Water-based printing inks have grown in popularity in recent years as customer preferences and industry regulations change, but achieving the same performance characteristics as solvent-based inks has historically been a challenge.
Printing inks for flexible packaging must be able to provide strong resistance properties to blocking, wear-and-tear, and water and chemicals, while also offering good resolubility for a smooth printing process.
Recent innovations in formulations and chemistry have led to the creation of high-performance binders and acrylic emulsions that enable water-based inks to deliver these important properties while remaining cost-efficient and offering improved sustainability.
JONCRYL FLX 5060 and JONCRYL 541, self crosslinking acrylic emulsions, are two best-in-class surface print binders helping to lay the foundation for the future of water-based inks with exceptional performance capabilities.
The resolubility–resistance balance
Modern high-speed printing presses are capable of printing thousands of impressions per minute and require high-quality inks to ensure each impression is transferred cleanly.
Resolubility, a key attribute of printing inks, refers to the ability of a dried ink to redissolved by the same ink in the wet state.
“The ink needs to stay in a stable liquid form during the printing process,” says Dave Tappa, Technical Manager for Printing and Packaging at BASF. “If ammonia and water evaporate during the printing process, traditional water-based inks may start to print less cleanly and viscosity may rise. If an ink has poor resolubility, this change can be irreversible and print quality is diminished. Good resolubility allows an ink to redissolve in itself and continue to print cleanly.”
While this balance is usually simple for a solvent-based ink to achieve without compromising the water resistance of the end product, water-based inks face a different challenge.
“Water-based inks can be modified by adding very hydrophilic components, but the trade-off is that you lose water resistance because those same materials that help the ink resolve in itself may make it more sensitive to water or other chemicals,” says Tappa.
Creating better binders
Early water-based resins and binders did not offer the same resistance-resolubility balance that modern binders provide, and formulators usually had to use less sustainable solvents in their inks to provide the required performance properties needed for high-speed printing presses.
Now, thanks to new innovations in chemistry and the introduction of high-performance resins and binders, the capabilities of water-based printing inks is on par with most solvent-based solutions.
JONCRYL FLX 5060 is a self-crosslinking styrene acrylic emulsion that offers great resolubility with superb resistance properties, even when tested against chemicals such as household cleaners and alcohols in rub-tests.
JONCRYL 541 is a water-based surface print binder with a unique polymer architecture and innovative crosslinking mechanism, providing best in class resolubility and improved resistance properties.
“Balancing resolubility and resistance has historically been a challenge for water-based printing inks on film and foil,” says Tappa. “You typically can achieve either very good printability and resolubility, or water resistance. With JONCRYL FLX 5060 and JONCRYL 541, you can achieve both.”
The way formulators look at water-based printing inks for flexible packaging is changing. The PRETHINK INK network is a group of like-minded ink makers, printers, converters and brand owners implementing sustainable water-based inks in their operations to reduce VOCs and lower their carbon footprint while improving health and safety.
Switching to water-based inks can also be cost-effective, especially as the price of solvent-based solutions rise with the increased demand for ingredients that go into sanitization products as a result of the ongoing COVID-19 pandemic.
“The same solvents that are going into a solvent-based ink are also needed in sanitizer production,” says Simon Foster, Industry Marketing Manager for Printing & Packaging at BASF. “As demand grows, the prices of solvents have increased, which has led to a market price increase in solvent-based inks.”
Performance without compromise
With the introduction of modern binders such as JONCRYL FLX 5060 and JONCRYL 541, formulators no longer have to compromise on performance to achieve sustainability.
“There's a desire among printers and ink manufacturers to be more sustainable without sacrificing performance,” says Foster. “With these new binders, a printer is not having to make a compromise in the quality of their printed product if they use a water-based versus a solvent-based ink.”
“These products enable the balance between an ink that is easy to print with and a printed product that does what you want it to do, which is to protect what's inside it.”
As the demand for sustainable and safer formulations in printing inks grows, products like JONCRYL FLX 5060 and JONCRYL 541 facilitate the transition to high-performance water-based printing ink solutions.
For more information on BASF’s line of water-based resins and emulsions, click here.