There are three main product types that come under the umbrella of flexographic inks - solvent-based inks, which continue to decline in popularity; water-based inks; and UV-flexo inks. Flexo inks are fast drying and have low viscosity. They are formulated to lie on the surface of non-absorbent substrates and solidify when the solvent is removed through heat or UV curing.
Gravure inks are also fluid with low viscosity that allows them to be drawn into the engraved cells in a gravure printing cylinder before being transferred onto the substrate.
Letterpress inks are more viscous and exhibit high tack. They are oil- or acrylate-based and use resins that oxidise rather than dry. Since the rise of offset litho and screen print, letterpress has all but disappeared and there are only a handful of products in the following tables that cater for it.
Changing markets
According to Perfectos Printing Inks sales manager Kushu Passi, there has also been a gradual decline in the flexographic textiles market as users switch to screen printed heat- and litho-applied transfers. He adds that many of the large clothing retailers, such as Next, H&M and Primark, are increasingly investing in tag-less care labels, where information is printed directly onto the material rather than onto a separate label.
Recent innovations in inkjet printing - for example the advanced use of UV inks and metallic effects that were on show at Fespa - have resulted in the flexo losing out to digital in all but the highest run jobs. However, flexo has struck back; the development of more eco-friendly ink products, including PVC-free and solvent-free UV flexo inks for film packaging, has boosted the sector's green credentials.
When sourcing ink, make sure you opt for a supplier that can offer extra help, such as technical expertise or waste collection. In order to be cost efficient, ink ‘mileage' has to be taken into consideration when purchasing, so pick products that will save time and cut waste. Passi advises customers to buy in bulk to reduce delivery costs. However, this has to be offset with storage limitations and the ebb and flow of production schedules.
What's new in flexo, letterpress & gravure inks
- Consumables giant Flint Group realigned its business in March. Product lines that serve the newspapers, inserts, magazines, catalogues, direct mail and stationery markets have been integrated into regionalised print media divisions. The business units now offer the full range of products and services, such as coldset inks, publication gravure inks, pressroom consumables and blankets. The company has also formed a global packaging and narrow-web division
- Last September, Sun Chemical teamed up with Keating Specialist Cylinders to bring to market a gravure packaging solution. The companies aim to develop their offerings to customers in the metal decorating, specialist coatings, decorative print, micro embossing, and security printing sectors
- At Drupa 08, five manufacturers joined together to produce the Gidue Athena digitally controlled mid-web press. The list of manufacturers included Sun Chemical, whose UV low migration inks the press utilises
