Post on 18-Dec-2015
LASER ENGRAVING
Laser engraving in decorative printing – 18 months of experience
Dr. Robert DavidResearch & Development
LASER ENGRAVING
Timetable of the project
March 2004 – November 2004: Evaluation of different engraving technologies
Stylus, Etching, Laser in Cu, Laser in Zn
December 2004: Purchase order
October 2005: Arrival of first tanks
23. December 2005: First cylinder engraved with stylus
Mid of January 2006: First laser engraved cylinder
February 2006: First laser cylinder with good engraving quality
ZOW 2006: First laser engraved decor presented
Interzum 2007: Interzum award
LASER ENGRAVING
Evaluation procedure
Questions to be answered:
Quality of engraving / printing
Speed
Ability for rechroming
Repeatability
Required space
Number of process steps
Stability of galvanic processes
Cost per cylinder
LASER ENGRAVING
Evaluation procedure
Stylus Laser Etching
Quality + ++ +
Speed - ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Quality:
Very high print quality:
Example: Soft Wear
and many other designs
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Speed:
Time for cylinder preparation: 100 min
Time for cylinder engraving: 100 min
Time for finishing: 60 min
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Rechroming:
Still not possible, no possibility expected in near future
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Repeatability:
Excellent repeatability of engraving
Example: It is possible to exchange a cylinder without extra colour match time:
Proven in several lab jobs
No shorter colour match time in production prints
Some problems come from finishing process
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Space:
More space necessary for laser engraving:
additional Zn-tank
two components for the laser
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Stability of electroplating:
Very stable Zn-electroplating
6 hours per day for all chemical tests
01.02.2006 01.04.2006 01.06.2006 01.08.20060
10
20
30
40
50
60
Zn-concentration
g /
ml
Date
LASER ENGRAVING
Facts after 18 months
Stability of galvanic:
Problems only with mechanical process (finishing)
Too many break downs of the finish star and all cylinders have to pass this machine several times
LASER ENGRAVING
Facts after 18 months
Stylus Laser Etching
Quality + ++ +
Speed o ++ o
Rechroming ++ - ++
Repeatability o ++ o
Space + o -
Process steps + + -
Stability of galvanic + ? ?
Cost per cylinder o ? -
LASER ENGRAVING
Facts after 18 months
Costs per cylinder:
Of course we will not discuss the costs here
LASER ENGRAVING
Facts after 18 months
Engraved cylinders: Number of engraved cylindersWeek 16/2006 to Week 21/2007
0
10
20
30
40
50
60
16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 2 4 6 8 10 12 14 16 18 20
Week
EMG Zylinder
Laser Zylinder
Laser Zylinder (logarithmisch)
EMG Zylinder (logarithmisch)
LASER ENGRAVING
Facts after 18 months
Changes:
Quality of cylinder balance had to be improved
due to high speed in Laser and Cutting: > 1000 rpm
Changed printout
Less missing dots
Smoother ink laydown
Less susceptible to changes of viscosity
Step from lab printing to production printing is different
Not all old designs can be switched to laser engraving