Coating system for metal bands and method for producing metal bands which are coated on one side

Abstract

The invention relates to a coating system for metal bands, comprising a melt bath with liquid coating material, a coating roller, and a band guide for the metal band which runs over the coating roller, wherein the coating roller only partially immerses in the melt bath, and this roller comprises a material which is not wettable by the liquid coating material.

Description

Further advantages and developments of the invention are explained in detail with reference to the schematic drawings.

In the drawings, in this case:

FIG. 1 shows a front view of a coating system with melt bath, and

FIG. 2 shows a side view of the coating system according to FIG. 1.

Parts which correspond to each other in all the figures are provided with the same designations.

A coating system 1 with a tin bath 2 is shown in FIG. 1, which bath is located in a heated melt tank with insulation 4. The one-sided tinning is carried out by a coating roller 6 which immerses in the tin bath 2. This coating roller comprises ceramic solid material in which no coating material adheres to the surface of the coating roller 2. FIG. 2 shows a side view of the coating system 1.

The coating roller 6 only partially immerses in the tin bath 2. At the same time, the metal band 14, which is to be coated on one side, is guided through the tin bath 2 by means of guide rollers 12, as a band guide with the necessary band tension, in a manner in which the band fits tightly against the coating roller 6 in order to avoid an unwanted penetrating of the molten metal between metal band 14 and coating roller 6. The individual process units are mounted on a supporting framework 10. The running direction L of the metal band 14 is identified in each case by means of an arrow.

In the coating system 1 which is shown in FIGS. 1 and 2, the roller pivot 8 of the coating roller 6 does not immerse in the tin bath 2. As a result of this, the coating roller 6 is only partially brought into contact with the melt. Since with metal coatings which contain tin the desired final thicknesses of the coating are appreciably below the thickness of the originally applied material, surplus tin is removed over two stages. For this purpose, by means of a doctoring unit 16 and a blast nozzle 18 which are located downstream of the melt bath 2, as seen in the running direction L of the band, the coating thickness is established in the coated metal band 14.

There can be further process units added upstream, as for example a chemical or mechanical cleaning unit of the band surface before the coating. In the same way, further process units can also follow downstream, as for example a furnace for temperature treatment of the applied metal coating.

LIST OF DESIGNATIONS

• 1 Coating system
• 2 Melt bath/tin bath
• 4 Melt tank with insulation
• 6 Coating roller
• 8 Roller pivot
• 10 Supporting framework
• 12 Band guide/guide rollers
• 14 Metal band
• 16 Doctoring element
• 18 Blast nozzle
• L Running direction

Claims

1. Coating system for metal bands, comprising a melt bath with liquid coating material, a coating roller and a band guide for the metal band which runs over the coating roller, wherein the coating roller only partially immerses in the melt bath, and at least the surface of the coating roller comprises a material which is not wettable by the liquid coating material.

2. Coating system according to claim 1, wherein the surface of the coating roller is concavely or conically formed towards the middle of the roller.

3. Coating system according to claim 1, wherein the pivot of the coating roller which immerses in the melt bath is located above the surface of the melt bath.

4. Coating system according to claim 1, wherein a doctoring element is located downstream of the coating roller, as seen in the running direction of the band.

5. Coating system according to claim 1, wherein at least the coating roller is located in a closed housing with protective gas.

6. Method for producing metal bands which are coated on one side by means of a coating system, comprising the steps: a metal band (14) is guided over a coating roller,a coating is applied on the metal band on a surface which lies opposite the coating roller, andsurplus coating material is removed down to the desired coating thickness, before or after the metal band is lifted from the surface of the coating roller.

7. Coating system according to claim 4, further comprising a blast nozzle located downstream of the coating roller, as seen in the running direction of the band.

8. Coating system according to claim 1, further comprising a blast nozzle located downstream of the coating roller, as seen in the running direction of the band.