METHOD FOR HIGH-SPEED COATING THE INNER SURFACE OF A BLANK

Abstract

In a method for the high-speed coating of the inner surface of a blank (1), preferably a can, the blank (1) rotates about it axis of rotation and a coating is applied to an inner surface of the blank (1). In order to allow for an increase in production rates and for a homogeneous coating of the inner surface of the blank (1), even with low coating thicknesses, without causing an increase in operating costs, a gas flow (10) is blown into the blank (1) via a nozzle (9) to accelerate the blank (1) and to distribute the coating in the direction of the axis of rotation (12).

Claims

1. A method for high-speed coating an inner surface of a blank said method comprising: rotating the blank about an axis of rotation thereof; and applying a coating agent to the inner surface of the blank; and blowing a gas flow into the blank via a nozzle so as to accelerate the blank and so as to distribute the coating agent in the direction of the axis of rotation.

2. The method according to claim 1, wherein the gas flow is directed against an attack surface of the blank, said attack surface extending substantially transversely to the axis of rotation and adjoining the inner surface of the blank that is coated.

3. The method according to claim 1, wherein individual blanks are conveyed by the carrier in a plurality of blank receptacles from at least one loading station to at least one unloading station, and wherein the blanks are each rotated about their an axis of rotation thereof between the loading station and the unloading station, and the blanks, when at least partially coated, are ejected from the carrier in the unloading station with aid of the gas flow.

4. A device for coating inner surfaces of blanks, said device comprising: a loading station; a rotating device rotating the blanks about an axis of rotation; an unloading station; and a carrier for conveying the blanks from the loading station to the unloading station; wherein the unloading station has a nozzle being directed in a direction of the axis of rotation and ejecting the blanks.

5. The device according to claim 4, wherein the carrier is mounted rotatably about a vertical axis and has blank receptacles open radially outwardly so as to provide loading of the blanks in a direction of the vertical axis and unloading of the blanks in the direction of the axes of rotation.

6. The device according to claim 5, wherein the carrier forms a ring with radially outwardly extending blank receptacles.

7. The device according to claim 5, wherein the vertical axis is vertically aligned and normal to the axes of rotation of the blanks.

8. The device according to claim 4, wherein the carrier is associated with at least two processing segments, each having a respective loading station and a respective unloading station.

9. The device according to claim 6, wherein the vertical axis is vertically aligned and normal to the axes of rotation of the blanks.

10. The device according to claim 5, wherein the carrier is associated with at least two processing segments, each having a respective loading station and a respective unloading station.

11. The device according to claim 6, wherein the carrier is associated with at least two processing segments, each having a respective loading station and a respective unloading station.

12. The device according to claim 7, wherein the carrier is associated with at least two processing segments, each having a respective loading station and a respective unloading station.

13. The device according to claim 9, wherein the carrier is associated with at least two processing segments, each having a respective loading station and a respective unloading station.

14. The method according to claim 2, wherein individual blanks are conveyed by the carrier in a plurality of blank receptacles from at least one loading station to at least one unloading station, and wherein the blanks are each rotated about an axis of rotation thereof between the loading station and the unloading station, and the blanks, when at least partially coated, are ejected from the carrier in the unloading station with aid of the gas flow.

Description

BRIEF DESCRIPTION OF THE INVENTION

[0011] In the drawing, the subject matter of the invention is shown by way of example, wherein:

[0012] FIG. 1 shows a top view of the device according to the invention and

[0013] FIG. 2 shows a section along line II-II of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A device according to the invention for coating the inner surface of a blank 1, preferably a can, comprises, as can be seen for example in FIG. 1, a loading station 2 for loading a carrier 3 with the blanks 1. The blanks 1 are rotatably mounted in blank receptacles 4 of the carrier 3. The rotation of the blanks 1 can be performed by rotation devices 5, which can accelerate the blanks 1 via a frictional connection with the blank bottom 6. The rotation device 5 can, for example, be an electric motor with a plate 7 cooperating frictionally with the blank bottom 6. The blanks 1 are conveyed by the carrier 3 from the loading station 2 to nozzles for coating 8 the inner surface of the blank 1. There, a coating agent is applied to the inner surface of the blanks 1, after which or while the blanks 1 are accelerated in the circumferential direction by the rotating devices 5. This results in an initial application, i.e. a distribution of the coating agent along the inner surface of the blanks 1. The application of the coating agent can take place via several nozzles 8. The carrier 3 then conveys the blanks 1 to the unloading station 9, where a gas flow 10 (FIG. 2) is blown into the blank 1 via a nozzle 11, thereby accelerating the blank 1 in the direction of its axis of rotation 12 and ejecting it from the carrier 3. In this way, a particularly uniform application of the coating agent to the inner surface is achieved, since the distribution takes place not only circumferentially by rotation of the blank 1, but also by acceleration along the axis of rotation 12.

[0015] Particularly efficient acceleration of the blank 1 can be achieved if, as can be seen in particular from FIG. 2, the gas flow 10 is directed against an attack surface 13 extending essentially transversely to the axis of rotation 12.

[0016] As shown in FIG. 2, the carrier 3 can be rotatably mounted about a vertical axis 14. To enable gravity-driven loading of the carrier 3 by the loading stations 2 and ejection of the blanks 1 from the carrier 3 induced by the gas flow 10 of the nozzle 11, it is advisable for the carrier 3 to have blank receptacles 4 which are open at the top in the direction of the vertical axis 14 and radially outward in the direction of the axes of rotation 12. Favorable design conditions are obtained when the axes of rotation 12 intersect the vertical axis 14 at a common point.

[0017] It can be seen from FIG. 1 that the carrier 3 can be designed as a ring, which has radially outwardly extending blank receptacles 4. The ring-shaped carrier 3 can be rotatably mounted on the stator 15. The nozzles 8, 11 can be arranged on the stator 15, whereby a supply of operating means to the nozzles 8, 11 can be effected via stationary lines 16. In order to prevent the entry of any dirt particles during the coating process, the carrier 3 can be arranged between two stationary shielding surfaces 17, which form receptacles for rotary devices 5. The loading station 2 can be provided on the cover-side shielding surface 17.

[0018] A particularly energy-saving loading and unloading of the blanks 1 can take place if, as is disclosed in FIG. 2, the vertical axis 14 of the carrier 3 is aligned vertically and is normal to the axes of rotation 12 of the blanks 1. This also results in the advantage that a centrifugal force-induced distribution of the coating agent outwardly in the direction of the axis of rotation 12 of the blanks 1 is achieved solely by the conveying process of the blanks 1 in the carrier 3.

[0019] From FIG. 1, which corresponds to a top view of the device according to the invention, it can be seen that the carrier 3 can be provided for several working segments 18. In this way, the production rate can be increased without having to increase the rotation speed of the carrier 3. A loading station 2, nozzles 8, 11 and an unloading station 9 are assigned to each working segment 18.