Drop on Demand

Nonimpact Printing. Interest is growing ia the use of nonimpact styles because of the quickness of color changeover and the abiUty to iaterface these machines to computer-aided design systems. Two basic types exist drop on demand and constant drop techniques. 

Droplet radius, in polymer blends, 20 333 Droplet size correlations, 23 190-191 Droplet size distribution, in polymer blends, 20 332-333 Droplet sizes, in sprays, 23 185 Drop-on-demand (DOD) inkjet printing, 9 222... 

Several xanthene derivatives are applied as acid dyes. For example, condensation of 3-diethylaminophenol with benzaldehyde-2,4-disulphonic acid, followed by cyclisation and oxidation, gives Acid Rhodamine B (6.197 Cl Acid Red 52). This dye is used in drop-on-demand ink-jet printing [36]. 

In many processes (such as oil recovery, blood flow, underground water), one encounters liquid flow through thin (micrometer diameter), noncircular-shaped tubes, or pores. In the literature, one finds studies that address these latter systems. In another context of liquid drop formation, for example, in an inkjet nozzle, this technique falls under a class of scientifically challenging technology. The inkjet printer demands such quality that this branch of drop-on-demand technology is much in the realm of industrial research. All combustion engines are controlled by oil drop formation and evaporation characteristics. The important role of capillary forces is obvious in such systems. 

Drop-on-demand (DOD) inkjet is the method that is universally adopted in the printers used in the home and the office environments. It takes its generic name from the fact that ink is delivered from the ink head directly to the substrate only as demanded by the printing information supplied by the software. 

J. Roeraade, Nanoliter Titration Based on Piezoelectric Drop-on-Demand Technology and Laser-Induced Fluorescence Detection, Anal. Chem. 1998,... 

The impulse or drop-on-demand ink jet is a system of fundamental simplicity. It differs from continuous ink jet systems in two aspects (1) The image-forming ink droplets are not charged, so no deflection device is involved (2) Electrical signals are only used to control the moment when an individual droplet is needed. 

As seen in Figure 5.1, there are two main types of drop-on-demand technologies. The thermal ink jet or bubble jet has a heating element that causes a vapor bubble to eject an ink droplet from the nozzle. The piezo ink jet uses a piezoelectric transducer for ejecting ink droplets. The microjet technology is a further... 

Generally, ink dyes for ink jet applications and writing, drawing, or marking materials are selected from food, acid, direct, sulfur, and reactive dyes. The choice of dye depends on the application and the ink used, whether it is aqueous, solvent based, or hot melt, and on the printer type continuous ink jet or drop-on-demand, piezo or thermal inkjet. 

Drop on demand Three-dimensional 25 mm wide None... 

Ink-jet Continuous Drop on demand Bubble Vegetable oil Rosin ester Cellosics Synthetic polymers Acrylated ester Water Alcohols Esters Ketones 80-100 1-80 No. 4 Cup ... 

Ink-jet Continuous Drop on demand Bubble Identification coding Identification coding Office documentation... 

Figure 94 Ink-jet printing (i) Continuous (ii) Impulse or drop on demand (iii) Bubble jet...

While all inkjet technologies can fundamentally be described as the digitally controlled ejection of drops of fluid from a print head onto a substrate, this is accomplished in a variety of ways. Industrial inkjet is broadly and most typically classified as either continuous (CIJ) or drop-on-demand (DOD), with variants within each classification. 

As the name implies, continuous inkjet technology ejects drops continuously (Fig. lA). These drops are then either directed to the substrate or to a collector for recirculation and reuse. Drop-on-demand technology ejects drops only when required " (Fig. IB). 

Drop-on-Demand Inkjet (DOD) is a broad classification of inkjet technology where drops are ejected only when required. In general, the drops are formed by the creation of a pressure pulse. " The... 

Dong H, Carr W, Morris J. (2006) An experimental study of drop-on-demand drop formation. Phys Fluids 18 article 072102. 

---