Expiry Date Inkjet Printer

This creates ultrasonic pressure waves in the inkjet ink, breaking it up into individual droplets. When these droplets fall between a set of electrodes, individual droplets are intermittently charged. The size of the charge given to each droplet determines how far it will be deflected out of the stream when passing through the deflector plates. This determines its placement on the product.

By placing a collection of these droplets close together, a variety of characters are printed as the product passes the print head. Ink droplets not deflected out of the stream are re-circulated to repeat the process. This is a highly efficient use of ink jet ink allowing many millions of characters to be printed from a litre of ink.