The get-it-yesterday attitude pervasive in today’s culture extends into large format print. Print service providers (PSPs) must keep pace with the last minute needs of print buyers and the grand scale of projects. At the same time, PSPs look for more revenue using less operator hours.
A grand format printer, a device over 95 inches in width, helps them succeed in advanced throughput. With it, they print more square feet per hour (sf/h) versus a narrower printer and process several jobs at once. For example, EFI’s VUTEk GS5000r simultaneously prints on up to three 60-inch rolls.
Efficiency is there. If one were to implement three printers to run three jobs, compared to a grand format device running all of them, loss of quality and color matching issues arise. Grand format printers offer PSPs maximum productivity.
Quality print production is essential to satisfying and keeping customers, but ultimately, throughput protects the bottom line. A PSP with a quicker device and higher throughput can do more in less time, with minimal labor costs. “Speed equals time and time equals money,” suggests Deborah Hutcheson, director of marketing, Agfa Graphics.
Agfa, Durst Image Technology US LLC, Fujifilm North America Corporation, and Hewlett-Packard (HP) offer grand format printers that produce large quantities of printed media at high speeds. These units all use piezo drop on demand inkjet print technology.
Whether it uses UV, solvent, or latex ink, each type of device features unique characteristics. UV printers benefit from instant curing and the ability to print on virtually any media. Solvent is especially durable, scratch resistant, and suited to outdoor applications. Latex printers use water-based ink that contains no hazardous air pollutants and are a fitting option for shops looking for an eco-friendly solution or bound by strict environmental regulations.
Speeds range significantly, but many run in the high 5,000 and 6,000 sf/h. The Inca Onset S70 from Inca Digital Printers is capable of printing high-quality display graphics up to 165 beds an hour at 600 dpi. The printer, available from Fujifilm in the U.S., is rated at 6,458 sf/h in production mode. Durst’s Rho 1000 clocks in at 6,240 sf/h. HP Scitex FB7500 runs at its fastest at 5,380 sf/h, or 95 full beds per hour. Agfa’s :Jeti 5048 UV JetSpeed XL R2R rates 5,000 sf/h.
Printing at a lower resolution, or in production mode, accelerates the process. “Any time high-quality images are printed at a lower resolution, a faster print speed occurs with less print passes,” notes Bill Grambsch, west regional sales manager, Polytype America.
When printing at a lower resolution to ramp up productivity, a device that includes multi-pass printheads, rather than single pass, possesses more flexibility. The device’s printhead takes multiple passes across the substrate, which masks banding or misfires and creates a higher resolution appearance.
Rapid printing at a lower resolution is a benefit, but other modes are also available to increase throughput. Durst’s Rho models print in a backlit mode, a process that puts twice the ink down without affecting speed during standard printing. “This is an important function that customers use quite often,” says Christopher Howard, VP of marketing and sales, Durst.
Hybrid grand format printers, including the Agfa :Jeti 1224 HDC FTR, Durst Rho, Fujifilm UVISTAR 5032, and Polytype Virtu, feature dual personalities, switching from roll-to-roll to flatbed printing. Transitioning from one delivery method to the other has no effect on production speed, as the majority only take between one and five minutes to change.
Under the Hood
Many equipment and workflow elements impact grand format output. Ink flux is a big contributor. Flux is the amount of ink laid out per unit of time. The size and frequency of drops, and the number of nozzles all play a role. “People sometimes think that smaller drop sizes are better and lead to higher print quality. Although this is true in some cases, in high-end presses the desired print quality is achieved without sacrificing speed by better controlling the dot placement accuracy,” notes Eviatar Halevi, director of technology, HP Scitex.
The number of printheads and nozzles hasten or slow equipment. In different print modes, a PSP balances between high print quality at slower speeds and higher speeds at a lower print quality. “The higher the number of nozzles in the system, the higher this curve can be, resulting in higher speeds at all print quality levels,” states Halevi. HP’s fastest grand format press, the HP Scitex FB7500 printer, features 40,000 nozzles operated by 312 printheads. The press produces between 50 and 100 full-size sheets per hour at resolutions ranging between 330 to 500 dpi.
Durst uses Quadro Array technology, integrating multiple print nozzle plates into a single array system. Its highest speed platform uses 65,000 nozzles for process colors, adding additional linear print speed.
The Onset S70 uses a fixed printhead array that consists of up 156 printheads with a moving print bed. The number of printheads allows speeds of 3,600 sf/h. Nozzle redundancy supports production of high-resolution output.
Other factors that effect productivity include media handling automation, flexibility to swap jobs, and press uptime. The HP Scitex FB7500 offers three-quarters automated loading for increased productivity. The Scitex TJ8600 includes a new Hot Folder solution, users automatically load from the RIP to the printer queue.
There is also print width to consider when evaluating throughput. Falsely, many believe the wider the width of a printer, the longer it takes for the printhead to travel across the media. On the contrary, grand format printers reaching widths of 200 and 196 inches still maintain high productivity, despite the printhead traveling a greater width.
Hang-ups and Solutions
Poor file design, consumables, and workflow minimize production speed. Besides printing in a lower resolution, graphic designers and press operators quicken the process in several ways.
Designers accelerate production through color selection. When using light colors, for example, the granularity of the image is significantly reduced. This allows an operator to designate the system for higher ink flux and operate faster, at lower print resolutions, without sacrificing quality.
Lower quality ink results in artifacts on the media, such as gloss banding. With that in mind, says Halevi, “one may need to slow the printing speed, add more passes, and thus somehow hide the artifacts. Proper ink formulations reduce the level of banding.”
White ink should be used sparingly if time is of the essence. “White inks can be printed separate from the CMYK inks or printed in-line or as an underprint or overprint layer. Either way this reduces the speed or output of the printer when printing white inks,” explains Terry Mitchell, director of marketing, graphic systems division, Fujifilm.
Finally, media selection can slow down a non-UV printer, as some substrates dry slower. Patrick Ryan, GM, Seiko Instruments USA – Infotech Division, notes that the Seiko ColorPainter H-104s mild solvent printer features a high pigment loaded ink. When using certain media types that dry unusually slow, PSPs are limited in how fast they print but still use the take-up system without transference.
Grand format printers help PSPs print a vast array of print products. They allow for larger size media to be used for grand-scale projects or multi-up production jobs. Some print at more sf/h than others, allowing PSPs to rapidly push projects out and bring in more capacity.
There are also techniques, such as lower resolution printing and color choice, that aid in the productivity of a print shop. PSPs with experience employ these tactics to get the highest throughput from equipment.
The next part of this series includes several successful PSPs with grand format printers in their portfolio.