When eco-solvent ink became available during the early parts of the previous decade, it was a sign that the industry was further improving on its use of inks. The earlier solvent inks, such as “strong” or “full” inks, were not environmentally friendly and less user-friendly. Earlier inks used cyclohexanone, which makes drying faster. However, it has been restricted due to safety concerns. Eco-solvent inks such as Roland, which has low chemical emissions, proved to be more manageable.
Solvent ink versus eco-solvent ink
Solvent ink (strong or full) is an oil-based ink that contains high volatile organic compounds (VOCs). It leaves a strong, lingering smell, making it not suitable for use indoors. Operators have to resort to ventilation and extraction processes to be free of the VOCs. Eco-solvent ink, on the other hand, originates from ether extracts of refined mineral oil. With low VOCs and less odour, they can be used indoors. While strong solvent ink can negatively affect inkjet components, eco-solvent ink does not. As a result, less cleaning is needed.
Evolving ink technology
Eco-solvent inks are still being perfected. Manufacturers are currently finding better ways to even refine the properties and composition of eco-solvent inks. One company has produced new “platform” chemistry in its wide-format inks using raw materials. Another has introduced inks with faster drying times, improving their overall performance. One manufacturer has invented a new form of eco-solvent ink, the hybrid solvent-UV ink, which improves scratch resistance.
Chemists are now drawn into their objectives not just to help make machines run faster but also to get rid of stronger solvents, making them biodegradable and eliminating nickel in the solution.
Ink technology has to evolve to meet safety and environmental standards. Eco-solvent ink is already a leap away from strong solvents, but more enhancements and innovations are already at work to perfect it.