Label converters have been vocal about what they want to see in the newest ink products. Converters require solutions that meet the latest market trends, including faster print speeds and increased sustainability, without compromising ink quality, durability or resistance properties.

For example, key drivers and trends that Sun Chemical’s customers look for include a focus on end-of-life and avoiding waste, such as recycling and composting, as well as the reduction of overall material use and weight in labels and packaging.

“This has involved a significant rethinking from the ground up of label and packaging designs and has led to a transformation across the packaging industry in terms of sustainable package designs,” explains Nikola Juhasz, global technical director, sustainability, Sun Chemical. “Our experienced global R&D team listens to those customer needs, then designs and delivers the products that best accommodate the customer requirements, including the sustainability objectives. Developing sustainable products and meeting those customer requests is a critical part of Sun Chemical’s three-pillar sustainability strategy, which includes focus on operations, on products and services, and on collaborations.”

Flint Group has a complete portfolio of Dual Cure technology under the brand name EkoCure. This range has been designed to cure using a traditional UV lamp or low-energy UV LED. These inks are compatible with any narrow or mid-web press curing system, enabling printers still using traditional mercury-based UV lamps to smoothly transition to more sustainable UV curing processes at their own pace.

“LED lamps cure using a fraction of the energy of their UV counterparts, which is itself an enormous advantage,” explains Niklas Olsson, Flint Group’s global director of product and commercial excellence for narrow web. “Estimates put the combination of carbon footprint and cost reduction at a 50-80% saving over classic mercury UV lamps.”

INX International Ink Co., meanwhile, has created an environment to perfect its ink sets under a wide variety of variables. “For energy curable technologies, INX is fortunate to have an array of laboratory equipment designed to mimic press conditions for UV, LED-UV, and H-UV type of curing equipment,” says Jonathan Graunke, vice president of UV/EB technology and assistant R&D director for INX International Ink Co. “Being able to test products at 800 fpm allows us to achieve the balance in our formulas for curing, and to meet stringent requirements such as low migration chemistry.”

Sun Chemical has also prioritized inks that perform exceptionally well with the latest machine technology, specifically performing at faster speeds and under various curing conditions. “As converters transition from conventional UV curing presses to UV LED technology, Sun Chemical has developed LED inks that provide improved adhesion at high print speeds, which has been a shortcoming for many LED-cured inks,” states Dennis Sweet, vice president, NWTL, commercial, Rycoline and Distributors, Sun Chemical. “Transitioning from conventional mercury UV curing to LED curing is not difficult because all LED inks cure under mercury lamp irradiation, hence they have often been referred to as ‘dual cure’ or ‘dual curing’ inks.”

Olsson concurs, as press technology is also a key consideration for Flint Group. “Another differentiator is the ability to address and support the growing demand for hybrid press technology, which combines analog printing, such as UV flexo, with digital printing like inkjet,” he comments. “As a result, converters must manage conflicting demands while enabling these two technologies to work seamlessly together. For example, configuring the print sequence where you must first have a UV flexo opaque white, overprinted with inkjet, or a coating that will create a superb gloss surface to protect the digital print below.”

Delivering a more stable source of UV light, LED curing also improves print consistency for the optimum results, unlocking new applications for these inks, explains Gary Seward, managing director of Pulse Roll Label Products. “A lower curing temperature has the added benefit of making PureTone DC suitable for use with a wider array of substrates, including heat-sensitive films,” he explains. “That’s not to mention the environmental and cost benefits of this technology. Not only are LED lights more energy efficient than traditional UV equivalents, the instant activation and deactivation means they do not have to be left running between jobs, needlessly wasting power. LED bulbs also produce less heat than alternatives, meaning less energy is wasted as excess heat, and eliminating the need for energy-hungry cooling systems.”

Other sustainability benefits include the fact that LED bulbs have longer lifespans than traditional bulbs, meaning they do not need changing as often, and they are easier to dispose of at end-of-life because they contain no harmful elements.  

When developing new inks, ACTEGA has optimized performance to handle some of the biggest challenges facing manufacturers today, including flexibility and stability at faster speeds. “Resins that typically cure with increased speeds tend to exhibit increased hardness and brittleness properties,” states Mark Lambert, product manager, labels and flexible packaging, NA, ACTEGA. “Increasing the photoinitiator to improve press speed can make the product more light-sensitive and allow for premature polymerization. ACTEGA has approached these hurdles with a new and innovative approach by evaluating and utilizing the newest chemistries and products now available in our market that have not existed in the past.”

Migration under demanding conditions is also a key consideration, adds Graunke. “Faster speeds specific to energy curing in printing equates to less dwell time,” he states. “Ink chemistries have to adapt to the speed challenges while trying to balance items such as low migration potential. This can be counter to each other, so having the capabilities to predict and analytically test chemical reactions is critical. Higher press speeds also present challenges such as misting, ink slinging in flexo, rheology control, effective tack, and others.”

Choosing the right ink

Printers often choose various processes for their unique characteristics. According to Sun Chemical, UV curing inks and coatings offer quick cure, strong bonding, and high gloss capabilities. Meanwhile, water-based flexo inks can be a great option having a lower cost and higher bio-renewable content. Digital inks allow for customizable print capabilities and economy in shorter run projects. In most circumstances, the choice comes down to the nature of the application, size of the run, and press capabilities at the converter.

Each of the different technologies is based on different core chemistries.  With those chemistries, they each possess their inherent strengths and weaknesses. “For instance, UV chemistry offers better durability vs. water-based chemistry,” ACTEGA’s Lambert remarks. “On the contrary, water-based chemistry is cheaper and more regulatory friendly.  The same fundamentals apply to digital, but there is an added level of complexity due to the mechanical requirements of digital delivery.”

When choosing the right ink, the substrate plays a pivotal role in the ultimate success of the label. “Printers use a variety of different quality films, which adds complexity in achieving print performance objectives, especially at higher press speeds,” states Sun Chemical’s Sweet. “At Sun Chemical, we’ve recently developed an ink series that adheres to difficult films at high speeds, which we call our Photon technology. This high adhesion ink series delivers strong performance with a lower amount of photoinitiator.”

“Each technology we offer has its unique strengths, and we have the in-house capabilities to help each customer individually determine the right solution for their pressroom,” adds Sun Chemical’s Juhasz.

Protecting the environment

ACTEGA analyzes the environment with all its product decisions, as sustainability is a core philosophy. “Our commitment to sustainability drives us to not only operate sustainably as a business ourselves, but to ensure that we are taking steps to support a sustainable future for our customers and the packaging industry as a whole,” says Lambert. “We take a holistic approach to achieving this goal, looking at all aspects of what it means to offer a sustainable solution.

“To achieve this, we reinvest 10% of our annual sales into R&D,” Lambert adds. “Through our products and technologies, we influence the sustainability of consumer packaging. We support the protection of food, help our industry simplify the recycling process and invest in new solutions to further packaging waste reduction.”

Flint Group has a focused development program for products that are designed to be used inline on existing printing presses, tailored for the two main applications used in narrow web PSL and shrink sleeves.

“What is clear from customers is that sustainability is paramount. For PSL, we have developed a UV-curable caustic resistant coating that will protect the printed image and thus enable PS label substrates to be washed off without contaminating recyclates or wastewater,” states Olsson. “We have also developed a UV-curable deinking primer for shrink sleeve applications that will function inline while printing UV inks. During the recycling process, the deinking primer will wash away in the caustic wash bath with the ink adhering to the primer, thus creating no discoloration of wash solutions or recyclates.”

Sun Chemical has made numerous strides in ensuring sustainable ink sets. The company has formulated inks using bio-renewable raw materials. The inks have been engineered to deliver high adhesion without the use of a primer, saving material and costs. Additionally, UV LED flexo recyclable inks for shrink and non-shrink applications have been designed for energy savings. Customized ink dispensing technology for UV flexo and water-based applications help save on finished ink inventory and transportation costs, as well.  

“In terms of sustainability, one challenge is to consider the complex set of end-of-life scenarios and recyclability requirements of specific materials within a label or container,” comments Sun Chemical’s Sweet. “Sun Chemical has extensive expertise here to support and guide customers according to the Association of Plastic Recyclers (APR) design guidelines.”

Another challenge, Sweet adds, is formulating products to deliver the right end-of-life solution without loss of application performance – including cost – which is a “tricky balance” that Sun Chemical achieves with its compost-compliant and recycle-friendly SunEco products.

INX has prioritized sustainable R&D. According to Mark Hill, senior vice president and director of R&D at INX, the company has engineered inks that use bio-renewable raw materials as much as possible to meet customer requirements. “We are developing products that help enable or will not inhibit recycling or improve recycling efficiency, and developing technologies that improve the shelf life of their packaged goods and enable the use of mono-material packaging,” he explains.

“When we introduced our Coloring a Safe and Sustainable (CSSF) model in 2020, it was structured to increase efficiencies, reduce carbon footprints and contribute to a circular economy,” adds John Hrdlick, INX president and CEO, who is retiring on April 30. “It guides the way we develop, manufacture and distribute our products, as well as how we work with our customers and suppliers.”

Product launches

Most recently, ACTEGA launched ACTExact SafeShield UV LED inks for low migration applications. The SafeShield inks were formulated with converters of all levels firmly in mind.

“By utilizing our ACTExact SafeShield UV LED inks, converters are now able to compete in this arena, many times as a new market for them, with the confidence of meeting stringent global and regional regulatory requirements,” states Lambert.

Flint Group recently introduced its Dual Cure ink range, EkoCure ANCORA F2 for food packaging and labeling applications. With optimized curing speeds, improved rheology and lower viscosity, EkoCure ANCORA F2 delivers better press performance for long runs in chambered doctor blade systems, the company notes.

“Many customers are switching to LED for precisely these reasons,” says Olsson. “We’re delighted with the strong response from customers using UV LED lamps and that customers using mercury lamps can print using the same high-performance solution. EkoCure ANCORA F2 meets printers’ evolving needs and helps them prepare for the future.”

INX has designed numerous new products to meet customer demand, including INXFlex Contour. This UV and LED cure flexo ink system has been optimized for shrink sleeve label solutions for brand owners. Plus, VerifyInk security inks are a proprietary solution, specially formulated to help reduce counterfeit packaging applications.

Renee Schouten, vice president of marketing for INX, states,  “Our Genesis washable inks are de-inkable from cPET films with roll-fed OPP labels in the recycling process. They follow in the footsteps of the highly successful Genesis GS gravure solvent washable inks for label printing. They also meet the PET-CG-02 Critical Guidance Protocol set by the Association of Plastic Recyclers.”

Meanwhile, Pulse Roll Label Products has unveiled its dual cure UV LED ink range, PureTone DC, which is designed to help printers beat rising energy bills. “With LED curing clearly looking like the future of the industry, this dual curing has the added benefit of allowing printers to switch to full LED printing at a pace that suits their business, phasing out older machines gradually, without the need for expensive up-front investment,” says Seward.

Sun Chemical has developed new photon ink technology, which uses less UV photoinitiator, generates less odor and provides higher adhesion. “The new SolarFlex CRCL is a UV flexo ink that allows the removal of ink from various films, without requiring a primer, thus increasing the recyclability of products that use crystallizable PET shrink sleeve labels,” explains Sweet. “Not using a primer reduces overall cost. SolarFlex CRCL inks can be used in both wash-off and retention modes and are designed for high-speed reproduction.”


The benefit of automated ink dispensing and software systems
By Maarten Hummelen, marketing director, GSE

Automating ink handling and color-making processes is no optional extra in label printing. In an increasingly service-driven, regulated and time-sensitive market experiencing rising operating costs and skills shortages, it’s essential for keeping competitive and protecting margins.

Gravimetric ink dispensing systems, combined with ink management software, standardize processes, thus helping converters meet brands’ high-quality expectations, minimizing human intervention and associated costs. 

Gravimetric ink dispensers accurately create special brand spot colors at the first attempt, in the desired amount needed for completing the job. Blending base inks and varnishes together in exact weights according to a formula to reach a color target, they create the color in just minutes, potentially cutting setup times.

Note that color targets and printed results should be communicated and compared using commonly understood values – like the L*a*b* scheme – and measured with a spectrophotometer.

The ink dispenser stores each job’s formula, for fast, easy retrieval and identical color results on repeat jobs. Using a dispenser reduces ink consumption considerably, especially as leftover inks from previous jobs can be used in new mixtures. Additionally, no human calculations are necessary, so the process does not depend on a specialist. Dispensers are available for all label and packaging applications.

Ink management software packages give better insights into operations, enabling faster, better decision-making and problem-solving. Capable of integrating with ERP1 or ink formulation software, programs automate processes including purchasing, real-time inventory control, reuse of press-return inks, job costing and traceability.

Performance advantages of ink logistics

Overall, controlled ink logistics, with dispensing and software combined, brings many long-term performance improvements, including:

• Reduce ink consumption by up to 30%: You dispense exactly what is needed, without preparing too much for a job to avoid running out during production.
• Strengthened reputation for quality: Assuring quality “first time right, every time” is the first step to preferred supplier status – your competitiveness improves further if you can do this without costly internal mistakes.
• Faster setup times, more machine uptime: Cutting color preparation and matching times eliminates the risk of bottlenecks and waiting times.
• Lower waste – lower operating costs: Achieving quality without defects or delay reduces indirect costs like scrapped substrate waste, energy, storage, administration and transportation, while automation reduces labor costs. Blending inks in-house means lower purchasing prices and simpler logistics.
• Improved reputation for sustainability: Reducing waste also reduces the carbon footprint.
• Increased responsiveness: Software’s data-handling capabilities accelerate processes, improving response times and decision-making.
• Optimize stock levels: Real-time inventory data, historic consumption reports and automatic purchase advice improves forecasting, balancing stocks with customer demand.

Ink suppliers increasingly incorporate dispensing and software systems in their offer to help converters become more competitive. It is also worth speaking directly to an ink logistics provider for customized solutions, advice and support.