Filling machine with hygienic chamber

A filling machine configured to form, fill, and seal individual packages is provided. The filling machine comprises a disinfection station and a hygienic chamber downstream the disinfection station, which hygienic chamber is configured to reduce the risk for re-contamination of the packages after passing the disinfection station. An inner hygienic zone is formed inside the hygienic chamber, whereby a positive air flow is established from the inner hygienic zone to the hygienic chamber outside the inner hygienic zone.

TECHNICAL FIELD

The invention relates to a filling machine, in particular to a filling machine being configured to form, fill, and seal individual packages. The present invention also relates to a method for such filling machine.

BACKGROUND ART

Within the food industry, beverages and other products are often packed in paper or paperboard based packages. Packages intended for liquid food are often produced from a packaging laminate comprising a core layer of paper or paperboard and an outer, liquid-tight layer of thermoplastic material on at least that side of the core layer which will form the inside of the packages.

One kind of frequently occurring packages are produced from so-called ready-to-fill packages. Such ready-to-fill package is provided as a sleeve of packaging laminate like the one described above, being sealed at its bottom end prior to filling. The upper end may either be formed by sealing and forming the upper end of the sleeve, or by adding an upper part in the form of e.g. a plastic top; the upper end/part may be provided with an opening/closing means, such as a screw cap.

The open-ended packaging material sleeve is received at an infeed station of the filling machine, whereafter the bottom end is sealed; the semi-finished package has at this point a shape being ready to fill, however further processes are required to provide a hygienic packaging. At a downstream station, the open sleeves are sterilized or disinfected at least on the inside in order to extend the shelf-life of the product to be stored in the packages. Depending on the desired length of shelf-life, and depending on whether the packages are to be distributed and stored in a refrigerated environment or at room temperature, different levels of sterilization/disinfection may be obtained.

After sterilization/disinfection of the packages, they are further transported to a filling zone for product filling, a sealing zone for sealing of the open end, and typically also to a final forming zone for final forming of the package.

Transportation of the packages is achieved by a sequence of carriers being guided along a conveying path. The conveying path is preferably continuous through the filling machine, such that a stream of packages is moving through the filling machine and all required stations.

After disinfection/sterilization of the ready-to-fill packages it is important to maintain hygienic conditions as the packages are filled and sealed by the associated stations. Hence, these filling machine stations are installed in a hygienic zone in order to ensure minimum re-contamination of the already sterilized or disinfected packages.

In order to allow for proper filling, sealing, and transport of the packages within the hygienic zone, complex mechanics and geometries are required. The constructional parts used in the filling and sealing stations in the hygienic zone (as well as associated stations for forming, etc.) are subject to service and maintenance; these stations must be accessed every now and then for high performance operation of the filling machine.

However, each time the hygienic zone is accessed there is a risk that unwanted particles and micro-organisms enter from outside, thereby increasing the risk of re-contamination of the packages.

As the speed and complexity of the filling machines are increasing in order to accommodate customer's needs, there is also increased need for service and maintenance, thereby requiring machine downtime and access to the hygienic zone.

Hence, there is a need for a filling machine reducing the risk for re-contamination of packages because of service and maintenance of components arranged within the hygienic zone.

SUMMARY

It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a hygienic zone of a filling machine which reduces the risk for re-contamination of packages being present within the hygienic zone.

To solve these objects a filling machine is provided. The filling machine is configured to form, fill, and seal individual packages whereby the filling machine comprises a disinfection station and a hygienic chamber downstream the disinfection station, which hygienic chamber is configured to reduce the risk for re-contamination of the packages after passing the disinfection station. An inner hygienic zone is provided inside said hygienic chamber, whereby a positive air flow is established from the inner hygienic zone to the hygienic chamber outside the inner hygienic zone.

The inner hygienic zone may be formed by a plurality of separation plates of which at least one is moveable such that the inner hygienic zone can be opened and accessed.

The separation plates may extend from a ceiling towards the floor, leaving a slit between the bottom end of the respective separation plates and the floor.

The separation plates may be distributed in an U-shape such that at least two longitudinal separation plates extend in the machine direction, and at least one transversal separation plate may extend perpendicular to the machine direction, connecting the two longitudinal separation plates.

At least one of the separation plates may be moveable in order to increase or reduce the size of the inner hygienic zone.

The inner hygienic zone may be open towards the upstream disinfection station.

The inner hygienic zone may be provided with a filtered air unit. The filtered air unit may be arranged at the ceiling of the inner hygienic zone. The filtered air unit is a high efficiency particulate absorbing (HEPA) filter unit.

The positive air flow from the inner hygienic zone may be controlled by controlling the air flow of the filtered air unit.

The hygienic chamber may comprise an air evacuation unit arranged outside the inner hygienic zone. The air evacuation unit may be arranged at the ceiling of the hygienic chamber.

According to a second aspect, a method for a filling machine configured to form, fill, and seal individual packages is provided. The filling machine comprises a disinfection station and a hygienic chamber downstream the disinfection station, which hygienic chamber is configured to reduce the risk for re-contamination of the packages after passing the disinfection station. The method comprises the steps of providing an inner hygienic zone inside said hygienic chamber, and establishing a positive air flow from the inner hygienic zone to the hygienic chamber outside the inner hygienic zone.

Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.

DETAILED DESCRIPTION

With reference toFIG.1a filling machine10is shown schematically. The filling machine10, being configured to form, fill, and seal packages4, has an infeed station12in which blanks2of packaging material are received. The blanks2are typically produced as sleeves of a carton-based packaging material, as is well known in the art and already described briefly in the background section. The infeed station12is arranged upstream a bottom sealing station14, in which the blanks2are erected to a sleeve-shape, and in which station the bottom end of each blank is sealed to form a semi-finished package having one bottom end being closed, while the upper end is still open.

The semi-finished packages are transported to a disinfection station16, in which the amount of living micro-organisms is reduced. As explained in the background section, the level of disinfection may vary depending on user objectives. Disinfection of the packaging material may e.g. be accomplished by means of treatment with hydrogen peroxide, UV light, electron beam radiation, etc. At the end of the filling machine, an outfeed station18is arranged which is configured to discharge the finished packages4from the filling machine10to downstream equipment, storage, and/or transport.

A hygienic chamber20is provided between the disinfection station16and the outfeed station18. The hygienic chamber20comprises further stations of the filling machine; immediately downstream the disinfection station16a filling station22is arranged. Here, the ready-to-fill packages are filled with their desired content. After filling, the packages may be transported to a pre-folding station24in which the upper part of the open-ended package is formed to a desired shape. After pre-forming the packages are transported to a heating station26in which heat-sealable material of the packaging material is heated to an elevated temperature. The elevated temperature of the upper end of the packages facilitates sealing of the upper end when the packages enter the sealing station28arranged immediately after the heating station26.

Once sealed, the packages4do no longer require hygienic conditions whereby they exit the hygienic chamber20, and are discharged (as previously explained) by means of the outfeed station18.

It should be realized that the hygienic chamber20may comprise more or less filling machine stations, as long as it provides hygienic conditions to the ready-to-fill packages at least for some time after disinfection or sterilization of the ready-to-fill packages. It should also be mentioned that the filling machine10may not be constructed exactly as described with reference toFIG.1, but the filling machine10may also be configured to produce other type of packages, such as plastic top packages, etc.

InFIG.2an embodiment of a filling machine10is shown in further details, especially with regards to the hygienic chamber20. The filling machine stations, i.e. the infeed station12, the bottom end sealing station14, the hygienic station16, etc. are all indicated by dashed lines and given the same reference numerals as ofFIG.1. Also inFIG.2a transport path50is indicated, representing the conveyors and carriers used to transport the packages, in the direction indicated by arrow A, from the infeed station12to the outfeed station18.

The hygienic chamber20covers the entire space of the filling machine10from the disinfection station16to a downstream position where the packages are entirely sealed; for the shown filling machine10, this occurs after the top end sealing station28.

Inside the hygienic chamber20an inner hygienic zone30is defined. The inner hygienic zone30forms a space inside the hygienic chamber20, extending essentially across the entire length of the hygienic chamber20but only across parts of the width of the hygienic chamber20. As is shown inFIG.2, the inner hygienic zone30is formed by at least three walls32,34,36. A first wall32extends on one side of the transport path50from the outfeed end of the disinfection station16, in a machine direction, across the filling station22, the pre-forming station24, the pre-heating station26, and the top end sealing station28. A second wall36is arranged in parallel with the first wall32. The second wall36extends on the opposite side of the transport path50from the outfeed end of the disinfection station16, in a machine direction, across the filling station22, the pre-forming station24, the pre-heating station26, and the top end sealing station28.

A third wall34is arranged in a direction perpendicular to the direction of the first and second walls32,36, at the downstream end of the inner hygienic zone30. Hence, the third wall34connects the first and second walls32,36and forms an exit wall for the packages4leaving the inner hygienic zone30. From this, it should be evident that the third wall34is provided with some kind of opening for allowing packages to exit the inner hygienic zone30.

The walls32,34,36, which can be of a total number greater than three, thereby delimits a U-shaped space protecting the disinfected packages from the outside environment, as will be further explained below. More specifically, the walls32,34,36of the inner hygienic zone30forms a barrier when the filling machine10is accessed for service and maintenance.

The filling machine10has a housing60, which forms an outer shell of the filling machine. One or more doors62,64are provided at the housing60in order to allow staff to enter the filling machine interior in order to investigate equipment and perform various tasks to the filling machine10. Typically, doors62,64may be arranged at the infeed station12as well as at the top end sealing station28. Especially at the top end sealing station28, which is arranged inside the hygienic chamber20, it is desired to maintain as hygienic conditions as possible. Due to the provision of the inner hygienic zone20, which is delimited from the rest of the hygienic chamber20, staff can enter the hygienic chamber20via the door64without exposing the packages4present in the inner hygienic zone30to an increased risk of re-contamination.

Preferably, as much mechanical parts as possible are arranged outside the inner hygienic zone30in order to allow service and maintenance without the need for entering the inner hygienic zone30.

The walls32,34,36of the inner hygienic zone30are preferably moveable in relation to the filling machine housing60, such that the size of the inner hygienic zone30can be adjusted. The first and second walls32,36may for this purpose be moveable in the direction transverse to the machine direction, while the third wall34may be extendable/retractable in order to be able to form a closure between the first and second walls32,36.

Also, at least one of the walls32,34,36of the inner hygienic zone30is preferably openable, e.g. by a sliding door mechanism, such that also the inner hygienic zone30can be accessed for service and maintenance. Such opening may preferably be provided with a sensor, providing a signal when the inner hygienic chamber has been opened. Hence, it is possible to monitor if and when the inner hygienic zone30has been accessed.

As can be seen inFIG.2the inner hygienic zone30may be provided with a partition wall38; the partition wall38is arranged between the filling station22and the pre-heating station24. The purpose of the partition wall38is to provide a thermal barrier for the filling station22, in order to prevent excessive heat from the pre-heating station24to heat up the filling station22. The partition wall38(which is provided with some kind of opening in order to let packages to pass through), is advantageous in particular when a chilled product is to be filled.

Now turning toFIG.3a schematic representation of the hygienic chamber20is shown in cross-section. The inner hygienic zone30extends laterally between the two walls32,36. Inside the inner hygienic zone30the transport path50is arranged, here only schematically represented by simple geometries. The separation walls32,36extends from the ceiling and downwards, leaving a slit42between their bottom end and the floor. This slit42is provided in order to ensure a positive air flow from the inner hygienic zone30to the outside hygienic chamber20.

The ceiling of the inner hygienic zone30is provided with air filter units38, preferably in the form of HEPA filters. The HEPA filters38will ensure a positive flow of clean and filtered air downwards. The air flow will be directed towards the floor, as indicated by the arrows, and forced out from the inner hygienic zone30through the slits42. The air will eventually be evacuated by means of air evacuation units40arranged at the ceiling of the hygienic chamber20, but outside the inner hygienic zone30.

Now turning toFIG.4, a method100for a filling machine10is schematically illustrated. As explained earlier, the filling machine10is configured to form, fill, and seal individual packages4, whereby the filling machine comprises a disinfection station16and a hygienic chamber20downstream the disinfection station16, which hygienic chamber20is configured to reduce the risk for re-contamination of the packages after passing the disinfection station16. The method100comprises a first step102of providing an inner hygienic zone30inside the hygienic chamber20, and a second step104of establishing a positive air flow from the inner hygienic zone30to the hygienic chamber20outside the inner hygienic zone30.

Now turning toFIGS.5a-cthe filling machine10is illustrated during a simulation in which a gas, representing a potential contamination, is released from the entire bottom surface of the disinfection station16and of the hygienic chamber20. As can be seen inFIG.5a, which is a cross-sectional side view of the filling machine10, the concentration of the contamination gas is substantially less at the inner hygienic zone30; this is even more clear fromFIG.5b, which is a cross-sectional top view of the filling machine10. From the cross-sectional view ofFIG.5c(the same view as ofFIG.3), it can be seen that the inner hygienic zone30is substantially free from any contamination gas.

InFIGS.6a-cthe pressure distribution is shown during operation of the filling machine10. These views, being the same cross-sections as forFIGS.5a-c, show that there is a small, but well defined, pressure gradient created at the areas where the inner hygienic zone30opens to the outside hygienic chamber20.

FIG.7is another cross-sectional view of the filling station22, illustrating the air flow through the inner hygienic zone30. The HEPA filters38provide for a downward uniform clean air flow.

A cold environment is established inside the hygienic zone30at the filling area, thereby minimizing micro-biological growth inside the filling station22. This cold environment is ensured due to the partition wall38shown inFIG.2.

As described above, the presented solution assists in preventing recontamination of the hygienic chamber20both during production mode and during stops in production.

A robust protection of the critical inner hygienic zone30is obtained as a small but defined pressure gradient is established between the inner hygienic zone30and the outer hygienic chamber20. Furthermore it prevents contamination from the cassette/conveyor/transport path50of the critical areas.

During stops in production when the hygienic chamber20needs to be accessed, the risk of causing contamination when opening of the large doors62,64to the hygienic chamber20is reduced as the small divider walls32,34,36only open the relatively small area when access is required. Additional benefits with the proposed concept also include a simplified supply system design as also the evacuation system can be placed above the hygienic chamber ceiling and as the divider walls32,34,36prevent splashing of the evacuation system design. Even further, a more efficient utilization of the HEPA filter is accomplished, thereby reducing the demands in terms of flow capacity.

From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.