Method for machine cleaning of used bottles and bottle washing machine

Abstract

A method for the mechanical cleaning of used bottles (2) and a corresponding bottle washing machine (1) are described. The bottles are transported in / through the contact zone of a first alkaline solution (6) to soften any labels (3) present on the bottles. After the softened labels have been removed, the bottles are immersed in a second alkaline solution (9) for the main cleaning. By handling the bottles in the contact zone of the first alkaline solution in such a way that the first solution cannot penetrate the interior (2c) of the bottles, the introduction of label residues into the interior of the bottles via the first solution is reliably prevented. This ensures that microparticles, especially those contained in the label residues, are reliably kept out of the interior of the bottles.

Description

[0001] The invention relates to a method for the mechanical cleaning of used bottles and a bottle washing machine.

[0002] To clean reusable bottles, lye baths and lye sprays, also known as lye soaking, are commonly used to soften dirt, labels, glue residue, and the like. It is common practice to completely immerse the bottles in the lye baths to treat both the exterior and interior.

[0003] In a conventional bottle washing machine, for example, the following treatment steps or stages are sequenced as follows: residual emptying; pre-cleaning; first caustic bath (immersion bath with a caustic solution) including label removal; second caustic bath (immersion bath with a caustic solution) with label removal; caustic spraying; post-caustic treatment; warm water rinsing; cold water rinsing; fresh water rinsing or fresh water spraying. A level compensation for the caustic solution is usually provided between the two caustic baths. The caustic baths usually have a common treatment circuit for the caustic solution used in them and are directly connected to each other via the level compensation.

[0004] It has proven problematic that dirt particles, label residues (e.g., paper, plastic, or aluminum), glue residue, and the like, detached from the outside of the bottles, also find their way into the interior of the bottles via the lye used for this purpose. A particular disadvantage of modern labels is the increased contamination of varnish and ink particles with the lye used, which also carries these particles into the interior of the bottle.

[0005] It has also been found that such particles are difficult or impossible to completely remove in subsequent cleaning steps. This leads to an undesirable contamination of the cleaned bottles with microparticles or similar substances.

[0006] DE 42 25 028 A1 also discloses a bottle washing machine with cleaning stages that, among other things, perform a pre-cleaning with a first caustic solution and a main cleaning with at least a second caustic solution. The bottles are completely immersed in each stage. The bottles are transported upside down in the area of ​​a pre-caustic bath included in the pre-caustic bath.

[0007] DE 30 34 413 A1 discloses the preamble of claim 1 and also describes a bottle washing machine in which bottles are transported through two pre-soaking baths in a substantially upright position. The pre-soaking baths are part of a pre-soaking zone, followed by a caustic bath. In a first pre-soaking bath, the bottle necks are held above the liquid level and optionally sprayed from above; in the second pre-soaking bath, they are then completely submerged. This is intended to reduce the amount of wastewater generated in the first pre-soaking bath and its COD value. Furthermore, the bottles can be temperature-controlled more efficiently in the first pre-soaking bath. For this purpose, the pre-soaking baths are supplied with liquid from a caustic spray station via a pipe and an overflow weir.

[0008] There is therefore a need for improved mechanical cleaning processes for labelled returnable bottles and for correspondingly improved bottle washing machines.

[0009] The object is achieved by a method according to claim 1 and by a bottle washing machine according to claim 7.

[0010] The process is used for the mechanical cleaning of used bottles, i.e. reusable bottles that have been returned from sale and use.

[0011] The bottles are transported into / through the exposure zone of a first caustic solution to soften any labels present on the bottles. After the softened labels have been removed, the bottles are immersed in a second caustic solution for the main cleaning process. Furthermore, the bottles are handled within the exposure zone of the first caustic solution in such a way that the first caustic solution cannot penetrate the interior of the bottles.

[0012] This prevents the interior of the bottles from becoming contaminated with particles detached from the exterior of the bottles and consequently contained in the first lye, especially microparticles such as paint and ink particles. Consequently, otherwise necessary and, based on experience, inadequate treatment steps for removing such particles from the interior of the bottles are unnecessary.

[0013] Preferably, the first lye is conducted and / or processed separately from the second lye in order to prevent the first lye and in particular label residues, glue residues, paint and ink particles or the like contained therein from entering the second lye used for the main cleaning.

[0014] In particular, a separate circuit for the treatment of the first lye and the second lye is provided. This means that the first lye cannot enter the second lye. However, the second lye, which is less contaminated with the aforementioned contaminants, is permitted to enter the first lye.

[0015] The first and second lye solutions can have identical ingredients and / or concentrations, with the exception of the contaminants, label residue, or similar removed from the bottles. However, the first and second lye solutions could, in principle, also have different ingredients and / or concentrations. It is crucial to prevent any significant contamination of the first lye used to remove the labels into the second lye used for the main cleaning process.

[0016] To soften the labels, the bottles are preferably immersed in a first immersion bath filled with the first alkali, and the mouths of the bottles are kept above the fill level to prevent the first alkali from penetrating into the interior of the bottles.

[0017] Preferably, a closure area at the mouth for accommodating a screw cap, crown cap, or the like remains above the fill level throughout the immersion of the bottles. This allows all wall areas of the bottles that are typically used for labeling to be completely immersed in the first immersion bath without introducing the first lye into the interior of the bottles.

[0018] In other words, the bottles are only partially immersed in the first lye, in particular excluding the usually unlabelled mouths of the bottles and / or a closure area for receiving a closure cap.

[0019] In the process according to the invention, the bottles are filled with the second alkali while passing through the first immersion bath. This allows, on the one hand, the softening of any contaminants present in the interior of the bottles to take place in the sense of a pre-soak in the area of ​​the label removal. On the other hand, filling the bottles with the second alkali reduces the risk of the first alkali inadvertently entering the interior of the bottles. This means that splashes of the first alkali can be diluted in the filled bottles to a potentially non-critical concentration using the second alkali.

[0020] Preferably, the bottles are exposed to the first solution to soak the labels for a contact time of two to six minutes. This allows most common labels to be reliably softened for subsequent removal or to be removed from the bottles.

[0021] Preferably, the labels softened by the first lye are removed using a liquid flow and / or a liquid jet. A liquid flow can be generated, for example, using an agitator in an immersion bath filled with the first lye. A liquid jet could be generated, for example, by spraying water or lye.

[0022] For example, the second solution could be directed as a liquid jet onto the softened labels to remove them from the bottles. In principle, the use of the first solution would also be conceivable if the bottle mouths in the area of ​​the liquid jet are shielded from the first solution and / or the bottle mouths are sealed in the process. This could be possible, for example, with the help of stationary cover rails under which the bottle mouths run, protected from the liquid jet.

[0023] With the help of the liquid flow and / or the liquid jet, the removal of the labels can be accelerated and carried out more reliably.

[0024] Preferably, the bottles, in particular including a transport system with bottle baskets that handles the bottles, are rinsed on the outside before immersion in the second lye. This allows any residues of the first lye and / or label residues of the type mentioned above still adhering to the bottles and, if applicable, the transport system to be removed before the bottles, including their insides / interiors, are immersed in the second lye. This particularly reliably prevents contamination of the second lye with contaminants resulting from the removal of the labels.

[0025] The described bottle washing machine accordingly comprises a label removal stage with a first immersion bath for softening existing labels on the bottles using a first alkali and for removing the softened labels. Furthermore, the bottle washing machine comprises a subsequent main cleaning stage with a second immersion bath for the bottles containing a second alkali.

[0026] Furthermore, the bottle washing machine comprises a transport system that guides the bottles into / through the first immersion bath during the label removal stage in such a way that the first lye cannot penetrate into the interior of the bottles. The advantages described in claim 1 can be achieved with the bottle washing machine.

[0027] Additionally, the label removal stage can include a first caustic spray to soften the labels on the bottles. In this case, the transport system is further configured to guide the bottles through the first caustic spray in such a way that the first caustic cannot penetrate into the interior of the bottles. This can be achieved, for example, by appropriately shielding the bottle mouths or temporarily closing them.

[0028] The label removal stage preferably comprises a caustic solution circuit separate from the main cleaning stage for the conveyance and / or treatment of the first caustic solution. This means that the first caustic solution is conveyed and / or treated separately in such a way that it cannot be introduced from the caustic solution circuit into the second caustic solution. However, the reverse introduction of the second caustic solution into the first caustic solution is generally permissible.

[0029] Preferably, the transport system is designed to immerse the bottles in the first immersion bath while keeping the bottle mouths consistently above the fill level of the first lye. This allows all bottle sidewall areas suitable for labeling to be immersed in the first lye without immersing the mouth area and / or a closure area for receiving caps. This reliably prevents the first lye from penetrating the interior of the bottles while simultaneously effectively softening existing labels.

[0030] In addition, the transport system can further be designed in such a way that it shields the mouths of the bottles against any initial spraying of the lye, for example by means of a stationary shield on the transport system, under which the mouths of the bottles run in a suitable manner in order to prevent the first lye from penetrating into the interior of the bottles.

[0031] The label removal stage preferably comprises a device for applying a stream of water and / or spraying water onto the bottles to remove the softened labels from the bottles. This is possible, for example, with the aid of an agitator present in the first immersion bath and / or with a water spray, caustic spray, or the like, as already described with regard to the method.

[0032] The bottle washing machine preferably further comprises an intermediate rinsing stage arranged between the label removal stage and the main cleaning stage for removing the first lye and / or label residues, such as paint and ink particles, from the outside of the bottles. The intermediate rinsing stage can be arranged, for example, at the exit of the label removal stage or at the entrance to the main cleaning stage. The intermediate rinsing stage is then particularly designed such that the transport system guiding the bottles through the bottle washing machine is also rinsed in a corresponding manner in order to remove any residues of the first lye and / or label residues of the type described before the respective transport means enter the main cleaning stage / second immersion bath.

[0033] The bottle washing machine according to the invention further comprises a second lye circuit for the second lye used in the second immersion bath and a connecting line which connects the second lye circuit to the label removal stage in order to fill the bottles therein with the second lye and optionally also to spray the bottles therein with the second lye to remove the labels.

[0034] Introducing the second lye into the label removal stage is generally uncritical. This is especially true if the first and second lye contain the same ingredients and / or the same concentration of ingredients during production. The second lye is then preferably further used in a second lye spraying unit located downstream of the second immersion bath and supplied via the second lye circuit.

[0035] Preferably, the bottle washing machine further comprises a residual emptying stage and a pre-cleaning stage located upstream or downstream of the label removal stage. Depending on the configuration of the bottle washing machine, the described label removal stage can thus be flexibly combined with conventional residual emptying and pre-cleaning stages.

[0036] Preferably, the label removal stage is designed as an upstream module spatially separated from the main cleaning stage, with its own housing / treatment chamber and its own caustic solution circuit for the first caustic solution. For example, the label removal stage can then be retrofitted upstream of a main cleaning stage to relocate the label removal process from the main cleaning stage and then use it only for unlabeled bottles.

[0037] This means that bottle washing machines of known design can also be subsequently improved with a label removal stage according to at least one of the embodiments described above to avoid the aforementioned contamination problem. The label removal stage can then also be installed upstream of an existing residual emptying stage and pre-cleaning stage.

[0038] Preferred embodiments of the invention are illustrated in the drawings. They show: Figure 1 a schematic representation of the bottle washing machine according to a first embodiment; and Figure 2 a schematic representation of the bottle washing machine according to a second embodiment.

[0039] As the Figure 1As can be seen, the bottle washing machine 1 for cleaning used bottles 2, for example reusable bottles returned after consumption, with labels 3 attached thereto, comprises a label removal stage 4 with a first immersion bath 5 (lye softener) for softening the labels 3 in a first lye 6 contained in the first immersion bath 5 and a subsequent main cleaning stage 7 with a second immersion bath 8 (lye softener) for cleaning the outside and inside of the bottles 2 in a second lye 9.

[0040] The bottle washing machine 1 further comprises a transport system 10 with bottle baskets 11 circulating in the bottle washing machine 1 in a manner known in principle, in multiple tracks, each of which guides a bottle 2 through the bottle washing machine 1. The bottle baskets 11 are arranged, for example, on endlessly circulating chains or similar transport means at regular intervals from one another, although Figure 1only some bottle baskets 11 are shown schematically.

[0041] As in the Figure 1 As further indicated, the bottles 2 are guided by the transport system 10 in the region of the label removal stage 4 in such a way that at least the mouths 2a and preferably also a closure region 2b adjoining it downwards of the bottles 2 do not dip into the first lye 6, but only the lateral wall regions 2c located underneath, which are provided for receiving the labels 3.

[0042] Thus, existing labels 3 can be effectively and reliably softened by the first lye 6 without the first lye 6 entering the interior 2d of the bottles 2 through the mouths 2a of the bottles 2.

[0043] In the Figure 1Furthermore, a circuit 12 for guiding and / or processing the first lye 6 is schematically indicated. The first lye 6, contaminated with the detached labels 3 and small-sized label residues 13, is circulated and filtered through the circuit 12 in a manner known per se in order to separate the labels 3 and the label residues 13, such as paint and ink particles or the like, and to discharge and dispose of them in a suitable manner.

[0044] The first immersion bath 5 comprises a device 5a, for example, an agitator, for generating a liquid flow 5b in the first lye 6 in order to detach the labels 3 softened by the first lye 6 from the bottles 2. Additionally or alternatively, a device 14 for spraying the bottles 2, for example, a lye spray or water spray, would be conceivable in the region of the label removal stage 4 in order to detach the labels 3 from the bottles 2 by means of a liquid jet.

[0045] For example, the second lye 9 used in the second immersion bath 8 could be used to spray the bottles 2 after softening the labels 3. The second lye 9 could be added to the first lye 6 for this purpose, particularly if the first and second lye 6, 9 contain the same ingredients.

[0046] The bottle washing machine 1 further comprises an intermediate rinsing stage 15 arranged between the first immersion bath 5 and the second immersion bath 8, which is preferably designed as a spraying stage for the bottles 2 which are now label-free.

[0047] For example, the bottles 2 can be sprayed there with water or the second lye 9 to remove residues of the first lye 6 and any label residues 13 still adhering to the bottles 2 before the bottles 2 are immersed in the second immersion bath 8. This prevents residues of the first lye 9 and / or label residues 13 from being incorporated into the second lye 9.

[0048] For this purpose, the intermediate rinsing stage 15 is preferably further designed to spray the transport system 10 in order to remove any residues of the first lye 6 and / or label residues 13 that may be present thereon before the transport system 10 reaches the area of ​​the second immersion bath 8.

[0049] The main cleaning stage 7 preferably comprises a second circuit 17 for guiding and / or processing the second lye 9. The second circuit 17 is separated from the first circuit 12 such that the first lye 6 cannot enter the second circuit 17 in order to avoid contamination of the second lye 9 with the first lye 6.

[0050] In the area of ​​the main cleaning stage 7, the transport system 10 is preferably designed such that the bottles 2 are completely immersed in the second immersion bath 8 and are thus exposed to the second lye 9 both on the outside and on the inside in order to soften any soiling present on / in the bottles 2.

[0051] A connecting line 18 can branch off from the second circuit 17, which supplies the label removal stage 4 with the second lye 9, for example in order to fill the bottles 2 that are incompletely immersed in the first immersion bath 5 with the second lye 9.

[0052] This allows any contamination present in the bottles 2 to be softened already in the area of ​​the label removal stage 4. Furthermore, the risk of unintentional entry of the first lye 6 into the interior 2d of the bottles 2 can be reduced, in particular by completely filling the bottles 2 with the second lye 9. For example, any splashes of the first lye 6 that may occur in the area of ​​the mouths 2a could be diluted to a non-critical level by the second lye 9 present in the bottle 2.

[0053] For the sake of completeness, the discharge 19 of the labels 3 and label residues 13 separated from the first circuit 12 is also indicated schematically.

[0054] The bottle washing machine 1 comprises a machine housing 20 into which the label removal stage 4, the intermediate rinsing stage 15 and the main cleaning stage 7 can be integrated, as well as upstream or downstream cleaning stages and rinsing stages of a basically known type, such as a residual emptying stage 21, a pre-cleaning stage 22, a caustic solution spraying stage 23, a post-caustic solution stage 24, warm water rinsing stages 25, 26, a cold water rinsing stage 27 and a final fresh water rinsing stage 28. The treatment stages downstream of the main cleaning stage 7 can be designed, for example, as spraying stages for the bottles 2.

[0055] In the downstream lye spraying system 23, the second lye 9 is preferably used, so that the lye spraying system 23 can also be supplied with the second lye 9 from the second circuit 17.

[0056] The Figure 2shows schematically the bottle washing machine 31 according to a second embodiment. Here, system components with identical functions described with respect to the first embodiment of the bottle washing machine 1 are designated by the same reference numerals and are therefore not described again below. Instead, the differences between the bottle washing machine 1 according to the Figure 1 and the bottle washing machine 31 according to the Figure 2 described.

[0057] A significant difference is that the label removal stage 4 of the bottle washing machine 31 is designed as a pre-module 32 that is spatially separated from the main cleaning stage 7, with a separate machine housing 33 and separate treatment chamber 34.

[0058] Likewise, label removal stage 4 can then be installed upstream of residual emptying stage 21 and pre-cleaning stage 22. However, this configuration is only optional. This means that residual emptying stage 21 and / or pre-cleaning stage 22 may not be present or may be installed separately upstream of label removal stage 4.

[0059] It is indicated in the Figure 2 Furthermore, the main cleaning stage 7 can be divided into at least two sub-stages 7a, 7b, each with a second immersion bath 8 in which the bottles 2 are exposed to the second lye 9. A leveling device 8a can then be provided, for example, between the second immersion baths 8 of the individual sub-stages 7a, 7b.

[0060] The second circuit 17 can then supply both second immersion baths 8 with the second lye 9 or prepare it for both immersion baths 8. The connecting line 18 can then branch off from the second circuit 17 and / or one of the immersion baths 8 in order to supply the label removal stage 4 with the second lye 9, if necessary.

[0061] The bottle washing machine 31 according to the second embodiment illustrates that the label removal according to the invention could also be retrofitted to an existing bottle washing machine, if necessary in the form of the upstream module 32.

[0062] This is particularly conceivable since conventional bottle washing machines typically have several sub-stages with immersion baths supplied with a common caustic solution. It is then only necessary to relocate the label removal stage 4 from an existing bottle washing machine to a pre-module 32 to prevent the first caustic solution 6 contaminated with label residues 13 from entering the interior 2d of the bottles 2, see above. Otherwise, existing immersion baths 8 can in principle be operated as before, i.e., with alternating level compensation 8a and at least one (possibly shared) treatment circuit 17 for the second caustic solution 9 used therein.

[0063] In addition to the first immersion bath 5, the bottles 2 could also be exposed to the first alkali 6 using the device 14 for spraying the bottles 2, for example, from suitably aligned nozzles, in order to soften the labels 3. The mouth 2a of the bottles 2 would then have to be shielded from generated liquid jets and / or stray splashes, for example by stationary rails and / or shields and / or by lids, caps, or the like running in the area of ​​the label removal stage 4.

[0064] In the area of ​​the label removal stage 4, the mouths 2a and / or the closure areas 2b of the bottles 2 are guided above the fill level 6a of the first lye 6 in the first immersion bath 5 and / or shielded from splashes of the first lye 6. This can be achieved, for example, by adjusting the fill level 6a to the path of the transport means 10 and / or to the respective bottle format. The separated labels 3 and label residues 13 can be removed and disposed of in a known manner.

[0065] The feeding of the bottles 2 into the bottle washing machine 1, 31 as well as the transport of the bottles 2 can be carried out in a known manner in multiple lanes and continuously. A simultaneous feeding and removal of bottles according to Fig. 1 and 2 is not mandatory, but merely serves to provide a clearer presentation.

Claims

1. Method for the mechanical cleaning of used bottles (2), wherein the bottles are transported into / through the area of action of a first immersion bath containing a first lye (6) in order to soften labels (3) present on the bottles, and wherein, after the softened labels have been removed, the bottles are immersed in a second lye for main cleaning (9), wherein the bottles are handled in the area of action of the first lye in such a manner that the first lye cannot penetrate into the interior (2c) of the bottles, and characterized in that the bottles (2) are filled with the second lye (9) when passing through the first immersion bath (5).

2. Method according to claim 1, wherein the first lye (6) is fed separately from the second lye (9) and / or is treated to prevent the first lye and, in particular, label residues (13) contained therein from entering the second lye used for main cleaning.

3. Method according to claim 1 or 2, wherein the bottles (2) are immersed in a first immersion bath (5) filled with the first lye (6) to soften the labels (3) and the openings (2a) of the bottles are kept above the level (6a) of the first lye and / or closed in order to prevent the first lye from entering.

4. Method according to at least one of the previous claims, wherein the bottles (2) are exposed to the first lye (6) for a soaking time of 2 to 6 minutes to soak the labels (3).

5. Method according to at least one of the previous claims, wherein the labels (3) softened by the first lye (6) are removed by means of a liquid flow (5b) and / or a liquid jet.

6. Method according to one of the previous claims, wherein the bottles (2), in particular including a transport system (10) for handling the bottles with bottle baskets (11), are rinsed on the outside before being immersed in the second lye (9).

7. Bottle washing machine (1, 31) for used bottles (2), comprising: a label removal stage (4) with a first immersion bath (5) for softening labels (3) present on the bottles by means of a first lye (6) and for removing the softened labels; a subsequent main cleaning stage (7) with a second immersion bath (8) containing a second lye solution (9) for the bottles; a transport system (10) which guides the bottles in the label stripping stage in / through the first immersion bath in such a way that the first lye cannot penetrate into the interior (2c) of the bottles; a second lye circuit (17) for the second lye (9) used in the second immersion bath (8); characterized by a connecting line (18) connecting the second lye circuit (17) to the label removal stage (4) in order to fill the bottles (2) therein with the second lye.

8. Bottle washing machine according to claim 7, wherein the label removal stage (4) comprises a first lye circuit (12) separate from the main cleaning stage (7) for guiding and / or treating the first lye (6).

9. Bottle washing machine according to claim 7 or 8, wherein the transport system (10) is designed such that it immerses the bottles (2) into the first immersion bath (5) and thereby keeps the mouths (2a) of the bottles consistently above the fill level (6a) of the first lye (6) and in particular shields the mouths of the bottles from a lye spray present in the label removal stage (4).

10. Bottle washing machine according to one of claims 7 to 9, wherein the label removal stage (4) comprises a device (5a) for flowing and / or a device (14) for spraying the bottles (2) in order to remove the softened labels (3) from the bottles.

11. Bottle washing machine according to one of claims 7 to 10, further comprising an intermediate rinsing stage (15) arranged between the label removal stage (4) and the main cleaning stage (7) for removing the first lye (6) and / or removed label residues (13) from the outside of the bottles. (2).

12. Bottle washing machine according to at least one of claims 7 to 11, with a residual emptying stage (21) and a pre-cleaning stage (22) connected upstream or downstream of the label removal stage (4).

13. Bottle washing machine according to at least one of claims 7 to 12, wherein the label removal stage (4) is designed as a pre-connected module (32) separated from the main cleaning stage (7) with its own machine housing (33) and first lye circuit (12) for the first lye (6).

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