WO2025176800A1 - Mould-filling machine, and method - Google Patents

Abstract

The invention relates to a mould filling machine (11) for shaping and filling a plastics container (13) with a liquid in a blow mould (15) via a filling opening (19). The plastics container (13) has, in the region of the filling opening (19), retaining elements (20) for attaching a closure. The mould filling machine (11) comprises one or more blow moulds (15), which can be closed and opened in order to be able to remove therefrom the liquid-filled plastics container (13) formed in the blow mould (15), and a first closure device (21) having a plurality of first closures (23), which first closure device (21) applies a first closure (23) to the filling opening (19) of each liquid-filled container (13). The first closure is a stopper (23) which can be inserted into the filling opening (19) and can be clampingly fixed in the filling opening without interacting with the holding elements (20).

Description

FORM FILLING MACHINE AND PROCESS

Field of the invention

The invention relates to a form-filling machine according to the preamble of claim 1 and to a method for preventing the overflow of a liquid in a plastic container blown and filled by the liquid in a blow mold of a form-filling machine according to the preamble of claim 16.

State of the art

It is well known that plastic containers can be manufactured from preforms using the stretch blow molding process. For some time now, it has also been possible to inflate the preform with the liquid filling material instead of using compressed air. This eliminates the filling step that usually takes place after container formation. This improved process is known as the mold-filling process.

A form-filling machine comprises a processing station for the expanding forming of plastic preforms into plastic containers in a hollow mold or a blow mold by filling a liquid filling material under pressure into the preforms and inflating them with the liquid filling material to form plastic containers.

After the containers have been formed and filled with the contents, a filled container must be conveyed out of the processing station. State-of-the-art discharge systems utilize a transfer star. Due to the unavoidable changes in direction in the discharge systems, the contents in the containers tend to overflow. With certain filling media, such as cleaning agents, body care products, etc., foam is generated. This foam formation leads to overflow from the container. This overflow or foaming occurs while still in the blow mold, before the container is conveyed out of the processing station or blow mold carousel. Instead of a blow mold carousel, the blow molds can also be arranged differently, for example, linearly or with only one blow mold.

To prevent spillage, a closure device can be provided for applying a closure to the mouth of the container formed in the processing station and filled with the contents. After the container has been formed and filled, a closure is applied to the mouth of the filled container using the closure device, which prevents the liquid from spilling out when it is transferred to the outlet device.

These closures must be adapted to each container type or each type of filling opening to reliably prevent spillage of the contents, and require a dedicated feed system. Accordingly, every product changeover inevitably requires conversion or setup time to provide the appropriate closure.

Known form-filling machines also have a limiting stroke when applying the closure, which restricts the product profile, especially the height of the closures.

Object of the invention

The disadvantages of the described state of the art result in the task of ensuring that spillage is avoided and at the same time improving the flexibility of the mold filling machine.

Description

The stated problem is solved in a mold-filling machine by the features stated in the characterizing portion of patent claim 1. Further developments and/or advantageous embodiments are the subject of the dependent patent claims.

The invention is preferably characterized in that the first closure is a plug that can be inserted into the filling opening and clamped into the filling opening without interacting with the retaining elements. The plug has the great advantage that when changing the product of the plastic container, the first closure device, which can also be referred to as a plug sealer, does not need to be converted. This is because the plug can seal a wide range of filling openings and the first closure device can remain unchanged. If the liquid is filled while hot, a vacuum is created in the container, which further improves the seal and spill protection. It has proven useful for the plug to include a conical closure element that can penetrate the filling opening. This allows filling openings with diameters between the largest and smallest diameters of the closure element to be sealed.

In a particularly preferred embodiment, the first closure device can apply the stopper to the container while it is in the closed blow mold. This allows the filling opening to be sealed immediately after blowing and filling the container. This is a significant advantage, especially for liquids that foam during filling, because the foam cannot escape from the container.

The first closure device is expediently designed so that the plug can be axially inserted into the filling opening. Sealing is thereby improved by creating a precise sealing line between the closure element and the edge of the filling opening.

In another particularly preferred embodiment of the invention, the mold-filling machine comprises a recirculation device that can recirculate the plugs. The recirculation device removes each closure from the container after the discharge device and transports it back to the first closure device. As a result, only a small number of plugs are required in the first closure device, as these serve as temporary closures or pre-closures. The recirculation device allows each plug to be returned immediately after removal from the container and applied to a new container still in the blow mold.

Preferably, the plugs are removed from the containers via a ramp surrounding the form-filling machine, along which the containers can be guided, and the plugs can be lifted off the ramp. This automatically removes the plug from the filling opening due to the linear movement of the container.

In a further preferred embodiment, the plug has a circular groove defined by the closure element and a skirt. The skirt acts as a guide element, ensuring that the plug is placed centered on the filling opening. It is also conceivable for the skirt to have locking elements on its inner side, thus locking on the outside of the wall that defines the filling opening, thus additionally securing the plug to the container. For example, the locking elements can rust on an external thread of the wall. In a further preferred embodiment of the invention, the height of the plug is limited by the stroke of an injection nozzle through which the liquid is injected into the plastic container for molding and filling. Because the plug has a low height, it can be placed over the filling opening immediately after filling, while the container is still in the blow mold. This reliably prevents overflow of any foam that has formed, since the plug is already in place when the foam has risen to the filling opening.

The invention is also preferably characterized in that the form-filling machine comprises a second closure device, having a plurality of second closures, which can apply a second closure to the filling opening of each liquid-filled container, wherein the second closure device is arranged in the form-filling machine immediately after the first closure device in the direction of movement of the containers. The final second closure is placed on the filling opening immediately after the plug is removed, thereby preventing liquid overflow between the change of plug and second container. The plug is removed only after the liquid has stabilized or the foam formed has reduced.

It is preferred if the second closure is free of any height restrictions. The second closure device, which can be a standard capper, is not restricted in height by any additional devices, and thus the second closure can have any height required by the container to be closed. The product profile is therefore not restricted by the second closure. The limited height of the stopper is irrelevant for the final product, as it is a temporary closure.

Conveniently, the plug comprises two closure elements. This makes it irrelevant how the plugs are inserted into the first closure device or in which position the plugs are returned to the first closure device by the circulation device.

It is advantageous if the two closure elements are arranged in a mirror-image manner on the stopper. This ensures that the stopper is always in the correct position and that one closure element is always facing the filling opening when the stopper is placed on the container. Advantageously, the two closure elements are identical or have different shapes. With identical closure elements, the position of the plug is irrelevant, as both closure elements seal the filling opening. If the closure elements are different, they can together cover a larger number of different diameters.

It is advantageous if the closure element is formed as an inwardly projecting inner cone, e.g. in the form of a sealing cylinder or a sealing ring, which is designed to cooperate sealingly with the inner wall of the plastic container that defines the filling opening. The inner cone clamps with the inner wall and can therefore be clamped into the filling opening. A positive connection between the inner wall and the closure element, which would limit the connection to a single diameter, can therefore be prevented. It is also possible for the plug to be designed as a top sealer and to be fastened outside the filling opening. This is equally possible for container opening variants with a thread or a snap fastener. The top sealer allows the inner wall to be sealed inside, at the top, or outside.

A further aspect of the invention relates to a method for preventing liquid from spilling over into a plastic container blown and filled by the liquid in a blow mold of a form-filling machine. The method is characterized in that the first closure, which is a plug, is applied to the filling opening with the first closure device while the plastic container is in the closed blow mold. This reliably prevents foam that forms during filling of the container from overflowing from the container. When the foam has risen to the filling opening, the opening is already sealed with the plug.

In a further embodiment of the invention, a plurality of plugs are circulated through a circulation device, in which the circulation device removes each plug from the containers after a discharge device and transports it back to the first closure device. This requires only a small number of plugs, which can be reused repeatedly.

It is advantageous to remove the plug using a ramp, along which the containers are guided, and the plug is lifted off the ramp. As the containers move in a lane, the plugs are automatically removed by being guided past the ramp. This lifting process is very reliable, as no mechanically moving parts are required.

In another particularly preferred embodiment of the invention, a second closure with a second closure device is applied to the filling opening of each plastic container immediately after the plug is removed. The final second closure is placed on the filling opening immediately after the plug is removed, thereby preventing liquid from overflowing between the plug and the second container.

Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic representations. These are not to scale:

Figure 1: a schematic representation of a form-filling machine according to the invention;

Figure 2: a first embodiment of a plug for pre-closing a plastic container;

Figure 3: a second embodiment of the plug and

Figure 4: the plug placed on the filling opening of a plastic container;

Figure 1 shows a form-filling machine, which is designated overall by the reference numeral 11. In the form-filling machine 11, plastic containers 13, in particular plastic bottles 13, are formed with a liquid or the liquid filling material in a blow mold 15 and simultaneously filled. A plurality of blow molds 15 can be arranged in a carousel 17. The blow molds 15 can be closed and opened. This allows a preform to be inserted into the open blow mold 15, in which the preform is filled with the liquid after the blow mold is closed and simultaneously formed or inflated into a plastic bottle 13. By opening the blow mold, the finished, formed and filled bottle 13 can be removed from the blow mold 15. The liquid is injected into the preform or bottle 13 through an injection nozzle via a filling opening 19. The bottle has holding elements 20, which are usually an external thread surrounding the filling opening 19. Once the container 13 is filled with liquid, the liquid may spill over in the event of a change in direction or vibration. Especially when filling media such as cleaning agents, body care products, etc., foam may form, which may spill or overflow.

Therefore, the form-filling machine 11 includes a first closure device 21, which applies a stopper 23 to each filled bottle 13 while the bottle is still in the closed blow mold 15. This reliably prevents liquid from spilling over, even if foam formation occurs immediately after the container is removed from the mold while the container 13 is still in the closed blow mold 15.

A stopper 23 is therefore located on each bottle 13 when it is transferred from the carousel 17 to a discharge device 25. Therefore, any spillage of the liquid caused by changes in direction is reliably prevented by the stopper 23.

The stopper 23, shown in Figures 2 to 4, can close bottles 13 with different filling openings 19. For this purpose, the stopper 23 preferably has a conical closure element 27. The closure element 27 is therefore an inwardly projecting inner cone, e.g., in the form of a sealing cylinder or a sealing ring. The stopper 23 is inserted into the filling opening 19 and is clamped in place in the filling opening 19. This reliably holds the stopper 23 in the filling opening 19 without interacting with the retaining elements 20.

The closure element 27 can fully or partially penetrate the filling opening 19, depending on the diameter 29 of the filling opening 19. When blowing with a hot liquid, a vacuum is created in the bottle as the liquid cools, thereby improving the retention of the stopper 23 on the filling opening 19. The stopper 23 has the advantage that the first closure device does not need to be rebuilt and equipped with different closures when a product change takes place on bottles 13 on the form-filling machine 11.

The plug 23 can also have two closure elements 27. If the closure elements 27 are identical, it is irrelevant how they are inserted into the first closure device. This facilitates the loading of the first closure device 21 with the plug 23. If the closure elements are not identical, a wide range of filling openings 19 with different diameters 29 can be covered with one plug 23. The plug 23 can have a circular groove 31, which is delimited by the closure element and a skirt 33. The skirt 33 acts as a guide element, allowing the closure element 27 to be placed centrally on the filling opening. The closure element 27 then cooperates sealingly with the inner wall 35 delimiting the filling opening 19. The closure element 27 therefore cooperates with the inner wall in a clamping manner and is thus clamped in the filling opening 19. A positive connection between the inner wall 35 and the closure element 27, which would limit the connection to a single diameter, can thus be prevented.

The plugs 23 are circulated through a circulation device 37. The circulation device 37 removes each plug 23 from the container 13 after the outlet device 25 and transports the plugs 23 back to the first closure device 21. The plugs 23 therefore remain in the circuit as a slosh guard. As a result, only a small number of reusable plugs 23 are required, even when a product change occurs that involves a change in the diameter of the filling opening 19.

The removal of the stoppers 23 from the bottles 13 is accomplished by a ramp 39 along which the bottles 13 can be guided. Each of the stoppers 23 is automatically lifted off the ramp 39 by the linear movement of the bottles 13 along the ramp 39. The stoppers 23 are then returned through the circulation device 37.

Since the plug 23 is applied to the filler opening 19 in the area of a fluid injection nozzle, which has a specific stroke, the height of the plug 23 is limited to the stroke. Otherwise, the plug 23 could not be applied to the filler opening 19. Since the plug 23 is not the final closure, the limited height does not pose a problem for product diversity.

The form-filling machine 11 comprises a second closure device 41, which has a plurality of second closures 43. The second closure device applies a second closure 43 to the filling opening 19 of each liquid-filled bottle 13. The second closures 43 are screwed onto the external thread 20. The second closure device 41 is arranged in the direction of movement of the bottles 13 after the first closure device 21 in the form-filling machine 11. At this position, the second closures 43 are not limited in their height by the stroke of the injection nozzle. Therefore, the second closures 43 can each have any height that is necessary for a product change of the bottles 13.

Legend:

11 Shape filling machine

13 plastic containers, plastic bottles

15 Blow mold

17 Carousel

19 Filling opening

20 retaining elements, external thread

21 First locking device

23 plugs, first closures

25 Outlet device

27 Conical closure element, inner cone

29 Diameter of the filling opening

31 grooves

33 Apron

35 inner wall

37 Circulatory device

39 Ramp

41 Second locking device

43 Second closures

Claims

1. Form-filling machine (11) for forming and filling a plastic container (13) with a liquid in a blow mold (15) via a filling opening (19), which plastic container (13) has holding elements (20) for fastening a closure in the region of the filling opening (19), comprising - one or more blow moulds (15) which can be closed and opened in order to be able to remove the liquid-filled plastic container (13) formed in the blow mould (15) from the latter, and - a first closure device (21) having a plurality of first closures (23), which first closure device (21) applies a first closure (23) to the filling opening (19) of each container (13) filled with liquid, characterized in that the first closure is a plug (23) which can be inserted into the filling opening (19) and which can be clamped in the filling opening without interacting with the holding elements (20). 2. Form filling machine according to claim 1, characterized in that the plug (23) is designed as a conical closure element (27). 3. Form-filling machine according to claim 1 or 2, characterized in that the first closure device (21) can apply the plug (23) to the filling opening (19) as long as the plastic container (13) is in the closed blow mold (15). 4. Form-filling machine according to one of the preceding claims, characterized in that the first closure device (21) is designed so that the plug (23) can be inserted axially into the filling opening. 5. Form-filling machine according to one of the preceding claims, characterized in that the form-filling machine (11) comprises a circulation device (37) which can circulate the plugs (23) in that the circulation device (37) removes each plug (23) from the containers (13) after the outlet device (25) and transports it back to the first closure device (21). 6. Form-filling machine according to one of the preceding claims, characterized in that the plugs (23) are removed from the containers by means of a ramp (39) surrounding the form-filling machine, past which the containers (13) can be guided, and the plugs (23) can be lifted off the ramp (39). 7. Form-filling machine according to one of the preceding claims, characterized in that the plug (23) has a circular groove (31) which is delimited by the closure element (27) and an apron (33). 8. Form-filling machine according to one of the preceding claims, characterized in that the height of the plug (23) is limited by the stroke of an injection nozzle through which the liquid for forming and filling the plastic container (13) is injected into it. 9. Form-filling machine according to one of the preceding claims, characterized in that the form-filling machine (11) comprises a second closure device (41) having a plurality of second closures (43), which can apply a second closure (43) to the filling opening of each container filled with liquid by the second closure (43) with the holding elements (20), wherein the second closure device (41) is arranged in the direction of movement of the containers (13) immediately after the first closure device (21) in the form-filling machine. 10. Form-filling machine according to claim 9, characterized in that the second closure (43) is free from a height limitation. 11 . Form-filling machine according to one of the preceding claims, characterized in that the plug (23) comprises two closure elements (27). 12. Form-filling machine according to one of the preceding claims, characterized in that the two closure elements (27) are arranged in mirror image on the plug (23). 13. Form-filling machine according to one of the preceding claims, characterized in that the two closure elements (27) are identical or have different shapes. 14. Form-filling machine according to one of the preceding claims, characterized in that the closure element is formed as an inwardly projecting inner cone (27), e.g. in the form of a sealing cylinder or a sealing ring, which is designed to cooperate in a sealing manner with the inner wall (35) of the plastic container (13) delimiting the filling opening (19). 15. Form-filling machine according to one of the preceding claims, characterized in that the plug (23) is made of polypropylene or polyethylene. 16. Method for preventing the overflow of a liquid in a plastic container (13) blown and filled by the liquid in a blow mold of a mold-filling machine (11), comprising the following method steps: - blowing a preform inserted in the blow mold into the plastic container (13) with a liquid while simultaneously filling the plastic container (13) with the liquid, and - Applying a first closure (23) to a filling opening (19) of the plastic container (13) with a first closure device (21), characterized in that the first closure, which is a plug (23), is applied to the filling opening (19) with the first closure device (21) as long as the plastic container is in the closed blow mold (15). 17. The method according to claim 16, characterized in that a plurality of plugs (23) are circulated through a circulation device (37), in that the circulation device (37) removes each plug (23) from the containers (13) after an outlet device (25) and transports it back to the first closure device (21). 18. Method according to claim 16 or 17, characterized in that the plug (23) is removed with a ramp (39) along which the containers (13) are guided and the plug (23) is lifted off the ramp (39). 19. Method according to claim 18, characterized in that a second closure (43) with a second closure device (41) is applied to the filling opening (19) of each plastic container (13) immediately after the plug (23) has been removed.