Fujifilm Business Innovations used the Japan Inkjet Technology Forum in Tokyo on 30 and 31 October to showcase a new type of ink, known as structural color, for industrial inkjet.
Takashi Fukui, supervisory group head for Fujifilm Business Innovation, explained: “Usually we express color by pigment or dye that absorbs specific light rays. But in structural color, the ink itself has no color.”
The ink appears to be clear and instead of pigments, it uses microstructures – hence the name – which are arranged to physically change the way that the light waves are refracted through the ink. Fukui adds: “We have three types of ink and each one has a specific structure. By changing the size and structure, we show particular colors.”
Consequently, the substrate itself plays a large role in the final appearance of the image, meaning that the same image can look dramatically different according to the background, with clear colors when against a black background that absorbs the transmitted light, and pale pearl-like colors with a white background where the transmitted light mixes with the structural colors. The color also changes dramatically according to the viewing angle.
The main advantage of structured ink is that it produces very vivid iridescent or pearl-like effects, which can be used for decoration in a number of fields from jewelry to interior design. A further advantage is that the color should not fade over time since it relies on physical micro-structures that are not affected by ultraviolet light rays. It’s also said to be a more sustainable solution since there’s no water or dyestuff used to produce this ink.
The basis behind structural colors is taken from nature where many creatures such as Morpho butterflies use structural elements rather than pigments in their skin to create a rich palette of colors.
The structural ink is UV-curable and Fukui says that most inkjet printheads designed for use with UV inks should be able to jet it. The inkset currently consists of three colors – red, green, and blue. The ink is designed to be jetted to a PET film from 50-150 microns thick though it can also be used for resin and glass decoration.
Fukui says that Fujifilm is keen to talk to customers about exploring different applications, adding: “We have some test machines for this ink up to 1m wide.” He continues: “If a product manufacturer wants to use our structural ink then we can sell to OEMs as well.”
Fujifilm has already worked with Citizen Watch to produce the dial for a wristwatch where the color tones vary depending on the angle and intensity of the lighting.
You can find further details from fujifilm.com
This story was first published on www.nessancleary.co.uk on 31 October 2023. Republished with permission.
