CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No. 60/626,480, filed November 10, 2004, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The present invention relates generally to a seal for a hot-fill or pasteurizable container, and more particularly to a moveable seal for accommodating resulting pressure/vacuum formed in a hot-fill or pasteurizable container. Related Art

[0003] Known blow-molded containers are usually made of plastic and employ flex panels and/or ribs that reinforce the integrity of the container while accommodating internal changes in pressures and volume in the container as a result of heating and cooling. This is especially true with hot-fillable containers and pasteurizable containers.

[0004] In order to obtain the necessary strength to withstand the manufacturing process, known plastic hot-fillable and pasteurizable containers tend to be formed with protruding rib structures that surround panels forming the container. While the protruding rib structures improve the strength of the container that is blow-molded out of plastic, panels and protruding rib structure detract from the desired sleek look. Accordingly, a hot-fillable or pasteurizable, blow-molded container and process of manufacturing same is needed to provide a container more closely simulating the strength and smooth outward appearance associated with glass containers. [0005] In addition to having protruding rib structures for strength, known plastic hot- fillable containers and pasteurizable containers tend to have rectangular panels for vacuum compensation. It is known in the art to cover the protruding rib structures and panels with a paper label to improve the aesthetics or overall appearance of the plastic container. Consequently, in order to provide support for the label, the panels of such containers are provided with additional protruding structures. Thus, hot-fillable and pasteurizable containers

are provided with more recesses and corners from which hot-filled solid products are not easily removed. Or, if the hot-filled product is subsequently chilled by placing the container in ice, the label covering the panels with protruding structures traps water inside the recessed panels resulting in spillage of the water after the container is removed from the ice. Another problem with plastic bottles having rib and vacuum structures is that these structures add weight to the container, making the container more expensive to manufacture. Accordingly, a hot-fillable or pasteurizable plastic container requiring fewer supporting structures in its body is desired to overcome the shortcomings of the prior art.

[0006] With respect to pasteurization processes currently practiced in the art, many seals are placed on the inside of a lid and the lid is placed on the container. This is because the seal, if present by itself, would not be able to withstand high pasteurization temperatures and pressures. Thus, a heavy and sturdy yet expensive closure is coupled to the seal, and the closure with seal are placed on the container, hi order to reduce manufacturing costs, a seal that is able to withstand pasteurization on its own is also desired.

BRIEF SUMMARY OF THE INVENTION

[0007] The present invention is directed to a closure system for a seal for a hot-fill or pasteurizable container. The seal includes a movable portion that can move in response to pressure changes in the container, and this moveable portion can take the shape of ribs or concentric circles. The ability of the seal to accommodate changes in pressure within the container reduces performance demands on the container. The closure system prevents air from passing through the container.

[0008] hi one embodiment, the seal can be capable of multi-directional movement and can be fixed the rim of the container. The seal can also be permanently fixed to the rim, and can have a tab to facilitate removal of the seal. The seal can be made of a metallic or polymeric material. [0009] hi an additional embodiment, the closure system can also include a closure, such as a nestable or domed closure. The container can be a wide-mouth container. The seal can be fixed to the closure, and the closure can have a vent.

[00010] The present invention is also directed to a method of manufacturing a hot-fillable or pasteurizable container, the method including placing a seal with a moveable portion in contact with an opening of the container and allowing the seal to move in a controlled manner in response to pressure inside the container. The container can be filled before the seal is placed on the container

opening. The container can be hot-filled, and the container can also be heated after it is filled. The container can be heated in a pasteurization or a retort process.

[00011] In one embodiment, the container has neck with a finish, and grooves can be preformed on the finish. The method can also include placing a seal on a closure the container and placing the closure on the container. The seal can be fixed to the container by, for example, gluing, spin welding, or thermal sealing. The closure can be placed on the container after the container has cooled. The closure can also be a vented closure.

[00012] Further objectives and advantages, as well as the structure and function of preferred embodiments will become apparent from a consideration of the description, drawings, and examples.

BRIEF DESCRIPTION OF THE DRAWINGS

[00013] The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

[00014] FIG. IA is a front view of an accordion seal for a hot-filled container according to one embodiment the present invention;

[00015] FIG. IB is a perspective view of the accordion seal shown in FIG IA;

[00016] FIG. 2A is a top view of an accordion seal according to one embodiment of the present invention.

[00017] FIG. 2B is a cross-section of the seal of FIG. IA, taken along line IE-II of FIG.

IA.

[00018] FIG. 3 A depicts an exemplary embodiment of an accordion seal of the present invention in a compressed state;

[00019] FIG. 3B depicts an exemplary embodiment of an accordion seal of the present invention in an expanded state;

[00020] FIG. 4A depicts a seal attached to a closure according to one embodiment of the present invention

[00021] FIG. 4B depicts the seal of figure 4A in an expanded state.

[00022] FIG. 5 depicts a seal attached to a container according to one embodiment of the invention.

[00023] FIG. 6 A depicts a seal according to an additional embodiment of the present invention.

[00024] FIG. 6B depicts the action of the seal depicted in FIG. 6 A.

[00025] FIG. 7 A depicts a seal according to a further embodiment of the present invention.

[00026] FIG. 7B depicts a seal according to an alternate embodiment of the present invention.

[00027] FIG. 8 depicts a seal according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[00028] Embodiments of the invention are discussed in detail below, hi describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention.

[00029] During the processes of hot-fill and pasteurization of a plastic container, undesirable deformation of the container can occur as a result of changes in internal pressures and volume due to the cooling of the filled hot product. Flex or vacuum panels were previously considered necessary to accommodate the change in internal pressure so that the plastic container has a finished look, instead of being collapsed or skewed due to the resulting vacuum. The seal of the present invention overcomes this problem by moving in response to container pressure, thus accommodating the force of the pressure/vacuum.

[00030] For example, a hot-filled container may be sealed with a moveable seal that can move in response to pressure or vacuum created in the container during the hot-fill or pasteurization process. In one embodiment of the invention, the seal can be accordion-shaped such as that illustrated in FIGS 1 A-3B.

[00031] As shown in Fig. IA, a seal 100 with a movable portion 102 may have an upper flange 112 that is adapted to be attached to the neck of a plastic, hot-filled container. The

movable portion 102 may have a number of collapsible portions or bellows 104 that can be folded next to one another to extend into the container when the seal is attached to the neck of the container. The collapsible portion or bellows 104 can expand so that the movable projection 102 can increase its volume inside the hot-filled container. The upper flange 112 is of a diameter to securely seal the neck of a plastic container.

[00032] hi the illustrated embodiment there are four collapsible portions 104 that may be folded as a bellows of an accordion and serves as the movable projection 102. The seal may have a lesser or greater number of collapsible portions, depending on, for example, the size of the container. Each collapsible portion can have an inner ring or inner hinge portion 106 and an outer ring or outer hinge portion 108. These inner 106 and outer 108 hinges are more clearly illustrated in the cross section shown in Figure 2B, taken along line E-II in FIG. IA. hi the embodiment of FIG. 2B, the hinges 106 and 108 take the shape of a ring at the exterior. This ring enables additional expansion of the movable projection 102. Of course, other hinges are contemplated by the invention. For example, inner hinge portion 116 and outer hinge portion 118 need not contain a ring.

[00033] hi the embodiment illustrated in Figure IA, the bellows 104 can become progressively smaller in diameter as they move away from flange 112. In other embodiments, the diameter of each bellows may remain constant, or exhibit a variety of other diameter patterns. The seal 100 can also have an extension 110 with a central recess 112. hi the illustrated embodiment, the extension 110 is dome-shaped, but other suitable shapes are also encompassed by the invention. Central recess 114 adds rigidity to the dome created by extension 110.

[00034] FIG. IB illustrates the interior of an accordion seal according to one embodiment of the present invention. Inner hinges 106 are more clearly depicted here. As discussed above, the accordion-shaped seal has an upper flange 112 that is of a diameter to sufficiently seal the neck of the plastic container. The upper flange 112 has a diameter that covers the neck of the plastic container and has a central recess 114 with a vertical skirt 116 (see FIG. IA) that may be held securely within the neck of the container by a friction fit to seal the same. Alternatively, the flange 112 can be sealed to the top of an opening in a container by, for example, gluing, spin- welding or thermal sealing. The outer diameter of the flange 112 can have ridges 118 for mating with the neck and a finishing cap or lid, for example. These ridges 118 can

have a vacuum break such as a vent 130 to permit air to move from the seal 100 to the outside of the container. The vacuum break does not permit air exchange between the inside and the outside of the container.

[00035] As shown in FIG. 3 A, the accordion seal 100 is initially compressed together so that the seal initially takes up a smaller volume in the container. Here, the inner rings 106 of each collapsible portion 104 are shown tightly together. As the container cools, pressure in the container decreases, creating a vacuum, hi response to this vacuum pressure, inner rings 106 of the collapsible portion 104 can expand to increase the volume of the three-dimensional seal 100.

(See FIG. 3B.) This expansion decreases the internal volume of the hot-filled container and helps prevent collapse of the container. As a result, the increased volume of the accordion- shaped seal 100 enables the container to substantially keep its original form during the cooling of the hot-filled container as the seal 100 compensates for the decreased internal volume of the container due to created vacuum forces. Additional states of expansion and compression can be achieved by the invention; Figures 3 A and 3B are merely an illustration of two possible positions.

[00036] hi one embodiment of the present invention, the seal 100 of the present invention is attached to a container after a substance at an elevated temperature is inserted in the container. A closure, such as a cap or lid, can then be placed on the container and over the seal 100. The closure may be attached immediately after placement of the seal on the container or after the contents of the container are allowed to cool. To empty the container, the closure is removed and the seal 100, including the flange 112, is removed from the container. The seal 100 may include a tab (not shown) formed in the recess 114 to facilitate removal. The closure can be placed back on the container if further storage of the container contents is desired. [00037] hi another embodiment of the invention, the seal 100 may be fixed to a closure 120 that is then placed on a container. (See FIG. 4A.) hi response to negative pressure created inside the container, the moveable portion 102 of seal 100 expands. (See FIG. 4B.) The closure 120 can also contain a vacuum break such as vent 122, to allow air into the moveable portion only, so that the moveable portion 102 can expand more easily. In embodiments employing an accordion-type seal, additional collapsible portions can be added for sealing larger containers to accommodate larger volumetric or barometric changes. On the other hand, fewer

collapsible portions may be required in wide-mouth containers as the movement of a bellows with a larger cross-sectional area will result in a larger change in volume. [00038] The accordion-shaped seal may be molded in multiple layers to avoid oxygen- egress into the container. That is, the plastic accordion-shaped seal may include a nylon layer or other layer that allows a longer shelf-life by protecting the product within the container from oxygen.

[00039] With respect to hot-fill or pasteurizable containers that are heated with their contents, these containers must be able to withstand pressure in two different directions. Specifically, while the container is being heated, positive pressure is created, causing the container volume to tend to increase. Thus, the container must be able to accommodate this increase in volume. As the contents cool, a negative pressure is created, causing the container volume to tend to decrease. Therefore, the container must be able to accommodate pressure in both directions and the increase and decrease in container volume.

[00040] Particularly suited to pasteurizable and retort containers as well as hot-fill containers is an embodiment of the present invention where the container seal is capable of multi-directional movement, meaning that the seal or a particular portion thereof can move both into and away from the container. This multi-directional movable portion contains additional material so that the movable portion is able to move beyond the substantially planar states of known prior art seals (seals that are mostly flat). In particular embodiments, the multi¬ directional moveable portions of the seal can move, for example, from approximately 1/8 to approximately 1/4 of an inch.

[00041] Figure 5 depicts a seal 200 attached to a container according to one embodiment of the present invention. The multi-directional seal 200 as pictured in FIG. 5 is particularly suited, but not limited to, wide mouth containers. In this illustrated embodiment, the seal 200 is welded to a container rim 204, preferably having grooves or scores 202 that are preformed on the container finish. In one embodiment, the grooves 202 are preformed on the inside of the container finish.

[00042] The center portion of the seal 200 that is over the opening of the container is able to move either into the container opening or away from it. (An example of multi-directional movement is more clearly illustrated in FIG. 6B.) Additionally, there can be a tab 206 on the seal 200 along the outer edge of the seal to facilitate removal of a portion of the seal. The

grooves 202 can form a circle leading from the tab 206 around the outside of the seal, ending at a point just on the other side of the tab. This enables the tab 206 to be pulled in a circular motion around the rim of the container inside of the finish, thus removing the inner portion of the seal. Alternate groove patterns are also possible depending on the shape of the container neck/rim, and the grooves 202 need not run all the way around the container rim 204. [00043] Because of the preformed grooves 202 that exist within the container rim 204, the seal is not fixed to the container at the grooves 202. When the tab 206 is pulled, the seal 200 separates along the outer edge, allowing the inner portion of the seal to be removed while the strip of seal attached at the rim 204 remains attached to the container rim 204. It is also possible to fix the seal to the container by gluing, thermal-sealing, or other methods known in the art. Additionally, neither grooves 202 or tab 206 are required to practice the seal of the present invention.

[00044] The multi-directional, movable portion of the seal in Fig 5 is the entire center of the seal 200 that is not fixed to the container rim 204. In other embodiments of the invention, only certain portions of the seal utilize multi-directional movement. One such example is illustrated in FIGS 6 A and 6B. FIG 6 A is a top view of a seal 300 having concentric circles 302 defining the areas 304 that are capable of multi-directional movement. FIG. 6B is a side view showing downward movement by dotted lines, and upward movement by dashed-dotted lines. As illustrated by Figures 6 A and 6B, the areas 304 between the concentric circles 302 are capable multi-directional movement. It is possible for portions of the seal 300 not designed for multi-directional movement to move somewhat in response to pressure/vacuum created during the manufacturing process; however, the multi-directional movable portions will exhibit significantly more movement.

[00045] m the embodiment illustrated in Figs 6A and 6B, concentric circles 302 defining multi-directional moveable portions 304 are placed throughout the entire seal 300. Figure 6B illustrates the upward movement 306 away from the container and downward movement 308 toward the container. The extent of movement in each moveable portion 304 can vary depending on the amount of pressure generated in the container. [00046] In alternative embodiments, the circles 302 and moveable 304 portions can be, for example, limited to the center of the seal. The circles 302 and multi-directional movable portions 304 can also be of a varying number, and be spaced apart at varying distances.

[00047] Figure 7A and 7B illustrate additional seal designs having portions capable of multidirectional movement. Fig 7A has rib-like multi-directional moveable portions, and Fig 7B is almost entirely multi-directional, expanding much like a balloon. Though tabs are not illustrated in Figs 7A and 7B, embodiments including tabs with these seals are encompassed by the invention.

[00048] For embodiments where the seal is fixed to the container, a closure may be added at any point after the container is filled. Because the seal is capable of withstanding the hot-fill and pasteurization processes, many closures known in the art, such as a twist fit closure or a snap-fit closure is suitable. Some particularly suitable closures include domed and nestable closures, which allow stacking of the containers.

[00049] It is also possible for multi-directional moveable seals to be attached to a closure which is then fitted on a container once the container is filled. Again, the seal can move toward the container in response to downward pressure/vacuum, and can move upward in response to upward pressure created as the container cools. A domed closure would be particularly suitable in this embodiment; however, alternate closures are also possible. [00050] A further embodiment speaks to a movable seal having a vent beneath the seal. For example, as illustrated in FIG. 8, seal 400 is placed in a closure and the closure shell 404 can contain a vent 408. The vent is designed to allow air exchange, which enhances the movement of the seal 400 and alleviates pressure within the container. This arrangement protects against vacuum collapse, and is thus particularly suitable for the processes of hot-fill and pasteurization which have higher fill temperatures. A ring liner 406 can also be present, hi this particular embodiment, the ring liner 406 and flexible seal 400 are molded into the closure shell 404, resulting in a one-piece style closure.

[00051] The seal of the present invention can be made of any metallic or polymeric material that provides suitable performance and barrier properties as required. The seal can be made of, for example, aluminum foil.

[00052] Blow-molded containers are preferably made of plastic, such as a thermoplastic polyester resin, for example PET (polyethylene terephthalate) or polyolefins, such as PP (polypropylene) and PE (polyethylene). The seal can also made be made from PET, polyolefins, or other pliable materials including EVOH barrier material.

[00053] One major benefit of the present invention is that the seal, with its ability to accommodate pressure/vacuum, takes some performance demand off the container. In utilizing a seal having a movable portion as described above, the need for flex panels and or rib-like support structures on the container body is eliminated or reduced. Not only does the reduction or elimination of flex panels or ribs lead to a more aesthetically-pleasing, less cumbersome container that is easier to handle, the weight of the container and its finish is reduced. This reduction in container weight translates to a significant reduction in container costs. [00054] As the seal of the present invention is able to withstand the high heat and pressure changes that result from the processes of hot-fill and pasteurization, an expensive, sturdy closure is not required. Thus, manufacturing costs are further reduced. Because a less- substantial closure is a sufficient companion for a sturdy seal, fewer resources are used, making a container that is more environmentally-sound.

[00055] hi embodiments where the seal is affixed to container and not the closure, a lid is not required until later in the manufacturing process and the ability to detect container defects in the neck area and in the seal is vastly improved. Defective containers can be identified easily and quickly so that additional resources are not wasted labeling and capping a defective container. More importantly, these defective containers do not end up in the hands of consumers.

[00056] The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.