High Speed Inline Coating

1. High Speed Inline Coating for Sheet Fed Printing Presses

2. High Speed Inline Coating for Sheet Fed Printing Presses • Preconditions - up to 12,000 prints/h the usual processing instructions are to be observed - for High Speed Inline Coating with a printing speed of up to 18,000 sheets/h the processing range must be adapted regarding - substrate- ink layer thickness- coating viscosity- coating selection- performance of the dryer- distance under the dryer

3. High Speed Inline Coating for Sheet Fed Printing Presses • Substrate - Ink - the combination of substrate and ink should be selected in a way to assure a good bond between ink and substrate - poor ink drying cannot be improved by coating - the result is bad rub resistance and insufficient scotch tape resistance

4. High Speed Inline Coating for Sheet Fed Printing Presses • Adhesion Substrate - Ink

5. High Speed Inline Coating for Sheet Fed Printing Presses • Ink Layer Thickness - Overinking of the ink layer thickness with parallel inline coating will reduce the performance of the printing press - as by reducing the printing speed the drying time is adjusted

6. High Speed Inline Coating for Sheet Fed Printing Presses • Ink Layer Thickness

7. High Speed Inline Coating for Sheet Fed Printing Presses • Cell Volume of the Screen Rollers - the cell volume of a screen roller is indicated with the scoop amount of water in ml/m² - the coating application amount corresponds to about 1/3 of the indicated cell volume of the screen roller Example: A cell volume of the screen roller of 15 g/m² corresponds to approx 5 g/m² coating application

8. High Speed Inline Coating for Sheet Fed Printing Presses • Gloss Diagram after 24h Drying Wet-on- Wet Printing 3 g/m² 2 g/m² 1 g/m² Gloss in % Drying Time in h

9. High Speed Inline Coating for Sheet Fed Printing Presses • Coating Viscosity • the coating viscosity depends on the temperature and is determined with a 4 mm DIN cup at 20°C • when the temperature in the coating rises the viscosity will decrease • in case of a viscosity decrease, e.g. below 25 sec., an even coating application cannot be assured any more

10. High Speed Inline Coating for Sheet Fed Printing Presses • Viscosity depending on the Temperature Viscosity in s Temperaturein °C

11. High Speed Inline Coating for Sheet Fed Printing Presses • Variable Coating Viscosities Cooling Units for Coatings by EASYLAC keep the coating stable in viscosity

12. High Speed Inline Coating for Sheet Fed Printing Presses • Too high Coating Viscosity - a too high coating viscosity, e.g. above 65 sec. can be adjusted by dilution with water to the required viscosity - a too high coating viscosity in connection with High Speed Inline Coating will lead to splashing

13. High Speed Inline Coating for Sheet Fed Printing Presses Viscosity in sec.DIN 4 mm Cup at 20 °C approximate Water Amount in % • Dilution of the Coatings with Water

14. High Speed Inline Coating for Sheet Fed Printing Presses • Coating Selection • the drying behaviour of coatings depend on the coating type • if for example the following coating types are used: • matt- semi matt- protection- gloss- high gloss- UV coatings their drying behaviour will be considerably different

15. High Speed Inline Coating for Sheet Fed Printing Presses • Coating Selection Rule of thumb: For dispersion coatings: The higher the gloss, the slower the thorough drying

16. High Speed Inline Coating for Sheet Fed Printing Presses • Gloss Diagram: different coatings on the same substrate

17. High Speed Inline Coating for Sheet Fed Printing Presses • Influence of the Surface Structure of the Substrate Carton 1 Carton2 Gloss in % Application Amount g/m² wet

18. High Speed Inline Coating for Sheet Fed Printing Presses • UV Coatings - UV coatings dry immediately by photo-polymerisation using short wave light - the acetone test shows whether the coatings have dried thoroughly

19. High Speed Inline Coating for Sheet Fed Printing Presses • Performance of the Dryers - the drying behaviour of the coatings is determined by the performance of the dryer - the thorough drying of dispersion coatings is primarily determined by the available amount of air  The more air, the better for the thorough drying - beginning at a pile temperature of approx. 35 °C problems may occur in the pile

20. High Speed Inline Coating for Sheet Fed Printing Presses • Drying of UV Coatings • for UV coating processes the condition of the UV lamps and a sufficient performance are responsible for a good coating result • the temperature in the pile is also decisive for UV coatings and may be responsible for subsequent problems in print finishing • too high temperatures may result in breaking of the printed matter during the grooving and folding process

21. High Speed Inline Coating for Sheet Fed Printing Presses • Drying Distance An extended delivery between coating tower and delivery is advantageous for the printing speed. A short delivery is a disadvantage for High Speed Inline Coating.

22. High Speed Inline Coating for Sheet Fed Printing Presses • Printing Press with Double Extended Delivery

23. High Speed Inline Coating for Sheet Fed Printing Presses • Special Coating Applications - for special coating applications, as e.g. application of blister coating, a coating amount of 6 – 8 g/m² has to be applied in order to assure good bonding with the plastic foil

24. High Speed Inline Coating for Sheet Fed Printing Presses • Result High Speed Inline Coating with 18.000 prints/h will not present any problems if the appropriate coatings are used and the printing press is well adjusted.