Low migration, strong adhesion, heat resistance, excellent lightfastness and quick drying are just a number of the demands being placed increasingly on ink manufacturers. But suppliers in the sector, as Tim Sheahan finds, are more than up to the task
Inks, it could be argued, are often the unsung hero of the print and production process. Much like packaging itself, it is most noticed when things go wrong, or when it has fulfilled its function and needs to be disposed of. However, developments in inks for packaging applications continue apace, and manufacturers across the sector are developing products that rise to the challenge of ever-increasing demands.
Coding and marking creations
Among these latest innovations is a new ink formation from the team at Linx Printing Technologies. Responding to market demands from companies that require an ink that doesn’t contain MEK and acetone, Linx has introduced Black Ink 3401, a ketone-free ink that is considered suitable for a raft of coding applications in the cosmetics, tobacco, food and drink, as well as the confectionery markets.
According to the manufacturer, Black Ink 3401 dries in between one and three seconds whether the substrate is porous or not. In addition, it has "excellent" adhesion on a diverse range of materials that include paper, plastics and cartonboard.
For use with the company’s 4900 and 7900 CIJ printers, the ink complements the firm’s portfolio of MEK-free ethanol-based inks and is capable of heat resistance of up to 30 minutes at 300°C with no adhesion or colour change, according to Linx.
"We know that many companies are now seeking reliable and effective alternatives to ketone-based inks for certain types of applications, and Linx Black Ink 3401 exactly meets this need, while maintaining the high quality performance that customers have come to expect from our inks ranges," says Susan Palmer, product manager of Linx Printing Technologies.
While Linx is forging ahead with launches in the coding and marking space, ink giant Sun Chemical is enjoying success with SunLit Crystal an ‘all-in-one’ ink solution, which was launched late last year for both packaging and commercial print houses.
Based on between 75% and 82% organic vegetable-based renewable raw materials, it is pitched as a universal sheetfed offset process ink set that can be used in both perfecting and non-perfecting presses. According to Sun Chemical, the inks can be pumped from their containers and are available from the manufacturer in both 1kg and 2.5kg vacuum-packed tins as well as cartridges and high capacity drums.
Fully aligned with the measures of the offset litho standard ISO 12647-2, the vegetable oil-based printing ink is considered "ideal" if one or more presses are supplied from a pumping station It is particularly efficient where pumping stations serve more than one press and its high drying capability leads to print work with very good mechanical resistance, ensuring optimum pressroom efficiency.
Sun Chemical also claims that SunLit Crystal is faster on ‘work-and-turn’ jobs than most standard printing inks and has strong mechanical and rub resistance, even in situations where no coating is applied.
Dr Bernhard Fritz, product manager for sheetfed systems Europe at Sun Chemical, says feedback from initial users has been positive, while interest from geographies such as Latin American and Asia was strong. "Customers who work with electronic media are used to high quality and vivid images, and SunLit Crystal can help replicate this quality in printed material to compete with all forms of media," he adds.
With ink and mineral oil migration issues rarely out of the food packaging sphere, German ink manufacturer Huber Group has developed a new low-migration UV offset ink designed specifically for food packaging – NewV pack MGA.
According to Huber, the formulation has a number of qualities. Notable is the ability to limit migration, even when inks are not fully cured, which is claimed to guarantee food packaging in the instances of UV lamps working at insufficient capacity.
"The new UV offset inks reliably stay below the thresholds," says Thomas Glaser, product manager for NewV at Huber Group. "This gives printing companies and food producers the best peace of mind they’ll find anywhere on the market right now.
"We are also the first ink manufacturer anywhere in the world to provide this assurance for UV products in the form of a written guarantee," he adds.
The company’s new MGA range of inks display "excellent" organoleptic attributes and when used in UV offset printing, the inks are suited for use on both paper and cartonboard, as well as UV letterpress printing with in-line corona pre-treatment. The manufacturer also claims that hotfoil embossing is possible with the new inks.
Developments in the ink sector are not restricted to the offset sphere, however, and digital manufacturer Fujifilm has recently detailed its latest advancements in the corrugated packaging space. The new Uvijet OC inks for corrugated applications offer a wide colour gamut and a flexible ink film to enable cutting, creasing and folding without cracking.
The first company to make its foray into print production using the Uvijet OC inks is Swiss packaging manufacturer Model AG, which has paired the new inks with the installation of a digital Inca Onset S40 wide format printer.
Handling work for multinational firms such as Unilever, L’Oreal, and Nestlé, the group produced 619 million m² of corrugated board, 26,300 tonnes of cartonboard packaging, and 284,200 tonnes of container board throughout 2011.
"Fujifilm’s ongoing investment in the research of high performance inks and technologies was pivotal to our decision-making process," says Edoardo Finotti, who heads up Model’s Innovation and Competence Centers (ICC). "We are pleased to be on the front line with Fujifilm to help in the formulation of the most appropriate inks for the extremely demanding packaging and display market."
He adds: "Not only do Fujifilm’s Uvijet OC inks deliver excellent performance in the POP and display market, but they also represent a breakthrough in the packaging sector. We are working closely with Fujifilm to achieve the best possible quality and push the boundaries of these innovative inks to provide our customers with outstanding packaging solutions."
While manufacturers such as Huber, Linx and Sun Chemical are pouring R&D resources into creating new ink formulations, software developers have a key part to play in simulating and assessing the performance any new ink will have on particular substrates.
One such example is OpenColor proofing software from GMG, which is designed to represent pure spot colours while simulating the often complex overprinting behaviour that takes place in the process.
The key USP of the software is the ability to create multicolour profiles that simulate printing behaviour across a range of printing technologies and substrates but, importantly, without the need for conventional chart-based press fingerprinting.
GMG claims that the combination of a CMYK profile with spot colour libraries would often result in the inaccurate simulation of spot colour overprints.
According to the manufacturer, spot colour simulation is achieved by coupling spectral modelling algorithms and ink measurements, which analyse not only the properties of each ink colour but also of the substrate. Spectral measurement information is then applied to a specific printing process such as flexo, followed by the addition of process specific information in order to simulate the press conditions.
Available in both ‘Basic’ and ‘Plus’ configurations, OpenColor features options for various print technologies such as offset, flexo and gravure, which are specified with individual profile creation algorithims.
Late last year, UK start-up Studio404, a graphics studio that specialises in the packaging design industry, became one of the first adopters of the new software, calling it a "huge step forward" in the colour measurement process.