The Great Debate
By Gretchen A. Peck
There are a lot of variables throughout the print process. For example, the quality of the graphics, media choice, and the lighting and environmental conditions at the installation point. All of these factors contribute to the overall success of a print job. The same is true for how consumables and the print technology itself, including printheads, work together.
“Printheads are a crucial area of printer design, and what differentiates one printer manufacturer from another,” explains Mark Radogna, product manager, professional imaging, Epson.
Hardware manufacturers decide what type of printhead—piezo or thermal—to place in a device based on many factors. These include temperature and ink chemistry.
Heat—or lack of—plays a large role in why a certain printhead is used in a device. Shulik Leshem, business manager, Scitex industrial presses, Hewlett-Packard (HP), provides input on the differences between thermal and piezo printheads and the temperature requirements of each.
With thermal printheads, the drop is formed when a heating element rapidly vaporizes the ink, which creates an air bubble. In the print process that involves a piezo printhead, drops are created using mechanical energy exerted by a piezoelectric element. The difference between the two is that a thermal printhead works in higher temperatures.
The higher temperature also affects durability, life span, and ink compatibility. “The warming element in a thermal printhead is more susceptible to physical corrosion due to its being dissolved in ink. Both a high temperature working mode and higher wear out of the heating element will lower the durability and life span of the thermal printhead, which is why piezo printheads are recommended for industrial printing. The fact that piezo printheads work in lower temperatures makes those printheads compatible with a wider range of inks,” continues Leshem.
Printheads must be designed to work with the ink at hand. Each component complements the other, which is why looking at the entire printing system together is the best way to generate high-level results.
With ink formulas and weight variations, digital ink sets are not one size fits all when it comes to matching up with a printhead.
“In an industry where fast turnaround times and high quality are crucial to success, it is a fundamental truth that using inks developed for a specific printer and printheads will provide better results, allow the system to work with maximum efficiency, and support longer lasting, more problem-free operation,” notes Leshem. He points to the HP Scitex FB10000 Industrial Press; the new HP HDR240 Scitex Ink was specifically formulated for use with HDR300 printheads.
Sean Roberts, manager, global customer experience centers, EFI, agrees, explaining the since EFI maintains the advantage of developing its inks in house, each one is formulated for a specific print engine and the printheads are individually tuned for the physical and chemical properties of a particular ink type.
Epson continues to advance its technology with the Epson PrecisionCore TFP printhead, made up of PrecisionCore chips. “Depending upon the application, Epson can tailor the ink chemistry to optimize the print quality and cost of production. This is possible due to Epson printhead technology being piezo based,” adds Radogna.
The Future of Print
In the past year, mainstream press attention was given to new types of print equipment and the printheads driving them—three dimensional print systems, for example. But that hasn’t pulled printer or printhead manufacturers away from continued development in the more lucrative world of two dimensional inkjet printing.
“Technology to advance the performance of printers is constantly being developed, and printhead design is key to the success of this development,” shares David Conrad, director of marketing, Mutoh America, Inc. “New ways to jet the ink, adding printheads to the printer, improving on the ink chemistry to allow for faster print speeds with better performance, nozzle size, and ink patterns, are all ways manufacturers in the digital inkjet realm are working to keep up with these demands.”
Just last year, Seiko Epson Corporation announced that it had made significant capital investments in two new manufacturing lines in Japan, dedicated to making new and better printheads for its business and industrial print systems.
Also in the past year, Durst Image Technology US LLC unveiled its new Rho 1012 continuous inkjet production system, which the manufacturer lauded for its latest generation Quadro Array 12M printhead technology. It features small droplets of only 12 picoliters.
HP focuses on improvements in image quality, productivity, and serviceability when it comes to developing its printheads. Of note, the evolution of printheads—from any manufacturer—to fire smaller drops and more drops at one time. For HP, this means either using the same nozzles with multi-drop technology or enabling high nozzle density, both increase production rates while maintaining high quality.
The Great Debate
Hardware manufacturers are tasked with creating a close-to-perfect device when it comes to the construction of wide format printers, the printhead is only one piece of the puzzle, albeit an important one.
Apr2014, Digital Output