Flexography is the process used in printing packaging materials, including cartons, corrugated containers, paper and plastic bags, food containers, newspapers, catalogs and more. This printing method continues to grow in popularity because of its simplicity and environmental friendliness. The most important part of the process is the application of the ink. Read on to find out more about the types of ink used in flexographic printing.
Types of Flexography Ink
The three main types of ink used in flexography are water-based, solvent-based and UV-curable flexography inks. The type of substrate (printing surface) dictates which type of flexography ink can or must be used. Each type of ink has its own set of pros and cons, so the type used by the printer is determined by factors such as cost, speed and packaging use (food, cleaning products or shopping bags).
A Bit of History
Originally called aniline printing, the early form of flexography used aniline dye ink. Due to its toxicity, aniline dye ink was banned from food packaging. The earliest inks, not chemically treated, were constantly subject to smearing and bleeding when used in the original printing machines. With much trial and error, new methods and machines were developed to perfect the use of the original aniline inks. The ink itself was also modified and improved, with the original form being replaced with formulas that included polyamide resins that allowed for faster drying time and increased production speeds.
Flexographic printing of the past utilized many solvent-based inks which, regardless of being safe for food packaging, were detrimental to the environment. The Clean Air Act, in the 1980s, led printers to begin focusing on water-based inks. With research and development, today, most printing presses are easily adapted to water-based inks, and also allow printers to recycle the ink for further use.
Function of Flexo Inks
Flexography ink is a key component in creating packaging materials that meet growing demands of manufacturers. Flexo ink must continually adapt as packaging materials change in order to maintain printability. Color is key and determines whether a product will be noticed. As inks adapt, the consistency of colors must remain true to meet the demands of clients who sell widely recognized brands. To achieve success, it takes a collaborative effort among ink manufacturers, printers, substrate manufacturers and clients.
Use with Caution
Constant contact with flexography ink and other chemicals used during the printing process can negatively impact the health of those who work in such an environment. Most states have enacted workplace safety laws and require employers to provide protective equipment to employees. Working with flexo inks can affect eyes, lungs and skin with prolonged exposure, therefore it is imperative that employees wear protective gear such as face masks, safety glasses or goggles, gloves and even clothing such as lab coats that help protect exposed skin.
George Sickinger, CEO of Color Resolutions International, states "Water-based inks in time will have much higher plant-based resin content and will become the new water-base formulation standard." Sickinger also stated that UV-curable inks require less energy and produce less waste, while quality is enhanced.
Tthe Environmental Protection Agency has collaborated with the flexography industry on the Design for Environment-Flexo Project in order to help businesses help the environment. In the Cleaner Technologies Substitute Assessment, findings revealed that, while water-based inks consumed the least energy and UV-curable ink systems used the least amount of ink, all ink systems contained chemicals that were clear health risks for those who work with these systems.