DEVICE FOR INTERNALLY COATING CONTAINERS

Abstract

A device for coating containers, in particular bottles, including a vacuum chamber, a plasma generator, and a gas lance having an outlet opening protruding into the container for introducing a material to be deposited on an inner wall of the container. The inside diameter of the gas lance in a region of the outlet opening is enlarged relative to the inside diameter in a main section of the gas lance.

Claims

1. A device (1) for coating containers (18), comprising: a vacuum chamber (12), a plasma generator (14), and a gas lance with an outlet opening (26), which, when in operation in the intended manner, protrudes into the container (18) and serves to introduce a material which is to be deposited on the inner wall of the container (18), and serves as an antenna for the electromagnetic field orientation in the vacuum chamber, wherein the inside diameter (D) of the gas lance (20) in the region of the outlet opening (26) is enlarged relative to the inside diameter (d) in a main section (22) of the gas lance (20), wherein the gas lance (20) is widened in the region of the outlet opening (26) in a trumpet or conical shape.

2. The device (1) according to claim 1, wherein the inside diameter of the gas lance (20) in the region of the outlet opening (26) is greater than the inside diameter in a main section (22) of the gas lance (20).

3. The device (1) according to claim 1, wherein the gas lance (20) consists in the region of the outlet opening (26) of another material than in the main section (22).

4. The device (1) according to claim 1, wherein the gas lance (20) consists at least in part of special steel.

5. The device (1) according to claim 1, wherein the gas lance (20) consists at least in part of Al.sub.2O.sub.3.

6. The device (1) according to claim 1, wherein the gas lance (20) exhibits at the outlet opening (26) a diameter (D) which is at least two times larger than the inside diameter (d) of a main section (22) of the gas lance (20).

7. The device (1) according to claim 1, wherein the widened part of the gas lance (20) is arranged in a mounting part (32), which is held on the main section (22) of the gas lance (20) in a replaceable manner.

8. The device (1) according to claim 7, wherein the mounting part (32) comprises a sleeve (34), which engages around the main section (22) and secures the mounting part (32) on the main section (22).

9. The device (1) according to claim 7, wherein the inside diameter (dl) of the mounting part (32), at its end facing the main section (22) of the gas lance (20), corresponds to the inside diameter (d) of the main section (22) of the gas lance (20).

10. The device (1) according to claim 9, wherein the orientation of the inner wall of the mounting part (32) is flush with the inner wall of the main section (22) of the gas lance (20) at their mutually facing ends.

11. The device (1) according to claim 1, which is configured as a mass coating device with a coating capacity of at least 1,000 containers, and in particular at least 10,000 containers (18), per hour.

12. The device (1) according to a claim 1, wherein the plasma generator (14) is a microwave generator.

13. The device (1) according to claim 1, wherein an end edge (28) of the gas lance (20) is rounded at the outlet opening (26).

14. The device (1) according to claim 1, wherein an end edge (28) of the gas lance (20) is seamed outwards at the outlet opening (26).

15. The device (1) according to claim 1, wherein the gas lance (20) is configured as multi-part, wherein an end section (24) comprises the outlet opening (26) and a main section (22) forms the axially larger part of the gas lance (20), wherein the end section (24) is preferably held on the main section (22) in a replaceable manner.

16. The device according to claim 1 wherein the plastic containers are made from at least one of Polypropylene, Polyethylene, and Polyethylene terephthalate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is described hereinafter by way of examples and on the basis of the schematic drawings in which:

[0029] FIG. 1a depicts a top plan view of a rotating coating device, in which the vacuum chambers can always accommodate and treat two containers,

[0030] FIG. 1b depicts a side section view through a vacuum chamber of a coating device and a gas lance and a microwave generator,

[0031] FIG. 2 depicts a detailed view of the upper end of the gas lance from FIG. 2 in a first embodiment,

[0032] FIG. 3 depicts a detailed view of the upper end of the gas lance from FIG. 1 in a second embodiment,

[0033] FIG. 4 depicts a sectional vertical cross-section view of a third embodiment of the upper end of the gas lance, with a mounting part, which comprises an outlet opening; and

[0034] FIG. 5 depicts a simple embodiment of a cylindrical gas lance with an enlarged inside diameter in the end section.

DETAILED DESCRIPTION OF THE INVENTION

[0035] FIG. 1a shows a rotating coating device 1, on the transport wheel 2 of which are arranged the circulating coating stations 3, which in each case comprise a vacuum chamber 12, and wherein, in the example shown, two containers 18 can always be accommodated and treated. The delivery section 5 conveys the containers 18, transported standing upright, to a distributing star 6, by means of which the containers 18 are brought into the required uniform distance interval spacing. From there the containers 18 are taken over in pairs by a transfer star 7, comprising gripper elements, and transferred to a delivery wheel 4. From the delivery wheel 4, the containers 18 are then conveyed in pairs into the accommodation elements, not represented in greater detail, of the vacuum chambers 12, and are held there. In an analogous manner, treated containers 18 are released from the accommodation elements, and the containers 18 are conveyed by a discharge wheel 8 onto a discharge section 10.

[0036] Connected here, downstream, is usually a filling machine, not represented, or a device for decoration, such as a labelling machine or a printing machine.

[0037] FIG. 1b shows in a very schematic form a vacuum chamber 12 of the coating device 1, with a vacuum chamber 12, which is surrounded by a microwave generator 14. Held on a base plate 16 of the vacuum chamber 12, as a container, is a PET bottle 18, which is to be individually coated, in differentiation to the embodiment according to FIG. 1a. By means of the very schematically represented vacuum unit 9, the vacuum chamber 12 is brought to the required internal pressure. A gas lance 20 projects into the bottle 18. The gas lance 20 has a first main section 22, forming the longer axial part of the gas lance 20, and an end section 24, arranged in which is the outlet opening 26. This end section 24 of the gas lance 20, or its inside diameter, is widened in the region towards the outlet opening 26, as can be seen from the following detailed cross-section drawings 2 to 5, which show alternative embodiments of the gas lance 20 from FIG. 1.

[0038] The end section 24 of the gas lance 20 in FIG. 2 is therefore widened in the shape of a trumpet, such that the diameter D of the outlet opening 26 is more than double the size of the inside diameter d of the gas lance 20 in the main section 22. Advantageous with this embodiment is the fact that the inner surface of the gas lance 20, between the main section 22 and the end section 24, is smooth and rounded, such that there is neither a step nor an edge present at that point at which vortices could occur. Preferably, therefore, the inner surface of the gas lance, between the main section 22 and the end section 24, is smooth and round, without any edges or corners. The end edge 28 of the end section 24 of the gas lance 20, which surrounds the outlet opening 26, is round, which in turn reduces the tendency to the depositing of SiOx layers at the end edge 28. FIG. 3 shows a largely identical embodiment to FIG. 2. Here, however, the end section 24 is not trumpet-shaped, but widened in conical form, which creates a small edge 30 between the main section and the end section 24 of the gas lance 20. Here too, the end edge 28 is rounded at the outlet opening 26, and even somewhat thickened in the form of a beading, which reduces the depositing of SiOx layers at this end edge 28. In terms of machining, this embodiment is easy and economical to produce.

[0039] A further alternative embodiment of the gas lance 20 is represented in FIG. 4. Here, the main section 22 of the gas lance 20 is formed by a cylindrical tube with a defined inside diameter, mounted at the free upper end of which is a mounting part 32, which comprises a sleeve 34, which engages around the main section 22 of the gas lance 20 in order to secure the mounting part 32 on the main section 22. The mounting part 32 forms in this case, so to speak, the end section 24 of the gas lance 20. The mounting part 32 has at its end facing towards the main section 22 of the gas lance 20 an inside diameter dl, which corresponds to the inside diameter d of the main section 22 of the gas lance 20. In this way, in the inner region of the gas lance 20, there is no step between the main section 22 and the mounting part 32. The mounting part 32 is widened in conical fashion, in the same manner as the end section 24 of FIG. 3. Accordingly, the diameter D at the outlet opening 26 of the mounting part is about double the size of the inside diameter d of the main section of the gas lance 20. The mounting part 32 can be held by means of the sleeve 34, by friction grip or other connection means, such as screw thread or bayonet fitting, to the main section 22.

[0040] As an alternative or in addition, the sleeve 34 can also engage around the inner wall of the tubular main section 22. Here, it would then be possible for the wall thickness of the main section to be reduced on the inner side, such that, due to the rear engagement of the tube of the gas lance 20 by the sleeve 34, the inside diameter of the gas lance 20 is not reduced, and, additionally, no step is formed at which vortices could occur of the coating gas, in particular process gas, such as siloxane gas.

[0041] Finally, FIG. 5 shows a very simple embodiment of the invention, in which the end section 24 of the gas lance 20 exhibits in relation to the main section 22 simply an inside diameter D, which is greater than the inside diameter of the gas lance in the main section 22 of the gas lance 20. Although the technical flow properties are not so good as with the previous embodiments, this embodiment also leads to a reduced depositing of SiOx layers at the outlet opening.

[0042] It is obvious that the embodiments described heretofore do not restrict the basic principle of the invention. This can be varied within the framework of the following claims.

[0043] For example, the idea of the widened diameter of the end section 24 of the gas lance 20 in relation to the main section 22 (FIG. 5) can be combined with a following conical or trumpet-shaped widening of the end section 24, as is represented in FIGS. 2 and 3. Accordingly, the embodiments of FIGS. 5, 2 and 3 can be combined. It is also possible for only one region with enlarged diameter to be provided in the mounting part from FIG. 4, as is represented in FIG. 5. In particular, one of the foregoing embodiments can be put into application in coating stations on devices in accordance with DE 10 2010 023119 A1 or also EP 1 507 893 B1, or also in linear coating devices.

REFERENCE NUMBER LIST

[0044] 1 Coating device [0045] 2 Transport wheel [0046] 3 Coating station [0047] 4 Delivery wheel [0048] 5 Delivery section [0049] 6 Distributing star [0050] 7 Transfer star [0051] 8 Discharge wheel [0052] 9 Vacuum unit [0053] 10 Discharge section [0054] 12 Vacuum chamber [0055] 14 Microwave generator [0056] 6 Base plate [0057] 18 ContainerPET bottle [0058] 20 Gas lance (e.g. for process gas delivery, such as siloxane) [0059] 22 Main section of the gas lance [0060] 24 End section of the gas lance [0061] 26 Outlet opening [0062] 28 End edge around the outlet opening [0063] 30 Edge between the main section and the end section [0064] 32 Mounting part [0065] 34 Sleeve