Patent Application
20220267134
The present disclosure relates to a method and system for processing containers, and in particular for containers for containing human consumable material.
Various types of beverages or products are stored in different types of containers for eventual consumption by consumers. Beverages and other products are typically filled in containers such as thermoplastic or glass liquid containers in an automated filling process. The product, the container, and container closure, such as a cap, must all be sterilized on the internal surfaces of the sealed container, or free from microorganisms, to provide the consumer with a safe product that has the respective quality attributes expected by the consumer.
Typically, containers can be filled with beverages in either a “cold-fill” process or a “hot-fill” process. The method of achieving sterilization within the container differs between the techniques, with each method having different benefits and cost implications.
The hot-fill process is less expensive and easier to maintain on a global basis, from an equipment and method perspective, but results in more expensive containers with little design freedom. The cold-fill process is typically much more expensive and difficult to maintain, but offers less expensive containers and more design freedom in the containers.
So called “hot-fill” containers are known in the art, therefore, as this technology is widely practiced globally. Plastic containers, such as PET (Polyethylene terephthalate) containers, are filled with various liquid contents at an elevated temperature, typically around 185° F. (85° C.). The product has been held in a batching process for a period of time prior to filling to ensure any microorganisms have been killed (referred to as pasteurization). The purpose is to kill microscopic bacterial life inside the liquid, ensuring the product stays fresher longer. After filling the product into the container, the container is sealed or capped and held at the filling temperature for a period of time, usually around 2-3 minutes. This is to allow the heated and sealed contents to sterilize the inside of the container. Following this the container is typically cooled to prevent heat damage to the containers, as they have generally only been ‘heat-set’ to withstand the hot fill temperature for a set period of time. Once the liquid within the container cools, the volume of the contained liquid reduces, creating a vacuum within the container that pulls inwardly on the side and end walls of the container. This in turn leads to deformation of the plastic container if it is not constructed rigidly enough to resist the vacuum forces. This need for rigid and strong containers leads to an inordinate amount of material being used as containers must be thick and strong.
Beverages are filled into hot-fill PET containers until they are almost full. The level where the beverage settles after filling is called the ‘fill point’ and this leaves a small amount of air above the fill point in the top of the bottle called the ‘headspace.’ When a hot-filled container cools the reduction in volume of the liquid results in an induced vacuum within the headspace.
Once a container is filled at a hot temperature, it is typically sealed via capping and quickly inverted. That is the container is laid on its side or completely turned upside down. This action allows the hot liquid to soak the upper end of the container and also the inside surface of the cap. After approximately 30 seconds the container is reinverted to its normal standing position and conveyed towards a cooler. After approximately 2-3 minutes it can be safely assumed that the container and its contents have been safely sterilized, and the container may enter the cooler unit. A cooler is usually a simple cold water shower tunnel that cools the bottles more rapidly to reduce the amount of time that the container is under the extreme stress of the hot contents, allowing the containers to then be labelled.
An alternative to filling a container with a heated liquid is to fill the container with a liquid, sealing the container and then subsequently applying heat to the container to sterilize the contents. Pasteurization is a common method of sterilizing a container and its contents. While similar to hot-filling the two main steps happen in reverse. First the container is filled and sealed, and then it is heated. This occurs in a pasteurization tunnel that heats the outer surfaces of the container until a targeted core temperature has be reached. This core temperature is calculated to achieve a desired PU count, the PU count being a unit of measurement that the industry uses to represent the cleanliness of the contents of the container. The container is then allowed to cool. During this process the internal pressure builds up significantly, leading to a plastic expansion in the container that is irrecoverable to a degree. As the liquid cools and shrinks the container is unable to completely recover the original size and so is left larger than when filled. The result is a build-up of vacuum within the container headspace.
The alternative to the hot-fill process of filling containers is the common method of ‘aseptic’ filling. To avoid hot-filling a container and therefore dealing with the consequences of cooling and allowing a build-up of vacuum, the containers are filled cold. Aseptic systems must, however, fill the containers in a completely aseptic or sterile environment. There is no provision for sterilizing the internal surfaces of the container and cap, as there is with hot-filling methods. Sterilized rooms and equipment process completely clean both the inside and outside surfaces of the containers, prior to filling a cold liquid into the container that has itself been sterilized to a degree through suitable flash pasteurization or other methodology. While this method of filling has been successfully implemented, the cost and expertise required to run such a filling lines are prohibitive barriers that cannot be overcome by many organizations. These environments are extremely difficult to control as they span large connected enclosures in which no contamination can take place, limiting access and serviceability. Staff expertise is required to be much higher, and this is often beyond the means of many manufacturers around the world. The filling system also needs to be stopped constantly and cleaned to ensure product integrity, as there is no useful method to detect contamination while the filling line is in production.
Aseptic systems therefore generally require the container to be blow-molded within the sterile environment, filled within the sterile environment, and sealed within the sterile environment. Sophisticated procedures are required to check sterility, unlike the hot-fill environment where sterility is much easier to predict based off simple temperature monitoring.
In summary, hot-filling a beverage is a very cost effective and reliable method to ensure a beverage will maintain a robust shelf-life and provide a way to easily sterilize the internal volume of a container. The containers may be supplied ‘off-line’ from independent channels. The biggest downside, however, to this technique is the resulting vacuum pressure that occurs within the container after cooling. Managing this vacuum requires heavier and therefore more expensive bottles. This counters the low cost appeal of hot-filling the containers to achieve pasteurization. Inversely, aseptic filling lines can employ very lightweight and inexpensive containers but are much more expensive and difficult to operate as the making, filling and sealing of the containers requires significant control and integration. Both of these systems counter their opposite advantages with their opposite disadvantages, leaving neither technology clearly superior.
The present disclosure generally relates to the field of hot-filled beverage production and represents an improvement over previous disclosures by the same inventor disclosed in PCT/NZ2009/000079, US Pat Application 2017/0305581 and US Pat Application 2017/0008745, all incorporated herein in their entirety. More particularly this disclosure relates to providing a method of pasteurizing a container filled with a heated liquid and counteracting the vacuum pressures that build up within the container once it is filled and sealed and cooled. Another object of this disclosure is to at least provide the consumer or public with a useful choice.
In particular aspects of the present disclosure can provide for a ‘hybrid’ filling line that incorporates hot-fill methodology for filling and sterilizing the internal contents of a container, coupled to aseptic methodology to provide additional benefits of removing vacuum pressure and improving the quality of the beverage to typical aseptic quality.
An aim of some aspects of the present disclosure is to provide a method of upgrading or converting a typical legacy hot-fill line into the modern equivalent of an aseptic line at a much lower cost than investing in a typical aseptic line.
A further aim of some aspects of the present disclosure is to provide a hybrid filling line that is much cheaper to construct, and much easier to operate and manage, than prior art aseptic filling lines. The hybrid filling line may also provide for the blowing of containers to be either integrated within the filling line, as is typical in modern blow-fill operations (and mandatory in aseptic filling lines), or off-line from commercial bottle suppliers as is common with global hot-fill lines.
More particularly some aspects of the present disclosure is relate to providing a method of pasteurizing a container filled with a heated liquid and counteracting the vacuum pressures that builds up within the container once it is filled and sealed and cooled.
Some aspects of the present disclosure provide an additional method step of opening a sealed container under sterile conditions within an aseptic chamber to modify the internal pressure of the container after it has been cooled.
Some aspects of the present disclosure propose a composite technological method that utilizes aspects of both hot-fill and cold-fill technologies, to create a completely new and novel method of hot-filling beverage containers to achieve ultra-lightweight containers in a vastly simplified and cheaper operational environment to full aseptic systems.
In some aspects of this disclosure, rather than require an entire aseptic production line spanning the handling of empty containers, completely aseptic cooled beverage tanks, aseptic filling stations right through to an aseptic capper environment, the present disclosure proposes a “Hybrid Filling Line” comprising a singular, localized aseptic environment coupled to a standard hot-fill production line. The line functions much as a typical hot-fill production line but with the addition of an “Aseptic Line Converter Chamber” after the cooling tunnel. The purpose of the Aseptic Line Converter Chamber is to receive the containers from the cooler and clean their outer surfaces that are considered to be contaminated. Once sufficiently cleaned the containers are reopened, by either puncturing of the cap, removal of a plug, removal of a seal, opening of a valve or vent, or the mechanical removal of an extruded portion of the cap. This action takes place within the aseptic environment and once the seal is broken the internal vacuum force of the cooled container will draw gas from the aseptic environment into the immediately expanding headspace of the container. In one embodiment this gas comprising the atmosphere of the aseptic environment will be hepa-filtered Nitrogen, but could also be clean air, a cleaned or otherwise filtered gas, heated water vapor or a mixture of all three. The fluid introduced into the container may also be an aseptic or pasteurized fluid or liquid.
The Aseptic Line Converter Chamber environment ensures that no contaminants will enter the sterile conditions already present within the container. Because the internal surface of the container is already sterile and this is the only point of contact with a new environment it is much easier to control the sterility of this singular location than an entire facility.
The “aseptic environment” as described herein refers to the point at which the container is cleaned and located inside a more sterile environment. This process may start as early as in the cooling tunnel or entry tunnel to the Converter Chamber. The location at which the cap seal is broken however may be a highly controlled environment where all necessary surfaces, atmospheric particulates and incoming parts are partially or completely sanitized. Immediately prior to this location is the sterilization area where the filled, capped and cooled containers are sterilized or cleaned on their outer surfaces. Sterilization may include the entirety of the container's outer surfaces, or just the cap, or an otherwise localized portion of the container that will then be further isolated by a Perforator Device when unsealing and resealing occurs.
The sterilization area in one embodiment constitutes cleaning of the outer surfaces and or cap of the container with hydrogen-peroxide, or similar disinfectant. Not only will the containers in this area be sterilized but the sterilization tunnel can clean itself in the process vastly reducing the necessity for machine down time and costly cleaning.
An alternate embodiment can provide the outer surfaces of the container sterilized by a short pasteurization tunnel that rapidly heats the outside surface of the container. Pasteurizing in this way is significantly faster than traditional pasteurization as the core temperature of the container does not require temperature elevation and is of no concern as it is already sterilized. The purpose of using pasteurization in this method is to heat and disinfect the outer-most surfaces of the container, therefore being a rapid process. As the container has been heat-set to withstand initial hot-filling, the container material is already heat-set to withstand the second heat treatment of the present disclosure.
This embodiment of the present disclosure may employ sterilization by heated steam. An open or enclosed tunnel that is heated via steam will disinfect all the present surfaces whether on the container or a part of the tunnel and integrated machinery also, and therefore provides ready acknowledgement of non-contamination status by temperature gauge monitoring.
In another embodiment of the disclosure, the outer surface of the cap and or container and or Aseptic Line Converter Chamber environment may be cleaned by means of Electron Beam radiation or gaseous sterilizing agent such as hydrogen peroxide.
In another embodiment the outer surface of the cap and or container and or Aseptic Line Converter Chamber environment may be cleaned by means of Ultraviolet Radiation. Ultraviolet Radiation may be generated in an Ultraviolet laser that is outside the respective container. The radiation may be introduced into the Aseptic Line Converter Chamber environment by means of reflectors.
Aspects of this disclosure also relate to any one or more of the following:
A method for processing plastic containers comprising steps of any one or more of:
The sanitized environment of the perforator or hole creating means may be shared with the sanitized environment of the converter chamber.
The sanitized environment of the perforator or hole creating means may comprise an additional supply line providing an additional sanitized fluid.
The heated or heatable liquid may include a sweetener.
The heated or heatable liquid may include flavour ingredients.
The second headspace pressure may be between 0.0003 psi and 0.001 psi.
The additional sanitized fluid may include a sweetener.
The additional sanitized fluid may include flavour ingredients.
The additional sanitized fluid may include nitrogen.
The sanitized environment of the sealing means may be shared with the sanitized environment of the converter chamber.
The sanitized environment of the sealing means may comprise an additional supply line providing an additional sanitized or pressurized fluid.
The additional sanitized fluid may include a sweetener.
The additional sanitized fluid may include flavour ingredients.
The sealing means may provide a pressure seal against a surface of the sealed or capped container and the additional sanitized fluid pressurizes the container creating a headspace pressure between about 0.001 psi to 15 psi.
The sanitized environment of the converter chamber may be shared with both means for perforating or creating a hole in the container and for sealing the container.
Both means for perforating or creating a hole and sealing the container may be pressurized and sanitized within a sealed environment increasing the headspace pressure above 0.001 psi.
The method may include conveying containers between an entry port, devices for sanitizing, perforating or creating a hole in the sealed container and sealing the hole, and an exit port.
The means for perforating or opening the cap or seal may include piercing the cap by means of mechanical puncture force.
The sealing means may increase a second headspace pressure to a third headspace pressure.
The perforation means or device may be a rotary device.
The sealing means or device may be a rotary device.
The method may include blow-moulding the container.
The method may include initiating cleaning or sanitizing of the container before the entry port to the converter chamber.
The means for maintaining the sanitization of the container may comprise at least one of a steam tunnel, hydrogen peroxide spray, flash heat or pasteurization, or ultraviolet light or radiation.
The above method may comprise any one or more, or any combination of the stated steps. Further, any one or more of the steps may vary in order.
According to another aspect there is provided a system or apparatus for processing plastic containers comprising structure and control means configured to:
Once the container has been sufficiently cooled (12) and a vacuum (20) has typically built within the container from the reduction in volume of the liquid, the container is then conveyed or moved from the Hot Fill processing portion of the Filling Line into the Aseptic processing portion of the Filling Line. Upon entry to the aseptic processing portion of the line the container will have a first internal pressure within the headspace, typically a vacuum.
The container is moved through the Entry Port (108) and into an Aseptic Line Converter Chamber (104), typically comprising an aseptic environment, wherein the outside surfaces of the container may be cleaned (15) by Sterilization or Pasteurization Cleaning Means (104b) emitted from a Sterilization Device (104c) as the outer surface of the container has not been sterilized in the same manner as the inner surfaces have been by the heated product filled into the container. Embodiments may include singular or multiple methods of the cleaning and may provide but are not limited to; steam tunnels, hot water sprays, hydrogen peroxide disinfectants, heated sanitization, and ultraviolet radiation techniques. The Hot Fill processing portion of the Filling Line does not comprise a completely clean environment, so it is most likely contaminated. The container may of course be cleaned initially outside the Converter Chamber, but this is generally only completed once the container has been moved into the aseptic environment of the Converter Chamber. When verifiably cleaned the container engages with a Perforator Means or Device (105) and the cap or seal may be perforated or otherwise opened (8) to allow for a first vacuum modification. At this point the headspace vacuum may be neutralized, or at least adjusted to the ambient pressure within the Perforator Means or Device. This is generally the same ambient pressure as found within the Converter Chamber and provides a second headspace pressure within the opened container. The second headspace pressure is generally higher than the first headspace pressure.
Following the step of repressuring the headspace, the container engages with, or is conveyed or otherwise transported (107) to a Sealing Means or Device (106) and the container may then be resealed (17). Depending on the particular method utilized, resealing can take place by applying a new seal, inserting a plug or localized melting of the cap to close a small opening. The perforation and/or resealing of the container may typically be conducted within a rotary unit to account for rapid speed of production. Just prior to this point of resealing, the headspace may remain neutralized or even be pressurized positively to a third headspace pressure to account for further cooling or contraction of the beverage inside if the container has entered the aseptic environment at a slightly elevated temperature. For example, the container liquid contents may be at a temperature of approximately 35 degrees Celsius upon entry to the Aseptic Converter Chamber, and the liquid will continue to contract after exit from the Filling Line often to as low as 4 degrees Celsius. If a positive pressure can be induced during processing in the Aseptic Converter Chamber, then this anticipated or calculated future vacuum build will be prevented.
The container may exit the Aseptic Converter Chamber with a positive pressure that then reduces as the liquid contents cool further. Any additional positive pressure residual in the container will also help to improve container qualities such as top load resistance.
The container is now vacuum modified (18) upon exiting the Converter Chamber and conveyed through the Exit port (109) to be labeled (19), and then packaged for distribution. As there is no requirement for the container to withstand a vacuum force after leaving the Filling Line, the container may be significantly light-weighted and utilize multiple design variations. Importantly, a typical Filling Line may be modified without the need to change existing moulds or designs. Existing Hot Fill bottles may simply be produced with a lighter weight preform and processed on the Hybrid Filling Line, where the heated liquid introduced with legacy Hot Fill equipment first cools to create a vacuum within legacy Cooling Tunnel equipment. The introduction to the line of the Converter Chamber effectively removes the vacuum within the container in an aseptic environment, in order to keep the pasteurized contents from being compromised by introduction of non-aseptic elements.
Air flows downward within the Chamber and then out the ports as desired, and to achieve this a typical minimum positive pressure above ambient recommended is 2.5 Pascal (0.01 inches of water). It will be appreciated therefore that positive pressurization within the Converter Chamber may be of the order of approximately 0.000362594 psi. It is anticipated therefore that the pressurization within the Converter Chamber of the present disclosure is of the order of about 0.0003 to 0.001 psi only.
The converter Chamber comprises a Sterilizing means or device (104c), in this embodiment emitting steam as a sterilizing means (104b) in a steam tunnel, although the means of sterilization may be of many different methods, without departing from the scope of the disclosure. Following cleaning of the critical external surfaces of the sealed container, the Perforator means or device (105) will create an opening in the container and raise the first headspace pressure to a second headspace pressure that may be approximately 0.0003 to 0.001 psi above the ambient air pressure outside the Converter Chamber. Following this the container is moved to a Sealing means or device (106). The Sealing means may typically be of a rotary means, as optional steps may now be included such as pressurizing the container headspace prior to sealing. Typically, the container headspace pressure may be elevated to a third headspace pressure that is between 0.5 psi to 15 psi above ambient pressure within the Converter Chamber or Filling Line. Alternatively, the Perforator Means or Device may also be of rotary design and it also may include additional steps while creating a hole in the cap or seal, such as introducing an additional fluid into the container such as an aseptic gas or liquid, or combination thereof and may also pressurize the headspace well above ambient pressures.
In the event or embodiment whereby a forced pressurization of the headspace is created, then at least the Sealing means or device (106) will preferentially seal tightly against the cap or container in order to introduce an amount of fluid well above ambient pressure within the open pathway of the Aseptic Converter Chamber. However, in other embodiments a dose of liquid nitrogen gas may be introduced immediately prior to, or within the operation of the sealing means that would also create a pressurized container upon exit, and the sealing device would not necessarily have to create a sealed environment against the container while sealing the hole in the cap within the Converter Chamber.
In this embodiment the fluid level within the container lowers (4a) as the Perforator mechanism pierces the container cap due to the inflow of aseptic fluid or gas from the environment within the Perforator being at a higher pressure to that of the pressure within the container. Upon perforation therefore the first headspace pressure is replaced by a second, raised or higher headspace pressure through the additional fluid material, which could for example be Nitrogen. In this embodiment the Perforator mechanism then retracts leaving a hole (62) in the now perforated cap (8).
This embodiment has the added benefits of providing for the addition of aseptic or pasteurized ingredients to the product. This has a particular advantage over existing Hot-Fill systems. With the present disclosure, products may be prepared through the hot-filling of heated water, or heated water and sweetener such as sugar, to first to pasteurize the internal surfaces of the container, and then during the perforation or sealing procedures may have important additional ingredients added that have not been subjected to the same rigorous heat treatment. For example, aseptic quality flavourings or product ingredients and components may be added during the aseptic phase through a Primary fluid supply line (39) thus providing for aseptic quality products to be generated without utilizing existing aseptic filling lines. As a result, not only is the vacuum removed from a hot-fill container, allowing lower weight containers, but the quality of the product is improved to be competitive to aseptic product.
In this embodiment an aseptic fluid liquid (9) may be introduced into the container via the Perforator mechanism. However, this insertion of aseptic fluid liquid or gas may be introduced through another means or device immediately following the perforation of the cap by the Perforator mechanism. The Primary aseptic fluid supply line (39) will provide the aforementioned aseptic fluid to the system and onto into container. In this embodiment the fluid level within the container lowers (4a) as the Perforator mechanism pierces the container cap due to the inflow of aseptic gas from the environment immediately outside the container being at a higher pressure to that of the pressure within the container. In further embodiments the perforation of the cap may be designed so the Perforator mechanism ensures a hermetic seal with the cap as perforation occurs. In this embodiment the Perforator mechanism then retracts leaving a hole (62) in the now perforated cap (8) but with the headspace raised from a first pressure to a second pressure, and the fluid level raised within the headspace also as a result of the addition of aseptic fluid to the contents.
It is further envisaged that the Perforator means or device could provide a hermetically closed chamber to form a seal against the cap or neck finish of the container. This would provide a seal between the gaseous environment of the open Converter Chamber and the fluid environment of the Perforator means or device it required, particularly if a different fluid to the fluid contained in the Converter Chamber is to be injected.
It will be further appreciated that the Sealing means or device may include additional fluid supply lines also. For example, the Sealing means may be configured to provide a pressure seal against the cap or neck finish or other part of the container and so the Secondary fluid supply line (40) may be configured to provide an aseptic pressurizing gas. Alternatively, a supply line may be additionally configured to supply an aseptic fluid into the headspace such as a liquid nitrogen drop immediately prior to sealing. This would provide for an increase in pressure within the headspace from the second headspace pressure to a third headspace pressure a short time after the container is sealed and released from the Sealing means or device.
| Number | Date | Country | Kind |
|---|---|---|---|
| 732317 | May 2017 | NZ | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16618298 | Nov 2019 | US |
| Child | 17667802 | US |
