Sterile blow-molding system and method for thermoplastic parison

Abstract

The present invention provides a sterile blow-molding system for a thermoplastic parison tube (5) to be formed, comprising an extrusion head (4) for extruding the tube (5), a blowing opening (3) at the center of the extrusion orifice, a filling assembly (2) with one or more nozzles (2.1 ) movable through the opening (3), and a sterile chamber (1) containing overpressurized air positioned above the extrusion head (4) and communicating with the opening (3). The nozzles (2.1) are positionable entirely in the chamber (1) when inactive. The blowing of the tube (5) is carried out by means of the air contained in the chamber (1). The system further comprises a vent channel (6) for aspirating the air from the chamber (1) and an air flow regulating valve (6.1).

Description

[0001] STERILE BLOW-MOLDING SYSTEM AND METHOD FOR THERMOPLASTIC PARISON

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of blow-molding systems for forming containers from thermoplastic material, and more particularly to a sterile blowmolding system and method for a thermoplastic parison using an overpressure chamber.

[0004] STATE OF THE ART

[0005] Blow-molding and forming systems for containers made of thermoplastic material are widely used in the pharmaceutical and food industries for the production of vials and other sterile containers. These systems typically involve the extrusion of a tube of thermoplastic material, called a parison, which is subsequently blown inside a mold to assume the desired shape of the final container. In the case of applications requiring sterile conditions, such as the packaging of drugs, it is essential to maintain a controlled and contaminant-free environment throughout the entire forming process.

[0006] In conventional sterile blow-molding systems, the area around the filling nozzles is usually very restricted, with a limited passage for the blowing gas. This configuration makes it difficult to monitor the sterility conditions inside the parison during the process. Furthermore, the rapid retraction of the nozzles from the dispensing position can cause under-pressures and collapse of the parison, compromising the quality and integrity of the final product.

[0007] A further critical issue with existing systems is the difficulty of inserting external components or inserts inside the parison while maintaining sterile conditions. This limits the possibilities for customization and functionalization of the produced containers.

[0008] It has been understood that there is a need for a sterile blow-molding system for a thermoplastic parison that overcomes one or more of these problems.

[0009] OBJECT OF THE INVENTION

[0010] It is therefore object of the invention is a sterile blow-molding system for a thermoplastic parison tube to be formed, comprising an extrusion head for a thermoplastic parison to extrude the tube to be formed. The extrusion head has an annular extrusion hole for the extrusion of the tube, a filling opening at the center ofthe extrusion orifice, a filling assembly comprising one or more nozzles configured to move through the filling opening from a first insertion position, in which it dispenses liquid inside the tube, to a second inactive position, in which it is completely outside the tube.

[0011] By orifice is meant any shape, whether circular, elliptical, or otherwise elongated, so as to extrude a parison tube suitable for forming one or more containers.

[0012] The nozzle assembly is smaller than the filling opening, so as to avoid contact with the extrusion head and consequently the parison tube and its damage. The system comprises a sterile chamber containing air at an overpressure with respect to the external environment, positioned above the extrusion head and communicating with the filling opening, so that the one or more nozzles is positionable entirely inside the chamber when in the second position with respect to the filling opening.

[0013] Advantageously, the chamber is sized so that the nozzle assembly, in its inactive position, can be positioned entirely within it. Thanks to this configuration, the filling nozzles are kept in a sterile and protected environment even when they are not operational, for example during the initial phases of parison extrusion or between one filling cycle and another. This prevents contamination of the nozzles themselves, a problem not solved by known solutions, and ensures a higher level of sterility for the entire process.

[0014] The blowing of the tube is carried out by means of the air contained in the chamber. This system allows sterile conditions to be maintained during the blowing process, avoiding product contamination.

[0015] The internal volume of the chamber is fixed, acting as a compensation buffer for pressure variations.

[0016] Still according to the invention, the chamber has an inlet hole for air coming from outside the chamber, provided with a filter for the purification of the air coming from outside the chamber. This allows the incoming air to be purified, maintaining sterile conditions inside the chamber, as well as overpressure conditions in the chamber that allow for greater control of the stability of the forming parison and of the entry of particles from the outside.According to a further aspect of the invention, the chamber comprises a vent channel from which the air contained in the chamber exits. This allows the pressure inside the chamber to be regulated.

[0017] In another embodiment, the vent channel comprises a non-return valve to avoid contamination with the external air. Alternatively, or in addition, a filter could be present. This prevents the entry of non-sterile air into the chamber.

[0018] According to another aspect, at least one of the vent channel and the inlet hole for air coming from outside the chamber has a regulating valve for the flow of air contained in the chamber exiting through the vent channel. This allows for precise control of the airflow and pressure in the chamber.

[0019] In a further embodiment of the invention, the chamber is in communication with a pressurized compartment inside which one or more inserts to be inserted inside the tube to be incorporated therein during forming are arranged. This allows any additional components necessary in the final product to be transferred from the compartment to the chamber under sterile conditions.

[0020] According to another aspect, the system comprises a probe for monitoring the presence of any particles or microbes. This allows the sterility conditions within the system to be constantly checked.

[0021] In one embodiment, the probe is positioned inside the chamber or inside the parison tube itself. This allows for effective monitoring at critical points in the system.

[0022] According to a further aspect of the invention, the chamber comprises a projecting plate, positioned inside the filling opening, parallel to the edges of the filling opening and having an extension corresponding to the height of the extrusion head. This configuration improves the control of the sterile air flow.

[0023] Also an object of the invention is a method for sterile blow-molding of a thermoplastic parison tube to be formed using the sterile blow-molding system described above, comprising the following steps: providing a predetermined operating pressure; providing at least one differential pressure sensor inside the chamber; calculating the amount of air to be inserted into the chamber to maintain the operating pressure on the basis of the values detected by the at least one sensor; inserting the calculated amount of air into the chamber. This method allows optimal pressure conditions to be maintained inside the sterile chamber. The operating pressure is advantageously set as a target value at the beginning of theoperating cycle. The system aims to keep this value constant to ensure stable and sterile conditions.

[0024] According to a final aspect of the invention, the method provides for a step of closing a mold around the tube immediately preceding a process interruption step. This allows the process to be interrupted in a controlled manner, maintaining sterile conditions.

[0025] BRIEF DESCRIPTION OF THE FIGURES

[0026] Aspects of the invention will be described, by way of example, with reference to the following drawings, in which:

[0027] FIG. 1 illustrates a schematic view of the sterile blow-molding system for thermoplastic parison tubes.

[0028] FIG. 2 shows a side view of the sterile blow-molding and forming system. FIG. 3 presents a detailed cross-section of the filling opening area.

[0029] FIG. 4 shows a side view of the complete system with chamber, filling assembly, and mold.

[0030] FIG. 5 provides a sectional view of the system, highlighting the internal components of the pressurized chamber.

[0031] Common reference numbers are used throughout the figures to indicate similar features.

[0032] DETAILED DESCRIPTION

[0033] The present sterile blow-molding system is designed for forming thermoplastic parison tubes in a controlled and aseptic environment. This innovative system offers several advantages over conventional methods of blow-molding and forming thermoplastic containers.

[0034] A key aspect of the system is the use of a sterile chamber containing air at an overpressure with respect to the external environment. This feature allows a controlled and contaminant-free environment to be maintained during the entire forming and filling process.

[0035] The presence of pressurized air inside the sterile chamber offers multiple benefits. Firstly, it creates a physical barrier that prevents the entry of particles or microorganisms from the outside, thus ensuring the sterility of the process. In addition, the positive pressure facilitates air flow in a controlled direction, further contributing to the maintenance of aseptic conditions.This approach represents a significant improvement over conventional systems, where the control of the sterile environment can be more complex and less reliable. The sterile blow-molding system described here offers a higher level of protection against contamination, making it particularly suitable for applications requiring high standards of hygiene and sterility, such as in the pharmaceutical or food sector.

[0036] The sterile blow-molding system comprises a sterile chamber 1 positioned above the extrusion head 4. The sterile chamber 1 is configured to contain air at an overpressure with respect to the external environment and communicates with the blowing opening 3 of the extrusion head 4.

[0037] The walls 1.2 of the sterile chamber 1.1 can be hermetic, but the overpressure of the chamber makes this superfluous; in any case, they are resistant to internal pressure, allowing for steam sterilization of the entire chamber environment 1, in a possible configuration of the system.

[0038] During the sterilization phase - for example by steam or other sterilization methods such as hydrogen peroxide, ETO, dry heat sterilization, etc. - a temporary plug can be used to seal the sterile chamber 1 and the blowing opening 3, to be able to pressurize the chamber 1 (even to 2.3 bar in the case of saturated steam sterilization). In particular, the filling opening can be sealed both from above, just above the extrusion head, and from below, under the extrusion head.

[0039] The sterile chamber 1 is provided with an inlet hole 1.1 for air coming from the outside. The inlet hole 1.1 may comprise a filter for purifying the air entering the sterile chamber 1. This filter ensures that the air introduced into the sterile chamber 1 is free of contaminants.

[0040] The configuration of the sterile chamber 1 above the extrusion head 4 and in communication with the blowing opening 3 allows the blowing of the parison tube 5 using the overpressurized air contained in the sterile chamber 1. This arrangement allows sterile conditions to be maintained during the parison forming and filling process.

[0041] The extrusion head 4 is a fundamental component of the sterile blow-molding system. An extrusion head 4 comprises an annular extrusion orifice through which the parison tube 5 of thermoplastic material is extruded. At the center of the annular extrusion orifice is a blowing opening 3.The parison tube 5 is formed through the continuous extrusion of molten thermoplastic material through the annular orifice of the extrusion head 4. The molten thermoplastic material exits the annular orifice forming a hollow cylindrical tube, i.e., the parison tube 5.

[0042] The blowing opening 3 at the center of the extrusion head 4 allows the passage of the nozzles of the filling assembly for dispensing the liquid inside the parison tube 5 during the forming and filling process.

[0043] The configuration of the extrusion head 4 with the annular extrusion orifice and the central blowing opening 3 allows for the efficient and sterile execution of both the extrusion of the parison tube 5 and its subsequent filling.

[0044] The sterile blow-molding system comprises a filling group 2 which includes one or more nozzles 2.1. The filling group 2 is configured in suitable dimensions to move through the blowing opening 3 of the extrusion head 4, without touching the latter, so as not to generate particles due to friction nor receive heat from the extrusion head or the parison, and so as to ensure a uniform air flow.

[0045] The nozzles 2.1 of the filling group 2 are designed to move between two main positions:

[0046] 1. A first insertion position (fig 1), in which the nozzles 2.1 are inserted inside the parison tube 5 to dispense the filling liquid.

[0047] 2. A second inactive position (fig 4), in which the nozzles 2.1 are completely outside the parison tube 5 and positioned inside the sterile chamber 1.

[0048] The movement of the nozzles 2.1 between these two positions occurs through the blowing opening 3. When the nozzles 2.1 are in the insertion position, they can dispense the liquid inside the parison tube 5 during the forming and filling process.

[0049] The configuration of the filling group 2 and the nozzles 2.1 allows sterile conditions to be maintained throughout the entire process. When the nozzles 2.1 are in the inactive position, they are completely contained within the sterile chamber 1, protecting them from potential external contamination.

[0050] This ensures the sterility of the nozzles 2.1 themselves even if the machine does not yet have a partially extruded parison tube to close the chamber 1 from below.The movement of the nozzles 2.1 between the insertion position and the inactive position can be precisely controlled to optimize the filling process and minimize the risk of product contamination.

[0051] The arrangement of the filling group 2 in relation to the sterile chamber 1 and the blowing opening 3 allows for an efficient transition between the parison forming and container filling phases, while maintaining the integrity of the sterile environment.

[0052] The sterile blow-molding system may comprise a vent channel 6 through which the air contained in the sterile chamber 1 naturally exits or is aspirated. The vent channel 6 is configured to allow the regulation of the pressure inside the sterile chamber 1 and the parison tube 5.

[0053] The vent channel 6 may include a non-return valve and / or be provided with a filter, to prevent contamination from the outside or the escape of possible toxic particles released by some filling products. This non-return valve prevents potentially contaminated air from entering the sterile chamber 1 through the vent channel 6, thus maintaining the integrity of the sterile environment inside the chamber 1 and the parison tube 5.

[0054] A regulating valve can be positioned on the vent channel 6 and / or on the inlet hole 1.1 for air coming from outside the sterile chamber 1. The regulating valve allows for precise control of the air flow into and out of the sterile chamber 1.

[0055] The sterile blow-molding system also includes a control system that calculates the amount of air to be introduced through the filter of the sterile chamber 1. This calculation is based on several factors:

[0056] 1. The air displacement caused by the movement of the filling group 2 2. The air outlet from the vent channel 6

[0057] 3. The swelling of the parison tube 5 during mold closure

[0058] The control system uses this information to determine the optimal amount of air to be introduced into the sterile chamber 1 , in order to maintain the desired pressure inside the chamber 1 and the parison tube 5. This precise pressure control is essential to ensure the correct forming of the parison tube 5 and to maintain sterile conditions throughout the entire blowing and filling process.

[0059] Furthermore, these parameters can be used during the sizing phase of the system and in particular of the sterile chamber 1 itself, so that the compensation of pressure variations is provided by the volume of air contained therein.During the mold closing phase, this volume of air must be compensated so as not to cause the rest of the parison to expand excessively.

[0060] Let us consider an example below, shown in figures 7-10, which provides for a mold for making a blister of 10 vials each 77 mm high (dimension C) and 14 mm wide (overall the parison will be D = 144mm deep + 10mm of waste on each side), with a distance from the extrusion head at the moment of closing of 70 mm (dimension B), and parison width at the extrusion point of 40mm (dimension A), as shown in figures 7 and 8.

[0061] During the phase just before the mold 9 closes, shown in figures 7 and 8, we can estimate an overall volume of air contained in the parison (which has approximately the shape of a triangular prism, where the base of the triangle is the width of the parison A, the tip converges at the closing point of the molds and the height of the triangle is the distance between the head and the distance from the extrusion head at the moment of closing (dimension B) plus the mold height (dimension C) and the depth is the width of the plastic necessary to form all the vials + the waste. This calculation results in a volume of (base A * height B+C) / 2) * depth D = 482 cm3

[0062] As soon as the mold 9 is closed (figures 9 and 10), the height of the triangle is only equal to the distance between the head and the distance from the extrusion head at the moment of closing (B) and therefore the volume becomes (base A * height B) / 2) * depth D= 229 cm3

[0063] Let's consider the parison 5 at an overpressure that can range from 2 to 100 pascals, although in reality this can vary and depends greatly on the material, thickness, length, width, and temperature of the parison itself.

[0064] Analyzing these calculations, it would therefore be a volume reduction of about 50% in 0.5 s (which is approximately the mold closing time).

[0065] If there were no vents and connections with the upper sterile chamber 1 , the pressure would go from almost ambient to 1 bar, which would cause the parison to explode.

[0066] There are known systems to avoid this, for example, moving the closing point of the molds away from the extrusion head, i.e. , increasing the distance B as much as possible in order to increase the volume of the parison and thus reduce the variation, however the nozzles become very long and the parison becomes verydelicate given the length; moreover, it is possible to use lower mold closing speeds, but this impacts the machine's productivity.

[0067] By adding the chamber 1 above the parison 5, connected through the channel 3, this volume variation is allowed to reduce the impact it has on the total pressure inside the parison.

[0068] Considering a sterile chamber (for example, about 50cm x 50cm by 70cm high) with a total volume of 175 liters, compared to a variation of 0.25 liters due to mold closure, it would be possible to contain in height the nozzles 2.1 and their possible extensions necessary in more complex machinery, and in width it could contain the entire arm / movement system.

[0069] In other words: the dimensions of the chamber in this case are to be sized so that the volume variation due to mold closure is negligible compared to the total volume of the chamber.

[0070] For example, if the chamber had a volume 10 times the volume reduction that occurs during mold closure, the hypothetical internal pressure increase would be greatly reduced, thus dropping to only a 0.1 bar increase.

[0071] In a variant of the invention, it is necessary to ensure that there is a downward flow E from the chamber towards the parison 5 which is then vented towards the vent 6 according to arrow F and finally towards the outside according to arrow G (figures 3 and 2).

[0072] This guarantees a mono-directional flow, so that the air inside the parison 5 can never rise into the sterile chamber 1 , but is always vented from the vent 6.

[0073] This flow, ensuring that during the mold closing all 253 cm3 in 0.5s are expelled from the vent 6, and that the air is not pushed into the chamber 1 , can be estimated at about 506 cm3 / s -> 30 l / min.

[0074] In this way, the size of the chamber has less impact on the volume variation, but the connection between the parison 5 and the upper sterile chamber 1 must be sized to allow the passage of all this air uniformly along the entire circumference of the parison.

[0075] If there were only two connection holes between the upper sterile chamber 1 and the parison 5, the air speed at the exit of these holes would be rather high, and could create vibrations of the parison 5 due to this speed and, consequently, high turbulence.Having a slot all around the blowing opening 3 allows for a large passage surface, making the flow uniform inside the surface of the parison tube 5.

[0076] In a second variant of the invention, the unidirectional flow is not guaranteed. In this case, the vent 6 can be smaller, the necessary air flow is significantly lower, as it only serves to compensate for the air lost through the vent 6, in order to be able to regulate the pressure correctly.

[0077] All the considerations made regarding the previous variant also apply to this case.

[0078] The air that is inside the parison 5, when the mold 9 closes, also passes into the upper sterile chamber 1 and vice versa.

[0079] Also in this case, the passage between the upper sterile chamber 1 and the parison 5 creates the least possible resistance to the air flow, to prevent an excessive overpressure from being created in the parison 5 when the mold 9 closes, which would risk making it explode.

[0080] Even when the nozzles 2.1 move in and out of the parison 5, they create a volume difference, although considerably smaller than that created by the mold 9.

[0081] Assuming they move completely out of the parison 5 in 0.5 s, we can schematically estimate a parallelepiped corresponding to the extensions for the nozzles - for 10 vials with about 14 mm center distance, 70 mm inside the parison, 15mm wide - having a volume of 147 cm3for the nozzle assembly, and consequently an air exchange flow of 294 cm3 / s is created upon its movement.

[0082] When the nozzles 2.1 exit, therefore, it is necessary that this volume be replaced by other air coming from the chamber 1 , in particular this pressure variation is negative, which therefore tends to make the parison collapse.

[0083] Thanks to the presence of a sufficiently large blowing passage 3 for air from chamber 1 , it is possible to carry out the necessary operations for forming and filling quickly and uniformly enough not to cause the parison to collapse (as instead happens in the state of the art of this technology).

[0084] The sterile containment chamber 1 can be arranged to house one or more inlet ports 1.3, each connected to a pressurized environment 1.4, through which inserts (external objects to be incorporated sterilely inside the BFS container) can be transported automatically.

[0085] Advantageously, with the high volume of air present in the sterile chamber 1 , it is possible to install a device 7 for monitoring viable and / or total particles; thisdevice can be positioned as close as possible to the opening 3, in order to have a representative reading of the particles present inside the parison.

[0086] Given also the high air passage that is allowed between the chamber 1 and the parison 5, it is possible to install this monitoring device 7 so as to sample the air present inside the parison 5, and thus be as close as possible to the area where the filling process takes place, without risking the collapse of the parison, since it is sufficient to increase the flow into the chamber 1 (Arrow I) to compensate for the amount that is aspirated by the monitoring system 7.

[0087] In a further variant, shown in figure 6, the chamber 1 is pressurized by a manifold 20 present between the extrusion head 4 and the upper chamber 1.

[0088] The air enters from the passages 10, and is diffused towards the nozzles 2. At this point the flow divides:

[0089] one part goes upwards, in the direction of arrows 13,

[0090] while one part goes downwards, in the direction of arrows 12.

[0091] The amount of air that goes upwards can be adjusted according to the size of the slit 11.

[0092] This system makes it possible to reduce the risk of any particles remaining in chamber 1 from entering the parison 5. Measuring the particles remains possible both in chamber 1, and inside the parison 5 or even in the manifold itself, by positioning the sampling probe 7 in the passage 14.

[0093] The walls 1.2 of the chamber 1 can be hermetic and resistant to internal pressure so as to be able to steam sterilize the entire environment 1 , in this case by means of a plug (not shown). This plug installed below the extrusion head allows the chamber 1 and opening 3 to be temporarily sealed, while still maintaining the connection with the passage 6 for the discharge of steam during the SIP phase.

[0094] Another possibility for plugging - during a machine stop phase - in the absence of a real physical plug, is to create a closure of the chamber 1 with the parison tube itself by closing the molds.

[0095] This measure allows for the filling of substances that require containment, as all areas potentially exposed to the substance are cleanable and never come into contact with the external environment.

[0096] A further advantage deriving from the structure of the opening 3 and passage 6 is that it is possible to add a thin layer of sheet metal 3.1 that acts as insulationaround the nozzles, which are less influenced by the high temperatures of the extruder 4.

[0097] Furthermore, this sheet metal 3.1 - in the case of a unidirectional flow as shown in figure 3 - keeps the inlet flows of cold air E and vent F defined as shown in figure 3.

[0098] The combination of the vent channel 6, the regulating valve 6.1, and the control system allows for accurate and dynamic management of the pressure inside the sterile blow-molding system, adapting to the volume and pressure variations that occur during the different phases of the forming and filling process of the parison tube 5.

[0099] This configuration of the projecting plate 6.1 creates an insulating layer around the nozzles 2.1 of the filling group 2, reducing the influence of the high temperatures of the extrusion head 4 and the parison 5 on the nozzles themselves and keeps them cool.

[0100] The sterile blow-molding system comprises further features that improve its functionality and performance.

[0101] The sterile chamber 1 includes a pressurized compartment 1.4 configured to contain one or more inserts. These inserts can be transported automatically through the pressurized compartment 1.4 to be subsequently incorporated inside the parison tube 5 during the forming process. The pressurized compartment 1.4 allows the sterility of the inserts to be maintained before their insertion into the parison tube 5.

[0102] A sensor 7 is provided for monitoring the presence of any particles within the system. The sensor 7 can be positioned inside the sterile chamber 1 or inside the blowing opening 3, or inside the parison tube 5. The position of the sensor 7 is chosen so as to obtain a representative reading of the particles present in the environment where the parison tube 5 is formed. The continuous monitoring carried out by the sensor 7 helps to ensure the maintenance of the sterility conditions required by the process.

[0103] Instead of a sensor 7, it can be a petri-dish for monitoring any microbiological contamination. In this case, it might not need active aspiration.

[0104] The combination of these additional features - the pressurized compartment 1.4, the sensor 7, and the projecting plate 6.1 - contributes to improving the overall performance of the sterile blow-molding system, ensuring greater control of operating conditions and the quality of the final product.SYSTEM OPERATING PROCESS

[0105] The operating process of the sterile blow-molding system begins with switching on the apparatus. Once started, the system performs a series of preliminary checks to verify the correct functioning of all components.

[0106] In this phase, the sterilization of the box 1 can take place, with the methods described previously; furthermore, the nozzles 2.1 are sterilized.

[0107] Subsequently, the sterile chamber is pressurized with filtered air until the preset operating pressure is reached. The control system constantly monitors the pressure inside the sterile chamber, regulating the intake of air through the filter and the vent through the vent channel to keep the desired pressure.

[0108] The extrusion head is then activated and begins to extrude the parison tube of thermoplastic material. The parison tube descends vertically through the filling opening.

[0109] When the parison tube reaches the desired length, a mold closes around the parison tube. The closing of the mold seals the lower part of the parison tube, creating a closed cavity inside the parison itself.

[0110] During the closing of the mold, a reduction in the volume of air inside the parison tube occurs. The control system compensates for this volume variation by regulating the airflow E from the sterile chamber 1 to the parison tube 5 through the blowing opening 3, thus avoiding the collapse or unwanted expansion of the parison 5.

[0111] Once the mold is completely closed, the filling group 2 moves from the inactive position inside the sterile chamber 1 to the insertion position through the blowing opening 3. The nozzles of the filling group 2 are inserted inside the parison tube 5 formed by the mold.

[0112] The filling liquid is then dispensed through the nozzles 2.1 inside the parison tube 5. Simultaneously, the air from the sterile chamber is used to blow the parison against the walls of the mold, giving it the desired final shape.

[0113] At the end of the filling, the nozzles of the filling group 2 are retracted from the insertion position to the inactive position inside the sterile chamber 1. The control system again regulates the air flow F, G to compensate for the volume variation caused by the movement of the nozzles.The mold remains closed for the time necessary to allow the cooling and solidification of the formed container. Once cooling is complete, the mold opens, releasing the finished container.

[0114] The cycle concludes with the preparation of the system for the start of a new production cycle. The parison tube resumes its descent from the extrusion head, ready for the formation of the next container.

[0115] Throughout the entire process, the control system constantly monitors and regulates the pressure inside the sterile chamber and the parison tube, ensuring the maintenance of sterile conditions and the correct formation of the container.

[0116] ADVANTAGES AND APPLICATIONS OF THE SYSTEM

[0117] The described sterile blow-molding system offers numerous advantages over existing technologies in the field of sterile container production using the blow-fill-seal process.

[0118] A significant advantage is the ability to fill substances that require containment. All areas potentially exposed to the substance are cleanable and never come into contact with the external environment. This ensures a high level of safety and sterility throughout the entire forming and filling process.

[0119] The system configuration, with the sterile chamber positioned above the extrusion head, allows for better control of the critical environmental conditions for the process. The pressurization of the sterile chamber and the controlled air flow towards the parison help to maintain a sterile environment and prevent contamination.

[0120] A further advantage derives from the structure surrounding the filling nozzles. The projecting plate acts as thermal insulation, reducing the influence of the high temperatures of the extrusion head on the nozzles themselves. This measure helps to keep the temperature of the nozzles more stable, improving the precision of the filling process.

[0121] The system also offers greater operational flexibility. The ability to sterilely insert external components inside the parison expands the potential applications of the system, allowing for the production of more complex containers or those with additional functionalities.

[0122] The potential applications of this system in the pharmaceutical industry are numerous. It can be used for the production of sterile containers for liquid drugs, parenteral solutions, eye drops, and other products that require a high level ofsterility. The ability to maintain a controlled environment throughout the process makes it particularly suitable for the production of sensitive or high-value-added drugs.

[0123] In the food industry, the system can find application in the production of sterile containers for long-life liquid foods, such as UHT milk, fruit juices, and other products that require an aseptic packaging process. The ability to constantly monitor environmental conditions during the process helps to ensure the safety and quality of the final product.

[0124] The system could be used without necessarily having to perform the filling; the process would produce empty containers, but the functionality of the chamber 1 and the air flow would remain unchanged.

[0125] In conclusion, this sterile blow-molding system represents a significant advancement in the technologies for producing sterile containers, offering advantages in terms of safety, flexibility, and process control. Its potential applications range from the pharmaceutical to the food industry, responding to the growing needs for sterile and high-quality production in these sectors.

[0126] The features of any example or embodiment described above can be combined to create further examples or embodiments without losing the desired effect. It should be understood that the description of an embodiment or an example provided above is for illustrative purposes only, and various modifications could be made by one skilled in the art. Furthermore, one skilled in the art will recognize that numerous further modifications and combinations of various aspects are possible. Accordingly, the described aspects are intended to encompass all alterations, modifications, and variations that fall within the scope of the appended claims.

Claims

CLAIMS1. Sterile blowing system for a thermoplastic parison tube (5) to be formed, comprising:an extrusion head (4) for thermoplastic parison to extrude the tube (5) to be formed,the extrusion head (4) having:an extrusion hole for the extrusion of the tube (5),a blowing opening (3) at the center of the extrusion hole, the blowing system being characterized in comprising:a compensation chamber (1) with an internal volume containing air at a pressure higher than the external environment, positioned above the extrusion head (4) and communicating with the blowing opening (3),the chamber (1) being sized so that one or more nozzles (2.1) can be positioned entirely inside the chamber (1) in an inactive position,the blowing of the tube (5) occurring by using through the air contained in the chamber (1),the internal volume of the chamber (1) being fixed.

2. Sterile blowing system according to claim 1, characterized in comprising a filling group (2) includingone or more nozzles (2.1) configured to move through the blowing opening (3)from a first insertion position, where it delivers liquid inside the tube (5), to a second inactive position, where it is completely outside the tube (5), the chamber (1) being sized so that the one or more nozzles can be entirely positioned inside the chamber (1) when in the second position relative to the filling opening.

3. Sterile blowing system according to claim 1 or 2, characterized in that the chamber (1 ) has an air intake hole for air from outside the chamber (1 ), equipped with a filter (1.1) for purifying the air coming from outside the chamber (1).

4. Sterile blowing system according to any one of claims 1-3, characterized in comprising a pressurization manifold (20) located between theextrusion head (4) and the chamber (1), equipped with an inlet passage (10), a first outlet slot (11), and a second outlet slot (15),the pressurization manifold (20) being configured to receive air through one or more passages (10) and to distribute it into the chamber (1 ) through the first outlet slot (11) and into the parison tube (5) through the second outlet slot (15).

5. Sterile blowing system according to any one of claims 1-4, characterized in comprising a vent channel (6) through which the air contained in the parison (5) exits.

6. Sterile blowing system according to claim 5, characterized in that at least one of the vent channel (6) and the air intake hole for air from outside the chamber (1) includes a flow regulation valve (6.1) for controlling the air flow entering / exiting the chamber (1).

7. Sterile blowing system according to any one of claims 1-6, characterized in that the chamber (1) is connected to a pressurized compartment (1.4) in which one or more inserts to be incorporated into the tube (5) during forming are housed, which can be moved from the compartment (1.4) to the chamber (1) when needed.

8. Sterile blowing system according to any one of claims 1-7, characterized in comprising a monitoring probe (7) for detecting the presence of any particles, positioned inside the chamber (1), the blowing opening (3), or the parison (5).

9. Sterile blowing system according to any one of claims 1-8, characterized in that the chamber (1) includes a protruding sheet (6.1), positioned inside the blowing opening (3), parallel to the edges of the blowing opening (3), and extending approximately to the height of the extrusion head (4).

10. Sterile blowing method for a thermoplastic parison tube (5) to be formed using the sterile blowing system according to any one of claims 1-9, comprising the following steps:- providing a predetermined operating pressure within the chamber (1 ), - providing at least one differential pressure sensor inside the chamber (1 ), - calculating the amount of air to be inserted into the chamber (1 ) to maintain the operating pressure based on the values detected by the at least one sensor,- inserting the calculated amount of air into the chamber (1 ).

11. Sterile blowing method for a thermoplastic parison tube (5) according laim 10, characterized in including at least one of the following steps:- closing a mold (9) around the tube (5) immediately prior to an interruption phase of the process,- mounting a cap on the blowing opening (3) below the extrusion head (4) immediately after a process interruption phase,- mounting a cap on the blowing opening (3) above the extrusion head (4) immediately after a process interruption phase.

12. Sterile blowing method for a thermoplastic parison tube (5) according laim 10 or 11 , characterized in including a step of:sterilizing the chamber (1) and its contents.

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