Printing inks rely on a variety of solvents (glycol ethers, esters, alcohols but also hydrocarbon solvents), depending on the printing process so that they can be applied properly, stay in place and display vivid colours. Solvents in printing inks control viscosity and allow flow without damaging printing rollers. Solvents also ensure optimal drying time for today’s high-speed printing presses and solvents are also used to clean the equipment after use or between print runs.
Wet wipes containing solvents may be used for the cleaning of screens. Electronic-grade solvents, with very low levels of metal ions in the solvents, are also used to produce microchips. Metal ions can cause short circuits that result in poor-quality microchips. Electronic-grade solvents are used to dissolve a photo-sensitive polymer that is then spun on a silicon wafer to produce the microcircuit. Solvents are also required to clean the surface of wafers and circuits. The solvents used to produce microchips are alcohols, esters and ketones.