Ink, for inkjet printers

Whereas gasoline is sold at large volume and low cost per pound, the ink for inkjet printers is sold in small volume at high cost per pound. It is a relatively new product that is riding on the crest of the information revolution, with great potential for growth and profit. Let us consider the marketing information needed in preparation for the introduction of a new product. 

The ink for inkjet printers is essentially colored water, and the current formulation of ink is about 75% water, plus dye and glue (Kang 1991, Le 1998, Pond 1999). The ink should flow readily from ihe inkwell to the nozzle, and then to the paper, without dripping or clogging. The viscosity of current inkjet ink is from 2 to 8 cP. The droplets formed should be very uniform in size, and should be as small as possible to increase the resolution. When the droplet hits the paper, the droplet should penetrate the fibers without splatter, which would increase the diameter of the dot on the printed text or picture. The surface tension of current ink is around 45 to 50 dynes/cm, which is much lower than water at 70 dynes/cm. It is believed that if the surface tension is raised from 45 to 65 dynes/cm, the spread (or ratio of diameter of spot on paper/diameter of droplet) would decrease from 3.3 to 1.1. Much higher resolutions... 

Examples of this trend are inks for inkjet printers. The pigments nsed are conventional Food Black 2 for black Direct Bine 199 for cyan a combination of Direct... 

Caputo P. (1998) Stable oil-in-water ink emulsion based upon water-reducible nigrosine dyes for inkjet printers and felt-tip and roller-ball pens, US5746815. 

Myata, Y Takemura, K. Inks changing color with temperature history for inkjet printers. Jpn. Kokai Tokkyo Koho JP 08003494, 1996 Chem. Abstr. 1996,124, 292582. 

Ink jet printing is now the dominant non-impact printing technology. It has achieved this position from a platform of low cost, full color, very good (and ever improving) quality, and reasonable speed. For example, good quality color inkjet printers currently retail for ca. US 70, whereas the cheapest color laser printer costs ca. US 1,400 at the time of writing 43... 

Over thousands of years for writing, the ancient people used naturally occurring colloidal fine material from ash (mostly charcoal) dispersed in oil (olive oil). Modem inkjet printers employing color are based on much more sophisticated components. Inkjet printers have a number of nozzles that inject ink droplets on the surface of paper. Simultaneously, different colors are mixed to obtain the desired color shade (more than hundreds of thousands). In a typical printer, there may be 30,000 injections per second, and there may be more than 500 nozzles (each with a size less than a human hair (pm =10 6 m). (The ink has a shelf life of more than a year.) In this process, the surface and colloidal principles most obvious are... 

Print head technology determines inkjet inks major characteristics, the latter being covered in the chapter "Inkjet inks Requirements". A major characteristic, substantially differing from standard printing inks, is the viscosity. While the viscosity of printing inks vary from several hundred up to several thousand cPs (centi Poise) — the viscosity of inks used for inkjet applications is in the range of a few cPs for the SOHO (Small Office and Home) printers and up to 20 cPs for commercial printers using industrial print heads. 

Since the introduction of HP s Thinkjet printer in 1984, to the end of 2007, over 500 million inkjet printers have been sold for home and business use by numerous manufacturers. Nearly all of these printers utilize water-based inks. In this chapter, a general overview of the composition and properties of water-based inkjet inks will be given. Particular emphasis is placed on the relationships between ink properties and print performance attributes. The unmistakable theme arises, that ink properties must be finely balanced to meet demanding performance specifications. 

FORMULATING SOLVENT INKS FOR CONTINUOUS INKJET PRINTERS... 

Wickramanayake P, Moffatt JR. (1993) Solubilization of water-insoluble dyes via microemulsions for bleedless, non-threading, high print quality inks for thermal inkjet printers, US5226957. 

Therefore, it is possible to summarize the motivation for printed electronics quite simply. Printed electronics is attractive as a means of fabricating electronic systems where reduced cost per unit area is an advantage. Based on the poor linewidth of printed electronics, this will almost certainly only be true for systems with low functional density, i.e., systems with no need for dense arrays of tiny transistors, etc. Printed electronics also potentially enables the use of low cost, flexible substrates such as plastics and metallic foils, and additionally, by using different inks in an inkjet printer, it also allows for the easy deposition of a range of materials onto a substrate in a spatially specific way. 

When a paper display is needed or when textual information is to be printed, as in a report, it is common to use a digital printer such as a laser jet or inkjet printer. These devices are inexpensive and provide 600 to 2400 dots per inch, more than adequate for most applications. The laser jet devices use an electrostatic transfer of black toner material to paper to form the desired image, which is then fused to the paper by passage over a heater. Color versions are available but are more expensive because they require three toner cartridges, one for each of the primary colors. The inkjet printers use movable solid-state heads with many fine holes through which small droplets of ink are ejected by selective localized heating behind the orifices. The ink is drawn by capillary action from a reservoir chamber and, by use of three primary colors, full-color images can be printed at up to 2400 dots per inch. 

Owing to the brilliant black color of magnetite a process similar to the above one was patented in 1905 for producing printing ink (6), but it was not until the seventies with the invention of the magnetic inkjet printer that a printing process depended on the magnetic properties of the ink. 

Part I, Chapter 12). Other examples are commercially available desktop inkjet printers modified for biological purposes, and filled with cells and a biocompatible ink [56, 57]. Three-dimensional thin layers of alternately printed cells were deposited, which initially formed clumps and later fused into vascular structures [58]. Given that the formation of vascular structures in artificial organ replacements is a very challenging task (see also Part I, Chapter 15), these rapid prototyping approaches promise significant rewards in the tissue engineering field. 

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