DE4033230A1 - Surface textures on metal press platens - are produced on plates or endless bands by subjecting surface to laser beam, controlling platen movements and beam intensity by computer - Google Patents

Abstract

Large metal platens and/or endless bands are given a surface texture by means of laser beams. The process pref. uses rubber, plastics or other elastomer in an intermediate stage. In prodn. of a texture on one continuous steel band for hot pressing application. The band (18/19) is passed round two parallel cylinders (25,26) suitably placed apart. A laser beam head (27) is mounted so that it can be moved on two tracks (28) while the band moves round. The movement of the band (18/19) and of the laser beam head (27), as well as the intensity of the laser beams (27') are controlled by a computer (30). The band can be moved continuously or stepwise, the laser beam can be directed in lines or from one edge to the other. ADVANTAGE - The method engraves textures in a precise manner and hence reproduces effects accurately.

Description

The invention relates to a method for bring embossed engravings to large-format, metal ones Press plates and / or endless belts for the surfaces treatment of sheets or sheets of plastic, Wood, leather or any other material or Press laminates for use in discontinuous or continuously working heating presses and one afterwards manufactured product.

Metal embossing dies are used, for example, in the Furniture industry for surface structuring of Plastic sheets made of PVC, polyester, cork, with Melamine coated chipboard, thermoset Laminates and the like used as a structure turbilder often wood pores, fine or Coarse grain, pictorial representations, but also have any other surface structure.

The structuring is usually done in hy draulic floor heating presses using large format Die press plates or in known, continuous endless belt systems.

For the production of embossed structures in such Press plates or endless belts are used known technologies, such as in the DE-PS 27 06 947 discloses. In this well-known Procedure is based on the endless steel belt or the flat, large-sized sheet on one or both sides an etch-resistant color using a suitable print device, for example a rotary printing machine, a structure pattern printed, whereby after drying the caustic paint, the steel band or the press plate is subjected to an acid etching treatment.  

The color-free areas are thereby in predetermined depth etched off, so that after the etching process, several times in order to maintain superimposed structures can be repeated, a desired embossed engraving profile arises. After the end of the etching treatment, the Endless steel strip or the press plate of a final one Polishing, matting and glossy treatment and possibly Subsequent hard chrome plating. Other Known manufacturing processes for obtaining embossing Use engravings on the press plates or endless belts a reproduction photographic or an electroplating Procedure.

These known embossed engraving processes are relative to agile and rely on traditional techniques, which, without exception, involve a high level of manufacturing effort.

The invention is therefore based on the object for the production of embossed engravings modern manufacturing to make the process usable and an essential one higher manufacturing accuracy of the structure achieve than was previously possible.

This is achieved according to the invention in that the Embossed engravings according to a given pattern directly or indirectly with the help of laser beams on the press plates and / or the endless belts be brought. The embossing is carried out engraving either directly into the metal of the press plates and / or endless belts by burning in the laser beams, or in that the press plate and / or Endless belt first with a full-area carrier sheet made of rubber, plastic, elastomer or a gal Vanic metal layer is coated, the through the embossed structure created only the thickness the carrier web detected, that is, applied indirectly becomes.  

By the idea of the invention one uses be known metal laser beam process and transmits it on the production of embossed engravings for large format metal press plates and / or endless belts at Surface treatment of sheets or plates Plastic, wood, leather or other materials or Press laminates for use in known heating presses.

The transfer of this modern metalworking Process opened on this special technical Completely new perspectives regarding the area Structural accuracy of embossed engravings. Besides, is it is possible through the proposal according to the invention become the required machine investment and the one previously used for an embossing process Significantly reduce manufacturing time.

In a special embodiment of the invention The laser beams are expedient computer controlled and that is on the press plates and / or endless ribbons design image to be transmitted on a magnetic tape connected to the computer saved. Preferably during the on effect of the laser beams the relative movement between the press plate or the endless belt and the laser beam head matched.

The laser beam head is stationary during manufacture firmly while the endless belt or the press sheet moved line by line, or the sequence of movements reversed. Because it is possible the laser beam guidance with very high sensitivity speed control is on the press plate or Endless belt a correspondingly fine design picture reproduced with the highest accuracy.  

Since the energy flow for the laser beam at all times, d. H. can be changed in fractions of a second can, it is possible even during manufacture to intervene in the process flow and ge targets different depths on the press plate or steel band. This was up with everyone known structural processes for large format term metal press plates and / or endless belts not possible.

According to a further feature of the invention Relative movement between the endless belt and the Laser beam head matched so that the The start of engraving and the end of engraving are exactly passer form exact transition. This proposal got of particular importance in practice because it is related to the previous manufacturing processes for metals Endless belts for the application according to the invention the unwinding length of a such a band, which is usually about a length from 7 m to 14 m, with zero tolerance put. So far, all tolerances have been met +/- 10 mm based on the total length. By the proposal according to the invention can be Inclusion of a calculator after measuring the exact length of each endless belt struk design tower patterns that are exactly to the lengths reports of the volume are coordinated. This leaves with the desired design patterns Adhere to exact repeat dimensions.

The invention opens up a further Ver Driving variant for the use of lasers with right reduced power. This is made possible by the fact that the endless belt and / or the press plate first with  coat an etch-resistant color film of defined thickness before it is exposed to laser beam engraving the energy of the laser beams is controlled in this way is that the coating down to the bare metal Make structural wear before the tape and / or the press plate is subsequently subjected to an etching treatment lung is subjected.

With this process variant, any one can be Ribbon length provided with a pattern without repeat. The remaining coating of the tape and / or the Sheet metal is after the subsequent etching treatment removed by means of a solvent, the Etching treatment as described in the beginning, in a known manner Repeat one or more times.

Different embodiments of the invention Procedures are based on the accompanying drawings explained in more detail below; show in the drawing:

Fig. 1 shows a partial cross section through a known hot press during the shaping,

Fig. 2 is a simplified side view of a heating press having endless belts during the structuring of a Preßlaminates,

Fig. 3 shows a revolving metallic endless belt with an upstream laser beam head and the computer while the laser beam action on the surface of the endless belt,

Fig. 4 is a schematic plan view of the A direction of Fig. 3 during laser engraving treatment,

Fig. 5 is a partial front view of a device for engraving a flat metal press plate by means of laser beams and

Fig. 6 is a plan view of the device according to Fig. 5.

Figs. 1 and 2 show two ways of applying the inventive method fro press plates made. Fig. 1 shows schematically a discontinuously operating known heating press, which essentially comprises an upper press frame 10 , a lower press frame 11 , an upper pressure and heating plate 12 , a lower pressure and heating plate 13 , on the mutually facing sides of the pressure and heating plates 12 , 13 fixed, with embossed engravings seen press plates 14 , 15 , between which a plate 16 to be structured is located and has a hydraulic pressure lifter 17 , which acts on the lower pressure and heating plate 13 .

Fig. 2 shows a continuously operating heating press, which comprises two endless ver with the embossed steel bands 18 , 19 seen . The mutually facing dreams of the steel strips 18 , 19 are pressed by two pressure transmitters 20 , 21 to the plate 16 to be structured. The steel strips 18, 19 run around four axle arranged parallel drums 20, 21, 22, 23, wherein the two a respective steel strip 18 and 19 respectively arranged in ordered pairs of drums 20, 21 and 22, 23 in the same axial spacing to each other each other.

FIGS. 3 and 4 show the production of the emboss engraving of one of the two in the continuous hot press ar beitenden of FIG. 2 steel belts 18 or 19 used. This device is equipped with two axially parallel cylinders 25 , 26 , over which a respective steel strip 18 or 19 is placed. The center distance of the cylinders 25 , 26 depends on the length of the steel strip 18 or 19 . The device is also equipped with a laser beam head 27 , which belongs to the prior art and is therefore not described in detail. The laser beam head 27 is along one of two guide rails 28 , the parallel and at a distance from the axis of rotation of the associated cylinder 25 extending guide track ver mobile. The movements of the steel strip 18 or 19 and the laser beam head 27 are controlled by a computer 30 . Likewise, the intensity of the beams 27 ' generated by the laser beam head 27 ' can be controlled by the computer 30 .

The embossed engraving is made using two different working methods. FIGS. 3 and 4, the steel strip 18 or 19 rotates. This can be done gradually, at a constant or changing speed. The laser beam head 27 stands still during one revolution of the steel strip 18 or 19 . Then it is moved one step further. The embossing is consequently carried out line by line from one longitudinal edge of the steel strip 18 or 19 to the other, ie parallel to the longitudinal edges. The area that has already been engraved is identified in FIG. 4 by the double-layered area. In the device according to FIGS. 3 and 4, however, alternatively when the steel strip 18 or 19 is at a standstill, the laser beam head 27 can be moved gradually, with constant or changing speed across the longitudinal edges of the steel strip along the guide 28 . If the laser beam head 27 has arrived at a long side of the steel strip, the steel strip 18 or 19 is advanced by one line. The engraved lines then run transversely to the longitudinal edges of the steel strip 18 or 19 .

FIGS. 5 and 6 show the production of the emboss engraving of a press plate 14 or 15 for the heating press according to Fig. 1. The press plate 14 or 15 rests on a horizontal table 29. The laser beam head 27 is on a transverse to the longitudinal edges of the press plate 14 or 15 traverse 31 ge stored and controlled by the computer 30 movable.

At the ends of the cross member 31 there are running rollers 32 so that the cross member 31 along and parallel to the longitudinal edges of the press plate 14 or 15 ver running guide rails 33 can be moved. The movement of the laser beam head 27 from one longitudinal edge to the other longitudinal edge of the press plate 14 or 15 is advantageous since the length of the press plate 14 or 15 is substantially greater than its width. In the illustrated embodiment, the laser beam head is moved for line-by-line engraving in the direction of the longitudinal edges of the press plate and transversely thereto. In a modification of the embodiment shown in the drawing, it is also possible that the table 29 is moved in the opposite direction in the longitudinal and transverse directions of the press plate 14 or 15 and the laser beam head is stationary. It is also possible that the laser beam head 27 is moved in one direction and the table 29 in the other direction. A magnetic tape is advantageously used as the memory for the data to be fed into the computer.

The laser beams act in the examples shown directly on the metal of the press plates or end tapes. But it is also possible to press sheet and / or the endless belt with a first full-surface carrier sheet made of rubber, plastic, Elastomer or with a galvanic metal layer to coat and the laser beams in their Inten sity so that control by the laser beams created embossing structure only the thickness of the carrier web or the carrier layer, d. H. the carrier web or the cover layer becomes so thick in its thickness structured until bare metal spots on the surface the press plate or the endless belt exposed be, so that the subsequent Etching treatment can be made.

Claims (13)

1.Surface-structured, large-format metal press plates and / or endless belts for the surface treatment of webs or plates made of plastic, wood, leather or any other material or press laminate for use in discontinuously or continuously operating heating presses, characterized by a surface structure by the action of laser beams. 2. Method for applying embossed engravings on large-format metal press plates and / or endless belts for the surface treatment of sheets or plates made of plastic, wood, leather or any other material or press laminate for use in discontinuously or continuously operating heating presses, characterized in that the embossed engravings In accordance with a pre-defined pattern, laser beams are applied directly or indirectly to the press plates ( 14 , 15 ) and / or the endless belts ( 18 , 19 ). 3. The method according to claim 2, characterized in that the press plate and / or the endless belt first with a full-surface carrier sheet made of rubber, art fabric, elastomer or a galvanic metal layer is coated and that by the laser embossed structure only radiate the thickness of the Carrier web detected. 4. The method according to claim 1 or 2, characterized records that the embossed engravings directly into the Metal of the press plates and / or endless belts inserted be burned.   5. The method according to claims 1 to 4, characterized ge indicates that the laser beams are computed be controlled. 6. The method according to claims 1 to 5, characterized ge indicates that this is on the press plates and / or Design image to be transferred on an endless belt magnetic tape connected to the computer becomes. 7. The method according to claims 1 to 6, characterized ge indicates that during exposure to the laser radiate the relative movement between the press plate and / or the endless belt and the laser beam head coordinated. 8. The method according to claim 7, characterized in that that during the structuring of the laser beam head is fixed while the endless belt and / or the press plate moved line by line, or vice versa. 9. The method according to claims 1 to 8, characterized ge indicates that the energy of the laser beams so it is controlled that embossed structures differ Licher depth from the endless belt and / or press plate or the carrier web are burned out. 10. The method according to claims 1 to 9, characterized ge indicates that the relative movement between the Endless belt and the laser beam head so on top of each other is agreed that the beginning of engraving and that The end of the engraving forms a precisely fitting transition.   11. The method according to claims 1 to 10, characterized ge indicates that the endless belt and / or the press first sheet with a caustic color film Finished thickness is coated before it Laser beam engraving is suspended and that the Energy of the laser beams is controlled so that the coating down to the bare metal is structurally removed before the endless belt and / or the press plate is then etched action is subjected. 12. The method according to claim 11, characterized in that the remaining coating of the endless belt and / or the press plate after the etching treatment with is removed by a solvent. 13. The method according to claims 2 to 12, characterized characterized that the embossing processes or repeated several times.