THE ROLE OF BINDER TYPE IN DEFINING INKJET PRINT QUALITY. Baden-Baden Taina Lamminmäki 1, John Kettle 1, - PDF

Description
THE ROLE OF BINDER TYPE IN DEFINING INKJET PRINT QUALITY Taina Lamminmäki 1, John Kettle 1, Pasi Puukko 1, Jukka Ketoja 1, Patrick Gane 2 1 VTT Technical Research Centre of Finland 2 TKK and Omya Development

Please download to get full document.

View again

of 25
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information
Category:

Advertisement

Publish on:

Views: 21 | Pages: 25

Extension: PDF | Download: 0

Share
Transcript
THE ROLE OF BINDER TYPE IN DEFINING INKJET PRINT QUALITY Taina Lamminmäki 1, John Kettle 1, Pasi Puukko 1, Jukka Ketoja 1, Patrick Gane 2 1 VTT Technical Research Centre of Finland 2 TKK and Omya Development AG Baden-Baden Motivation Increasing trends for high-speed inkjet commercial printing. Challenges the hydrophilic and absorptive properties of surface. In order to have optimal image quality in the inkjet printing, the high solvent amount of the ink should be absorbed rapidly into the paper structure. Need to further develop the coating layer properties on the mechanisms which control absorption of inkjet inks. 2 Aims To clarify the role of polyvinyl alcohol and styrene acrylate latex binder in the formation of CaCO 3 coating structure for the purpose of inkjet printing. To find out how dye-based ink moves in the coated paper structure. Facilities of KCL Pilot plant TMP/ CTMP refining MC bleaching Stock preparation Paper making Slitting- Winding & Sheet cutting Calendering Coating Heatset web offset printing Sheet-fed offset printing High-speed Inkjet printing Flexo printing (Versamark VX5000e) 3 Rotogravure printing Content Coating layer production Clara penetration tester Ink penetration in coated papers Printing with aqueous-based dyes Conclusions 4 Studied coatings Binders: 1.Polyvinyl alcohol (PVOH), Mowiol (non-ionic) 2. Styrene acrylate latex (SA), Latexia 212 (anionic) Pigment: PCC, OMYAJET B5260 Mean pigment diameter 2.7 µm Specific surface area, 63.7 m² g -1 7, 12 and 30 pph Pre-coating 8 g m -2 7 g m -2 Wood-free base paper 7 g m -2 5 Air permeance and ink absorption speed DIGAT 6 Pore diameter of coating layers 7 CLARA 8 Capacitive method to detect liquid penetration VTT TECHNICAL RESEARCH CENTRE OF FINLAND CLARA Variables: external pressure ( bar) liquid (conductive) material Removable plate Pressure or vacuum Liquid Electrode Paper Capacitance measurement Plastic Inkjet ink penetration through CaCO 3 coating CLARA Anionic cyan ink Permeation flow Diffusion Capillary flow 10 Inkjet ink penetration as a function of time at 1.5 bar external pressure PVOH SA Inkjet ink needs more time to penetrate through PVOH coatings than through SA coatings 11 Inkjet ink penetration at 1.5 bar external pressure PVOH SA 12 Effect of external pressure Anionic cyan ink Pressure caused by inkjet droplet At lower pressures, ink has not penetrated so far into the structure at a particular time 13 Effect of PVOH vs. SA latex levels Anionic cyan ink Ink penetrates more quickly into SA coatings than into PVOH coatings at an external pressure 0.1 bar 14 What is happening during inkjet ink setting process? Binder absorption PVOH absorbs inkjet ink clearly more than SA latex binder swelling 15 What is happening during inkjet ink setting process? Binder dissolving PVOH dissolves to the inkjet ink more than SA latex 16 What is happening during inkjet ink setting process? Colourants fixing PVOH colourants are transported during the diffusion into the binder film, but only in the top part of the film PVOH 50 µm PVOH SA latex colourants do not diffuse into the binder film or fix to the film SA 17 Printing with aqueous-based high-speed inkjet printing press - VERSAMARK VX5000e 18 Print density Aqueous dye-based inks (100 m/min) SA PVOH 1 7 pph PVOH 7 pph SA Print density 50 µm 20 Water fastness SA latex coatings PVOH coatings SA coating cannot fix colourants as well as PVOH Black ink fix better than cyan ink 21 Conclusions ink penetration process ~20 µm 67 µm 7 µm PVOH Latex Wood-free base paper 0 Permeability High With CLARA we can detects penetration speed and depth of conductive liquids into the substrate study the penetration under the external pressure easier to follow the movement of liquid front than with commercial absorption devices results are highly reproducible. 22 Conclusions print quality PVOH coating - swelling v top1 v in1 v top 1= v top 2 v in 1 v in2 SA coating - non-swelling v top2 v in2 PVOH fixes the colorants effectively in the coating layer SA latex cannot fix the colorants and therefore colorants can penetrate deeper in the structure 23 Thank you for your attention! You are welcome to discuss with us at VTT Stand 125 (2nd floor)! Taina Lamminmäki John Kettle Pasi Puukko Jukka Ketoja and Patrick Gane 24 25 VTT creates business from technology VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Related Search
Similar documents
View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks