Printing, of the good, old 2D variety, might these days strike a person as a somewhat passé industry.
Hewlett-Packard, understanding this, has been making an effort to share more about exactly what it does, and how it does it, in hopes that people might better appreciate the effort that’s gone into—and the expertise that’s come out of—its more than three decades of figuring out how to best put ink to paper.
Sue Richards and Brad Freeman, directors of research and development at HP printing labs in Corvallis, Ore., and Vancouver, Wash., respectively, recently offered some insights into the two metrics that are the measure of excellence in printing: specificity and speed.
Consider, for example, that early ink-jet printer heads each held 12 nozzles; today, they hold more than 42,000 each. Or that each nozzle is 15 microns wide—and that a human hair is 75 microns wide.
The Corvallis site, in an area sometimes called the Silicon Forest, according to Richards, started out developing calculators, then integrated circuits and eventually thermal ink jets. Today, it includes everything from lab benches for testing inks to microphone-filled booths that listen to the sounds printers make so that engineers can turn screeches into hums.
“One of the key things between our sites is the system that’s been developed,” Richards explained. “There’s just a tremendous amount of technology and intellectual property involved … which has enabled us to do things like go from printing one page every three minutes [in the early days of ink-jet printers] to 72 pages per minute.”
“The key thing we want to articulate,” she continued, “is that the technology that goes into printing today is phenomenal, and we’re bringing thermal ink-jet printing into places we never thought we could.”
Most people don’t think much about credit card statements, which are one-off items printed alongside millions of other so-called unique documents, and that rely on digital data being communicated to the printer head. HP sells printers to the companies that perform services such as statement printing.
“These are 42-inch-wide, high-speed Web presses that run in excess of 800 feet of paper per minute,” explained Freeman. “You have to fire the ink at a high frequency and accuracy. We’re firing them at up to 350 degrees, in a matter of microseconds inside the firing chamber of the print bar. You’re creating a vapor bubble that creates the drop of ink, thousands of times per second.”
In the early days of ink jets, the volume of a drop of ink was 220 picoliters. Today it’s 6 picoliters.
“Huge drops don’t make for as good an image quality,” said Freeman.
HP’s printers are enabling its customers to move into areas such as just-in-time printing, where authors or readers or students can request one-off printings of a book, or 10 or 100 copies.
“We’ve really taken our thermal ink-jet technology and pushed it into this industrial and graphics space to really be able to enable digital content and transform the so-called mom-and-pop publishing space,” said Freeman. “There’s so much opportunity,” he added, in identifying markets that still need to transition from analog presses to digital.
When it comes to office printers, however, Richards said she and Freeman already have the road map for the next 30 years—and much of it is informed by the advances that have been made in the company’s most sophisticated products. Richards offered ink as an example.
“You may be able to have 42,000-plus nozzles on a printer head, but you’re not printing with each of them all the time. When a nozzle isn’t being used, its water can evaporate and a plug can form,” she explained. “We’ve engineered our ink to be able to form a nano-layer of film within the nozzle, so it doesn’t dry out. And when it’s ready to fire, that nano-layer is ejected [without introducing any imperfections to the printed product].”
Freeman added that a good amount of time is also spent considering power and waste and how each area can be improved. One “breakthrough,” he said, included eliminating the need for a heater in ink-jet printers, through HP’s product design and ink development, which resulted in a power-consumption savings of 20 percent and significantly reduced the amount of physical waste associated with the printers.
Richards, in a discussion about the subtlety of picoliters and the detailed nature of the work, made clear also the enormity of the task—the idea of creating precision within a machine undergoing 1,200 psi of pressure, and that “has to last billions of firing cycles in excess of 400c temperatures.”
“It’s really a challenge for the organization,” she said, “to make sure we’re meeting the needs of the customer, and of the market.”