What is ebeam and how does it work?
ebeam is electron beam curing technology. The key to electron beam is high-voltage and high-vacuum. Electrons are emitted by a cathode sitting at a high negative voltage inside an ultra-high vacuum. The cathode is comprised of one or more tungsten filaments. Passing current through the tungsten wires generates electrons. When high-voltage is applied, electrons escape and start flying towards a grounded (0 Volts) window. The electrostatic 'optics' that are part of the system steer the electrons toward the window and focuses them into a strip or a “curtain”. The window is made of a thin titanium foil. This foil is thin enough to allow most of the electrons to fly through it, but strong enough to maintain a hermetic seal and retain the ultra-high vacuum. The electrons then fly through the window into atmosphere and onto the substrate.
Schematic of a typical electron beam curing station
Once the electrons reach a substrate where an ink is applied, the polymerisation of the ink itself is triggered and completed within milliseconds: this is curing! Accelerated electrons carry enough energy to initiate the chemical curing reaction without the need for photoinitiators. In addition, they are able to penetrate through the entire ink layer to the substrate below.
Not a new game for inkjet – it’s a new playing field
While it is true that electron beam technology has long been used for curing and crosslinking, the development of compact ebeam systems has opened up a fresh approach and new playing field to printing and coating markets.
Electron beam curing for inkjet provides a diversity that is needed to stimulate the industry and to take a step towards progress for a healthier environmental future. In today’s world, less means more. With a flexible and compact size and self-shielded vacuum sealed technology, factory footprint is greatly reduced. Along with minimal space requirements, the technology is exceptionally energy efficient, producing minimal heat and no VOCs, meaning a vastly reduced environmental impact.
What about consumer safety?
In the food packaging and labeling industry, consumer safety is the priority topic. Eliminating photoinitiator from ebeam ink reduces the potential problems from migration of harmful ink components. Ensuring the highest curing quality, constant in time and for all colours sets the standards for consumer safety.
Elsa Callini of ebeam Technologies will be descibing the technology and benefits of electron beam curing as part of the Inkjet Drying & Curing course, to be held 15-16 June 2017 at the IMI Europe Inkjet Summer School.