The Next Big Thing in Inkjet: Printing Water-Based Ink on Flexible Film

From concert tickets to coupons, water-based inks have been utilized to print on a variety of substrates throughout the years. But one substrate  has been particularly problematic to print on: shrink sleeves. 

Often found on food packaging, shrink sleeves have historically been printed on using solvent-based and UV-curable inks. The problem with using these inks is that they require the use of UV rays during curing, which can damage the substrate and cause additional problems.

The research and development team at Kao Collins recognized an opportunity for improvement and created a solution for printing on shrink sleeves called LUNAJET Ink.

What is LUNAJET Ink?

LUNAJET Ink is the first water-based, pigmented inkjet ink of its kind.

Using a technique known as nano dispersion, pigment concentration is increased to allow ink to cover shrink sleeves evenly and efficiently. During nano dispersion, pigments collide into each other through stress, breaking into primary particles. These pigment particles then begin to absorb polymers until they reach primary particle size. The pigments become encapsulated by polymers and stabilize dispersion, which helps avoid clustering. This results in the pigment particles spreading out evenly, and ultimately creating a smooth surface on shrink sleeves and other types of flexible film.

Nano dispersion technology allows pigment particles to evenly spread out.

What problems does LUNAJET Ink solve?

Shrink sleeves have historically been a challenging substrate to print on for several reasons. UV-curable inks have been used to print on shrink sleeves in the past, but they commonly create issues with uneven and low gloss surfaces, odor, and low image quality.

By utilizing LUNAJET Ink instead of UV-curable ink on shrink sleeves, these issues are alleviated. Nano dispersion technology allows pigment particles to be distributed evenly, creating a smooth surface with a high gloss, giving the shrink wrap a high-quality look and feel. Another advantage of LUNAJET Ink over UV-curable ink is the ability to avoid UV rays during curing, which can cause surface damage and an unpleasant odor to shrink wrap due to heat.

Nano dispersion technology lets pigment particles distribute smoothly, creating a high-quality gloss.

LUNAJET Ink is also eco-friendly and produces extremely low amounts of volatile organic compounds (VOC) emissions. This makes LUNAJET Ink especially safe for food manufacturers to use on shrink sleeves for food packaging items. In 2017, LUNAJET Ink even received the Innovation Award at Japan’s 2017 National Commendation for Invention due to its eco-conscious design.

The Future of Lunajet Ink

Since LUNAJET is a relatively new inkjet ink, many food manufacturers are unaware of its capabilities. Moving forward, LUNAJET Ink will be vital in the food packaging industry, primarily on shrink sleeves and other flexible film types. LUNAJET Ink will be particularly enticing to manufacturers who are focused on high image quality, consumer safety, adaptability, and sustainability.