Vad menas med digitalt tryck?• Från dator till tryck• Variabel data• Hastighet och format

• Några begrepp:– Dator till film– Dator till plåt– Dator till press– Dator till tryck

De vanligaste principerna

• Bläckstråle– Drop on demand

– Continious jet

• Elektrofotografi– Torr toner

– Våt toner

De vanligaste systemenFabrikat Princip Toner Ark/rulle Via gummidukIndigo elektrofotografi våt ark jaXeikon elektrofotografi torr rulle nejNexpress elektrofotografi torr ark ja

Digital tryckning

ElcorsyDigital tryckpress för dags-tidningsproduktion.

Heidelberg Nexpress

Stort format - ink-jet2.44m by 1.6m max imagesize

Xaarjet heads

Sericol UV curing ink

Ink-jet - material på trummaServer Scheduler

RIPPCI

Operatorinterface

UVcuring

Drive

Encoder

Splice sensor

Pumps

Filtration

Pressurecontrol

Purge and wipesystem

Big image

Digital tryckning - kostnader

Digital tryckning vs traditionell

Provtryckning - digital vs offset•Print trials were conducted by IMT in corporationwith SCA, Stora Enzo and MoDo Finepaper

•Print quality measurements were made by IMT andSTFI

•Perceptual evaluation/analysis of print quality wasperformed by STFI in corporation with MoDoFinepaper

•Additional data from this study will be presented insession 3a “Percieved print quality in digital and offsetprinting” by Siv Lindberg

The aim of the project

The aim of this project was to get betterknowledge about expected print quality fordifferent papergrades when printed withdigital presses.

Paper grades

• Uncoated

• Matte medium coated

• Matte high coated

• Glossy coated

Printing presses

• Xerox DocuColor 40. Electrophotographic, dry toner.

• Xeikon DCP/32D. Electrophotographic, dry toner.

• Indigo E-Print 1000. Electrophotographic, wet toner.

• Heidelberg Quickmaster DI. In-press CTP-waterlessoffset.

• Heidelberg GTO. Conventional offset, reference.

Results - General print quality

0

10

20

30

40

50

Xeikon Quickm. Indigo Xerox GTO

Qua

lity

num

ber

UcMmMhGl

Picture: “portrait”

Results - Gloss mottle

0

510

15

20

2530

35

Xeikon Quick Indigo Xerox GTO

UcMmMhGl

Gloss-mottle, %

0

5

10

15

20

25

30

35

Xeikon Quick Indigo Xerox GTO

UcMmMhGl

Gloss-mottle, %

400 % (CMYK) 100 % black

GT O

-60

-40

-20

0

20

40

60

80

100

-70 -50 -30 -10 10 30 50 70

QU IC K M AS T ER

-60

-40

-20

0

20

40

60

80

100

-70 -50 -30 -10 10 30 50 70

IND IGO

-60

-40

-20

0

20

40

60

80

100

-70 -50 -30 -10 10 30 50 70

X EIK ON

-60

-40

-20

0

20

40

60

80

100

-70 -50 -30 -10 10 30 50 70

X ER OX

-60

-40

-20

0

20

40

60

80

100

-70 -50 -30 -10 10 30 50 70

Glossy coated

Matte high coatedhögbestruket

Matte medium coated

Uncoated

Results- Colour gamut

Conclusions• Visual image quality vs paper grade

– Wet toner correlates– Electrophotographic methods showed low correlation

• Print mottle vs paper grade– 100 % area showed clear correlation 30 % area not

• Gloss mottle vs paper grade– Clear correlation for all printing methods

• Colour gamut vs paper grade– No correlation for electrophotographic printing