This month’s interview is with Dr. Ray Work, who heads Work Associates, a consultant firm specializing in inkjet printing technologies, applications and markets. He worked for more than 28 years in research, research management, business development and business management with DuPont.
What career path led you into the field of digital printer ink technology?
After 15 years as a researcher and research manager in DuPont Photo Products, management asked me to help them develop and execute a plan to enter the new field of digital printing. I studied all of the technologies from both the technical and business perspective. I concluded in 1987 that in the desktop office and home markets, the future would be dominated by inkjet and HP. In 1989, DuPont and HP seriously embarked on a development program. In 1993, HP introduced the first office printer with pigmented black inks. This was later extended to color pigmented inks for wide-format printing.
What do you consider the greatest technological breakthrough in ink to have occurred during your career?
During my DuPont career, the development of water-based pigmented inkjet inks was the most difficult and important advance in inkjet. It enabled inkjet’s success in both the desktop and graphics markets beginning in the 1990s. Even though a number of scientists in the industry told me it couldn’t be done. With a willing partner and unique DuPont polymer technology, it was done.
What promising ink technology failed to live up to expectations?
Early developments in direct-to-vinyl water-based inks, two-part inks that react on the substrate and inks with heavy pigments like white and metallic needed much more effort to develop than anticipated. All were started in the 1990s, but it took many more years to implement in commercial printing.
Ink costs are one of the biggest expenses for print service providers. Can you give a little explanation on why printer ink is one of the most expensive liquids on Earth?
Most inks today are not extremely expensive to manufacture but do require special techniques to provide the correct particle size for pigments and clean dye inks. Compared to screen printing or offset printing, the cost to prepare inkjet inks is significantly higher. Cost and price vary primarily due to the volumes of ink used, the way they are provided and the profit model of the supplier. In the early desktop printers in addition to the ink, you were purchasing a completely new print engine, electronics and printhead. So ink cost was exaggerated and was only a small part of the cost of the cartridge. This led to the refill market.
How long does it normally take for an ink to go from the drawing board to mass production?
Generally, for new printer systems, the ink and printing system are developed together so that the result is an optimum solution. It is an iterative process, so it is not only dependent upon ink development but also print system development. For the first pigmented black it took about five years. Today, with vendors supplying pigment dispersions and purified inks intended for inkjet inks, it is more driven by printer development.
What has been the biggest driving factor in the advancement of today’s inks?
Graphics quality now exceeds silver halide photography. With UV-curable and Latex inks, durability has become much less of a problem. Ink price in high-productivity printers has moderated primarily due to competitive pressures, and safety issues are better understood. In high-productivity printers, there is clearly a drive toward water-based pigmented inks. This is for two reasons, cost and safety. If you can successfully use water-based inks instead of solvent inks or UV inks to achieve the desired graphics products, it is wise to do so. The ingredients in UV-curable inks are much more expensive than water-based inks, so the minimum price that can be offered is higher for UV.
What are some of the most important safety precautions shops should employ to make sure their inks don’t cause harm to employees?
Water-based dye and pigment inks are relatively safe for employees. With all inks, it is important to follow precautions outlined by the printer or ink manufacturer. Solvent inks, even those that have little odor, should have adequate ventilation to avoid inhalation of large amounts of solvent. For UV-curable inks, much more care should be taken. Eye protection and gloves should always be used when handling. UV ink is a hazardous material before complete curing. Incomplete curing can cause a rash on people handling the printed materials, particularly fabrics used in apparel. UV inks in direct contact and in some cases indirect contact with food is to be avoided.