Challenges of High Quality Flexo Printing

Contents General Information on High Quality Flexo Printing High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

Contents General Information on High Quality Flexo Printing High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

What „High Quality“ means to Flexo Printing It is the future of flexo printing. The future development of flexo printing has been frequently discussed in the past. Since then, the available technologies have evolved considerably. On the one hand the quality of image illustration has improved. On the other hand the ongoing development of printing inks lead to a quality level which lives up to classical gravure and offset printing qualities. It’s all about the application profile. On top to the general requirements for the printing inks used in flexo printing, some special adaptations of the printing inks are necessary to enable high quality flexo printing.

High Quality Flexo Printing – It‘s all in the Mix High quality flexo printing is a technological development based on the combination of… …4.000 dpi high resolution optics, …Round Top Dot (RTD) or Flat Top Dot (FTD) technologies and …Microcell screening technology for solid tone areas.

The Advantages of High Quality Flexo Printing Perfect illustration of finest tonal values and color spreading in flexo printing. Practically zero unwanted spreading. Clean print result on both negative and positive text motives. Minor dot bridging Improved layers of printing inks High color densities at reduced film thicknesses

The Interaction of High Quality Technologies The printing ink shows the interaction of high quality technologies ! Repro-duction + Plate Technology High Quality Flexo! Doctor blades + Anilox roller Ink Technology Operator + Flexographic printing press Setup Image source: Flint Group / Sun Chemical Plate-adapter + Mounting- tape

High Quality Flexo Printing Examples for a good and bad print result ? ? Image source: Flint Group Image source: Sun Chemical

Contents General Information on High Quality Flexo Printing High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

High Quality Flexo Printing – Relevant Parameters for the Printing Ink Color strength Flowability of printing ink Drying speed Performance characteristics

High Quality Flexo Printing- Screen Rulings 34 L/cm 44 L/cm 54 L/cm 70 L/cm 3 Image source: Siegwerk

High Quality Flexo Printing and Printing Inks - How to meet the Requirements? Reduction of ink tranfer and adjustment of drying speed anilox roller L/cm cell volume anilox roller cm³/m² amount of ink transferred g/m² dry design selection colors (screen / solid) white 500 2,9 0,3 HQ Flexo 400 5,0 0,5 Process screen 300 7,5 0,7 screen / solid 220 9,0 0,9 screen/ solid / white 140 12,0 1,2 white gravure standard Image source: Siegwerk

Printing Inks - Impact of Low Ink Transfer 12 cm³/m² 9 cm³/m² 7,5 cm³/m² 5 cm³/m² 2,9 cm³/m² Image source: Siegwerk

High Quality Flexo Printing – Printing Ink Requirements Higher color strength Optimized flowability Slow drying speed Adaption of performance characteristics (e.g. rub off resistance)

Contents General Information on High Quality Flexo Printing High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

Precise Reproduction - 1:1 Copy Digitally imaged LAMS layer e.g. nyloflex® NExT UV UV UV UV O2 O2 O2 O2 O2 O2 O2 O2 1:1 copy Image source: Flint Group

High Resolution improves Reproduction Quality Image source: Flint Group 2 % highlight dots at 2540 dpi 2 % highlight dots at 4000 dpi A higher image resolution improves the image contrast due to additional gray scales. It can also improve the dot definition.

Surface Screening – Ink Laydown Solid tone areas show improved ink laydown by using Microcell screening technology Image source: Flint Group Solid tone area without screening Solid tone area with screening

Surface Screening – Ink Laydown Solid tone areas show improved ink laydown by using Microcell screening technology Image source: Flint Group Solid tone area without screening Solid tone area with screening

Examples of possible High Quality Workflows Flint Group  nyloflex® NExT Kodak  KODAK FLEXCEL NX MacDermid  LUX ® DuPont  Cyrel® DigiFlow Esko  Inline - UV

Contents General Information on High Quality Flexo Printing High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

High Quality Flexo Printing – Requirements for Anilox Rollers Reduction of ink volume Fine engraving to be fit for 70 L/cm process screening Optimized emptying behavior

High Quality Flexo Printing – Cell Structures of Anilox Rollers Hex pattern 60° Long Cell structure Slalom Ink Channel structure

Anilox Rollers - Hex Pattern 60° Image source: Jörg Rohde, Kurt Zecher GmbH Usable for high quality flexo printing < 5 cm³ volume

Anilox Rollers - Long Cell Patterns Image source: Jörg Rohde, Kurt Zecher GmbH Usable for high quality flexo printing < 5 cm³ volume

Anilox Rollers - Slalom Ink Channels Image source:Jeanine Graat , Apex Europe B.V. Usable for high quality flexo printing < 5 cm³ volume

High Quality Flexo Printing – Anilox Rollers Requirements Anilox rollers have to be adjusted for high quality flexo printing Image source: Siegwerk

Anilox Rollers - Screen Resolution on Flexo Printing  HQ screen 70 L/cm dot size Tone 10% 4% 3% 2% 1% HQ Flexo 52µm 32µm 29µm 23µm 16µm Anilox Cup Size 500 17µm 450 20µm 400 340 26µm  Smallest printing dot must be bigger than the cup of the anilox roller!

Contents General Information on High Quality Flexoprinting High Quality Flexo Printing & Printing Inks High Quality Flexo Printing & Printing Plate Exposer High Quality Flexo Printing & Anilox Rollers Other Quality related Factors Summary

Further Quality Factors of High Quality Flexo Printing Mounting tape and Plate adapter Reproduction Doctor blade Elastomer-sleeve Process- Operator Flexo printing press Images: Sun Chemical / Windmöller & Hölscher KG

Contents General Information on High Quality Flexoprinting High Quality Flexoprinting & Printing Inks High Quality Flexoprinting & Printing Plate Exposer High Quality Flexoprinting & Anilox Rollers Other Quality related Factors Summary

Summary Positive print results Image source: Sun Chemical

Summary Positive print results Image source: Flint Group

Summary If all parameters are perfectly matched, an optimal print result on high quality flexo printing can be achieved. High quality flexo printing offers opportunities for the packaging printing market… ... to achieve similar high quality printing results as gravure printing or offset printing. ... to develop new markets or strengthen existing business for brand owners and customers with very high quality requirements. ... to meet the higher quality standards in this market segment.