Cleaning of press plates or endless press belts

Abstract

The invention relates to a method for cleaning a structured surface (1) of a press tool (2), in particular a press plate or an endless press belt, the contaminations on the surface being burnt away by at least one laser beam and combustion residues being subsequently removed from the surface by means of an air or gas stream.

Claims

1. A method for cleaning a structured surface of a press tool, in particular a press plate or an endless press belt, the method comprising: burning away contaminations on the surface with at least one laser beam without altering structures in the surface, and subsequently removing combustion revenues from the surface via an air or gas stream.

2. The method according to claim 1, wherein the combustion residues are aspirated.

3. The method according to claim 1, wherein the at least one laser beam for cleaning an endless press belt circulates the surface on a helical path, to which end the endless press belt and/or a laser generating the laser beam are/is moved.

4. The method according to claim 1, wherein the surface of the press tool of the laser beam is traversed by the laser beam in parallel lines.

5. The method according to claim 1, wherein a laser generating the laser beam for cleaning a press tool is disposed on a sledge that can be moved transversally to the longitudinal or rotational direction of the press tool.

6. The method according to claim 1, wherein the laser beam travels on the surface in partially-overlapping paths.

7. The method according to claim 1, wherein the laser beam is pulsed.

8. A method for creating a structured surface of an embossing tool, having the following steps in the order shown: i. masking of the surface with a structured mask; ii. etching of the unmasked parts of the surface to create a structured surface; iii. cleaning of the structured surface with a method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of the method according to the invention are explained below using the figures.

(2) These show as follows:

(3) FIG. 1 sketched arrangement of an endless press belt rotating on rollers and a laser head; and

(4) FIG. 2 sketched view of a press belt with a helical path traced on the surface of the press belt.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(5) FIG. 1 shows a sketched arrangement for cleaning according to the invention of the outer surface 1 of an endless press belt 2, passed over two drums 3, 4. At least one of the drums 3, 4 is driven, so that the press belt can be driven in the direction shown and/or in the opposite direction.

(6) At approximately the level of the plane in which the axes of rotation of the drums 3, 4 are positioned, outside of the press belt a laser head 5 is disposed, which can be moved transversally to the direction of rotation of the endless press belt 2 and parallel to the axes of the drums 3, 4 on a support 6.

(7) The positioning of the laser is controlled by software as a function of the desired gradient of the helical path in the direction transversal to the direction of rotation of the endless press belt.

(8) FIG. 2 shows the edges of a helical path 7 given as an example, along which the laser is moved over the surface of the endless press belt. In the case explained the turns of the helical path overlap. The overlapping front edge of a path is shown as a hatched area. The belt moves in the direction of the arrow. Thus the gradient a of a turn after the endless press belt has rotated once corresponds to the width of the non-overlapped part of a path.