Multicolor printing

Uses. Cinnamyl alcohol and its esters, especially cinnamyl acetate, are widely employed in perfumery because of their excellent sensory and fixative properties. They are frequently used in blossom compositions such as lilac, jasmine, lily of the valley, hyacinth, and gardenia to impart balsamic and oriental notes to the fragrance. In addition, they ate utilized as modifiers in berry, nut, and spice flavor systems. The value of cinnamyl alcohol has also been mentioned in a variety of appHcations which include the production of photosensitive polymers (49), the creation of inks for multicolor printing (50), the formulation of animal repellent compositions (51), and the development of effective insect attractants (52). 

Offset Printing Roll-transfer method of decrating. In most cases less expensive than other multicolor printing methods. Ranges from low-cost hand presses to very expensive automated units. Drying, destaticizers, feeding devices. 

P.R.184 affords a red which is somewhat on the bluish side of P.R.146, to which it is closely related in terms of chemical constitution. Both products also behave very similarly in application. Their prints are fast to soap, butter, paraffin, dibutyl phthalate, white spirit, and toluene. P.R.184 produces a shade which matches that of the standard magenta for multicolor printing on the European Color Scale CIE 12-66. This shade results from formulating an ink at 15% pigment concentration and printing the ink in a standard layer (1 pm). 

UV inks have been readily and successfully adopted by flexographic label printers, many of them having had several years of experience with letterpress UV systems. Because the common thickness of the printed ink in flexography is typically 2 to 4 pm, in multicolor printing it is often necessary to cure individual layers of inks by UV. With radical UV-curable flexographic printing inks, it is possible to achieve printing speeds of 250 m/min (750 ft/min) or even more.22... 

If the foamable composition Is to be used for printing, the composition Is designed to have a useful life of 8 to 10 hours after foaming for a very practical reason. For a multicolor printing operation, It would be Impractical to have a mechanical foamer for each color being applied to the fabric. Instead each foamed color composition Is sequentially prepared In the color shop. The foamed colors are then treated as conventional print pastes and applied to fabric by either screen or Intaglio printing techniques. 

Traugott Sandmeyer s 1896 discovery of acid glaucine red (38) led to the colorant better known as peacock blue, later employed extensively in multicolor printing. It came to prominence in the 1930s, with the introduction of flushed color production that enables retention of the required degree of fineness of pigment particles and provides uniform dispersion (Scheme 15)54,55. 

Three mechanisms can be considered for the migration of an ink vehicle such as oil capillary imbibition, spreading, and bulk diffusion. It takes about 100 ms for a fresh print to travel from one nip of the printing press to the next in a commercial multicolor printing press. In this time the oil vehicle is sufficiently drained from the ink that set off does not occur in the second colour unit. The driving force for capillary imbibition is surface tension ... 

In the case of offset lithography the wetting of the surface of paper and subsequent sorption of fountain solution is Important for the avoidance of printing problems such as Ink refusal in multicolor printing, llntlng and picking, and Interference with ink drying mechanisms when residual acid In paper is solubilized. 

Roll-transfer method of decorating. In most cases less expensive than other multicolor printing methods. 

Offset has grown in popularity because it is fast, allows for high-resolution multi-ink (multicolor) printing, and the printing plates can be manufactured in a matter of minutes (through a photolithographic process) with relatively inexpensive equipment that can be operated easily at the printing location. 

First-down color n. In a multicolor printed material this is the first color printed on the substrate usually subsequently overprinted by other colors. 

On the other hand, in a photo-like paper, the substrate does not have water absorbability, and the amount of ink per unit area is increased, if multicolor printing is performed to obtain a fine image. As a result, the glossy layer may contain a large amount of moisture immediately after printing. Thus, high water resistance is required for the recording layer. 

---