Janoschka magazine Linked_V8_2023

82 t o t e l l t h e t r u t h
issue #8 © l i n k e d 83
Dot screen
ONE BEAM PER CELL
Masterscreen technology
SEVEN BEAMS PER CELL
During printing of the different colours,
different screen angles prevent the moiré effect.
DIRECT LASER
IMAGING
Cylinders for direct laser imaging have a copper or zinc coating.
In the direct laser system, image data is transferred via a
laser beam directly onto the copper or zinc layer.
Up to 70,000 cells can be laser-engraved per second.
LASER ETCHING
This technique also begins with a copper-plated cylinder. A coating of etching resist is applied
to the cylinder to a thickness between 4 and 10 μm (depending on the etching depth).
The resist protects the cylinder surface during the subsequent etching process.
The desired motif is transferred to the coated cylinder by the laser ablating the paint coating
in the image area. After the laser process, the cylinder is etched with ferric chloride.
This only affects the areas where the resist was removed. It deepens and widens these
areas to form cells. The paint coating is then removed from the whole cylinder before it is
finally chrome-plated.
Human hair
ø~100µm
Laser
ENGRAVING SPEED
70,000 CELLS/ SEC.
Laser Etching
1 2
IRON(III)-CHLORIDE
(Fe C l 3
)
Copper layer
4-10 µm
Etching resist
Copper layer
Masterscreen
ø~35 µm
Direct laser
ø~10µm
The cell geometry is completely variable. Lasered cylinders transfer
the colour better, above all on difficult substrates like aluminium
foil and uncoated paper, and guarantee excellent printing quality.
The cell geometry can only be varied in size during etching.
Cell geometric shape: square
Imaging only on coating layer.
Screening range: normally from 70 to 120 screens
Wide range of screen types, e.g. cushion, hexagon or special.
3
CHROME LAYER
(Cr )
Exposition laser
ø~2µm