Equipment
UV Ink Curing Units: Curing units for UV inks range greatly in price. While UV inks cure with
even the simplest system, the following are important in
selecting UV processing equipment: the type, width, number of
units, cooling method, and temperature of operation.
Conveyorised or modular: Conveyorised units can be placed behind existing equipment with little effort. They usually have interlocks that shut lamps down when cooling system, power or conveyor mechanical failures occur. These complete, self-contained units are usually more expensive, but offer features like vacuum hold-down, conveyor speed indicator and trouble lights.
In many cases, a modular lamp may be all that is needed. Modular lamp and power packs are readily available for adding to existing presses or conveyors. Although less expensive, they require adaptation to existing equipment. In general, modular systems have fewer interlocks and more limited cooling systems than their conveyorised counterparts.
Width: Width selection is based on belt speed and substrate size. In general, wider width units require greater capital investment.
Number of units: While good price discounts exist for buying in multiples, it is possible that one or two UV ink curing units could entirely replace dozens of racks, or four to five conventional hot air dryers. A high-speed cylinder press and one small curing unit may replace five or six flat bed screen presses and accompanying drying systems. Starting with one unit may be better than buying too many units.
Type of lamps and reflectors: Although there are a wide variety of lamps and reflectors available, medium pressure mercury vapor, focused-type reflectors are extremely efficient and allow for high belt speeds at energy levels sufficient to cure most inks on the market.
Cooling: The cooling system is an integral part of a unit's operation. UV lamp suppliers can offer assistance in selecting an appropriate unit, based on printing applications and substrates.
Number of lamps: Curing units are available with 1, 2, 3, 4 or more lamps. The number of lamps required will depend on the substrate, coating and desired line speed. UV inks cure well in many of the one or two-lamp systems at speeds approaching 400 ft/min. A two-lamp curing unit with high/low settings on each lamp is highly versatile, lengthens lamp life and conserves energy.
Finally, substrates, coating, and printing speeds will determine the appropriate curing unit. A printer should start by matching the first processor unit to the printing segment that would be easiest to convert to energy curing, and learn how to print the inks well before converting the whole plant.
Electron Beam Curing Units: The advantages of EB curing include complete through-curing and no residual monomers. For some specialty applications, these advantages more than offset what are sometimes seen as disadvantages of EB equipment. First, EB units are large, so they require more space than UV units. Second, they can be more costly to install and operate because of special safety requirements. (These costs however, are receding as technical refinements are made.)
Whenever an electron beam strikes a surface, x-rays can be generated, which can present a health hazard within an unprotected range of several meters. Lead shielding and a radiation detection system are therefore essential.
There are two main configurations for EB generators: the scanned beam type and the linear cathode type. In both cases, electrons are generated by a hot metal cathode within a high vacuum.
In the scanned beam unit, electrons are accelerated through a positively charged grid, then focused into a beam by a magnetic lens. A magnetic field then deflects the beam, scanning it across the width of the emission window.
In the linear cathode unit, a filament cathode of press width is suspended in a vacuum tube. Again, electrons are accelerated towards a positive grid, but in this case an unfocused beam of electrons passes through the emission window to the printed film.
While the linear cathode unit is less powerful than the scanned beam type, it is smaller in size and easier to shield, so it is generally preferred for printing applications.
Conveyorised or modular: Conveyorised units can be placed behind existing equipment with little effort. They usually have interlocks that shut lamps down when cooling system, power or conveyor mechanical failures occur. These complete, self-contained units are usually more expensive, but offer features like vacuum hold-down, conveyor speed indicator and trouble lights.
In many cases, a modular lamp may be all that is needed. Modular lamp and power packs are readily available for adding to existing presses or conveyors. Although less expensive, they require adaptation to existing equipment. In general, modular systems have fewer interlocks and more limited cooling systems than their conveyorised counterparts.
Width: Width selection is based on belt speed and substrate size. In general, wider width units require greater capital investment.
Number of units: While good price discounts exist for buying in multiples, it is possible that one or two UV ink curing units could entirely replace dozens of racks, or four to five conventional hot air dryers. A high-speed cylinder press and one small curing unit may replace five or six flat bed screen presses and accompanying drying systems. Starting with one unit may be better than buying too many units.
Type of lamps and reflectors: Although there are a wide variety of lamps and reflectors available, medium pressure mercury vapor, focused-type reflectors are extremely efficient and allow for high belt speeds at energy levels sufficient to cure most inks on the market.
Cooling: The cooling system is an integral part of a unit's operation. UV lamp suppliers can offer assistance in selecting an appropriate unit, based on printing applications and substrates.
Number of lamps: Curing units are available with 1, 2, 3, 4 or more lamps. The number of lamps required will depend on the substrate, coating and desired line speed. UV inks cure well in many of the one or two-lamp systems at speeds approaching 400 ft/min. A two-lamp curing unit with high/low settings on each lamp is highly versatile, lengthens lamp life and conserves energy.
Finally, substrates, coating, and printing speeds will determine the appropriate curing unit. A printer should start by matching the first processor unit to the printing segment that would be easiest to convert to energy curing, and learn how to print the inks well before converting the whole plant.
Electron Beam Curing Units: The advantages of EB curing include complete through-curing and no residual monomers. For some specialty applications, these advantages more than offset what are sometimes seen as disadvantages of EB equipment. First, EB units are large, so they require more space than UV units. Second, they can be more costly to install and operate because of special safety requirements. (These costs however, are receding as technical refinements are made.)
Whenever an electron beam strikes a surface, x-rays can be generated, which can present a health hazard within an unprotected range of several meters. Lead shielding and a radiation detection system are therefore essential.
There are two main configurations for EB generators: the scanned beam type and the linear cathode type. In both cases, electrons are generated by a hot metal cathode within a high vacuum.
In the scanned beam unit, electrons are accelerated through a positively charged grid, then focused into a beam by a magnetic lens. A magnetic field then deflects the beam, scanning it across the width of the emission window.
In the linear cathode unit, a filament cathode of press width is suspended in a vacuum tube. Again, electrons are accelerated towards a positive grid, but in this case an unfocused beam of electrons passes through the emission window to the printed film.
While the linear cathode unit is less powerful than the scanned beam type, it is smaller in size and easier to shield, so it is generally preferred for printing applications.
Flint Group Headquarters
26b, Boulevard Royal
L-2449 Luxembourg
Luxembourg
L-2449 Luxembourg
Luxembourg
For Information
T +1 734 781 4600
F +1 734 781 4699
F +1 734 781 4699