This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

1 October 6, 2015

A new concept to simulatecommercial print trials on labscaleIntroduction of a lab printing device

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

2 October 6, 2015

Intention and motivation

• High quality appearance of printed products

Main targets of the market

• Key factor in accomplishing a high quality product in differentmarkets

Evaluation of the print quality duringdevelopment and optimization

• Many are unsuitable for print quality prediction• Many are lacking in their overall applicability• Many are strongly limited towards troubleshooting to a given

and well-known print problem

A variety of lab test exist for simulatingall kinds of print aspects

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3 October 6, 2015

Intention and motivation

• reel-to-reel printing production• simulation under consistent conditions• reproducible drying processes on commercial printing machines• use of commercially available printing plates• suitability for a broad range of substrates (e.g. packaging materials)• application of commercial inks• runnability and converting performance – (key factors nowadays)• dimensionally equivalent electrostatic print assist (ESA) for

rotogravure evaluation

Simulation on a lab scale of typicalcommercial print phenomena requires

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

4 October 6, 2015

Intention and motivation

• Expensive• Time consuming• Inflexible in terms of experimental design

Commercial print trials are

• Constructing a reel to reel lab printing press to simulatecommercial printing trials with regard to print quality andrunnability

Decision

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5 October 6, 2015

Demands on the system

flexible setup fordifferent printing

technologies

flexible handling of abroad range of

substrates to print onusage of a wide range

of printing plates

usage of an extensiverange of commercialinks for print trials

different printingtechnologies (e.g.

water-based, solvent-based, UV-curing inks

etc.) applicable

flexible drying setup

flexible adjustment ofmachine speed at areasonable level (tomatch commercialprinting speeds)

printing width has tomatch the existing in-house machinery (e.g.

lab coating system,lab calendering)

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6 October 6, 2015

Machine setup laboratory flexo

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7 October 6, 2015

Process parameters laboratory flexography

• 2 print units with or without in-between drying• Wet on wet or wet on dry

Press Setup

• Process speed continuously up to 100 m/minSpeed

• Any conventional photopolymer or rubber plate• Thicknesses of 1.14 mm and 2.54 mm

Plate/Sleeve characteristics

• 120, 260, 340 l/cm, ~ 15.2 to 4 cm3/m2 (URMI), 60° hexagonalAnilox Roller Characteristics

• Inks are circulated in a closed loop (no loss of solvent)• Chambered doctor blade

Ink supply

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8 October 6, 2015

Process parameters laboratory flexography

• Reel to reel• Web tension control and web edge control

Printing concept

• 150 mm

Printing width

• Variety of different substrates applicable, e.g. coated oruncoated Liner

Substrates

• Water and solvent based ink can be used

Ink system

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9 October 6, 2015

Comparison of a flexographic print trial

Lab printing machineCommercial printing pressCommercial printing pressLab printing machine

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10 October 6, 2015

Example of a flexographic print trial

• Two ply 140 g/m2 fiber liner of the production line• Ground ply: recovered paper grades• Top ply: high recovered grades, surfaced sized with starch and

copolymer• Optical brightening agent in the top ply

Testliner base

• Film press (4 g/m2)• Rod (10 g/m2)• Double coated (precoat rod 9 g/m2), topcoat blade 8 g/m2)

Coating of testliner

• Pilot supercalender

Calendering

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11 October 6, 2015

Example of a lab flexographic print trial

• Flint ART 2,54 mm

Printing plate

• 22 sec. (4 mm cup)

Viscosity

• Lohmann 200

Mounting tape

• 340 L/cm, 4.5 cm3/m2

Anilox roller

• Water based flexo ink from Huber – series Hydro X

Ink

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12 October 6, 2015

Testform flexo trials and evaluation parameter

• 100 % magenta, 100 % cyan

Print gloss

• 100 % magenta, 100 % cyan

Optical density

• 100 % cyan

Mottling

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

13 October 6, 2015

Testform flexo trials and evaluation parameters

Testform commercial printing Testform lab printing

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

14 October 6, 2015

Results print gloss

R² = 0,999

R² = 0,996

20

30

40

50

60

70

80

20 30 40 50 60 70 80Prin

tGlo

ssTa

ppi7

5°[%

]Com

mer

cial

Prin

ting

Print Gloss Tappi 75° [%] Laboratory Printing Print Gloss Magenta

Print Gloss Cyan

Good correlation between commercial and laboratory printed samples

Values are comparable 1:1

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

15 October 6, 2015

Results optical density (OD)

Good correlation between commercial and laboratory printed samples

Offset between the OD`s of commercial and laboratory print trials

R² = 0,980

R² = 0,988

1,0

1,1

1,2

1,3

1,4

1,0 1,1 1,2 1,3 1,4

OD

[-]C

omm

erci

alP

rintin

g

OD Magenta [-] Laboratory Printing Optical Print Density Magenta

Optical Print Density Cyan

Lab prints show a higher optical density for magenta and cyan

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

16 October 6, 2015

Results Optical Density

Possible reasons observed divergences

• Higher print speed at commercial press leads to shortercontact times between all printing components

• Shorter relaxation behaviour at higher print speed has aninfluence onthe ink transfer

• Anilox rollers has nominally the same parameters, but notnecessarily the same ink release behavior

• The impression might not be exactly the same

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17 October 6, 2015

Results mottle

R² = 0,984

0,0

0,5

1,0

1,5

2,0

2,5

0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8Mot

tleC

yan

[-]C

omm

erci

alP

rintin

g

Mottle Cyan [-] Laboratory Printing

Measured with Verity I/A fromprüfbau Dr.-Ing. H. DürnerGmbH

Good correlation between commercial and laboratory printed samples

Different densities means different ink coverage on the substrateHigher mottling at higher OD

Mottling only for Cyan because of an insufficient print out of magentamottling field

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

18 October 6, 2015

Summary and Outlook

• Closes the existing gap between lab methods and commercialprinting

• Allowing predictions of the resulting print quality of commercialprints

Reel to reel laboratory printing press

• Good correlations were observed

Results of gloss, mottle and optical density

• Evaluation of the phenomen in a new print trial with comparableconditions for printing speed and impression

• Developing a new test form with defined elements to visualizethe impression

Further studies

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

19 October 6, 2015

Summary and Outlook

• Validation of this printing technology and comparison to acommercial press has started and will be finalized

• Good correlations observed

Rotogravure

• High speed inkjet• Offset

Possible print units

• Machine can be equipped with rotogravure printing units

Besides Flexo

This document contains proprietary information which shall not beused and disclosed without Omya explicit written authorization.

20 October 6, 2015

Questions

Do you haveany questions?

Thank you for listening