Digital Printing Blessing or Trap for Print Finishing?

Transcription

1 1st WEILBURGER Graphics Partner Meeting Digital Printing Blessing or Trap for Print Finishing?, InfoStar, Munich - Michael Kirmeier, publicly certified expert,

2 Consultant and independent Expert InfoStar, Munich Michael Kirmeier Publicly certified Expert

3 Disparate Partners in Graphic Arts Industry Print converters are whipping boy of the graphic Industry.

4 Disparate Partners in Graphic Arts Industry No Influence on product development and on materials of printing jobs. Low added value in relation to the product value. High responsibility and high product liability in case of claims. Financial damage and loss of face.

5 Billions A4 Can we count on Rates of Increase in Digital Printing? Number of Prints (A4) in US and Western-Europe 8,00 7,40 7,32 7,21 7,04 6,96 6,89 7,00 6,00 Offset-/Tiefdr. Digitaldruck 5,00 4,00 3,00 2,00 1,00 0,67 0,73 0,89 1,41 1,93 2,15 0, (15 Years) Source: Caslon; Océ

6 Billion Pages/Year Added Values for Print Converting? Number of printed pages in US and Europe Digitaldruck Offset-Tiefdruck Periodica 1816,7 1703, Books (Book on Demand) Catalogs ,7 1036, Manuals 350,7 255,6 201,4 90,5 85,9 79,2 85,9 47,5 4, Years Source: Caslon; Océ Stdler

7 Digital Printing from typographic point of view: What is possible, what is not possible? Short runs Personalization Photo albums Good ink coverage and big colour space on uncoated papers. General good reproduction of 4CImages. B/W-Prints Book production Wide format printing. Dipl.-Ing. Dipl.-Ing.(FH) (FH) Peter PeterStadler Stdler

8 For Digital Printing the End Consumer has same Demands on Print Finishing as for conventional Printing Processes. Perfect Binding Folding Cutting Die Cutting Embossing Hot Foil Embossing Varnishing Film Laminating Is it possible??? Stdler

9 100 µm Comparison of transferred Ink Amounts (3 Ink layers) Elektrophotography Inkjet Offset Dry Toner Fluid Toner Water based Solvents Binder Pigments Paper wet 4.5 µm dry Synthetic Resin, Metallic Oxides, Additives, Silicone 18 µm dry 4 µm 15 µm Drying 1.5 µm (Penetration) wet dry wet dry Further UV- Inkjetapplications incl. UV- Varnishing are state of the Art. Consistency during transfer pasty solid pasty highly fluid Fixing Penetration, Cross linking Melting Melting Penetration, Evapuration Source: Dr. Andreas Paul, Océ

10 Ingredients of Ink and Toners What can lead to Dysfunctions in Print Finishing? Producers are not willing to publish formulations of ink and toners. Wide range of products (toner, inks, papers, different systems). Variable settings and system parameters. Print finishers are not supported and have to operate by trial and error.

11 Digital Printing Problems for Print Finishing Drying-out of the Paper In contrary to sheetfed offset printing the thermal stress in digital printing systems is very high and differs from system to system. Source: M. Kirmeier (FH) Peter

12 Digital Printing Problems for Print Finishing Waviness Problems Waviness-Problems arise caused by the toner fixing and by further finishing treatments (gloss). Mainly cockling caused by drying-up. Source: M. Kirmeier

13 Digital Printing Problems for Print Finishing Waviness Problems/Electrostatic Charging Waviness caused by moisture pick-up. Electrostatic charging. Runability problems for foil laminating and varnishing processes. Source: M. Kirmeier

14 Digital Printing Problems for Print Finishing Stepwise Appearance of the Book Block Mixed productions!! Toner based digital prints dimension variations by moisture pick-up. Source: Fogra

15 Digital Printing Problems for Print Finishing Folding Differences Caused by electrostatic charging. Source: M. Kirmeier

16 Digital Printing Problems for Print Finishing Breaking of Coating Caused by drying up of the paper. Source: M. Kirmeier

17 Digital Printing Problems for Print Finishing Trimming Problems Flaking in the area of trimmed edges (middle high ink coverage). Interaction paper/toner. Fixing problems.

18 Digital Printing Problems for Print Finishing Trimming Problems Trimming - Result of an insufficient toner adhesion.

19 Digital Printing Problems for Print Finishing Further problems can occur at deforming processes like: Scoring Die cutting Embossing caused by drying-up of paper and flaking of the toner. Partial or large area insufficient adhesion of foils at hot foil embossing.

20 Digital Printing Problems for Print Finishing Decreased Strength of Perfect Bindings Problems can occur at perfect binding applying Dispersions- and Hotmeltsystems. Less problems known with PUR-systems. (Toneradhesion!!) Source: M. Kirmeier

21 Digital Printing Problems for Print Finishing Defects in Film Laminations Particles (toner/fiber) reside underneath the foil (between substrate and foil). This causes tensions between substrate and foil after film laminating. During handling partial delaminating and air bubbles around the particles increase the visibility of the fault. White spots remain.

22 Digital Printing Problems for Print Finishing Ghosting Ghosting - often not visible at non-finished prints. Estimation: Ghosting is caused by print finishing

23 Digital Printing Problems for Print Finishing Ghosting In fact the increase of gloss after film laminating makes the ghosting effect visible. Also possible for varnishing.

24 Digital Printing Problems for Print Finishing Ghosting Client s arguments: It s print finisher s fault. Set-off of print in the pile after film lamination/varnishing by pile heating. Primary causes: Too long running time of blankets in the printing machine (memory effect). Use of non-certified papers. Transfer of the ghosting image in calanders or other rollers.

25 Papier 1 Papier 2 Papier 3 Papier 4 Papier 5 Papier 6 Papier 7 mn/m Digital Printing Problems for Print Finishing Insufficient Wettability 45 Benetzungsprüfungen Wetting Test Ink coverage 200 % A C B System Maschine The wettability of digital prints depend on the system and on paper. Values for surface tension from 26 until 41mN/m (limit >35 mn/m). This leads to varnishing problems. Paper Papierqualität

26 Digital Printing Problems for Print Finishing Insufficient Foil Adhesion Peeling Forces of Film Laminations Ink coverage 200 % The printing system has a decisive Influence on stability of film laminations. Papers are only partly certified. Only a few prints can achieve the foil adhesion of offset prints.

27 Digital Printing Problems for Print Finishing Insufficient Foil Adhesion Consequences of high ink coverage for film lamination? Increasing ink coverage influences the foil adhesion negatively.

28 Flash Tests for Digital Prints Only a few subjective tests are possible because of the complex mechanism of inks and toners. Measurement of wetting properties using testing inks. This gives information about the acceptation of varnishes and foil adhesion.

29 Flash Tests for Digital Prints The measurement of toner adhesion using adhesive tapes gives information about the possible film adhesion for film laminating.

30 Certification Center for Digital-Print-Papers Test lab in US. About 800 papers (each) are registered for HP- and for Kodaksystems. Source: RIT Rochester, NY, USA

31 Certification Center for Digital-Print-Papers Extract of RIT s test program. Definition of product properties for the print, but nothing for print finishing (ability for varnishing, perfect binding or film laminating!!!). Source: RIT Rochester, NY, USA

32 Further Competition for Print Finishers Digital varnishing systems (Inkjet) could take market shares of conventional print finishing. Speed sheet/h (52 cm x 74 cm).

33 Print Finishing Plans for the Future Don t get demoralized! Digital varnishing processes and inline film laminating could substitute the conventional print finishing. Toner fixing, surface properties and toner adhesion cause problems for print finishing. Certification centers are not informed about the concerns for print finishing. Think positive!!! Increase of book market expected. Concentration on niche markets like film laminating with effect foils, special varnishes for books, packaging or advertising folders. Concentration on print finishing of large format prints using special foils and embossing systems. There is still a lot of potential capacity for the future!

34 How can Print Finishers protect themselves against Processing Defects on Digital Prints? Possible addition of the Standard Business Conditions???

35 Thank you very much for your Attention!!