EP0452943B1 - Method and device for applying a liquid onto bottles - Google Patents

Description

2. The invention relates to a method and a device for applying a liquid to bottles according to the preamble of claims 1 and 2 respectively.

Reusable bottles made of glass, plastic, etc. often become unsightly after several cycles due to the heavy use in the bottling plants and during transport to and from the consumer. In particular as a result of striking one another in the bottling plants, chafing spots as well as other chips and scratches are preferably formed in the upper and lower edge region of the cylindrical bottle body. In some filling companies, therefore, a thin film of liquid plastic, for example a siloxane, is applied to the reusable bottles, which largely covers the scratches and chafe marks and gives the bottles a new appearance (DE-OS 29 41 105). It has also already been proposed to wet the reusable bottles with a liquid cold-end tempering agent, as is similarly applied to the bottles in the glassworks, with each pass in the filling system. This is intended to refresh or maintain the protective film originating from glass production. Finally, it is known to apply a color film to bottles as well as liquid or pasty plastics as a protective jacket and to increase stability. All of these as well as other liquid ones or pasty agents suitable for application to the surface of bottles or the like are hereinafter referred to as "liquid" for the sake of simplicity.

For the application of liquids to bottles, special machines with their own drive and a transport star moving the bottles on a circular arc path have already become known (BE-PS 882 671; GB-A-20 47 578). The bottles in the transport star are set to self-rotation by rolling on a fixed friction segment and acted upon by rollers or sliding shoes made of elastic material rotating with the transport star, which are continuously wetted with the liquid by means of a feed device. These known, generic machines, with which unlabelled bottles are generally treated, can be quite satisfactory in terms of their application effect. However, it has been found that a relatively large amount of liquid has to be supplied in order to achieve a satisfactory transfer from the supply lines to the application elements and to ensure that the quantity of liquid absorbed is sufficient before the next rewetting so that it is evenly transferred to the bottles can. In this case, a large amount of liquid is generally sucked up in the application elements, which is then pressed out again by contacting the bottles and flows off downwards.

Finally, it is known from US-A-4,586,458 to transfer the liquid from a spray nozzle moving relative to an application element by means of intermediate rollers.

The object of the invention is to solve this problem and to improve a method and a device for applying liquids of the type mentioned in such a way that a wide variety of types of liquids with low liquid consumption could be applied evenly.

This object is achieved with the method specified in claim 1 and with the device specified in claim 2 with which this method can be carried out.

By applying the liquid with spray nozzles, which at least partly move at a distance from the application elements, it is possible to apply the liquid to the bottles in very thin layers with small amounts of liquid immediately before the liquid is taken over. As a result, it is not necessary for the application elements to have to store excessive liquid stocks. This leads to a reduction in fluid consumption.

The dependent claims reflect advantageous developments of the invention.

Through the use of the spray nozzles and the corresponding design of the application area, a full-area application of the liquid to the cylindrical bottle body according to claim 14 and also a targeted application to the upper and lower regions of the bottle body particularly susceptible to chafing are possible. Because the liquid is applied through the rotating nozzles directly to the outside of the application elements or the application surface formed thereby, this can consist of a sponge-like material with predominantly closed pores. As a result, the application element cannot soak itself up with liquid that would drip unused on the underside.

Finally, claim 19 describes an advantageous arrangement of the device according to the invention, the device being part of the outlet star of a labeling machine there.

Figur 1

eine im Auslaufstern einer Etikettiermaschine integrierte Vorrichtung nach der Erfindung,

Figur 2

den Schnitt A-B nach Figur 1,

Figur 3

eine teilweise Draufsicht auf die Etikettiermaschine mit der erfindungsgemäßen Vorrichtung und

Figur 4

den Schnitt C-D nach Figur 3.

Exemplary embodiments of the invention are described below with reference to the drawing. It shows

Figure 1

a device according to the invention integrated in the outlet star of a labeling machine,

Figure 2

the section AB of Figure 1,

Figure 3

a partial plan view of the labeling machine with the device according to the invention and

Figure 4

the section CD of Figure 3.

It should first be pointed out that the device according to the invention can be used equally at various points, independently of upstream or downstream fillers or labeling machines, in order to apply liquid to bottles. The invention is described below in a special application, where this device is part of a labeling machine and is integrated in the outlet star of the labeling machine.

This labeling machine according to FIGS. 1 and 2 is set up for labeling and subsequent coating of upright bottles 1, namely reusable glass bottles with a liquid, namely with a liquid plastic for covering chafing spots. This coating device is implemented in the star conveyor 7, which is referred to below as the discharge star.

The labeling machine has a box-like housing 21 in which a drive motor, not shown, is accommodated. On the housing 21, a turntable 2 with an upstream inlet star 6 and the star conveyor 7 designed as an outlet star and the outlet star 10 are rotatably supported about vertical axes.

The inlet star 6 is preceded by an inlet screw 22 which can be rotated about a horizontal axis and which brings the bottles 1, which are transported to the labeling machine on a horizontal conveyor belt 12, at a distance and transfers them to the inlet star 6 in accordance with the division. In its pockets 9, the bottles 1 are held by a stationary inlet bend 23 and then run onto the turntable 2, where they are fixed on controllable turntables (not shown) by means of lifting and lowering centering bells, not shown. The bottles 1 are then transferred from the turntable 2 to the first outlet star 7, on the circumference of which a stationary outlet arch 24 is arranged. The second outlet star 10 takes over the bottles 1 from the first outlet star 7 and places them on a horizontal conveyor belt 11, through which the bottles are transported away from the labeling machine. On the feed conveyor belt 12, the discharge conveyor belt 11 and on the circumference of the second outlet star 10, the bottles are guided through appropriately arranged fixed railings 26. In the area of the stars 6, 7 and 10, the bottles stand on stationary slide plates 29. The conveyor elements 2, 6, 7, 10 and 22 and the conveyor belts 11 and 12 are driven synchronously with one another and continuously in the direction of the arrow by the drive motor of the labeling machine, so that the bottles 1 can be transported precisely and gently even at high outputs.

On the housing 21, two conventional labeling stations 3 and 4 are also arranged which, with their rotating gripper cylinders 27, affect the orbit of the bottles 1 on the rotary table 2 and are driven synchronously with the rotary table 2 by the drive motor of the labeling machine.

By means of the first labeling station 3, the bottles 1 are provided with a body label and a breast label, which are firmly nestled to the bottles in a subsequent brushing station 28 with brushes and sponge rollers, not shown. The bottles 1 are provided with a back label by the second labeling station 4, which is pressed onto the bottles in a further subsequent brushing station 28 with brushes and sponge rollers (not shown). Then the fully labeled bottles 1 run into the first outlet star 7.

As shown in FIG. 2, the first outlet star 7 has an upper star plate 7 a and a lower star plate 7 b. The two star plates 7 a and 7 b are fixed parallel to each other at a distance on a common hub 7 c. On the top of the upper star plate 7 a and on the underside of the lower star plate 7 b, freely rotatable rollers 14 with axes parallel to the axis of rotation of the outlet star 7 are each mounted in the front and rear region of each pocket 9. The rollers 14 engage on the lowermost or uppermost area of the cylindrical bottle body and thus on the one hand enable an exact, division-appropriate transport and on the other hand an effortless rotation of the bottles 1 in the first outlet star 7.

The first outlet star 7 is assigned the device 8 for applying the liquid to the finished labeled bottles 1 which are moved in its pockets 9 on a circular arc path. This device 8 has a fixed friction and application element 13, which is arranged concentrically to the outlet star 7 and has an arcuate, more precisely partially cylindrical, friction and application surface. The friction and application element 13 consists of a closed-pore neoprene foam which is placed on a partially cylindrical support plate 30 is glued on. The support plate 30 is in turn attached in a vertical position to the stationary outlet arch 24. The arrangement is such that the bottles 1 located in the pockets 9 of the first discharge star 7 easily press into the neoprene foam of the friction and application element 13 and therefore come into frictional contact therewith. When the spout 7 rotates, the bottles 1 are therefore set to self-rotation continuously by means of the friction and application element 13.

In the arrangement according to FIG. 1, the bottles 1 are moved in the first outlet star over an angular range of approximately 270 degrees, the outlet star 7 having the same diameter as the inlet star 6. This relatively large angular range, which is the case with the usual bottle and star diameters An at least four times self-rotation of the bottles 1 is possible due to the opposite deflection in the subsequent second outlet star 10 and the arrangement of the discharge belt 11 laterally offset with respect to the feed belt 12.

Another possibility is indicated in Fig. 3. Here the diameter of the outlet star 7 is larger than that of the inlet star 6. There is no second outlet star. Instead, the discharge conveyor 11 runs in its initial region tangentially to the outlet star 7 and thus at an acute angle to the feed conveyor 12. A relatively long friction and application surface can also be realized in this way, which is completely sufficient for applying the usual liquids to bottles.

The device 8 on the first outlet star 7 has, in addition to the friction and application element 13, a further essential component the friction and application area from the outside metered with liquid wetting supply line 15. Their active elements are spray nozzles 16, which are attached radially outward in height between the star plates 7 a and 7 b and circumferentially between two adjacent pockets 9 on the first outlet star 7. The spray nozzles 16 thus rotate together with the first outlet star 7. In the exemplary embodiment according to FIGS. 1 and 2, a spray nozzle 16 is provided after every second pocket 9, which is suitable for many applications. If there is a higher consumption of liquid or a thicker coating, one or more spray nozzles 16 can also be provided after each pocket 9. On the other hand, a spray nozzle 16 can also be provided, for example, only after every third or fourth pocket 9 with low consumption or a smaller layer thickness.

As shown in FIGS. 1 and 2, the slot-shaped nozzle opening of each spray nozzle 16 is oriented in such a way that it directs a jet which widens out in a fan shape past two adjacent bottles 1 onto the fixed friction and application element 13. The jet extends radially outward with respect to the axis of rotation of the first outlet star 7, specifically in a vertical plane passing through the axis of rotation. The bottles 1 themselves are therefore not reached by the spray jet. On the other hand, when the second outlet star 7 rotates, the friction and application surface of each individual spray nozzle 16 is sprayed with liquid essentially over the entire height and over a certain length, ie in the form of a surface. The spray jet expediently ends at a short distance from the upper and lower edge of the friction and application surface, so that the spray jet is reliably prevented from going beyond the friction and application element 13.

Each spray nozzle 16 is connected via a short pipe or hose piece with its own switching valve 19 which is attached to the upper star plate 7 a in such a way that its spring-loaded switching pin protrudes upwards. Each switching valve 19 is connected by a further short piece of pipe or hose to a common rotary distributor 17 which is concentric with the first outlet star 7. The rotatable part of the rotary distributor 17 is attached to the upper star plate 7 a. The fixed part of the rotary distributor 17 is secured against rotation via a horizontal arm 25, which is supported with its free end on a vertical column 5. A longer piece of pipe or hose runs from this distributor 25 from the rotary distributor 17 to the closed reservoir 18 for the liquid. From this, the liquid is pushed up and pushed through the spray nozzles 16 by introducing compressed air at an adjustable pressure.

A fixed control cam 20 for the switching valves 19 is also attached to the arm 25. This is designed as an arcuate stroke curve and projects into the orbit of the switching pins in such a way that they are pressed down in the area of the control curve 20 and thereby release the liquid supply to the spray nozzles 16. As FIG. 1 shows, the control cam 20 begins shortly after the start of the friction and application element 13 and ends approximately after two thirds of its length. Outside the control curve 20, the switching valves 19 are automatically closed under the influence of their spring elements; the liquid supply to the spray nozzles 16 is prevented.

As shown in Fig. 2, the effective friction and application area of the almost completely over its entire height with liquid sprayed friction and application elements 13 over the entire cylindrical area of the bottle body, including the labeled area. Of course, it is also possible to apply only certain partial areas of the bottle body, as indicated in FIG. 4. Here, the friction and application element 13 is made in two parts and only covers the upper and lower edge area of the cylindrical bottle body. Each part of the friction and application element 13 is supplied by its own spray nozzle 16.

When production of the labeling machine described above is started, the supply of the liquid to the spray nozzles 16 is initiated by manually or automatically opening a control valve 31 which regulates the compressed air supply to the storage container 18. As a result, the spray nozzles 16 standing in the area of the control curve 20 are supplied with liquid under pressure and begin to spray the relevant areas of the friction and application element 13 with liquid. If the labeling machine is still at this point, only parts of the friction and application area are applied. Since, as a result of the closed-pore design, the friction and application element 13 does not store any liquid, it runs downward and is collected in a channel 32 which covers the entire lower edge of the friction and application element 13. If the labeling machine is already rotating, the first two thirds of the friction and application element 13 are wetted over the entire area by the spray nozzles 16, which are always open in this area. In this case too, the excess liquid drips down as long as there are no bottles 1 present. The control valve 31 is therefore expediently only opened shortly before the first labeled bottles reach the outlet star 7. Automation of this process is extremely simple, since in any case any conventional labeling machine has at least one bottle sensor, through which the label dispensing is controlled. The channel 32 can then also be dispensed with.

The labeled bottles 1 entering the first outlet star 7 are rotatably received in the pockets 9 thereof by the rollers 14 and continuously rotated by rolling on the stationary friction and application element 13. At the same time, the bottles 1 absorb from the rubbing and application surface the liquid previously applied by the spray nozzles 16 running between the bottles 1, distributed uniformly over the circumference. In the end region of the friction and application element 13, in which the spray nozzles 16 are already closed, there is another intensive rolling on and, if necessary, squeezing off excess liquid. Layer thicknesses of a few millimeters thick or from a few milligrams of liquid can be achieved without any problems. By appropriate selection of the pressure in the reservoir 18, the number and design of the spray nozzles 16 and the choice of shape and material for the application and friction element 13, a simple adaptation to the operating conditions is possible.

The application and friction element 13 according to FIG. 2 additionally intensively rolls up the body and back labels which are wetted with the liquid plastic or the like. This leads to an extremely advantageous appearance of the finished bottles 1.

Claims (19)

1. Method for applying a liquid to bottles, in which the bottles are conveyed spaced apart over part of a transport path in contact with at least one applicator element and at the same time, while rotating, receive liquid on at least part of their outer surface, characterised in that the liquid is applied to the stationarily mounted applicator element (13) by neans of at least one spray nozzle (16) which moves at a distance from the applicator element and points directly at the applicator element.
2. Apparatus for applying a liquid to bottles, with a conveying device (7) for the bottles, with at least one applicator element (13) past which the bottles are transported in contact and while rotating, and with a supply pipe (15) for supplying liquid to the applicator element, characterised in that the supply pipe (15) comprises at least one spray nozzle (16) which is movable at a distance from and relative to the stationarily mounted applicator element (13) and also points directly at the applicator element (13).
3. Apparatus according to claim 2, characterised in that the spray nozzle (16) is arranged on the conveying device (7).
4. Apparatus according to claim 2 or 3, characterised in that the conveying device is constructed as a star conveyor (7) with recesses (9).
5. Apparatus according to claim 4, characterised in that the applicator element (13) is mounted stationarily at the circumference of the star conveyor (7) with an arcuate applicator surface.
6. Apparatus according to claim 4 or 5, characterised in that the spray nozzle (16) is mounted between two recesses (9) of the star conveyor (7) and is essentially oriented radially outwards.
7. Apparatus according to claims 3 to 6, characterised in that several spray nozzles (16) are arranged evenly distributed at the circumference of the star conveyor (7).
8. Apparatus according to any of claims 4 to 7, characterised in that the spray nozzles (16) comprise a slot-like nozzle opening arranged parallel to the axis of rotation of the star conveyor (7).
9. Apparatus according to any of claims 4 to 8, characterised in that the spray nozzles (16) are mounted between the two parallel plates (7a, 7b) of the star conveyor (7).
10. Apparatus according to any of claims 4 to 9, characterised in that -he spray nozzles (16) are connected by a rotary distributor (17) arranged concentrically with the axis of rotation of the star conveyor (7), to a storage tank (18) for the liquid.
11. Apparatus according to any of claims 2 to 10, characterised in that the supply pipe (15) comprises a control device (19, 20) which supplies the spray nozzles (16) with liquid only on passage of the applicator element (13).
12. Apparatus according to claim 10, characterised in that the control device (19, 20) is constructed in such a way that the spray nozzles (16) wet only an initial region of the applicator element (13) with liquid.
13. Apparatus according to claim 11 or 12, characterised in that in front of each spray nozzle (16) is mounted a separate control valve (19) which is opened or closed by a stationary cam (10).
14. Apparatus according to any of claims 2 to 13, characterised in that the applicator element (13) essentially acts upon the whole of the cylindrical region of the bottles including any labelled zones and is essentially wetted with liquid over its full height.
15. Apparatus according to claim 14, characterised in that the spray nozzles (16) emit a fan-like jet passing radially outwards between adjacent bottles.
16. Apparatus according to any of claims 2 to 15, characterised in that the applicator element (13) comprises several narrow arcuate applicator surfaces which act upon the cylindrical region of the bottles preferably at the upper and lower edges.
17. Apparatus according to claim 16, characterised in that each of the narrow applicator surfaces is wetted by at least one separate spray nozzle (16) rotating with the star conveyor (17).
18. Apparatus according to any of claims 2 to 17, characterised in that the applicator element (13) is made of a sponge-like material with predominantly closed pores.
19. Apparatus accordina to one or more of claims 2 to 18, characterised in that the star conveyor is the output star conveyor of a labelling machine.

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