A type of photo reactive vehicle ink that dries, or sets, with the application of a beam of electrons, in a manner similar to that of ultraviolet curing ink. The EB curing ink vehicle is composed of fluid oligomers and monomers that, when exposed to a beam of high-energy electrons, release free radicals that cause the polymerization of the vehicle, which hardens to a dry ink film containing the pigment. EB and UV curing inks are designed to replace heatset inks whose solvents emit potentially toxic and environmentally unsound gaseous emissions.
The expense of UV curing inks is obviated by EB curing inks, as the reactive materials used in UV inks are very expensive; EB curing inks can utilize less expensive and less reactive materials, and do not require costly initiators. The real expense involved in EB curing inks is the cost of equipping a press to utilize them. There is also a danger of EB-curing equipment producing X-rays.
The equipment for electron-beam curing is either a scanned beam generator (electrons are produced from a cathode and shot at a positively-charged screen, which uses a magnetic lens to focus them to a thin beam), or a linear cathode beam generator (producing electrons from a cathode but not focusing them into a beam, merely allowing them to bombard the wet ink in a shower. The latter type is the more popular, as it is smaller and more effectively shielded against X-ray leakage. (See Photo Reactive Vehicle.)