Inkjet Printer Technology Primer

Inkjet Machine Configurations - Roll-to-Roll type printers

This type of printer can print from rolls of material of varying widths. There are both dedicated roll-to-roll devices and devices that can be adapted to be flatbed printers (hybrids). Roll devices can be as small as 17 inches in width and can go all the way up to the current limit of five meters in width. Solvent-based units have at least one heater to help in the evaporation of the solvent ink. Many of these units have more than one heater, usually a pre-heater, platen heater, and a drying heater. Aqueous-based printers do not need heaters, while UV-curable inks have UV lamp units on both sides of the print head for ink curing.

Inks for these systems can be water-based, eco-solvent, solvent or UV-curable. Textile inks are used in textile printers only. Some roll machines can utilize dye sublimation inks, depending on the head s in the unit. There are also printers that have an integrated cutting system, making a turnkey solution for the manufacturing of decals or print and cut products.

Options for roll-to-roll (depending on manufacturer)

• Multiple roll printing for wider units
• Four color or extended gamut ink systems, silver ink, white ink
• Integrated cutting systems
• Simultaneous two-sided printing
• Uninterruptable ink supply for continuous printing
• Ability to print on range of rolled materials and textiles
• Wide range of printing speeds depending on head technology and number of heads per color.
• Specially equipped printers to handle textiles stretch, and other textiles only.

True Flatbed

This type of printer can only print flat objects, usually with a limited height of a few inches maximum. There is no provision for roll-to-roll printing. These units can be as small as 14 inches by 18 inches to units that can print five by 10-foot boards in 45 seconds, in production quantities. There are a few variations of flatbed devices. The basic system is where the media is fed past a traversing head unit by using a vacuum belt, grit rollers or moving vacuum table. Another is where a traversing head unit (Mimaki) is on a gantry that traverses down the length of the substrate. Yet another system (Inca Onset) uses a moving vacuum bed assembly that moves the substrate under an array of inkjet heads that index across the board's width. These devices can use either the mercury lamps for pinning and curing the UV ink, or they can use the LED UV-curing heads that accomplish the same curing action, but without the enormous heat generation and energy consumption. Small format UV flatbed units are capable of very high resolutions (greater than 1000dpi) and can have the option of using white ink, varnish, or metallic silver color.

Flatbed-Hybrid

This type of printer can print flat objects, usually with a limited height of a few inches maximum. With hybrids there is an option for roll-to-roll printing. The roll-to-roll units are either part of the unit with accessory tables, or the roll-to-roll part is the option. In the case of truer flatbed units, the roll sits on the end of the imaging bed with the gantry in a fixed position over the roll for imaging. Other units have the roll follow the normal imaging path that would be the same for any rigid material. Flatbed roll materials could include papers, films, cast or calendared vinyl for banner or fleet use. Units of this type can be found using both mercury lamp curing units and LED lamp-curing units. The LED units will not limit the machine to the types of materials that can be printed, as do the mercury lamp units. There are a few flatbed solvent-based units on the market but they are in the minority of the number of total units sold. Mutoh sells a ValueJet 1608HS 64" printer that uses a bio based ink, which has 60% of its content derived from plant materials.