Laser Technology for the Packaging Industry Today and Tomorrow.

Transcription

1 Laser Technology for the Packaging Industry Today and Tomorrow. Schepers GmbH & Co. KG Karl-Benz-Strasse Vreden/Germany

2 Outlook A. History of gravure printing B. Laser technology today C.Laser technology tomorrow

3 A. History of gravure printing - Gravure printing at the very early beginning (1446), done by hand-engraved copper plates. - Compared to the letterpress process, ink could be transferred with hand-engraved copper plates for the first time. - Hand-engraved copper plates could only illustrate line work Tools to manufacture hand engraved copper plates. Picture of Hl. Christopherus, 1446

4 A. History of gravure printing First copper or steel plate which was done by chemical etching around Coating of the copper or steel plate. - Removal of the coating to be able to transfer ink later. - The image was transferred by etchant or chloride into the copper or steel plate.

5 A. History of gravure printing First reproduction of continuous tone around 1700 due to the usage of an engraving tool called, Mezzoti (Mezzo tint = Half tone). Mezzotint achieves tonality by roughening the plate with thousands of little dots made by a metal tool with small teeth, called a "rocker." In printing, the tiny pits in the plate keep the ink when the face of the plate is wiped clean. A high level of quality and richness in the print can be achieved.

6 A. History of gravure printing Photomechanical (1860) transfer of the artwork screened/unscreened to the printing form. - Conventional (area constant / depth variable) - Autotypical (area variable / depth constant) - Half-autotypical (area and depth variable)

7 B. Laser technology today b1) By mask ablation and chemical etching

8 B. Laser technology today With an indirect laser you can serve the following markets: - Packaging industry - Decorative industry - Technical rollers, such as embossing rollers - Security industry

9 B. Laser technology today The indirect laser machine is able to engrave image setter principle. - Image setter principle: All applications are engraved with the Image setter principle! - Multibeam ability 2, 4, 6 up to 8 beams

10 B. Laser technology today High quality due to high resolution - Max resolution - min. 3 my beam size - max. 0.5 my/rev. The engraving time depends on the respective resolution and on the number of laser beams, but not on the screen or the cylinder circumference. - Outline: An outline, dotted or as a contour, can be stored in the data base for improving the text quality.

11 B. Laser technology today High quality due to high flexibility - Screens and angles: Most different screen combinations which can be freely chosen are engraved in one pass by means of the Digilas. Each screen can be rotated by 360 degree. - Multi-stage etching process: Multi-stage etching processes for the technical roller field can be adjusted in register, and thus are reproducible.

12 B. Laser technology today Coating Laser ablation Chemical etching After etching After chrome After proof

13 B. Laser technology today

14 B. Laser technology today Typical machine information: Machine bed : from 2900 mm up to 9000 mm Engraving width : from 0 mm up to 7500 mm Total length : from 0 mm up to 9000 mm Diameter min. : 50 mm Diameter max. : 1200 mm Cylinder weight max. : up to kgs Machine weight max. : kgs

15 B. Laser technology today By direct engraving into zinc

16 B. Laser technology today Laser General: - Engraving speed cells per second (1 Head) - Direct engraving - Touch-free engraving tool with high repeatability - Considerable ink savings (depending on printing substrate) LASERSTAR E - Manual or Full automated machine

17 B. Laser technology today Surface Finishing ZINCSTAR 80 % immersion Laser Engraving Surface Finishing Remove amorphous zinc with nitric acid ms/cm. Polish with stone. Remove the polish dust with a rinse of nitric acid 55-65mS/cm. Neutralise with TJ16 solution µs/cm. Cylinder get dried. High Speed Chrome Solution MDC CR 624 Surface Finishing FINISHSTAR Zn with stone LASERSTAR FINISHSTAR La with stone CHROMSTAR 50 % immersion FINISHSTAR Cr with tape Ready for Printing

18 B. Laser technology today Conventional Half-autotypical Super half-autotypical Side view Top view{

19 Minimum Maximum Screen Range 75 l/cm. 140 l/cm. Cell Diameter 45 um. 135 um. Cell Depth 1 um. 35 um. Market Segment Screen Range [l/cm.] Paper Aluminium Flexible Carton Conventional Cell at 100% at 5% Conventional Cell at 100%

20 Minimum Maximum Screen Range 80 l/cm. 160 l/cm. Cell Diameter 35 um. 135 um. Cell Depth 1 um. 38 um. Market Segment Screen Range [l/cm.] Paper Aluminium Flexible Carton Half-Autotypical Cell at 100% at 5%

21 Minimum Maximum Screen Range 75 l/cm. 100 l/cm. Cell Diameter 45 um. 145 um. Cell Depth 1 um. 35 um. Market Segment Paper Aluminium Flexible Screen Range [l/cm.] n.a. n.a. Carton Super Half-Autotypical Cell at 100% at 5%

22 Minimum Maximum Screen Range 112 l/cm. (40) 370 l/cm. (90) Cell Diameter 80 um. 250 um. Cell Depth 1 um. 40 um. Market Segment Screen Range [l/cm.] Paper Aluminium Flexible Carton at 100% Master screen conventional

23 Minimum Maximum Screen Range 112 l/cm. (40) 400 l/cm. (115) Cell Diameter 80 um. 250 um. Cell Depth 1 um. 40 um. Market Segment Screen Range [l/cm.] Paper Aluminium Flexible Carton Masterscreen Halfautotypical At 100% Master screen half-autotypical

24 B. Laser technology today Compatible with EM but... Fast up to color Better color stability Smoother vignettes, uniform ink layer Optimized ink usage

25 B. Laser technology today By direct engraving into ceramic Line count l/cm ( lpi )

26 B. Laser technology today Cell is generated by multi laser pulses and by the laser beam profile Laser pulse Compressed structure by re-melting the CrO 2 - layer Materialablation Melt Wall generation Porous CrO 2 - layer Re-melting of the CrO 2 layer - Compressed structure of the ceramics - Increase of the wear-resistance of the cell wall - Generation of hexagonal cell structure

27 The surface of an Anilox or screen roller is coated with a µm ceramic layer. This surface contains millions of cells with dimensions between µm. The volume of the ink transfer or the ink film thickness is defined by of the screen -frequency, -angle, -shape, -depth, -wall/cell ratio Flexo cliché Anilox roller Anilox roller surface Typ. Values: Screen frequency : 200 l/cm Cell depth : 17 µm Ink film transfer : approx. 2 4 µm

28 B. Laser technology today

29 C. Laser technology tomorrow Statement: Laser will be the future for direct structuring of metal/epdm for industries like: - Packaging industry - Embossing industry - Décor industry - Security industry A time frame cannot be given because those developments are linked to the laser manufacturing companies and their ability to provide the right laser technology. The key for such developments are: - A high precision and fundamental machine construction - A corresponding laser source with a stable front end.

30 C. Laser technology tomorrow, aluminium

31 C. Laser technology tomorrow, steel

32 C. Laser technology tomorrow, nickel

33 C. Laser technology tomorrow, copper

34 Thank you!