Green Printing: Perception vs. Reality and the UV Edge

Older Solvent-based vs. Current UV Systems in Sign Production

As sign-printing technology has evolved from screen printing to wide-format digital printing, a number of the same “green” lessons have been learned as solvent-based fluid inks are replaced by UV inks. While very few commercial, label or package printers also offer digital wide-format signs and banners, the “green” message shared with the different markets is so similar it is actually reinforcing.

Large-format inkjet printers previously used solvent-based technology to adhere ink to substrate. The process entails mixing ink pigment with a solvent vehicle to create liquid ink. The printer head(s), one for each color, then transfer the liquid onto a substrate. As the solvent evaporates a hard layer of ink remains.

Water-based inks work similarly except more water is often absorbed into the paper rather than evaporating into the atmosphere as with solvent. While water is harmless, solvents in printing are toxic. To ensure the safety of employees and customers at a printing facility, complex ventilation systems must be installed to remove and capture hazardous airborne chemicals, called VOCs.

UV printing is fast becoming the new industry standard in signage production. Because there are no solvents used, this system produces no dangerous VOCs, requires no ventilation, has a higher percentage of recyclable content, and cuts cost because of reduced drying time. In addition, UV printed foil-type metallic inks on paper and plastic yield a fully recyclable product.

Eco-friendly UV Supplies Advancements

A universal problem, which is experienced by all sheetfed and web UV printers, is the tendency of the printing blankets to fail prematurely. Blanket failure is typically caused by a latent image of the printing form adhering to the blanket after a few thousand impressions. This latent image cannot be removed with conventional blanket wash. UV printers often refer to this phenomenon as “ghosted image,” “latent image,” “burn-in” or “image memory.”