Abstract
In some embodiments, a sealing and pressure dosing apparatus may be provided. The sealing and pressure dosing apparatus may include a sealing machine having one or more of a driven turret, a sealing head, a pressure sealing member, and a pressure sealing chamber. The sealing and pressure dosing apparatus may also include a pressure dosing system which may be integrated with the sealing machine.
Claims
1. A method of filling a container with a fluid, the method comprising: introducing the fluid through an open end of the container so that the fluid, at least substantially, fills the container, heating the fluid before or after its introduction into the container, applying a seal or cap to close and seal said container, moving the container to within a pressure sealing chamber, wherein the container has a sealed headspace below the seal or cap, enclosing the seal or cap of the container within the sealing chamber, wherein the container has a first headspace pressure below the seal or cap when enclosed within the sealing chamber, providing a pressure within the pressure sealing chamber that is greater than the first headspace pressure, providing an opening or aperture in said seal or cap, providing an additional amount of fluid, liquid and/or gas through the opening or aperture to raise the first headspace pressure to a second headspace pressure, wherein the additional fluid, liquid or gas is nitrogen, and, sealing the opening or aperture under the raised second headspace pressure, so as to compensate for a pressure reduction in the headspace of the container under the seal or cap following a cooling of the heated fluid contents.
2. The method of claim 1, wherein cooling of said container includes a forcible cooling of said container to bring at least part of an outside wall of the container to a temperature below 75 degrees Celsius substantially immediately after sealing or capping said container.
3. The method of claim 2, wherein said cooling occurs substantially within one minute of said sealing or capping.
4. The method of claim 1, wherein the opening or aperture is provided within said seal or cap with a temporary or partial seal through which the additional fluid liquid and/or gas is provided.
5. The method of claim 4, wherein said seal or cap has a liner material on an inside surface, said liner temporarily sealing the opening or aperture.
6. The method of claim 1, further comprising sealing the container under a neck support ring within the sealing chamber.
7. A method of filling a container with a fluid, the method comprising: introducing the fluid through an open end of the container so that the fluid, at least substantially, fills the container, moving the container into a pressure sealing chamber wherein the container has a headspace above the fluid contents, enclosing the open end of the container within the sealing chamber, closing and sealing the chamber, wherein the chamber is and sealed against the seal or cap or container, wherein the container has a first headspace pressure above the fluid when enclosed within the sealing chamber, providing an increased pressure within the pressure sealing chamber and passing at least one additional fluid, liquid and/or gas through the open end under pressure to raise the first headspace pressure to a second headspace pressure within the container, wherein the at least one additional fluid, liquid and/or gas nitrogen injected through the open end, providing a seal or cap within the chamber, sealing the open end under the increased second headspace pressure conditions, and, opening the chamber and removing the container from the pressure sealing chamber.
8. The method of claim 7, further comprising: heating the fluid introduced through the open end of the container before or after it has been introduced into the container, providing for subsequent pressure reduction in the headspace of the container under the seal or cap by cooling the heated fluid contents, including forcibly cooling at least a part of the outside walls of said containers after sealing or capping said containers to bring at least part of an outside wall of the container to a temperature below 75 degrees Celsius.
9. The method of claim 8, wherein said cooling occurs substantially immediately or within one minute of said sealing or capping.
10. The method of claim 8, wherein the open end is provided with a temporary or partial seal through which the at least one liquid and/or gas is provided.
11. The method of claim 8, wherein said containers is filled with a heated liquid above 80 degrees Celsius.
12. The method of claim 11, wherein at least part of an outside wall of the container is cooled to a temperature below 75 degrees Celsius substantially immediately after sealing or capping the container within the pressure sealing chamber.
13. The method of claim 12, further comprising maintaining a temperature below 60 degrees Celsius on at least a part of an outside wall of the container.
14. The method of claim 12, further comprising of maintaining a temperature above 75 degrees Celsius on at least a part of an inside volume of the container.
15. The method of claim 12, further comprising maintaining a temperature above 80 degrees Celsius on at least a part of an inside volume of the container.
16. The method of claim 12, further comprising maintaining a temperature above 85 degrees Celsius on at least a part of an inside volume of the container.
17. The method of claim 7, further comprising sealing the container under a neck support ring within the sealing chamber.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0128] FIG. 1A shows a side elevational, diagrammatic view of a capping and pressure dosing apparatus embodying some of the principles of one embodiment of the present invention.
[0129] FIG. 1B shows a plan, diagrammatic view of a capping and pressure dosing apparatus embodying the principles of part of one embodiment of the present invention.
[0130] FIG. 1C shows a side elevational, diagrammatic view of a sealing chamber.
[0131] FIG. 2 shows a method according to part of an embodiment of the invention with a Sealing Unit or Capper capable of pressurizing the headspace of a container prior to capping or sealing;
[0132] FIGS. 3A-3C show a container and Sealing Chamber according to part of an embodiment of the invention;
[0133] FIGS. 4A-4C show a method and Sealing Chamber according to a further embodiment of the invention with a Sealing Unit or Capper capable of pressurizing the headspace of a container;
[0134] FIGS. 5A-5C show enlarged views of part of one possible embodiment of the cap of FIGS. 3A-C;
[0135] FIGS. 6A-6C show part of one embodiment of enclosing the cap of FIG. 5 with a pressure application device;
[0136] FIGS. 7A-7C show part of one embodiment of a cap-sealing device suitable for use in the pressure application device of FIGS. 6A-C;
[0137] FIGS. 8A-8C show part of one embodiment of cap-sealing device of FIGS. 7A-C closing the cap while under compression;
[0138] FIGS. 9A-9C show withdrawal of the cap-sealing device of FIGS. 8A-C following sealing and subsequent decompression of the compression chamber;
[0139] FIGS. 10A-10C show the container cap of FIGS. 9A-C following release from the compression chamber (container not shown fully);
[0140] FIGS. 10D-10F show a part of a further embodiment of the container cap of the present invention;
[0141] FIGS. 11A-11C show enlarged views of part of a further embodiment of the cap of FIGS. 3A-C;
[0142] FIGS. 11D-11F show enlarged views of a further part embodiment of the cap of FIGS. 3A-C;
[0143] FIGS. 12A-12C show part of one embodiment of a cap-sealing device suitable for use with caps such as those illustrated in FIGS. 11A-F;
[0144] FIGS. 13A-13C show part of one embodiment of cap-sealing device of FIGS. 12A-C piercing the cap while under sterilization;
[0145] FIGS. 14A-14C show withdrawal of the piercing and delivery device of FIGS. 13A-C following sterilization and subsequent pressure equalisation of the headspace;
[0146] FIGS. 15A-15C show the resealing of the container cap of FIGS. 14A-C prior to container release from the sterilization chamber (container not shown fully);
[0147] FIGS. 16A-16C show additional views of a cap such as those illustrated in FIGS. 12A-12C, 13A-13C, 14A-14C, and 15A-15C according to one possible method of headspace modification;
[0148] FIGS. 17A-17D show additional methods according to further possible embodiments of this invention;
[0149] FIG. 18: shows a further possible part embodiment of the invention using a sealing chamber;
[0150] FIGS. 19A-19B show a possible part embodiment of the invention in the form of a sealing machine;
[0151] FIGS. 20A-20F and FIGS. 21A-21F show a further possible embodiment of the invention using a pressure chamber;
[0152] FIGS. 22A-22C and FIGS. 23A-23C show diagrammatically a possible method of the present invention;
[0153] FIGS. 24 to 27: show diagrammatically a further possible embodiment of the invention in the form of a capping machine;
[0154] FIGS. 28A-28D and FIGS. 29A-29D show further alternative embodiments of the invention using a cold water spray or cold water bath to cool the containers; and
[0155] FIG. 30 shows a method according to one embodiment of the invention with a Sealing Unit or Capper capable of pressurizing the headspace of a container prior to capping or sealing, optional cooling of the container surface within the Sealing Unit and following release.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0156] The present invention in one particular embodiment is directed to an apparatus that includes a capping and gas pressure dosing system configured to overcome shortcomings associated with previously known arrangements by injection of a medium in any state, for example gas, liquid, steam or any combination into containers at about the time of sealing a container by the apparatus.
[0157] In the present specification, including the claims, the term “fluid” covers both liquids and gases unless the context clearly indicates otherwise.
[0158] While the present invention is capable of various embodiments, there is shown in the drawings and specification some presently preferred embodiments, or parts of presently preferred embodiments, with the understanding that the present disclosures are to be considered as exemplifications of the invention, and are not intended to limit the invention to any specific embodiments illustrated. It will be appreciated that the terms capping and sealing may be used interchangeably at times.
[0159] With reference to FIGS. 1a-b, a capping and pressure dosing apparatus 102 is disclosed embodying some of the principles of the present invention. As will be further described, the present apparatus includes a rotary capping machine which is configured for high speed application of closures to associated bottles or like containers. As will be recognized by those familiar with the art, this type of machine serially receives filled bottles from an associated in-feed conveyor or so-called star-wheel, with a machine being configured to substantially continuously apply threaded closures to respective ones of the containers as they are moved through the machine about a generally circular path. The closures are typically applied by rotation to inter-engage the screw threads of each closure with its respective container before the container is moved out of the machine and received by an associated output conveyor or star-wheel. While such equipment exemplifies the configuration of the present invention, it is to be understood that the present capping and pressure dosing apparatus can be configured to operate in accordance with the principles of the present invention by use of other, like equipment, including linear or in-line capping machines.
[0160] The pressure dosing system of the present apparatus may also be generally configured in accordance with known capping systems, such as disclosed in U.S. Pat. No. 7,219,480 to Winters et al, which is incorporated in its entirety by reference.
[0161] In distinction from arrangements known heretofore, the pressure dosing system of the present system has been electronically integrated within the capping machine to facilitate injection of pressure medium into each of the containers being filled simultaneously with the application of the closure to the container. In accordance with the present invention, this is effected by providing the pressure dosing system within a sealing chamber which is positioned to extend generally over and seal off the upper neck finish or cap of the filled containers as they are moved by the capping machine.
[0162] With further reference to FIGS. 1A-B, the present apparatus includes a capping machine 102, as described above. Capping machine 102 is configured to receive containers 1, such as bottles, from an infeed conveyor or starwheel 66 along a circular path 666 in FIG. 1B, and to deliver the filled and sealed containers to an output conveyor or starwheel 77 along a circular path 777 in FIG. 1B. The capping machine 102 includes a rotatably driven carrier or turret 1022 which rotates around a centerline (FIG. 1A) and moves the containers 1 along and about a generally circular path which intersects the circular paths defined by the input and output starwheels 66 and 77.
[0163] As the containers 1 are moved about the circular path by the capping machine 102, the closures 80 are applied to a respective one of the containers. To this end, the capping machine includes a plurality of capping heads 101. Each of the capping heads 101 is rotatably driven so that a closure 80 received thereby can be positioned above a respective one of the containers 1, and the closure rotated downwardly onto the container into sealing relationship therewith, closing the container and completing packaging of its contents.
[0164] As containers 1 are handled by the capping machine 102, the containers each move along the generally circular path defined by the capping machine from an input point to an output point. As will be recognized by those familiar with the art, the input point is sometimes referred to as the transfer point, that is, the theoretical point at which filled container 1 is positioned for receiving a closure thereon, and shown as the bottle infeed area 1023.
[0165] In accordance with the present invention, pressure dosing with any medium, for example compressed air or nitrogen in FIG. 1B, is effected within a sealing chamber 84 to facilitate consistent dosing of the containers 1. To this end, the present invention includes a pressure dosing system within operative association with the pressure sealing chamber 84, which is integrally connected to the capping or sealing head of the capping machine 102.
[0166] By this configuration, the pressure sealing chamber is positioned to dispense a medium not only to surround and envelope the upper end of the container 1 or cap 80, but also downwardly directly through the opening or mouth of each of the containers 1 received by the rotary turret of the capping machine 102 within the air/fluid pressure area 1024 just prior to final application of a closure or seal to each of the containers within the capping or sealing area 1025 by one of the capping heads 101.
[0167] Not only does the present apparatus provide consistent positioning of the container package for pressurization, the container is substantially stabilized, reducing or eliminating further potential for product spillage, allowing for full pressurization. Additionally, dosing simultaneously with closure application prevents any pressure dissipation.
[0168] In the preferred form of the present invention, electronic controls are provided which are operatively connected with the electronic controls of the capping machine for accurate timing of the pressure dosing system. The pressure sealing chamber or pressure delivery mechanism supplying the sealing chamber can be provided with a suitable fitting which permits a suitable device to be positioned for controlling and monitoring operation of the system. By electronically controlling the pressure dosing system, and coordinating its operation with the capping machine 102, the present apparatus provides extremely accurate pressure dosing throughout the entire speed range of the capping machine.
[0169] FIG. 1C shows in closer detail one example of a sealing chamber. The chamber is capable of sealing under the neck support ring of a container, and prior to applying a cap. The sealing chamber could be one of many such chambers for example on a rotary system for torque sealing the cap to the container. Sealing under the neck provides for multiple changes in container styling without the need for change parts providing each container has the same neck finish diameters. Further, by providing for support under the neck the container may be raised upwardly and supported in the capper to avoid any top load pressure and to also allow for multiple bottle heights without the need for change parts also.
[0170] Referring to FIG. 2, a method of pressurizing containers is illustrated whereby the sealing unit or capper receives the filled containers, subsequently seals the headspace from everything but the internal chamber of a sealing chamber, pressurizes the headspace within the sealing chamber and therefore the headspace within the container, and subsequently seals or caps the container so that a raised pressure exists in the sealed container which is then ejected from the pressure sealing unit.
[0171] Referring to FIGS. 3A-C, part of an exemplary embodiment of the present invention is shown with a cap 80 engaged with the container neck finish 120. According to one aspect of the present invention a container 1 may enter a capping or sealing station after being filled with liquid contents such that a headspace exists above the fluid level 40. The upper neck region of the container is sealed from the ambient environment by a sealing chamber 84 that has a sealing surface 841 in contact with a sidewall of the container. According to the invention, prior to tightening or applying torque to the cap to seal the headspace finally, a pressure is applied within the sealing chamber 84 such that the internal chamber of the container is pressurized, more particularly the headspace above the liquid is pressurized. Once pressurized the cap is tightened down by the capping or sealing station such that the container has a raised internal pressure prior to release from the unit, as seen in FIG. 3B.
[0172] The sealing mechanism may be of many styles, but there is distinct advantage in ensuring the size of the pressure sealing chamber is kept to a minimum. This ensures rapid pressurization of the chamber in high speed rotary situations.
[0173] In this embodiment it is envisaged that standard caps are applied to the containers and the pressure capping unit applies internal pressure to the container prior to applying caps.
[0174] The sealing mechanism may be of any style, for example the chamber could seal some distance from the neck finish 120 of the container and down the shoulder region, as illustrated in FIG. 3B, or more preferably immediately under the neck support ring 33, as illustrated in FIG. 3C.
[0175] With reference to FIGS. 4A-C, the process within the sealing chamber for the method of a further embodiment is shown whereby a typical cap applied by a standard capping unit but without having been forcibly torqued into position is shown on the container. The neck finish is enclosed within the chamber 84 of the pressure sealing unit. Following the introduction of fluid or gas or medium under pressure, the liquid or gas is forced into the container through the gap between the cap and the thread mechanisms of the neck finish, as shown by passage of liquid 86. Once the desired pressure is obtained, the cap, as shown in FIG. 4B, can then be torqued into position by advancing the torque rod 85 within the chamber 84 while holding the container headspace at pressure. In this embodiment the method may be achieved using standard caps or modified caps as will be discussed next. FIG. 4C illustrates removal of the torque rod 85, correctly torqued cap 80, immediately prior to ejecting the container head from the chamber 84.
[0176] It will be appreciated that the present invention offers multiple choices in carrying out a headspace modification procedure. Such a piece of machinery could easily be employed to also provide the function of capping the container in addition to modifying the headspace during the procedure. Various examples are disclosed in my further PCT specifications WO 2009/142510 and WO 2011/062512, both of which are incorporated in their entirety by reference.
[0177] In facilitating the present invention, the complete or substantial removal of vacuum pressure by displacing the headspace prior to the liquid contraction now results in being able to remove a substantial amount of weight from the sidewalls due to the removal of mechanically distorting forces.
[0178] As discussed above, to accommodate vacuum forces during cooling of the liquid contents within a heat set container, containers have typically been provided with a series of vacuum panels around their sidewalls and an optimized base portion. The vacuum panels deform inwardly, and the base deforms upwardly, under the influence of the vacuum forces. This prevents unwanted distortion elsewhere in the container. However, the container is still subjected to internal vacuum force. The panels and base merely provide a suitably resistant structure against that force. The more resistant the structure the more vacuum force will be present. Additionally, end users can feel the vacuum panels when holding the containers.
[0179] Typically at a bottling plant the containers will be filled with a hot liquid and then capped before being subjected to a cold-water spray resulting in the formation of a vacuum within the container that the container structure needs to be able to cope with.
[0180] Figures onward from FIG. 4A all refer to upper portions of containers as similarly shown in FIG. 3A.
[0181] According to a further embodiment of the present invention, and referring to FIGS. 5A-C, following the introduction of a liquid, which may be already heated or suitable for subsequent heating, a cap may be applied to the open end 20, the cap including a small opening or aperture 81. Thus a headspace 23a is contained under the main cap body 80 and above the fluid level 40 in the container. The headspace 23a is communicating with the outside air at this stage and is therefore at ambient pressure and allowing for the fluid level 40.
[0182] As seen in FIGS. 6A-C, in part of one embodiment, a sealing chamber 84 is applied over the neck finish and cap combination to seal the liquid from the outside air (the upper, closed end of the structure 84 is not shown). As shown, the lower portion of the chamber 84 may seal against the outer border 11 of the neck support ring, a horizontal border 12 of the neck support ring and below the neck support ring 13. Following the introduction of a compressive force 50, for example by way of injecting air or some other gas, the increased pressure within the sealing chamber provides for a subsequent increase in pressure within the headspace 23b and also forces the fluid level 40 to a lower point due to the subsequent expansion of the plastic container.
[0183] As an alternative to the injection of gas, a heated liquid could be injected, for example heated water. This would provide further advantage, in that the liquid injected would not be subject to the expansion that would normally occur when injecting gas into a heated environment. Thus less force would be ultimately applied to the sidewalls of the container during the early hot-fill stages.
[0184] Even further, the injected liquid would contract less than a gas when subsequently cooled. For this reason less liquid is necessarily required to be injected into the headspace to provide compensation for the anticipated vacuum forces that would otherwise occur.
[0185] As a further alternative, steam could also be injected into the headspace, providing for the increased pressure environment.
[0186] Now referring to FIGS. 7A-C (the compressive force not shown), while pressure is maintained within the sealing chamber 84, a plug mechanism 82 is moved downwardly from a delivery device 83 towards the aperture 81. It will be appreciated the plug mechanism could be of many different styles, for example a pressure-sensitive seal, an ultrasonic weld or the like.
[0187] As can be seen in FIGS. 8A-C, while pressure is maintained within the sealing chamber 84, the hole is closed off permanently by the placement of the plug 82 into the hole 81.
[0188] At this point, and as can be seen in FIGS. 9A-C, the headspace 23b is charged under a controlled pressure, dependent on the amount of gas delivered, and the sealing chamber may provide for withdrawal of the delivery device 83 following a release of pressure within the chamber as the container is ejected and returned to the filling line.
[0189] As shown in FIGS. 10A-C, as the bottle subsequently travels down the filling line and is cooled, the headspace 23b expands as the liquid volume shrinks. The fluid level 40 lowers to a new position 41 and the pressurized headspace 23b expands and loses some or all of its pressure as it forms a new headspace 23c.
[0190] Importantly, however, once the contents are cooled there is little or no residual vacuum in the container, or even perhaps a positive pressure.
[0191] As an alternative, and as shown in FIGS. 10D-F, the plug 82 may be temporarily attached to the cap, for example by member 821, during production of the cap. A liquid, as in the example illustrated, or steam or gas, could be injected in the same manner under pressure to circumnavigate the plug and enter the container headspace under pressure, and a rod mechanism 93 is then forced downwardly to advance the plug 82 into the hole permanently. In this alternative there is no need to load the rod with multiple plug mechanisms.
[0192] Further embodiments of the present invention are now described and summarized in also referring to FIGS. 17A-D.
[0193] Referring to FIGS. 11A-C, following the introduction of a liquid, which may be already heated or suitable for subsequent heating, a cap may be applied including a small opening or aperture 81 which is temporarily covered by a communicating seal 91. Thus a headspace 23d is contained under the main cap body 80 and above the fluid level 40 in the container. The headspace 23d is not communicating with the outside air at this stage and is therefore at typical container pressure during the stages of cooling down on the filling line.
[0194] Alternatively, as seen in FIGS. 11D-F, the opening may be temporarily covered by a liner seal contained within the underneath side of the cap and affixed to cover the hole. Construction of the cap would be virtually the same as any other cap containing an induction seal or internal liner, except the cap would contain a small hole that is non-communicating when the liner is in situ.
[0195] As seen in FIGS. 12A-C, and again also referring inclusively to the example shown in FIGS. 11A-C, once the container has been typically cooled to a level providing for labelling and distribution, the headspace 23e will be in an expanded state with a lowered fluid level, and will have created a vacuum due to the contraction of the heated liquid within the container.
[0196] As seen in this preferred part embodiment of the present invention, in order to remove the vacuum pressure a sealing chamber 84 is applied over the neck finish and cap combination to seal the communicating seal 91 from the outside air (the upper, closed end of the structure 84 is not shown).
[0197] Following the introduction of a sterilizing medium 66, for example by way of injecting heated water, preferably above 95 degrees C., or a mixture of heated water and steam, or steam itself, or a mixture of steam and gas, the sterilizing medium provides for the sterilization of the internal surfaces of the sealing chamber 84 and the communicating seal 91.
[0198] Now referring to FIGS. 13A-C, while the sterilizing medium is maintained within the sealing chamber 84, a plug mechanism 82 is placed downwardly from a delivery device 83 towards the aperture 81. The plug mechanism pierces the communicating seal 91 and is withdrawn again temporarily as shown in FIGS. 14A-C, providing for communication between the sterilized volume within the sealing chamber above the cap 80 and the headspace 23e below the cap. The container pressure rises and so the fluid level 40 will drop unless replenished with liquid from the sealing chamber.
[0199] As can be seen in FIGS. 14A-C, the sterilizing medium, for example heated water at 95 degrees C., is immediately drawn into the container through the open hole 81 due to the communicating seal being pierced. This causes equalization of pressure or removal of vacuum pressure within the container, such that the level of the headspace 23f rises higher. In another preferred embodiment the liquid would in fact be injected into the container under a small pressure supplied from the sealing chamber 84 such that the pressure within the container would in fact be a positive pressure and the headspace would in fact be very small.
[0200] The integrity of the product volume within the container is not compromised as the environment above the cap has been sterilized prior to communicating with the headspace, and the additional liquid supplied into the container replaces the volume lost due to shrinkage of heated liquid within the container prior to the method of headspace replacement described.
[0201] Following the pressure equalization, and now referring to FIGS. 15A-C, the delivery device 83 is advanced again such that the plug 82 will be injected into the hole to close it off permanently. At this point, the headspace 23f is under a controlled pressure dependent on the volume of liquid having been delivered to compensate for previous liquid contraction, as described above.
[0202] The sealing chamber may now provide for withdrawal of the delivery device 83 which may now be done following a release of sterilizing medium and/or pressure within the chamber as the container is ejected and returned to the filling line.
[0203] It will be appreciated that many variations of sealing chamber may be utilised, for example the sealing chamber may only seal directly to the top surface of the cap, rather than enclosing the entire cap.
[0204] It will also be appreciated by those skilled in the art that many forms of seal may be employed to provide the temporary seal and also the plug mechanism to be utilised.
[0205] Thus a method of compensating vacuum pressure within a container is described. Referring to FIGS. 16A-C, the original headspace level 40, experienced following cooling of heated contents within a closed container, provides for a vacuum to be present within the first headspace 23d. Following compensation, according this embodiment of the present invention, the headspace level changes and perhaps rises to level 41 depending on the pressure contained within the headspace, and the pressure within the headspace 23f is now preferably virtually at ambient pressure, or preferably slightly positive, such that the sidewalls of the container are supported by the slight internal pressure.
[0206] This particular embodiment of the present invention is summarised in FIG. 17A.
[0207] As a further alternative to the present invention, and with reference to FIG. 17B a method of pressurizing containers is illustrated whereby the Pressure Sealing Unit receives the filled containers after the containers have already been through a capping unit and received a cap. However, in this method the capping unit has not torqued down the cap, such that the headspace within the container is not sealed and is still in communication with the ambient environment through the gap that exists between the cap and the neck finish threads. The Pressure Sealing Unit subsequently seals the headspace from everything but the internal chamber of the sealing chamber, pressurizes the headspace within the sealing chamber and therefore the headspace within the container, and subsequently applies torque to the caps on the container in order to seal off the headspace with a raised pressure existing in the sealed container, which is then ejected from the pressure sealing unit.
[0208] As a further alternative to the present invention, and with reference to FIG. 17C a method of pressurizing containers is illustrated whereby the Pressure Sealing Unit receives the filled containers after the containers have already been filled with a heated liquid, capped and left to pasteurize for an appropriate length of time, typically while being conveyed a distance from the capping unit to the cooling tunnel of a processing line. Once substantially pasteurized the containers enter the Pressure Sealing Unit where the cap or seal may be separately pasteurized or sterilized on its outside surfaces. The cap may be perforated either prior to entry to the Sealing Chamber or within the Sealing Chamber itself. The Pressure Sealing Unit subsequently seals the headspace from everything but the internal chamber of the sealing chamber, pressurizes the headspace within the sealing chamber and therefore the headspace within the container, and subsequently applies a seal or cap, plug or the like to the container in order to seal off the headspace with a raised pressure existing in the sealed container, which is then ejected from the pressure sealing unit. The containers are then returned to the production or processing line. The containers may be conditioned or temperature controlled throughout the Pressure Sealing Unit and placed into the Cooling Tunnel after exit from the Pressure Sealing Unit for cooling.
[0209] As a further alternative to the present invention, and with reference to FIG. 17D a method of pressurizing containers is illustrated whereby the Pressure Sealing Unit receives the filled containers after the containers have already been filled with a heated liquid, capped and left to pasteurize for an appropriate length of time, typically while being conveyed a distance from the capping unit to the cooling tunnel of a processing line. Once substantially pasteurized the containers enter the Cooling Tunnel and finish pasteurization, wherein the sidewalls cool down to between approximately 20 C and 40 C, and a vacuum develops within the container. The containers enter the Pressure Sealing Unit after exiting the Cooling tunnel where the cap or seal may be separately pasteurized or sterilized on its outside surfaces. The cap may be perforated either prior to entry to the Sealing Chamber or within the Sealing Chamber itself. The Pressure Sealing Unit may subsequently seal the headspace from everything but the internal chamber of the sealing chamber, and increase the pressure of the headspace within the sealing chamber and therefore the headspace within the container. A seal or cap, plug or the like is subsequently applied to the container in order to seal off the headspace with a raised pressure, and the container is then ejected from the pressure sealing unit. The containers are then returned to the production or processing line for labeling. The pressure in the containers may be increased only to remove the vacuum from the container or significantly increased, depending on the amount of pressurization applied. Even a return to generally ambient conditions represents a reasonably significant increase from vacuum conditions that may be in the order of greater than 1 psi negative vacuum.
[0210] A further embodiment is provided in FIG. 18. In this part embodiment of the invention the cap 80 has a plug 82 temporarily attached by a member (not shown). A sealing chamber 84 encloses the cap and provides an internal sealed chamber headspace 87 through the compression of sealing rings 89 against the upper surface of the cap. Gas or liquid, or a combination of both, is injected into the chamber headspace 87 from a pressure source 888 through an inlet 86 and through the spaces around the plug into the headspace of the container. Once the required pressure within the container is obtained, the push rod 88 is advanced downwardly to force the plug 82 into position within the cap and therefore seal the container headspace under the required pressure. This provides for a calculated internal pressure to be achieved precisely at the time of sealing the container, when the plug is advanced into final position. This provides for forward compensation of the effects of subsequent vacuum generated by a cooling of any heated contents within the container.
[0211] With reference to FIGS. 19A and 19B, the present invention may be manufactured to function exclusive of cap application and for final sealing of any temporary cap hole or pathway only. A typical capping machine head unit 101 encapsulates the sealing chamber 84 and provides the function of sealing and pressurising the container through applying the cap to seal the container while under increased pressure. Alternatively, a typical capping unit may have optionally already torqued the cap into position, but the container would remain unsealed due to the presence of a plug, being in an ‘unplugged’ position within the cap, and allowing the passage of liquid or gas between the inside and outside of the container. The precise moment of sealing the container occurs as the plug is rammed into position and the headspace within the cap is not at ambient pressure, as would be typical of prior art capping procedures within the filling and capping area, but instead, with the present invention, a headspace modification unit 102 including the capping head unit 101, the pressurizing and sealing unit 84, and the rotatable turret 103, which may optionally be of typical rotary style in mechanics, may receive capped containers 1, and subsequently pressurize the container immediately prior to sealing the container with a cap sealing plug.
[0212] As an alternative, the headspace modification unit 102, including the capping head unit 101, the pressurizing and sealing unit 84, and the rotatable turret 103, can also perform the usual function of a typical capping machine. The unit could receive empty containers, apply caps containing the plugs and subsequently torque the caps into position as well as pressurize the container prior to ultimately sealing the container through advancing the plug or some other sealing method.
[0213] Still further examples of alternative embodiments of the present invention are illustrated in FIGS. 20A-F. The cap 80 may incorporate a rubber, or other suitable material, plug 182 within the cap. This would provide the advantage of having an initially leakproof seal to the container prior to pressurising the headspace. In this way, the container could be charged with pressure from a liquid or gas either prior to the cooling of the contents, for example immediately after filling and capping by way of overpressure, or the procedure could occur after the contents have been cooled and there is a vacuum within the container. By way of example, the cap and sealing plug 182 could be sterilized by very heated water 66 after the liquid contents have cooled. This would sterilize the upper surface of the cap and a heated liquid could then be injected to compensate for vacuum pressure. Following withdrawal of the injecting needle 202 the sterilizing heated liquid could be removed as the container is ejected from the pressure chamber. The rubber seal 182 would have closed off and sealed the container to prevent any communication between the headspace under the cap and outside air present as the chamber is opened.
[0214] A further alternative for a suitable plug mechanism within a cap 80 is illustrated in FIGS. 21A-F. A ball-valve type closure 882 could be utilized to provide a hole through which headspace modification may occur within the pressure chamber unit as previously described. Once the headspace has been pressurized, a rotating push rod 883 can close the ball valve while the headspace is maintained under exact pressure as illustrated in FIGS. 21D-F.
[0215] FIGS. 22A-C shows a typical example method of headspace modification using the method of the present invention. An empty container (not shown below the neck finish) is filled or even ‘overfilled’ to the brim of the neck finish, and a cap is applied that has an opening through which headspace modification can be achieved, for example a ball closure device. The capped neck finish, at least, is contained within a pressure chamber (not shown) and the container is placed under a calculated pressure. This increase in pressure may be by injection of a gas as in the illustrated example, or by overinjection of further liquid. During this process the container will increase in size to a degree allowing the fluid level to drop (if gas is being injected) and the ball-valve closure may then be closed to maintain the increased pressure within the container.
[0216] The same method procedure may occur using a more typical ‘push-pull’ type sport closure as illustrated in similar manner in FIGS. 23A-C.
[0217] FIG. 24 shows how a container could be contained within a typical sealing chamber 84 from immediately below the neck support ring 33 of the container.
[0218] FIG. 25 illustrates how the whole container could be contained within a sealing chamber 84. In this embodiment the container will not be stressed from the increased pressure until after ejection from the sealing chamber.
[0219] FIG. 26 shows an alternative embodiment of the present invention. It is envisaged that the sealing chamber 84 could comprise optionally a lower end sealing skirt 884. In this example, a sealing ring of soft material may be inflated under pressure of water or gas through an inlet 883 to form a close contact with the container shoulder. Gas or liquid may then be charged into the pressure chamber headspace 87 through inlet 86 to modify the container headspace prior to final sealing.
[0220] FIG. 27 shows how the sealing chamber of FIG. 26 could be incorporated into a typical capping unit station with rotary head applicators. This would allow for a modified capping unit to apply a cap in the normal manner, but to modify the headspace prior to application of torque to seal the cap on the container. Apparatus 844 moves the pressure chamber into engagement with a surface on the container to provide a sealed connection.
[0221] In facilitating the present invention, the complete or substantial removal of vacuum pressure by displacing the headspace prior to the liquid contraction now results in being able to remove a substantial amount of weight from the sidewalls due to the removal of mechanically distorting forces.
[0222] With reference to FIGS. 28A-D, a further alternative embodiment of the present invention is provided. A rotary sealing unit 900 is disclosed that clamps the hot-filled container 1 by the neck finish and just under the neck support ring 33. As the unit contains the upper neck thread of the container and prepares to increase the pressure contained in the pressure chamber 84 of the sealing unit, and the headspace of the container, the container is subjected to temperature modification. In this example a cold water spray 991, typically below ambient temperature and preferably between approximately 4 degrees C. and 15 degrees C.
[0223] The cold water spray causes the container shell to immediately fall below the glass transition temperature of the sidewall material. The temperature within the container does not fall as rapidly however, and so the liquid contents are able to subsequently be used to sterilise the internal cap surface when the container is released from the Pressure Chamber and laid down in a horizontal position, typically for a period exceeding 30 seconds.
[0224] The container sidewalls are forcibly cooled until the central core temperature of the container falls below the glass transition temperature of the sidewalls. The cold spray of this example is maintained throughout the pressurisation and sealing period, beyond release from the unit and through the period immediately subsequent when the container is inverted, as is typical. The container liquid temperature will fall below the threshold value required soon after inversion has been completed. Once this has occurred the container may be returned to the production line without further cooling prior to entering the main cooling tunnels typically found some minutes down the production line.
[0225] As the container has now been ‘pre-chilled’ the efficiency of the main cooling process is improved also.
[0226] It will be appreciated that many cooling methods may be employed, for example a cold water bath 992 or the like, as illustrated in FIGS. 29A-D, may be used instead of a spray. The cooling may be directed only at the base region or all over the container. A cooling jet of air may be used instead of a liquid for further example. Other cold gases may be used, eg nitrogen, or even ice may be used in some applications.
[0227] It will be appreciated that by preventing the material of the sidewalls of the container to be above a certain temperature, and below the temperature of the liquid contents for a critical period of time, then the pressure increase induced in the container will not cause damage to structures that would otherwise occur.
[0228] Preferably the cooling is applied for a period of time between 1 and 2 minutes, which time allows for the container to be pressurized, inverted to sterilise the cap underside with still-hot contents, and for the liquid to fall rapidly to below about 60 degrees C.
[0229] The time required will vary depending on line speed and fill temperature, however, and the cooling time required may be extended to over 2 to 4 minutes.
[0230] It is a preferred object of the present invention to provide a device which enables the pressurisation and sealing of freshly filled containers after sealing off the upper neck region of the container, and to initiate the differential cooling process to prevent the sidewall temperature exceeding approximately 70 degrees C. and so avoid the deformation of container sidewalls that occurs through high thermal stresses and high pressure stresses. The process is summarized with reference to FIG. 30.
[0231] In a preferred embodiment of the present invention, the bottles must have a retained internal temperature above 80 degrees C. for up to 30 seconds, and preferably up to 1 minute, more preferably up to 2 minutes, and occasionally even more preferably up to 3 minutes. During this time the temperature of the container body shell must be kept differentially below 70 degrees C. and preferably below 60 degrees C. for this time. During this period of time the containers may be inverted or laid horizontally to sterilize the inside underneath of the cap.
[0232] According to a preferred embodiment, the containers are rotated through an angle of between 70 degrees and 110 degrees, more preferably between 80 degrees and 95 degrees, so that they are transported approximately in a horizontal orientation.
[0233] The temperature of cooling medium and rate of application must be carefully controlled to provide only for the outside container surface to be held below 70 degrees C., and so cause the internal container temperature to be maintained above 70 degrees C., and more preferably above 80 degrees C., and even more preferably above 90 degrees C.
[0234] Of course it will be appreciated that if the glass transition point of an alternative sidewall material is above the fill temperature then applying a cooling period during sealing or inversion would not be required.
[0235] A particular advantage of the present method and system is the greater and more precise control of fluid injection into the headspace of a container. The injection is not based on measured dose of gas, but on a measured or pre-determined pressure to be achieved. Therefore each container receives a specific dose dependent on the fill point level within the container. The system provides for a first pressure to be present above the fill point, and to then raise this pressure to a second, higher level. This allows for much lower pressure dosing for hot fill containers. In prior methods a minimum pressure value can only be assured by over pressurisation on average, such that the lowest dose achieved will meet specifications. This has resulted in generally high pressures achieved during the early stages of hot fill, when the container is hot and malleable. As a result the container is stressed significantly in most occasions, necessitating the need for example for petaloid bases and container designs more suitable to carbonated or pressure vessels. This reduces significantly the design options available for containers, and requires additional weight in the container surrounding the base in order to achieve reasonable results.
[0236] Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth.
[0237] Although this invention has been described by way of example and with reference to possible embodiments thereof, it is to be understood that modifications or improvements may be made thereto without departing from the scope of the invention as defined in the appended claims.
