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1.2 Overview of Printing Technologies. Ref. H. Kipphan, Handbook of Print Media: Technologies and Production Methods, Springer, 2001, sec 1.3, ch 2, ch 5. Overview of Printing Technologies. Two classes of printing technologies Technologies requiring a printing plate
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1.2 Overview of Printing Technologies Ref. H. Kipphan, Handbook of Print Media: Technologies and Production Methods, Springer, 2001, sec 1.3, ch 2, ch 5
Overview of Printing Technologies • Two classes of printing technologies • Technologies requiring a printing plate • Flexography, gravure, screen printing, micro-contact printing • Technologies not requiring a printing plate • Inkjet printing, laser printing
Letterpress/Flexographic Printing • Characteristic of letterpress printing is • The printing elements of the printing plate are raised above the non-printing elements • Flexographic printing is a type of letterpress printing where printing plate is soft • Printing can be done on rough surfaces & on fabrics ink splitting, fig. 1.3-5 fig. 1.3-9
Letterpress/Flexographic Printing contd • Questions • Why anilox roller was introduced for inking the printing stamp? • Can directly roll printing stamp through the ink tank do the job? • Why the printing was done in the liquid phase, not in the solid phase?
Gravure Printing • Characteristic of gravure printing is • The image elements are engraved into the printing cylinder • Schematic of gravure printing (fig. 1.3-10)
Gravure Printing contd • Questions • Why the inking here is done through directly rolling over the ink tank? • Why the printing is done in the liquid phase?
Lithography or Offset Printing • Characteristic of lithography is • The printing and non-printing areas of the printing plate are on the same level • The printing areas are made “ink-philic” (親墨水) while the non-printing areas are “ink-phobic” (不親墨水). • Lithography was invented by the end of 18th century (yr 1796) • “The image to be printed was drawn on the stone with a special liquid. The stone was dampened before it was inked up, after which the non-image areas of the stone surface did not take on ink.”
Lithography or Offset Printing contd • Schematic of lithography/offset printing (fig. 1.3-18)
Lithography or Offset Printing contd • Ink transfer of offset printing (fig. 2.1-8)
Lithography or Offset Printing contd • Questions • How were the patterns created on the printing stamp at the first place? • What is the purpose of the blanket roller? • Why are multiple rollers used in the ink delivery subsystem? multiple rollers
Screen Printing • “… a process in which ink is forced through a screen.” Fig. 1.3-22
Ink-Jet Printing • Continuous vs. drop-on-demand ink-jet printing Fig. 1.3-30
Micro-Contact Printing – Chemisorption • A specially designed letterpress printing • Proposed by Whitesides et al. in 1993 based on SAM (self assembled monolayer) technique (CP)
Micro-Contact Printing – Chemisorption contd • 2 steps of SAM process • 1. Chemisorption of "head groups" onto a substrate • 2. Self organization of "tail groups" Schematic of self-assembly mechanism for alkanethiols on Au(111). (A) Thiols adopt the highly mobile lattice-gas phase at very low coverage. (B) Above a critical value of surface coverage, striped phase islands, characterized by surface-aligned molecular axes, nucleate heterogeneously and grow in equilibrium with a constant-pressure lattice gas. (C) Surface reaches saturation coverage of striped phase. (D) Surface undergoes lateral-pressure-reduced solid-solid phase transition by nucleation of high-density islands at striped-phase domain boundaries. (E) High density islands grow at the expense of the striped phase until the surface reaches saturation. http://en.wikipedia.org/wiki/Self_assembled_monolayer G. E. Poirier and E. D. Pylant, “The self-assembly mechanism of alkanethiols on Au(111),”Science 272 (1996) 1145-1148
Micro-Contact Printing – Chemisorption contd • Two classes of SAM: thiol-based and silane-based thiol-based SAM silane-based SAM http://personalpages.manchester.ac.uk/staff/Sven.Koehler/media/index.html http://nanostructure.usc.edu/research/bio1.shtml
Micro-Contact Printing – Physisorption • Deficiency of chemisorption CP • Applications limited by few choices of SAM pairs of molecule and substrate • Physisorption CP exploiting physical adsorption, for example through van der Waals interaction Source: 呂冠毅, 中正大學機械所碩士論文, 2010