More and more, flexible packaging fills store shelves with products ranging from baby food to beverages. US demand for converted flexible packaging is expected to hit nearly $300 billion in 2024, up from $138 billion in 2010. Food and other manufacturers know that consumers want convenience. They also know that environmentally conscious consumers turn to companies committed to sustainability.
Until now, no inks have delivered an environmentally friendly solution. Shrink sleeves have historically been printed using solvent-based and UV-curable inks, neither of which are environmentally friendly and pose dangers for food packaging.
On the other hand, water-based inks have been used to print on a variety of substrates, from concert tickets to coupons. However, it has been problematic to print on flexible packaging and shrink sleeves with water-based inks.
Kao Collins recognised the growing demand for environmentally friendly products and the increasing use of flexible packaging. Equally committed to environmental responsibility, Kao Collins began research on LUNAJET, an environmentally friendly water-based ink for flexible and shrink packaging.
"Our R&D team at Kao recognised an opportunity for improvement and created an environmental solution for printing," says Kristin Adams, marketing manager at Cincinnati-based Kao Collins.
While water-based ink has been used for printing many products, it doesn't perform well on plastics, metals and glossy surfaces. That left UV-curable inks for printing shrink sleeves, but not for foodgrade packaging. From low image quality to emitting volatile organic compounds (VOCs), these inks delivered only satisfactory results. Further, the UV-curing methods risked damaging the packaging. Kao Collins solved that. Using a technique known as nano-dispersion, the solution increases pigment concentration that covers shrink sleeves and flexible packaging evenly and efficiently. During nano-dispersion, pigments collide into each other through stress, breaking into primary particles. The pigment particles absorb polymers until they reach primary particle size. The pigments become encapsulated by polymers and stabilise dispersion, which helps avoid clustering. The pigment particles spread evenly, and ultimately create a smooth surface on shrink sleeves and other types of flexible packaging.
"Since LUNAJET is a relatively new inkjet ink, many food manufacturers are unaware of its capabilities," Adams said. "It has three main benefits. It offers high reliability, high image quality and a wide range of applications."
The fast-drying ink doesn't require curing lamps or other heat sources. Furthermore, it reduces clogging of the nozzles in the inkjet head because of its extreme stability. Whether used on coated, uncoated paper or plastic film, LUNAJET Ink offers consistent image quality. Because of its versatility of formulations, it performs well in both industrial and commercial operations.
LUNAJET Ink emits extremely low amounts of VOC emissions. This makes it exceptionally safe for food manufacturers to use on shrink sleeves for food packaging items. Japan's 2017 National Commendation for Invention awarded LUNAJET Ink the Innovation Award for its eco-conscious design. Adams said, "We think the LUNAJET Ink fits cleanly into the environmental demands of our customers and the end consumer."
LUNAJET Ink will be vital in the food packaging industry, primarily on shrink sleeves and other flexible film types. It will be particularly enticing to manufacturers who are focused on high image quality, consumer safety, adaptability, and sustainability.