Molding system with protection of semi-finished containers during their formation process

Abstract

The invention relates to molding system (1 ), comprising a mold (4) provided with two molding shells, capable of moving from a first extrusion zone of the thermoplastic tubular material to a second filling zone of the open semi-finished container (3). The molding system (1 ) comprises a protection device (2) for protecting the open semi-finished container (3) from contamination, equipped with a connection element (5) to a compressed air supply system, a filter (6) for filtering said compressed air, and a dispensing slot (2a) downstream of said filter (6), the protection device (2) is positioned above the mold (4) to dispense filtered air at the cutting area of the open semi-finished container (3) during the cutting of the thermoplastic tubular material and when the mold (4) moves from the first extrusion zone of the thermoplastic tubular material to the second filling zone of the open semi-finished container (3).

Description

[0001] MOLDING SYSTEM WITH PROTECTION OF SEMI-FINISHED CONTAINERS DURING THEIR FORMATION PROCESS

[0002] *****

[0003] The present invention relates to a device for protecting still open containers during their formation process by means of blow-fill-seal.

[0004] Field of invention

[0005] In particular, it is a protective device integral with the mold, which allows the upper wall of the still open container to be protected, from the moment the plastic tubular is cut to the moment of filling, and potentially up to the moment of welding.

[0006] In the following, the description will be addressed to a machine for the formation of pre-filled containers, using a “shuttle” type process, but it is clear that the machine should not be considered limited to this specific use.

[0007] Prior art

[0008] Blow-fill-seal technology is often used to produce containers of pharmaceutical products, and it is therefore necessary to ensure the cleanliness of the process to avoid contamination that could jeopardize the sterility of the product.

[0009] The blow-fill-seal process consists of at least an extrusion step, a forming step, a filling step, and a sealing step.

[0010] There are several types of blow-fill-seal processes, however the most common is called “shuttle”, which works as follows:

[0011] 1- an extrusion head extrudes one or more plastic tubulars into which sterile air is blown to prevent them from collapsing;

[0012] 2- a mold, which has the shapes of the containers to be made, moves under this extrusion head and closes around these hot and malleable plastic tubulars;

[0013] 3- a vacuum system inside the mold allows the tubular to adhere and conform to the shape of the mold, thus forming the container;

[0014] 4- a knife, usually a hot blade, cuts the upper part of the tubular still connected to the extrusion head, allowing the mold to move freely;

[0015] 5-the mold moves from the extrusion zone to the filling zone;

[0016] 6-In the filling area there is a clean air shower (usually grade A) that protects the upper part of the still open containers and the filling nozzles.

[0017] 7-At this point the nozzles descend and fill the containers, and once completed they return to the upper position;8-finally the upper part of the mold closes and welds the head of the container.

[0018] During the movement of step 5, the top of the container is exposed to the air inside the machine. This may constitute a contamination risk as the air inside the machine could carry unwanted particles into the open container.

[0019] It is necessary to protect the upper part of the container being formed even during this step to ensure the complete absence of contamination in the closed containers and during the entire process.

[0020] Scope of the invention

[0021] The main scope of the present invention is to provide a device for protecting still open containers during their formation process, which allows the aforementioned drawbacks to be overcome and which in particular allows contamination to be avoided easily and immediately.

[0022] More in detail, the scope of the invention is to create a molding system equipped with a protection device that guarantees sterility even during the delicate cutting and translation steps of the open container.

[0023] Another scope of the present invention is to create a molding system equipped with a protection device that guarantees sterility even after several work cycles, or following the opening of the machine for extraordinary maintenance or an emergency.

[0024] Object of the invention

[0025] It is, therefore, object of the invention is a molding system for the production of containers from a tubular thermoplastic material, comprising:

[0026] a mold provided with two molding shells,

[0027] a blade configured to cut the upper part of the thermoplastic tubular material to separate it from an open semi-finished container at its cutting area. More in details, the mold being configured to move from a first extrusion zone of the thermoplastic tubular material to a second filling zone of the open semi-finished container comprising a protection device for protecting the open semi-finished container from contamination, equipped with a connection element to a compressed air supply system, a filter for filtering said compressed air, and a dispensing slot downstream of said filter. More specifically, the protection device being positioned above the mold to dispense filtered air at the cutting area of the open semi-finished container during the cutting of the thermoplastic tubular material and when the moldmoves from the first extrusion zone of the thermoplastic tubular material to the second filling zone of the open semi-finished container.

[0028] Preferably, the protection device is integral with one shell of the mold. In this way, the device advantageously protects the open container during the delicate step of translation between the cutting zone and the filling zone.

[0029] Still, according to the invention, the protection device can be positioned in close proximity, for example adjacent, to the cutting area of the open semi-finished container.

[0030] This advantageously allows the flow of filtered air to flow directly into the container opening.

[0031] Furthermore, according to the invention, it can be comprised a diffusion plate equipped with a plurality of holes uniformly distributed over its entire area, so as to increase the uniformity of the air diffusion.

[0032] Also according to the invention, a guiding sheet can be positioned above the dispensing slot and oriented to direct the filtered air onto the opening of the open container. This allows for better direction of the flow of filtered air.

[0033] In this case, according to the invention, the guiding sheet can project beyond the dispensing slot.

[0034] Furthermore, according to the invention, the guiding sheet can be inclined towards the mold to reduce the passage area for the filtered air.

[0035] For example, according to the invention, the guiding sheet can be inclined so that its extension does not intersect the cavity of the mold.

[0036] In any case, according to the invention, the protection device can comprise a proportional pressure regulator and / or an air flow sensor for the filtered air to regulate the flow of filtered air and avoid undesired turbulence.

[0037] Furthermore, according to the invention, the protection device (2) can be attached to the molding system, for example by threaded means, to allow its removal, replacement, or cleaning.

[0038] Brief description of the figures

[0039] The present invention will now be described, by way of example and not by way of limitation, according to some of its preferred embodiments, and with the aid of the attached figures, in which:

[0040] figure 1 is a top view of the molding system of the invention;

[0041] figure 2 is a sectional view of the molding system of figure 1 ;figure 3 is a detail of the molding system in figure 1 , in which three different positions of the cutting blade are visible along its trajectory.

[0042] Detailed description

[0043] In the various figures, similar parts will be indicated with the same numerical references.

[0044] The solution identified to ensure the absence of contamination in the container is to distribute a flow of filtered air uniformly above the open containers held in the mold, as it can be seen in figure 1.

[0045] More in detail, in the molding system 1 the device 2 is assembled in close proximity to the tubular 3, above the mold 4. In particular, the device 2 is assembled above the supports 4a whose function is to ensure that the tubular 3 is kept open during the translation, filling, and welding process.

[0046] Preferably, this attachment is reversible, to advantageously allow the device to be removed for replacement, maintenance, or sterilization.

[0047] This protective device 2 is supplied with compressed air from a tube 7, which is filtered by a filter 6, which ensures the cleanliness of the air; finally, this air, filtered by the filter 6, is inserted into the protective device 2 through a connection 5.

[0048] This filtered air can be regulated by a proportional valve (not shown) to allow precise control of its pressure, and can be monitored by a flow sensor (not shown) to ensure it is within the desired values, as will be explained later.

[0049] Once inside the protective device 2, the filtered air is distributed evenly along the entire length of the protective device 2 itself, exiting from the slot 2a in the direction indicated by the arrow 8, and creating a layer of clean air above the openings of the containers 3.

[0050] A more detailed view of the protective device 2 is shown in figure 2.

[0051] The filtered air entering through connection 5 passes inside the protection device 2 and it is distributed along the entire length of the mold 4.

[0052] In this embodiment, a perforated diffusion plate 2d that further improves distribution is provided. Specifically, this plate features multiple holes evenly distributed across its entire surface.

[0053] In particular, the slot 2a is visible, from which the flow of clean air indicated by the arrow 8 exits, which is guided between the upper sheet 2b and the lower sheet 2c of the protection device 2 and creates a layer of clean air above the opening of the container 3.In a further embodiment, such sheet 2c could be absent, and the upper surface of the supports 4a could be used in its place.

[0054] The filtered air exiting the protective device 2, according to the flow indicated by arrow 8, creates a low-pressure zone, resulting in entrainment of ambient air and therefore possible contamination of open containers. The resulting flow is represented in figure 2 by arrow 8a.

[0055] The optimal positioning of the protective device 2 is therefore as close as possible to the opening of the containers 3, without interfering with the plastic tubular; however, there is a construction constraint related to the size of the plastic cutting knife, indicated by 9c, 9b, and 9a in its various positions along the cutting path of the tubular. To make room for the latter, it is therefore necessary to move the protective device 2 away, with a consequent increase in the risk of entraining unfiltered air into the container 3. This risk is reduced by the sheet 2b positioned as shown in figure 2.

[0056] It should be considered that during production, the knife 9 remains at high temperatures and can therefore be considered sterile; its presence does not impact the risk of contamination.

[0057] The sheet 2b has been designed so that the mixing of the filtered and unfiltered airflows indicated respectively with 8 and 8a occurs only once they have passed the area above the opening of container 3, so as to guarantee the cleanliness of the area surrounding container 3.

[0058] In particular, it protrudes from the dispensing slot 2a, and converges towards the opening of the container 3, to convey the flow indicated by the arrow 8 as close as possible to the opening of the container 3 itself.

[0059] More specifically, the sheet 2b is fixed above the dispensing slot 2a and its free end is inclined towards the mold 4, to reduce the passage area for the filtered air. The inclination of the sheet is such that an extension of the sheet 2b in its main development direction exceeds the farthest edge of the opening of the container 3. In other words: if the device 2 is fixed to a first shell of the mold 4, the sheet is inclined so that an extension of the sheet 2b itself in its main development direction exceeds the cavity of the second shell of the mold 4.

[0060] In this way, the filtered air is conveyed towards container 3 so as to cover the entire opening area, and moving the interaction with the unfiltered air present in themolding system to a subsequent area, so as to avoid turbulence right in the proximity of container 3.

[0061] The presence of the aforementioned proportional pressure regulator and flow sensor ensures precise control of the amount of air coming out of slot 2a in order to ensure the correct balance between the air flows, limiting the drag effect while maintaining good air coverage.

[0062] The protection device of the invention, being integral with the mold 4, is capable of maintaining the flow of clean air according to the arrow 8 above the container 3 even during the translation of the mold 4 from the extrusion zone to the filling zone, thus ensuring the protection of the container 3 during the entire production cycle.

[0063] Since the filtered air flow is adjustable via the protection device 2, the flow rate can be adapted to the needs and phases of the production cycle. In fact, the flow can be increased during the translation of the mold 4 or slowed down or turned off once below the sterile shower in the filling area, thus reducing potential turbulence.

[0064] Operationally, during the blow-fill-seal process, called “ shuttle”, specified above, following the creation of a vacuum in step 3, the protection device 2 is activated, which delivers a flow of filtered air from the slot 2a. During the step 4 of hot-blade cutting of the tubular material, the filtered air flows against the opening of container 3, thus isolating it from the unfiltered air present inside the machine.

[0065] Subsequently, the protection device 2 moves in conjunction with the mold 4, moving from the extrusion zone to the filling zone. Once the movement is complete, the protection device 2 can be deactivated, thus advantageously preventing the filtered air supplied from interfering with the clean air shower, which could create unwanted turbulence.

[0066] The invention thus conceived and illustrated here is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept.

[0067] Furthermore, all details may be replaced by other technically equivalent elements.

[0068] Finally, the components used, provided they are compatible with the specific use, as well as the dimensions, may be any according to the needs and the state of the art.Where features and techniques mentioned in any claim are followed by reference signs, such reference signs have been included for the sole purpose of increasing the intelligibility of the claims and, accordingly, such reference signs have no limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. A molding system (1) for the production of containers from a tubular thermoplastic material, comprising:a mold (4) provided with two molding shells,a blade (9c, 9b, 9a) configured to cut the upper part of the thermoplastic tubular material to separate it from an open semi-finished container (3) at its cutting area,the mold (4) being configured to move from a first extrusion zone of the thermoplastic tubular material to a second filling zone of the open semi-finished container (3)the molding system (1) comprising a protection device (2) for protecting the open semi-finished container (3) from contamination, equipped with a connection element (5) to a compressed air supply system, a filter (6) for filtering said compressed air, and a dispensing slot (2a) downstream of said filter (6),the protection device (2) being positioned above the mold (4) to dispense filtered air at the cutting area of the open semi-finished container (3) during the cutting of the thermoplastic tubular material and when the mold (4) moves from the first extrusion zone of the thermoplastic tubular material to the second filling zone of the open semi-finished container (3).

2. A molding system (1) as in claim 1, characterized in that the protection device (2) is integral with one shell of the mold (4).

3. A molding system (1 ) as in claim 1 or 2, characterized in that the protection device (2) is positioned in close proximity, for example adjacent, to the cutting area of the open semi-finished container (3).

4. A molding system (1 ) as in any one of claims 1 -3, characterized in that the protection device (2) comprises a diffusion plate (2d) equipped with a plurality of holes uniformly distributed over its entire area.

5. A molding system (1 ) as in any one of claims 1 -4, characterized in that the protection device (2) comprises a guiding sheet (2b) positioned above thedispensing slot (2a) and oriented to direct the filtered air onto the opening of the open container (3).

6. A molding system (1) as in claim 5, characterized in that the guiding sheet (2b) projects beyond the dispensing slot (2a).

7. A molding system (1) as in claim 5 or 6, characterized in that the guiding sheet (2b) is inclined towards the mold (4) to reduce the passage area for the filtered air.

8. A molding system (1) as in claim 7, characterized in that the guiding sheet (2b) is inclined so that its extension does not intersect the cavity of the mold (4).

9. A molding system (1 ) as in any one of claims 1 -8, characterized in that the protection device (2) includes a proportional pressure regulator and / or an air flow sensor for the filtered air to regulate the flow of filtered air and avoid undesired turbulence.

10. A molding system (1 ) as in any one of claims 1 -9, characterized in that the protection device (2) is reversibly attached to the molding system (1).

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