Manufacture of Ink Jet Coding & Marking Inks

Inks for bar coding, batch numbering, use-by date marking and other identification purposes are used in many industries especially pharmaceuticals and food. Viscosity is in the range of 2 to 30 centipoise. Formulation varies widely according to the method of application and end use. The two main "non impact" print methods can be summarized as follows: * Continuous ink jet (CIJ) A continuous jet of ink is selectively charged by an electrode then passed through an electric field which directs the droplets either onto the substrate or back into the ink channel. The inks are conductive, and very fast drying, based on dyes and volatile solvents e.g. MEK and alcohol. Used for non-absorbent substrates such as metal, plastic or glass etc. * "Drop on demand"(DOD) Similar to desktop "bubblejet" technology, the print head consists of a series of very small ink jet nozzles which are individually operated to produce drops of ink as required to make up the image.Water or glycol based inks are used, mainly with dyes although pigments are being introduced. For printing on paper, board and other absorbent surfaces.