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

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

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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)

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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

LASER ENGRAVING

Laser engraving in decorative printing –

18 months of experience

Still a successful story