from seal

102. If product remains in the container, the consumer may replace closure 100 onto container 11 so that closure liner 104 forms a secondary air and liquid tight seal. [0068] While one or more preferred embodiments of the invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example only and are not intended as limitations upon the present invention. Thus, it should be understood by those of ordinary skill in this art that the present invention is not limited to these embodiments since modifications can be made. Therefore it is contemplated that any and all such embodiments are included in the present invention as may fall within the literal and equivalent scope of the appended claims.

Claims

What is claimed is: 1. A container and sealing system that is capable of withstanding retort conditions comprising: a container having a generally cylindrical container spout having a first end and a second end, and a first inner circumference and a first outer circumference, wherein said first inner and said first outer circumferences define a land at said first end of said generally cylindrical container spout; a generally cylindrical closure having an open third end, a closed fourth end, a second inner circumference, a second outer circumference; and a hermetic multilayer polymeric seal having a polymer layer, a co-extruded polymeric layer comprising two layers of polymers wherein said two polymer layers are extruded together to create an interface, and at least one gas impermeable barrier layer intermediate and bonded to said polymer layer and said co-extruded polymeric layer, wherein said co-extruded polymeric layer of said multilayer polymer seal is releasably fused to said land and is capable of fracturing at said interface when said multilayer polymeric seal is removed from said container spout. 2. The container and sealing system of claim 1 wherein said container is a multilayer structure comprising a first polymer layer, a second polymer layer, a first adhesive layer bonding said first polymer layer and said second polymer layer, a third polymer layer, and a fourth polymer layer, and a second adhesive layer bonding said third polymer layer and said fourth polymer layer. 3. A container and sealing system that is capable of withstanding retort conditions comprising: a container having a generally cylindrical container spout having a first end and a second end, and a first inner circumference and a first outer circumference, wherein said first inner and said first outer circumferences define a land at said first end of said generally cylindrical container spout; a generally cylindrical closure having an open third end, a closed fourth end, a second inner circumference, and a second outer circumference; and a hermetic seal releasably fused to said land; and a multilayer polymeric liner received in said closure adjacent to said closed fourth end of said closure wherein said polymeric liner comprises a polymer adapted to withstand retort conditions. 4. The container and sealing system of claim 3 wherein said polymer in said polymeric liner comprises an elastomer. 5. A container and sealing system that is capable of withstanding retort conditions comprising: a container having a generally cylindrical container spout having a first end and a second end, a first inner circumference and a first outer circumference, a first thread on said first outer circumference; a first annular flange formed on said first outer circumference of said container spout and located axially below said first thread, wherein said first inner and said first outer circumferences define a land at said first end of said generally cylindrical container spout; a generally cylindrical closure having an open third end, a closed fourth end, a second inner circumference, a second outer circumference; a second thread on said second inner circumference adapted to operatively engage said first thread on said container spout, wherein said first annular flange on said container spout and said closure form a moisture exit channel; and a hermetic seal releasably fused to said land. 6. A method of hermetically sealing and retorting a container and its contents comprising: providing a multilayer polymeric container having a mouth and a land at said mouth; providing a closure having a liner received therein; providing a multilayer polymeric releasable seal; filling said container with an unsterilized product; releasably fusing said multilayer polymeric releasable seal to said container land to form a hermetic seal; and heating said sealed container and product to sterilize said product. 7. The method of hermetically sealing and retorting a container and its contents of claim 6 further comprising the step of securing said closure to said container prior to sterilizing said product.