Sign Builder Illustrated - October 2008 - (Page 34)

Hingst’s Sign Post BY JIM HINGST UV Ink and Printer Update, Part One UV-curable technology makes an imprint on the market. n the sign industry, UV inkjet printers are the up-and-coming technology, even though UV inks are nothing new. A wide spectrum of the graphic arts field—including screen printing, digital printing, offset lithography, and flexographic printing—has used this technology for years. What’s remarkable is that usage of UV inks is growing remarkably fast. In the wide format digital printing market, UV inkjet has taken market share from traditional forms of printing in the screen print industry—particularly among those companies engaged in the point-of-purchase (P-O-P), billboard, and tradeshow markets. There are several factors driving this growth: More affordable print systems; The ability of UV inks to adhere to a broader range of rigid and flexible substrates without ink-receptive top coatings; The nearly instant cure of the inks; Lower Volatile Organic Chemical (VOC) emissions; and The development of more flexible inks. With the development of more flexible UV inks, the range of printable substrates has expanded to include banner materials, flexible sign face materials, and pressure-sensitive vinyl films. Applications here include exterior signage, vacuum-formable parts for vending machines, outdoor advertising displays, banners, window and wall graphics, and even vehicle graphics. I ☞ ☞ ☞ ☞ ☞ The Chemistry of UV-curable Inkjet Inks Unlike solvent, eco-solvent, or water-based inks, UV-curable inks don’t evaporate into the air. Instead these inks dry—or “cure”—instantly through a polymerization chemical process, which is initiated by exposing the inks to a certain spectrum and intensity of UV light. UV inkjet inks are classified as 100 percent solids. You might wonder how an ink could be a liquid and still be classified as “100 percent solids.” This means 100 percent of what’s printed on the media stays on the media. By comparison, solvent inkjet inks are less than 20 percent solids, and solvent screen print inks are about 50 percent solids. Everything that isn’t a solid evaporates into thin air. Two of the key ingredients in a UVcurable ink formulation are monomers and oligomers. Monomers are very small molecules that can combine (through polymerization) to form much larger molecules called polymers. Monomers are classified as “reactive diluents” (materials that ink manufacturers can use to replace organic solvents). In an ink formulation, the monomers perform the same purpose as a solvent by reducing or thinning the viscosity of the ink. However monomers don’t evaporate (whereas solvents do). As the solvent in a conventional ink dries, it evaporates, causing these VOCs to get into the air and contribute to air pollution. (Note: These airborne solvents also pose a health risk to your employees.) Just like monomers, oligomer molecules 34 Sign Builder Illustrated October 2008 Photo by Gerber Scientific Products.

Table of Contents Feed for the Digital Edition of Sign Builder Illustrated - October 2008

Sign Builder Illustrated - October 2008 Contents SBI Agenda Quotes & Comments Contributors Revving Up for WrapQuest Dispatches Sign Show Sandblasted and Dimensional Sign Rescue, Part Three UV Ink and Printer Update, Part One Black is Black! Makin' Money With Molded Letters Making a Monster A Custom Built Sign Shop The Evolution of Architectural and ADA�Signage Finishing That Makes the Cut Maximizing In-store Signage and P-O-P Displays Wide Format Opportunities Panel Saws: A Precise Cut SBI Marketplace Q&A

Sign Builder Illustrated - October 2008

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