Transport arrangement, blow-moulding machine arrangement, and method for transporting preforms

Abstract

The invention relates to a transport arrangement for transporting preforms (3), in particular preforms (3) for forming beverage containers, comprising at least one linear guide (20) which is designed to guide the preforms (3) along a transport path section (27, 28) during transport. According to the invention, a spacing device (22) is provided and is designed to space apart at least two preforms (3), which are guided in succession in the linear guide (20), in a defined spacing range from one another in the transport path section (27, 28).

Description

[0001] Transport arrangement, blow molding machine arrangement and method for transporting preforms

[0002] Description:

[0003] The invention relates to a transport arrangement for transporting

[0004] Preforms, especially preforms for forming

[0005] Beverage containers, with at least one linear guide designed to guide the preforms along a transport path section during transport.

[0006] In this context, a linear guide is understood to be a device designed and configured to guide preforms along a substantially straight transport path, although curved sections may also be included. In particular, it is stipulated that the linear guide is completely straight, at least in a top view.

[0007] The preforms can be transported in various ways within such a linear guide. In particular, the linear guide is designed to accelerate the preforms solely by their own weight and thereby transport them along the guide.

[0008] The invention relates in particular to transport arrangements used in the food industry, especially in the beverage industry. Accordingly, the preforms are preferably designed to be formed into beverage containers. Such preforms are also commonly referred to as preforms and have a pre-formed upper opening section, which already features an external thread for receiving a cap and a neck ring projecting below the external thread.

[0009] The area below the neck ring, which is also referred to as the body area, can then be subjected to plastic deformation. This is done, for example, within a blow molding machine, particularly a stretch blow molding machine. Here, a blowing fluid is introduced into the interior of the preform, which is then plastically deformed by the application of pressure. Typically, the containers are preheated in a heating device so that the material of the containers, which is preferably polyethylene terephthalate (PET), softens, allowing the plastic deformation process to be carried out easily. In stretch blow molding, a stretching bar is also moved along the container axis to cause axial elongation of the preforms.

[0010] The blow molding fluid is usually a gaseous fluid, such as compressed air. However, it is also known to use a liquid blow molding fluid. In this case, it is typically the filling medium that is to be introduced into the container formed from the preform anyway. Accordingly, the plastic shaping of the preforms and the filling process are carried out in a single step. This process is also commonly referred to as the mold film process.

[0011] To feed the preforms into the blow molding machines, they are typically transported within a conveyor system. The preforms are delivered pre-manufactured and are then arranged in a random order within a collection container. From there, they must first be separated and aligned. This can be done, for example, within a suitable conveyor system, where the preforms are first arranged in a row behind one another within a separating device, with the container opening simultaneously oriented upwards. This is generally done within a so-called roller sorter. This roller sorter has two counter-rotating conveyor rollers, which are spaced apart from each other in the transverse direction in such a way that the container can be guided between the conveyor rollers.Simultaneously, the containers rest on the conveyor rollers with one section, which is typically the protruding neck ring. The counter-rotating roller sorter is designed so that the conveyor rollers cause the preforms to move upwards within the conveyor lane, continuously lifting them and allowing them to line up within the lane. Furthermore, the conveyor rollers are generally angled to ensure the containers are transported along the conveyor lane.

[0012] Following singulation, the containers are either transferred directly to a blow molding machine or to a feeding device. This feeding device typically has a transport lane arranged at an angle to the conveying lane of the singulation unit. Accordingly, the preforms must be tilted along their container axis. This tilting occurs within the linear guide.

[0013] In practice, this design has generally proven effective. However, it has also been shown that, particularly with linear guides that facilitate the transfer between a sorting unit and the blow molding machine, the preforms can be so close together that they can overlap and become jammed within the linear guide. This is especially problematic when the container axis also tilts within the linear guide, as is the case, for example, with curved sections.

[0014] Against this background, the invention is based on the objective of providing a transport arrangement which enables, in a simple manner, a safe and reliable conveying of the preforms along a transport path.

[0015] The subject matter and solution of this problem is a transport arrangement according to claim 1, a blow molding machine arrangement according to claim 14, and a method for transporting containers according to claim 15.

[0016] According to the invention, a spacing device is provided and configured to space at least two preforms guided one behind the other in the linear guide within a defined distance range.

[0017] Accordingly, the preforms are not only guided within the linear guide, but also spaced apart from each other in a transport path section of the linear guide. This ensures that the preforms do not directly touch each other, thus preventing, in particular, the neck ring from overlapping or tilting. The spacer device is designed to define a predefined distance range within which the preforms are spaced apart. This distance range is preferably between 1 and 10 mm. Such a design is particularly advantageous when the linear guide has at least two spaced-apart guide rails.These guide rails are then arranged parallel along the transport path, with the distance between the guide rails serving to allow the preforms to extend with the body area between the guide rails, while at the same time resting on the guide rails with the neck ring.

[0018] This design is commonly referred to as a neck ring guide and is particularly suitable for preforms, but also for plastic bottles. However, with this design, tilting of the preforms is especially problematic, as the center of gravity is located below the guide rails. Consequently, in the event of longitudinal or lateral acceleration, the preforms can tilt upright or slide over one another. Therefore, given this design, it is particularly advantageous to position the spacing device below the guide rails. In this case, the spacing device not only ensures that the preforms are spaced apart but also prevents, or minimizes, tilting by positioning it as close as possible to the center of gravity of the preform.The spacing device is preferably arranged a maximum of 15 mm, and particularly preferably a maximum of 10 mm, below the guide rails. In this context, "arrangement" means that the spacing device acts on the preforms within this area. Of course, sections of the spacing device can also be arranged outside this spacing range, provided that the actual effect on the preforms occurs within this range. In principle, all designs that define the distance between the preforms in a defined manner and, in the case of preforms arranged directly adjacent to one another, also space them apart, are suitable as spacing devices. However, a design in which the spacing device has at least one rotatable star wheel with a plurality of circumferentially arranged receiving pockets is particularly preferred.

[0019] Spur gears of this type are common in the beverage industry and are used to transport containers along a conveyor path using rotary motion. By connecting several spur gears in series, the containers can be transported over long distances. In this case, however, the spur gear is not intended for transporting the containers. Rather, the receiving pockets serve solely to space the containers apart. The specified spacing range is determined by the division of the receiving pockets around the circumference of the spur gear. These pockets are typically designed with an interference fit compared to the preforms, allowing for easy insertion. This interference fit then defines the spacing range.

[0020] Furthermore, the star wheel preferably does not have an associated drive mechanism. Instead, the preforms are transported exclusively via the linear guide, with the rotation of the star wheel resulting from the linear transport of the preforms. These engage in a receiving pocket of the star wheel, and their continued movement along the transport path causes the star wheel to rotate. Accordingly, it is advisable for the star wheel to be designed to run particularly smoothly so as not to significantly disrupt the transport of the preforms along the linear guide. Assuming a design with a neck ring guide, the star wheel then acts on the preforms within the previously described distance below the guide rails, so that the star wheel is positioned at a corresponding distance from the guide rails.

[0021] The receiving pockets are preferably bulges or recesses in the star wheel, extending inwards from the circumference of the star wheel. The star wheel preferably has a diameter of 100 to 130 mm. Furthermore, preferably between 8 and 14, and in particular between 10 and 12, receiving pockets are formed along the circumferential direction on the at least one star wheel.

[0022] A preferred embodiment of the inventors further provides that the at least one star wheel has a rotation axis arranged substantially perpendicular to a transport direction running along the transport section. Accordingly, the rotation axis runs substantially parallel to a vertical direction, the vertical direction being arranged along the perpendicular. In this context, "substantially perpendicular" orientation means that a maximum deviation of ±10° from the vertical direction is possible. Accordingly, the at least one star wheel has a rotation axis which exhibits a velocity component parallel to the transport direction, at least in certain sections.

[0023] Furthermore, according to a preferred embodiment, at least two star wheels can be provided, arranged one above the other with a common axis of rotation and / or side by side with parallel axes of rotation. An arrangement one above the other allows, in particular, for uniform support of the preforms to minimize tilting. Alternatively, two star wheels can also be arranged side by side. These are then preferably located on one side of the linear guide. According to such an embodiment, the two star wheels can also overlap, at least partially, so that the preform transitions into the second star wheel with a section while it is still essentially within the first star wheel.Furthermore, the star wheels can also be arranged on different sides of the linear guide, particularly the guide rails, so that the preforms are supported evenly on both sides. Regardless of the arrangement, the star wheels can be coupled or uncoupled with respect to their rotational movement.

[0024] According to a further embodiment, at least one star wheel can be connected to a preloading device, which is configured to apply a preload force to the star wheel in the direction of the linear guide. In this embodiment, the preloading device serves to press the star wheel in the direction of the linear guide. This ensures that the star wheel is always positioned within the area of ​​the linear guide. At the same time, the preloading device can also be adjusted so that at least a slight retraction of the star wheel is possible if excessive forces from the preforms act on the preloading device. In this context, the preload force preferably acts primarily in the transverse direction of the linear guide.

[0025] A spring element is preferably provided to exert the preload force. Of course, several elements can also be provided, acting on the star wheel in parallel or in series. According to a further embodiment of the invention, the linear guide has different transport directions on at least two transport path sections arranged in series. Accordingly, the transport direction is adjusted via the transport path sections, thus aligning transport path sections that are at an angle to each other. This configuration can usually be achieved by a curved or arc-shaped form of the transport path sections. In particular, it is provided that, in a top view, the transport path sections continue to run along a straight transport path, so that this transport direction effects an adjustment exclusively in the vertical direction.

[0026] According to a further development of the invention, it is provided that a plane extending in the transverse direction and in the transport direction within each transport path section is arranged relative to each other at a transfer angle. Accordingly, planes can be defined which are arranged relative to each other at a corresponding transfer angle. In principle, a first transport path section can refer to the inlet and a second transport path section to the outlet of the linear guide. In particular, the transfer angle refers directly to the inlet and the outlet of the linear guide, with the inlet being located in the area of ​​the linear guide where the preforms are first introduced. Accordingly, the outlet defines the area from which the preforms are no longer in contact with the linear guide.This assumes, for example, that an upstream singulation device is inclined relative to downstream transport devices, with the linear guide between the inlet and outlet adjusting the position of the preforms accordingly. Thus, the transfer angle essentially defines the angle at which the conveyor lane of the singulation device is inclined relative to downstream transport lanes. According to a preferred embodiment, the transfer angle is between 5 and 25°.

[0027] According to a preferred embodiment of the invention, the spacer device is configured to space the preforms within an inlet transport path section, which extends over a maximum of 20% of the length of the linear guide or the transport path on the linear guide. The inlet transport path section begins at the inlet of the linear guide. The total length of the linear guide or the transport path of the linear guide is determined by the distance between the outlet and the inlet. Particularly preferably, the inlet transport path section extends over less than 15%, and more preferably less than 10%, of the length of the linear guide.

[0028] A further development of the invention provides that the linear guide connects to an upstream sorting device along a transport path. This sorting device is, in particular, a roller sorter as previously described. An inclined conveyor can also be connected upstream of the roller sorter, so that the containers, starting from the inclined conveyor, first enter the roller sorter and then the linear guide.

[0029] The sorting device then accordingly has a conveyor lane formed from two counter-rotating conveyor rollers spaced apart from each other in a transverse direction, with the conveyor lane directly adjoining the linear guide.

[0030] According to a further development of the invention, a feeding device for feeding the preforms into a treatment device connects to the linear guide, wherein the linear guide is designed to transfer the preforms from the sorting device to the feeding device.

[0031] The feeding device can, for example, be an air conveyor that transports the containers towards a processing unit. Accordingly, the spacing device can be located in a transition area between the sorting device, in particular a roller sorter, and a feeding device or a further transport section, or it can connect these two components. The feeding device or the transport section is essentially arranged horizontally.

[0032] The treatment device can be, for example, a cleaning device, a coating device, or a forming device. In particular, it is intended that the device be a forming device in the form of a blow molding machine, especially a stretch blow molding machine. However, the invention is not limited to this, and any device that optically, chemically, or physically influences the preforms in any way can be understood as a treatment device.

[0033] The invention further relates to a blow molding machine arrangement comprising a blow molding machine and a transport arrangement for transferring the preform into the blow molding machine, wherein the transport arrangement is designed according to the invention and the linear guide connects directly or via the feeding devices to the blow molding machine.

[0034] The blow molding machine is preferably designed as a stretch blow molding machine. The forming process is carried out either with a gaseous blowing fluid, e.g., compressed air, or with a liquid blowing fluid, which is then primarily a liquid filling material, in particular a beverage.

[0035] The plastic forming preferably takes place in a blow molding wheel, which has a plurality of circumferentially arranged blow molds in which the preforms are placed. The blow molds have an inner contour that corresponds to the shape of the beverage containers to be produced. Each blow mold is assigned a blowing module through which the blowing fluid can be introduced into the interior of the container. During the blow forming process, the blow molding wheel rotates, so that the preforms are transported further during the plastic forming. Preferably, the blow molding wheel is assigned an inlet arrangement and an outlet arrangement, whereby the containers can be fed into the blow molding wheel via the inlet arrangement and removed again via the outlet arrangement. Both the inlet arrangement and the outlet arrangement can be designed as a star conveyor arrangement.

[0036] Furthermore, a heating device can be installed upstream of the blowing wheel to warm the preforms before they are fed into the blowing wheel. The heating device is preferably located between the blowing wheel and the transport assembly and can be connected to the linear guide either directly or via the feeding devices.

[0037] The invention further relates to a method for transporting preforms according to claim 15, wherein in particular preforms for forming beverage containers are fed to a transport arrangement according to the invention and are spaced apart from each other in a defined distance range during transport along a transport direction within the transport path section in the linear guide.

[0038] In particular, spacing is achieved by inserting the preforms into receiving pockets of at least one star wheel and by rotating the star wheel relative to each other.

[0039] In this arrangement, at least one star wheel is preferably driven exclusively by the transport of the preforms along the linear guide. Accordingly, no additional drive device is provided to cause the star wheel to rotate.

[0040] Furthermore, the preforms can be tilted within the linear guide during transport. This involves, in particular, tilting the container axis. This axis is typically rotationally symmetrical. Tilting this container axis aligns the preform during transport, with the tilt angle typically ranging from 5 to 25°.

[0041] According to a further development of the invention, the containers are separated and aligned during transport along a conveyor lane by counter-rotating conveyor rollers before being inserted into the linear guide. This results in a configuration similar to a roller sorter, whereby the features mentioned in this context can also be adopted for the method. In particular, the conveyor rollers have an upward direction of rotation in the conveyor lane. Furthermore, a further development of the method provides that the preforms are then transferred directly or via a feeding device, in particular an air transport device, to a blow molding machine, and the preforms are then plastically deformed by pressurizing the interior of the container.

[0042] The invention will now be explained using exemplary embodiments. The figures show:

[0043] Fig. 1 is a schematic representation of a device according to the invention.

[0044] Blowing machine arrangement,

[0045] Fig. 2 is an isometric representation of a transport arrangement known from practice,

[0046] Fig. 3 shows a side view of a transport arrangement with a linear guide known from the prior art,

[0047] Fig. 4 shows a top view of a transport arrangement according to the invention,

[0048] Fig. 5A, 5B alternative embodiment of the transport arrangement according to the invention.

[0049] Fig. 1 shows a schematic representation of a blow molding machine arrangement, which can also be used within the scope of the present invention. The blow molding machine arrangement has a blowing wheel 1 with a plurality of circumferentially arranged blow mold halves 2, over which preforms 3 are formed into beverage containers. This is done by introducing a blowing fluid, which in this case is compressed air or the product to be filled. In order to insert the preforms 3 into the blow molds 2, they are first fed via a feeding device 4 to a feed wheel 5, which inserts the preforms 3 into a heating device 6. Within this heating device 6, the preforms 3 are heated by associated heating elements 7 and simultaneously fed via receptacles 8 to a parting star 9, which inserts the preforms 3 into the blow molds 2.

[0050] The preforms 3 are usually supplied to the blow molding machine arrangement in a pre-fabricated state, initially present in a random arrangement within a collection container 10, which is shown in Fig. 2. Accordingly, the preforms 3 must first be arranged in a row one behind the other or separated and simultaneously aligned with their container opening 4 pointing upwards.

[0051] This takes place within a transport arrangement shown in Fig. 2. Here, the preforms 3 are removed from the collection container 10 via an inclined conveyor 11 and then fed to a sorting device 12. This sorting device 12, as shown in Fig. 3, has two conveyor rollers 13 spaced apart from each other in the transverse direction Q. These rollers are arranged to rotate in opposite directions and, due to their spacing, together form a conveying lane 14. Within the conveying lane 14, the conveyor rollers 13 rotate at a speed oriented in the vertical direction V. This causes the preforms 3 to be continuously thrown upwards along the conveying lane 14, aligning themselves with their container opening 4 facing upwards and simultaneously aligning themselves one behind the other within the conveying lane 14.The preforms 3 then rest on the conveyor rollers 13 with a neck ring 15, with the container body 16 extending through the conveying lane 14 formed by the conveyor rollers 13.

[0052] In practice, so-called air transport devices are used as the feeding device 4, which conveys the preforms 3 into the blow molding machine. Unlike a feed chute, these do not overcome any difference in height and are therefore arranged essentially parallel to the floor. In contrast, the sorting device 12 is inclined, so that the preforms are guided along different transport directions T within the sorting device 12 and the feeding device 4. This requires tilting the container axis 18 to achieve the corresponding angle adjustment.

[0053] To enable the appropriate tilting of the container axes 8, a linear guide 19 is typically provided, in which the preforms 3 with the neck ring 15 rest on the guide rails 21. The linear guide 19 is curved or has two transport sections 27, 28 arranged at a transfer angle W to allow for appropriate adjustment, the transfer angle W typically being between 5 and 25° and corresponding to the inclination of the singulation device 12.

[0054] However, this curved design means that the preforms 3, as shown in Fig. 3, can partially slide over each other, causing the preforms 3 to oscillate and jam, which inevitably leads to a standstill in the production operation.

[0055] To prevent such unfavorable tilting, Fig. 4 shows a transport arrangement according to the invention, wherein a spacer device 22 with a star wheel 23 is arranged below the guide rails 21. Fig. 4 refers to a view below the guide rails 21, so these are not shown. As the preforms 3 are conveyed along the transport direction T, they engage in receiving pockets 24 of the star wheel 23 and thereby cause the star wheel 23 to rotate along an axis of rotation D. The spacing of the receiving pockets 24 separates the preforms 3 from each other, whereby a predefined spacing range is formed by the defined division of the receiving pockets 24 and an interference with the preforms 3.

[0056] Furthermore, the star wheel 23 connects via a preload device 26 having a spring element 25, so that a predefined pressure of the star wheel 23 can always act on the preforms 3.

[0057] The axis of rotation D is also arranged essentially perpendicular to the transport direction T and to the transverse direction Q and is preferably located within a first transport section 27 designed as an inlet transport path section, which extends over a maximum of 20% of the length of the linear guide 20.

[0058] Figures 5A and 5B show alternative embodiments of the invention, wherein, according to Figure 5A, two star gears 23 with a common axis of rotation D are arranged one above the other. The axis of rotation D runs essentially parallel to the vertical direction V.

[0059] According to Figure 5B, the star wheels 23 are still arranged one above the other, but do not have a common axis of rotation; instead, they have axes of rotation D that are offset from each other parallel to each other along the transport direction T.

[0060] Furthermore, both star wheels 23 are arranged on one side of the linear guide 20.

[0061] Reference symbol list

[0062] 1 Blow wheel Blow mold halves Preforms Feeding device Feed wheel Heating device Heating elements Mounts Dividing star

[0063] 10 collection containers

[0064] 11 conveyor belts

[0065] 12 sorting unit

[0066] 13 conveyor rollers

[0067] 14 Fördergasse

[0068] 15 Neckring

[0069] 16 container bodies

[0070] 17 Container opening

[0071] 18 Container axle

[0072] 20 linear guides

[0073] 21 guide rails

[0074] 22 Spacing device

[0075] 23 Star wheel

[0076] 24 recording bag

[0077] 25 spring element

[0078] 26 Pre-tensioning device

[0079] 27, 28 transport sections

[0080] D axis of rotation

[0081] T Transport direction

[0082] V vertical direction

[0083] Q transverse direction

[0084] W Transfer angle

Claims

Patent claims:

1. Transport arrangement for transporting preforms (3), in particular preforms (3) for forming beverage containers, with at least one linear guide (20) which is configured to guide the preforms (3) during transport along a transport path section (27, 28), characterized in that a spacing device (22) is provided and configured to space at least two preforms (3) guided one behind the other in the linear guide (20) in the transport path section (27, 28) at a defined distance from each other.

2. Transport arrangement according to claim 1, characterized in that the linear guide (20) has at least two spaced-apart guide rails (21), wherein the spacer device (22) is arranged below the guide rails (21).

3. Transport arrangement according to one of the preceding claims, characterized in that the spacing device (22) has at least one rotatable star wheel (23) with a plurality of receiving pockets (24) arranged in the circumferential direction.

4. Transport arrangement according to claim 3, characterized in that the at least one star wheel (23) has a rotation axis (D) arranged substantially perpendicular to a transport direction (T) running along the transport path section (27, 28).

5. Transport arrangement according to claim 3 or 4, characterized in that at least two star wheels (23) are provided, which are arranged one above the other with a common axis of rotation (D) and / or next to each other with axes of rotation (D) running parallel to each other.

6. Transport arrangement according to one of claims 3 to 5, characterized in that the at least one star wheel (23) connects to a preloading device (26) which is configured to apply a preload force to the star wheel (23) in the direction of the linear guide (20).

7. Transport arrangement according to claim 6, characterized in that the pretensioning device (26) has at least one spring element (25).

8. Transport arrangement according to one of the preceding claims, characterized in that the linear guide (20) has different transport directions (T) on at least two transport path sections (27, 28) arranged one behind the other.

9. Transport arrangement according to claim 8, characterized in that planes extending in the transverse direction (Q) and in the transport direction (T) in the transport path sections (27, 28) are positioned at a transfer angle (W) to each other.

10. Transport arrangement according to one of the preceding claims, characterized in that the spacing device (22) is configured to position the preforms (3) within an inlet transport path- to space the section which extends over a maximum of 20% of the length of the linear guide (20).

11. Transport arrangement according to one of the preceding claims, characterized in that the linear guide (20) along the transport path connects to a sorting device (12).

12. Transport arrangement according to claim 11, characterized in that the sorting device (12) has a conveying lane (14) formed from two conveying rollers (13) spaced apart from each other in a transverse direction (Q) and arranged to rotate in opposite directions.

13. Transport arrangement according to one of the preceding claims, characterized in that a feeding device (4) for feeding the preforms (3) into a treatment device connects to the linear guide (20), wherein the linear guide (20) is designed to transfer the preforms (3) from the sorting device (12) to the feeding device (4).

14. Blow molding machine arrangement comprising a blow molding machine and a transport arrangement for transferring the preforms (3) into the blow molding machine, wherein the transport arrangement is designed according to one of the preceding claims and wherein the linear guide (20) connects directly or via the feed device (4) to the blow molding machine.

15. Method for transporting preforms (3), in particular preforms (3) for forming beverage containers, in a transport arrangement according to one of the preceding claims, wherein the preforms (3) are fed and during transport along a The transport direction (T) within a transport path section (27, 28) in the linear guide (20) is spaced apart from each other within a defined distance range.

16. Method according to claim 15, wherein the preforms (3) are inserted into receiving pockets (24) of at least one star wheel (23) and spaced apart from each other by rotation of the star wheel (23).

17. Method according to claim 16, wherein the at least one star wheel (23) is driven exclusively by the transport of the preforms (3) along the linear guide (20).

18. Method according to one of claims 15 to 17, wherein the container axes (8) of the preforms (3) are tilted during transport in the linear guide (20).

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