Printing processes, coating

In the late 1800s, when the demand for coated paper for the halftone printing process increased, casein rapidly replaced glue. Casein forms a hard, tough film when dry, and can be waterproofed easily with formaldehyde (qv). The properties of soy protein are similar to those of casein, and soy protein has been substituted for it in many types of coated papers requiring a casein-type binder (see Soybeans and other oilseeds). Casein, a valuable food product, is seldom used as a paper adhesive, in spite of its excellent adhesive properties. 

Letterpress. Letterpress is the oldest and, until the mid-1960s, the dominant and most versatile printing process. As of the 1990s, it is used mainly in high quaUty design work, fine books, and quaUty stationery. Unlike Hthography, which prints best on coated papers, letterpress can print on any paper, provided that the paper is of even thickness, fiat, and reasonably rigid. 

Printing Inks. Printing ink preparation is similar to many coating systems. The resin is dissolved in the solvent, followed by pigment dispersion to produce the ink. In most printing operations, the solvent must evaporate fast for best production speed. Alcohol—hydrocarbon solvent combinations are used with polyamide resins for some printing processes (see Inks). 

The primary substrates or support iaclude many types of paper and paperboard, polymer films such as polyethylene terephthalate, metal foils, woven and nonwoven fabrics, fibers, and metal cods. Although the coating process is better suited to continuous webs than to short iadividual sheets, it does work very well for intermittent coating, such as ia the printing process. In general, there is an ideal coater arrangement for any given product. 

The same principle is also applied in the manufacturing of printing plates for modern printing processes. Moreover, photopolymerization is used for coating of metals or wood and it finds also application in dentistry. 

Krebs FC (2009) Fabrication and processing of polymer solar cells a review of printing and coating techniques. Sol Energy Mater Sol Cells 93 394... 

Photoresists - [ELECTRONIC MATERIALS] (Vol 9) - [PHOTOGRAPH/] (Vol 18) - [SULFONICACIDS] (Vol23) -as electronics coatings [ELECTRONICS, COATINGS] (Vol 9) -for printing processes [PRINTING PROCESSES] (Vol 20) -thin films for [THIN FILMS - MONOMOLECULARLAYERS] (Vol 23)... 

---