Extrusion blow moulding machine

Abstract

The invention relates to an extrusion blow moulding machine (100) comprising an extruder and a blow moulding tool (20). The blow moulding tool (20) is separated from the environment by an enclosure (30).

Description

[0001] Extrusion blow molding machine

[0002] The present invention relates to an extrusion blow molding machine according to the preamble of the independent claims.

[0003] Various extrusion blow molding machines for producing plastic containers are known from the state of the art.

[0004] Nowadays, even highly sensitive products, such as medicines, are packaged in plastic containers. Depending on the product's requirements, these require specific conditions during packaging or filling. This may also apply to the containers themselves. In particular, it may be necessary to clean the containers before use so that only a small number of particles adhere to them, not exceeding a predetermined limit.

[0005] The subsequent filling of the containers and / or their packaging takes place in particular under clean room conditions.

[0006] To eliminate the need for laborious container cleaning, it has already been proposed to convert entire production halls containing extrusion blow molding machines into clean rooms. This requires considerable technical effort, and if a blow molding machine malfunctions, there is a risk that entire production batches and / or neighboring production lines will be contaminated.

[0007] The object of the invention is to remedy at least one or more disadvantages of the prior art. In particular, an extrusion blow molding machine is to be created that makes it possible to produce plastic containers that no longer require cleaning before further use and, in particular, that meet cleanroom standards. This object is achieved by the device defined in the independent patent claim. Further embodiments can be found in the dependent patent claims.

[0008] An extrusion blow molding machine according to the invention comprises an extruder and a blow molding tool for producing a container. The blow molding tool is separated from the environment by a housing.

[0009] By isolating the blow molding tool from the environment, an atmosphere can be created within this separation, i.e., within the enclosure, that meets the desired conditions. Thus, the enclosure can reduce the influence of the environment on the blow molding tool. In particular, it makes it possible to prevent the entry of pollutants, especially dirt particles, into the area where the container is manufactured.

[0010] It can be provided that a compressor is arranged on the housing at a first front end in order to supply the housing with air.

[0011] The term "frontal side" or "frontal end" refers to a spatial assignment. The front side must be distinguished from a top side and a bottom side. Particularly in the case of elongated elements, i.e., elements with two long sides and two short sides, such as an elongated enclosure, the front sides are those that limit the longitudinal extension, i.e., the short sides.

[0012] If the enclosure is pressurized with air, excess pressure builds up within the enclosure. This excess pressure can further reduce the ingress of dirt particles into the enclosure. Furthermore, such an arrangement allows for certain tolerances regarding the enclosure's tightness. It is not necessary for the enclosure to seal the blow molding tool airtight from the environment; rather, certain leaks or gaps are possible.

[0013] By creating positive pressure within the enclosure, particularly by supplying air, a directed airflow can be forced from within the enclosure toward the environment. Any dirt particles that may arise within the enclosure due to the operation of the blow molding tool are carried outward by the blow molding tool. This increases production quality in terms of the potential number of dirt particles.

[0014] Additionally or alternatively, it can be provided that a compressor is arranged on the housing at a second end, opposite the first front end, for supplying the housing with air.

[0015] In addition to the advantages described with regard to the compressor at the first end of the enclosure, a second compressor enables the creation of a specific air flow within the enclosure.

[0016] In addition, by providing a second compressor, the first compressor, and accordingly also the second compressor, can be designed with a reduced size.

[0017] In addition, it is possible to apply air to the blow molding tool within the housing from different sides, so that it is exposed to air from several sides and any dirt particles that may arise are reliably removed.

[0018] It may be provided that outlet openings are arranged on the sides of the housing, creating a substantially horizontal flow. In this context, "lateral" is to be understood relative to the flow. With a frontal arrangement of the compressors, a flow occurs in the longitudinal direction. "Lateral" therefore means perpendicular to this direction.

[0019] The horizontal flow transports the dirt particles in the same direction as the containers, whereby, when two compressors are arranged in one area, the flows collide. The horizontal flow makes it possible to arrange the outlet openings centrally and laterally. This is not possible with a vertical flow.

[0020] This configuration leaves a free space above the blow molding machine, which can be accessed, for example, by crane. This allows maintenance work on the blow molding machine, especially on the blow mold, to be carried out quickly and cost-effectively, as access from above is not obstructed by additional equipment.

[0021] Preferably, each compressor is assigned a filter element, in particular a HEPA filter.

[0022] By providing a filter element on each compressor, air of a predefined quality can be introduced into the enclosure. This results in a corresponding atmosphere quality within the enclosure. This can be classified according to a quality or purity class according to ISO 14644-1, provided the filter element has the appropriate filtration performance.

[0023] The design as a HEPA filter according to EN 1822-1:2009 ensures a certain level of quality of the incoming air.

[0024] It can be provided that a conveyor belt is arranged within the housing for transporting the bias-molded articles to a clean room. In other words, the housing can extend to a clean room arranged at a distance from the blow molding machine, with the conveyor belt being arranged within this extension of the housing.

[0025] Such an arrangement allows the articles produced by the blow molding machine, typically plastic containers, to be conveyed immediately after production under the same conditions as those existing in the enclosure. In other words, the articles remain in the same clean atmosphere until further processing, preventing contamination with dirt particles.

[0026] A particle sensor may be installed within the enclosure to constantly monitor the conditions within the enclosure. If necessary, the performance of the compressor(s) can be controlled based on the current contamination level.

[0027] In the clean room, the items can be filled directly or packaged for further processing, for example for shipping.

[0028] The area or extension of the housing in which the conveyor belt is arranged can, for example, be designed as an extension of the original housing in which the blow molding tool is arranged.

[0029] Alternatively, the conveyor belt can be separated from the environment by a separate enclosure, such as a clean air tent. This separate enclosure can also be supplied with air separately.

[0030] It can be provided that the housing, in particular the housing in which the blow molding tool is arranged, is arranged within a safety fence.

[0031] The safety fence allows for the placement of other components of the extrusion blow molding machine in close proximity to the blow molding tool, yet outside the enclosure. This allows, for example, for permanent visual inspection of these components, while ensuring that safety regulations and minimum clearances are observed. Furthermore, the placement outside the enclosure prevents the entry of dirt particles into the area where the articles, such as containers, are manufactured.

[0032] In order to protect the atmosphere inside the enclosure from dirt particles, the extruder is preferably arranged outside the enclosure, but especially within the safety fence.

[0033] The enclosure is preferably at least partially spaced from the ground and / or in particular not sealed.

[0034] This allows for an airflow in the floor area, i.e., in the lower area of ​​the extrusion blow molding machine, directed from inside the housing toward the environment. This arrangement carries dirt particles away from the blow molding tool and out of the housing.

[0035] In this case, the floor is an area or level on which the blow molding machine is installed.

[0036] The volume enclosed by the enclosure is preferably less than 10 m 3 This maximum value ensures that the effort required to introduce air and create overpressure within the enclosure remains within an economical framework.

[0037] Preferably, each compressor has a capacity of 1200 m 3 or less, preferably a capacity of 900 m 3or less. This also has a positive influence on the economic efficiency of the blow molding machine. The invention is explained using schematic figures.

[0038] It shows :

[0039] Figure 1 : A schematic view of a production plant with an extrusion blow molding machine;

[0040] Figure 2 : an enclosure .

[0041] Figure 1 shows a schematic view of a production plant with an extrusion blow molding machine 100. The production plant also includes a clean room 80 which is connected to the extrusion blow molding machine 100 via a conveyor belt 60. The extrusion blow molding machine 100 has a safety fence 70 within which a housing 30 is arranged. A blow molding tool 20 is arranged within the housing 30. An extruder is arranged outside the housing 30, but within the safety fence 70. A discharge conveyor belt 21 extends from inside the housing 30 to the outside in order to remove sections of the production from the material flow. The housing 30 has a first end 31 and a second end 32. The housing 30 also extends along the conveyor belt 60 and encloses this conveyor belt 60.The conveyor belt 60 ends in the clean room 80, in which the articles produced with the extrusion blow molding machine 100 are further processed, in this case with a packaging device 81.

[0042] Figure 2 shows a housing 30. The housing 30 has a longitudinal extension which is delimited by a first end 31 and a second end 32. At the first end 31, i.e. at the front, a compressor 40 is arranged which is equipped with a filter element 41. The filter element 41 is in this case a HEPA filter. At the second end 32, opposite the first end 31, a compressor 50 is arranged which is equipped with a filter element 51. The filter element 51 is in this case a HEPA filter. Between the first end 31 and the second end 32, lateral outflow openings 33 are arranged on the housing 30 through which the air conveyed by the compressors 40 and 50 can flow out. By means of appropriate diffusers in the outlet openings 33 it is ensured that an overpressure is formed within the housing 30.

[0043] The blow molding tool, not shown here, is arranged within the housing 30.

Claims

Patent claims 1. Extrusion blow molding machine (100) comprising an extruder and a blow molding tool (20) , characterized in that the blow molding tool (20) is separated from the environment by an enclosure (30).

2. Extrusion blow molding machine (100) according to claim 1, characterized in that a compressor (40) is arranged on the housing (30) at a first end face (31) for supplying the housing (30) with air.

3. Extrusion blow molding machine (100) according to claim 2, characterized in that a compressor (50) is arranged at a second end (32) opposite the first end face (31) of the housing (30) for supplying the housing (30) with air.

4. Extrusion blow molding machine (100) according to claim 2 or 3, characterized in that outflow openings (33) are arranged laterally on the housing (30) so that a substantially horizontal flow is created.

5. Extrusion blow molding machine (100) according to one of claims 2 to 4, characterized in that each compressor (40, 50) is assigned a filter element (41, 51), in particular a HEPA filter.

6. Extrusion blow molding machine (100) according to one of claims 1 to 5, characterized in that a conveyor belt (60) is arranged inside the housing (30) for conveying the blow molded articles into a cleanroom (80).

7. Extrusion blow molding machine (100) according to one of claims 1 to 6, characterized in that the enclosure (30) is arranged within a safety enclosure (70). Extrusion blow molding machine (100) according to any one of claims 1 to 7, characterized in that the extruder is arranged outside the enclosure (30), in particular within the safety enclosure (70). Extrusion blow molding machine (100) according to any one of claims 1 to 8, characterized in that the enclosure (30) is at least partially spaced from the ground, in particular not sealed. Extrusion blow molding machine (100) according to any one of claims 1 to 9, characterized in that a volume enclosed by the enclosure (30) is less than 10 m³. A 3 is an extrusion blow molding machine (100) according to one of claims 2 to 10, characterized in that each compressor (40, 50) has a conveying capacity of 1200 m³ / h A 3 or fewer, preferably with a conveying capacity of 900 m³ / h A 3 or less.

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