STERILIZATION APPARATUS FOR STERILIZING PARISONS OR CONTAINERS MADE OF A THERMOPLASTIC MATERIAL AND METHOD FOR EVACUATING PARISONS OR CONTAINERS FROM A STERILIZATION CHAMBER

Technical field

The present invention relates to a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material and a method for evacuating parisons or containers from a sterilization chamber.

The reference sector is the bottling of so-called“sensitive” food products, that is, products that are particularly sensitive to bacteriological contamination and oxidation, such as, for example, isotonic drinks, juices, nectars, soft drinks, tea, milk-based drinks, coffee-based drinks, etc., for which the prevention of possible microbiological contamination throughout all packaging stages is of fundamental importance.

Background art

Packaging lines using aseptic technology are already known in the prior art, wherein the various operations take place in a controlled contamination environment, so that the bottled products can be stored for a prolonged period of time and have chemical/physical and organoleptic stability even at room temperature.

Aside from differences in design, a“conventional” aseptic bottling line includes:

- forming the container starting with a parison made of a thermoplastic material;

- sterilization of the formed container;

- rinsing, filling and capping of the filled container, to be carried out inside a clean room.

A modern concept of an aseptic bottling line instead envisages:

- sterilization of the parison;

- “aseptic” forming of the container starting from the sterilized parison; - filling and capping of the filled container, to be carried out in a sterile environment.

In this context, reference is made to the sterilization of the container or the parison by chemical agents, for example hydrogen peroxide.

The focus here is on the management of discarded parisons or containers, for example in the event of jamming or line stops.

If the parisons or containers are evacuated upstream of the corresponding sterilizing unit, it is possible to discard them directly into the external environment.

If, however, there is a need to evacuate parisons or containers downstream of the corresponding chemical sterilization units, purging them of hydrogen peroxide becomes necessary.

One solution proposed in WO2017/102539 envisages accumulating the discarded items in a drawer located at the base of the sterilizing unit.

When the drawer is full, the line is then stopped, the hydrogen peroxide is extracted, the drawer is removed, emptied and repositioned beneath the sterilizing unit.

The main limitation of this solution lies in the expenditure of time and costs due to the stop of the line.

In this context, the technical task underpinning the present invention is to provide a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material and a method for evacuating parisons or containers from a sterilization chamber, which obviate the drawbacks of the prior art cited above.

Disclosure of the invention

In particular, the object of the present invention is to propose a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material and a method for evacuating parisons or containers from a sterilization chamber, making it possible to reduce or eliminate the down times compared to solutions of the prior art, thereby increasing the production efficiency of the line. The defined technical task and the specified aims are substantially achieved by a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material, comprising:

- a sterilization chamber configured to sterilize said parisons or containers with a chemical agent, said sterilization chamber having an outlet for the parisons or containers to be discarded;

- a storage chamber for discarded parisons or containers having an inlet and an outlet,

characterized in that it comprises:

- an extraction device for extracting the chemical agent from the storage chamber;

- first means for enabling selective communication between the outlet of said sterilization chamber and the inlet of said storage chamber;

- second means for enabling selective communication between the outlet of said storage chamber and an external environment.

Preferably, the apparatus also comprises a device for supplying air into said storage chamber.

In accordance with one embodiment, the first means comprise:

- a first wall that is movable between a closed configuration wherein it is interposed between the outlet of the sterilization chamber and the inlet of the storage chamber in such a manner as to stop the stream of parisons or containers to be discarded from the sterilization chamber to the storage chamber, and an open configuration, wherein it does not interfere with the outlet of the sterilization chamber and the inlet of the storage chamber in such a manner as to allow the stream of parisons or containers to be discarded from the sterilization chamber to the storage chamber;

- a first system of gaskets operatively active on the first wall in the closed configuration so as to realize a sealed-tight closure between the sterilization chamber and the storage chamber.

Preferably, the first system of gaskets comprises first inflatable gaskets and a first supply circuit for supplying a gaseous fluid to the first inflatable gaskets.

Preferably, the first means further comprise a first cylinder that is operatively active on the first wall to move it from the open configuration to the closed configuration and vice versa.

Preferably, the first cylinder is located inside the storage chamber.

In accordance with one embodiment, the second means comprise:

- a second wall that is movable between a closed configuration wherein it is interposed between the outlet of the storage chamber and the external environment in such a manner as to stop the stream of parisons or containers to be discarded from the storage chamber to the external environment, and an open configuration, wherein it does not interfere with the outlet of the storage chamber in such a manner as to allow the evacuation of the parisons or containers from the storage chamber;

- a second system of gaskets operatively active on the second wall in the closed configuration so as to realize a sealed-tight closure between the storage chamber and the external environment.

Preferably, the second system of gaskets comprises second inflatable gaskets and a second supply circuit for supplying a gaseous fluid to the second inflatable gaskets.

Preferably, the second means further comprise a second cylinder that is operatively active on the second wall to move it from the open configuration to the closed configuration and vice versa.

Preferably, the second cylinder is located in the external environment.

In accordance with one embodiment, the apparatus comprises a level sensor that is operatively active on the storage chamber to detect the level of the parisons or containers.

In accordance with an alternative embodiment, a weight sensor is present that is operatively active on the storage chamber to detect the weight of the parisons or containers present therein. The technical task mentioned and the aims specified are substantially achieved by a method for evacuating parisons or containers from a sterilization chamber wherein they are subjected to sterilization with a chemical agent, comprising the steps of:

- conveying the parisons or containers to be evacuated towards a storage chamber having an outlet leading to an external environment;

- closing the outlet of the storage chamber and isolating it with respect to an external environment;

- putting the sterilization chamber in communication with the storage chamber;

- upon the occurrence of a pre-established condition, interrupting the communication between the sterilization chamber and the storage chamber;

- isolating the sterilization chamber from the storage chamber;

- extracting the chemical agent from the storage chamber;

- opening the outlet of the storage chamber and discarding the parisons or containers into the external environment.

Preferably, the extraction of the chemical agent from the storage chamber takes place by supplying air into the storage chamber in such a manner as to flush it with air and, at the same time, suck the chemical agent.

In accordance with one embodiment, the step of putting the sterilization chamber in communication with the storage chamber occurs by sliding a first wall interposed between the chambers so that an outlet of the sterilization chamber leads into an inlet of the storage chamber. The step of interrupting the communication between the chambers is then achieved by inverting the sliding direction of the first wall so that it is interposed between the inlet of the storage chamber and the outlet of the sterilization chamber.

Preferably, the step of isolating the sterilization chamber from the storage chamber comprises a step of supplying a gaseous fluid to the first inflatable gaskets located in proximity to the first wall when the latter is interposed between the chambers.

In accordance with one embodiment, the step of closing the outlet of the storage chamber takes place by sliding a second wall so that it is interposed between the outlet of the storage chamber and the external environment. The step of opening the outlet of the storage chamber is therefore achieved by inverting the sliding direction of the second wall so that the outlet of the storage chamber leads into the external environment. Preferably, the step of isolating the storage chamber from the external environment comprises a step of supplying a gaseous fluid to the second inflatable gaskets located in proximity to the second wall when the latter is interposed between the outlet of the storage chamber and the external environment.

In accordance with one embodiment, the method further comprises a step of detecting the level of the parisons or containers in the storage chamber. When the level detected reaches or exceeds a pre-established level, the communication is interrupted between the sterilization chamber and the storage chamber.

In accordance with an alternative embodiment, the method comprises a step of detecting the weight of the parisons or containers in the storage chamber. When the weight detected reaches or exceeds a pre-established weight, the communication is interrupted between the sterilization chamber and the storage chamber.

In accordance with a further embodiment variant, the method comprises a step of detecting the number of the parisons or containers in the storage chamber. When the number detected reaches or exceeds a pre- established number, the communication is interrupted between the sterilization chamber and the storage chamber.

Brief description of drawings

Further characteristics and advantages of the present invention will more fully emerge from the indicative, and therefore non-limiting, description of a preferred but not exclusive embodiment of a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material and a method for evacuating parisons or containers from a sterilization chamber, as illustrated in the accompanying drawings, in which:

- figures 1 and 2 schematically show a sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material, in accordance with the present invention, in two different operating steps;

- figure 3 schematically shows a part of the sterilization apparatus of figures 1 -2, in a further operating step.

Detailed description of preferred embodiments of the invention

With reference to the figures, the number 1 indicates a sterilization apparatus for sterilizing parisons or containers 100 made of a thermoplastic material. In the following, reference will be made to parisons 100 for the sake of brevity, it being understood that throughout the description, it can also refer to formed containers 100.

The sterilization apparatus comprises:

- a sterilization chamber 2 configured to sterilize the parisons 100 with a chemical agent, such as hydrogen peroxide;

- a storage chamber 3 for discarded parisons 100.

Advantageously, an extraction device 4 for extracting the chemical agent from the storage chamber 3 is envisaged. For example, this extraction device 4 is a suction device of known type.

A device for supplying air 14, for example compressed air, is also envisaged inside the storage chamber 3.

The sterilization chamber 2 and the storage chamber 3 can selectively communicate.

In particular, the sterilization apparatus 1 comprises first means 5 for enabling selective communication between an outlet 2a of the sterilization chamber 2 and an inlet 3a of the storage chamber 3.

In accordance with an embodiment described and illustrated herein, the first means 5 comprise a first wall 15 and a first system of gaskets 25 associated with the first wall 15. In particular, the first wall 15 is movable between a closed configuration wherein it is interposed between the outlet 2a of the sterilization chamber 2 and the inlet 3a of the storage chamber 3 in such a manner as to stop the stream of parisons 100 to be discarded from the sterilization chamber 2 to the storage chamber 3 (see figure 1 ), and an open configuration, wherein it does not interfere with the outlet 2a of the sterilization chamber 2 and the inlet 3a of the storage chamber 3 in such a manner as to allow the stream of parisons 100 to be discarded from the sterilization chamber 2 to the storage chamber 3 (see figure 2).

Preferably, the movement of the first wall 15 from the closed configuration to the open configuration (and vice versa) takes place by means of a first cylinder 55.

Preferably, the first cylinder 55 is located inside the storage chamber 3 or in an adjoining area that is in fluid communication with the storage chamber 3.

The first system of gaskets 25 is operatively active on the first wall 15 in the closed configuration so as to realize a sealed-tight closure or separation between the sterilization chamber 2 and the storage chamber 3.

Preferably, the first system of gaskets 25 comprises:

- first inflatable gaskets 35;

- a first supply circuit 45 for supplying a gaseous fluid (e.g. air) to the first inflatable gaskets 35.

The storage chamber 3 can also selectively communicate with an external environment 200.

In particular, the sterilization apparatus 1 comprises second means 6 for enabling selective communication between an outlet 3b of the storage chamber 3 and the external environment 200.

In accordance with an embodiment described and illustrated herein, the second means 6 comprise a second wall 16 and a second system of gaskets 26 associated with the second wall 16. In particular, the second wall 16 is movable between a closed configuration wherein it is interposed between the outlet 3b of the storage chamber 3 and the external environment 200 in such a manner as to stop the stream of parisons 100 to be discarded from the storage chamber 3 to the external environment 200 (see figure 2), and an open configuration, wherein it does not interfere with the outlet 3b of the storage chamber 3 in such a manner as to allow the evacuation of the parisons 100 from the storage chamber 3 (see figure 1 ).

Preferably, the movement of the second wall 16 from the closed configuration to the open configuration (and vice versa) takes place by means of a second cylinder 56.

Preferably, the second cylinder 56 is located in the external environment 200.

Preferably, the actuation of the second cylinder 56 is separate and independent from the actuation of the first cylinder 55.

The second system of gaskets 26 is operatively active on the second wall 16 in the closed configuration so as to realize a sealed-tight closure or separation between the storage chamber 3 and the external environment 200.

Preferably, the second system of gaskets 26 comprises:

- second inflatable gaskets 36;

- a second supply circuit 46 for supplying a gaseous fluid (e.g. air) to the second inflatable gaskets 36.

Figure 3 shows a possible embodiment of the first and second supply circuits 45, 46.

In particular, the two supply circuits 45, 46 originate from a common pressure reducer 47, for example calibrated at a pressure of 1 bar.

The first supply circuit 45 comprises a first valve 451 , a second valve 452 connected to a discharge outlet and a pressure switch 453 configured to monitor the operating pressure.

When the first inflatable gaskets 35 must be inflated, the first valve 451 of the first supply circuit 45 is open, while the second valve 452 is closed. When the first inflatable gaskets 35 must be deflated, the first valve 451 is closed while the second valve 452 is opened so that the gaseous fluid present in the gaskets 35 discharges.

The second supply circuit 46 comprises a first valve 461 , a second valve 462 connected to a discharge outlet and a pressure switch 463 configured to monitor the operating pressure.

When the second inflatable gaskets 36 must be inflated, the first valve 461 of the second supply circuit 46 is open, while the second valve 462 is closed.

When the second inflatable gaskets 36 must be deflated, the first valve 461 is closed while the second valve 462 is opened so that the gaseous fluid present in the gaskets 36 discharges.

In accordance with one embodiment, the sterilization apparatus 1 further comprises a level sensor 7 that is operatively active on the storage chamber 3 to detect the level of the parisons 3.

As an alternative to the level sensor, a weight sensor is envisaged (e.g. load cell) that is operatively active on the storage chamber 3 to detect the weight of the parisons 100 present therein.

As an alternative, the storage chamber 3 can be equipped with means configured to detect the number of parisons 100 that pass from the sterilization chamber 2 to the storage chamber 3.

The sterilization apparatus 1 proposed here is, for example, used to sterilize the parisons 100 prior to their forming. In this case, the apparatus 1 is located upstream of an apparatus for aseptic forming.

Alternatively, the sterilization apparatus 1 can be used to sterilize formed containers. In this case, the apparatus 1 is located downstream of an aseptic forming apparatus and upstream of a filling apparatus of the containers in a sterile environment.

The method for evacuating parisons or containers made of a thermoplastic material from a sterilization chamber wherein they are subjected to sterilization with a chemical agent is described below.

To aid understanding, refer to figures 1 -2.

Consider figure 2 first, wherein the first wall 15 is in the open configuration, thus the parisons 100 can pass from the sterilization chamber 2 to the storage chamber 3.

The second wall 16 is instead in the closed configuration, thus the parisons 100 that have reached the storage chamber 3 remain in the latter. In particular, the parisons 100 are stored one above the other above the second wall 16.

The second inflatable gaskets 36 form a seal because they are inflated, that is, filled with gaseous fluid (e.g. air).

The stream of parisons 100 (to be discarded) from the sterilization chamber 2 to the storage chamber 3 continues until the occurrence of a pre-established condition, after the communication between the sterilization chamber 2 and the accumulator chamber 3 is interrupted.

In accordance with one embodiment, the level of the parisons 100 in the storage chamber 3 is detected by the level sensor 7.

When the parisons 100 reach or exceed a pre-established level in the storage chamber 3, the stream from the sterilization chamber 2 to the storage chamber 3 is interrupted by putting the first wall 15 in the closed configuration. In this case, the term "pre-established condition" is intended as reaching or exceeding the pre-established level.

In accordance with an embodiment variant, a load cell is present instead of the level sensor 7, which detects the weight of the parisons 100 in the storage chamber 3.

When the weight detected equals or exceeds a pre-established weight, the stream from the sterilization chamber 2 to the storage chamber 3 is interrupted by putting the first wall 15 in the closed configuration. In this case, the term "pre-established condition" is intended as reaching or exceeding the pre-established weight.

An embodiment variant envisages interrupting the stream from the sterilization chamber 2 to the storage chamber 3 when a pre-established number of parisons 100 is reached or exceeded in the storage chamber 3. In this case, the term "pre-established condition" is intended as reaching or exceeding the pre-established number.

In all these three embodiment variants, the interruption of the stream of parisons 100 (to be discarded) from the sterilization chamber 2 to the storage chamber 3 is carried out by putting the first wall 15 in the closed configuration.

The sterilization chamber 2 is also isolated from the storage chamber 3 by the introduction of the gaseous fluid (e.g. air) in the first inflatable gaskets 35 when the first wall 15 is in the closed configuration.

The storage chamber 3 is then cleaned thanks to the introduction of compressed air by the device 14 and, at the same time, thanks to the extraction of the chemical agent by the extraction device 4. The devices 4, 14 are activated for a predefined period of time which is sufficient to ensure the cleaning of the storage chamber 3.

At this point, the parisons 100 can be discarded into the external environment 200 by opening the outlet 3b of the storage chamber 3.

In particular, the gaseous fluid is extracted from the second inflatable gaskets 36 and the second wall 16 passes into the open configuration.

The parisons 100 are preferably discarded onto a carriage 300 placed below the outlet 3b of the storage chamber 3.

It is also possible to arrange a further level sensor (not shown) that is operatively active near the outlet 2a of the sterilization chamber 2, in addition to the level sensor 7 that monitors the level in the storage chamber 3. From the above description, the characteristics of the sterilization apparatus for sterilizing parisons or containers made of a thermoplastic material and the method for evacuating parisons or containers from a sterilization chamber, are clear, as are the advantages.

In particular, by providing a device for the extraction of the chemical agent from the storage chamber of the parisons (or containers) to be discarded and providing selective communication of this chamber with both the sterilization chamber and with the external environment, it is possible to evacuate the parisons (or containers) continuously during production.

There is thus no need to stop the line to evacuate the parisons or containers to be discarded.

Furthermore, the embodiment employing two movable walls and relative gasket systems is structurally simple, compact and reliable.