Sellenis’ Valvejet DOD

Sellenis Valvejet DOD Brochure

Working principle Ink jet valvejet printers sometimes called Large Character Printers (LCP) or Drop On Demand (DOD) are software controlled printers for marking cardboard boxes, timber, concrete blocks, shrink-wrap and similar items. They operate by firing solenoid valves in a particular sequence in front of a moving product. As the valves open, they release pressurised ink through an array of nozzles. By opening the valves in the correct sequence at the correct speed, text, images and barcodes are formed on the product by the ejected droplets of ink. A valve plunger seals the nozzle. The ink is held under pressure. When a valve is opened an ink drop is ejected. The ejecting of ink drops from each of the nozzles is controlled by a solenoid valve. Such a valve comprises an electromagnetic plunger that moves up and down an electromagnetic coil. When current is fed through the coil, this acts on the plunger to move it axially and thus, open or shut the inlet to the nozzle orifice. Typically, the magnetic field acts to retract the plunger against the bias of a spring to create an ink flow path between the ink under pressure in the printhead and the nozzle orifice. When the electric current no longer flows in the solenoid coil, the magnetic field ceases and the bias spring acts to return the plunger to seal against the inlet to the nozzle orifice. This stops the ink flow and hence the ejection of printing drops.

A wide range of high quality robust valvejet printers. Choose a 7, 16 or 32 nozzle printer to meet all of your outer box printing requirements. The nozzle pitch is 4.5 mm and the operating frequency is up to 1200 strokes or bars per second.

Facility for the operator to enter/input and store/save selectable opening voltage and opening timing values for each valve. This is to allow the operator to calibrate the array of solenoid valves to compensate for mechanical and electrical tolerances/variations between the valves, and thus obtain uniform drop sizes across the array.

Basic Specifications
Printing Principle Drop-on-demand Valve jet; Large Character Printing (LCP)
Compatible inks MEK, Alcohol solvent based inks also water based inks (Dye and pigment based)
Number of nozzles 7, 16 and 32
Nozzle pitch 4.5 mm
Frequency 1.2kHz (Maximum)
Print height Up to 142 mm
Print Speed Up to 600 ft/min