This fact has never been more evident than during the past six months. The global COVID-19 pandemic has indeed impacted the flexo inks industry. With converters as essential businesses and facing increased workloads due to public demand for food, beverage, health and personal care products, among others, the inks must hold up to scrutiny. That requirement for faster turnaround times necessitates inks that can accommodate greater speeds while producing labels with the utmost quality.
Converters have been faced with extraordinary workloads, and flexo inks must accommodate a diverse range of narrow web applications. Historically, printers have been expanding their businesses into new arenas such as flexible packaging and shrink sleeves. However, that expansion has increased tenfold. Companies are now printing signage and floor decals, as well as security and safety labels, all intended as a response to the new normal. Inks are now required to be versatile.
Suppliers have answered the bell, too. “The ink industry is fortunate to be quite diverse in applications,” notes Paulo Vieira, Flint Group’s R&D director for North America.
“Energy curable flexo inks have completely changed in the market: the higher strength, lower viscosity, and faster cure speeds of today could not have been imagined several years ago,” comments Bill Phillips, business development manager of liquid inks at hubergroup USA. “Acquisitions and mergers in raw material suppliers to the market have caused a slight decline in development of new raw materials from suppliers to meet our customers’ needs.”
The pandemic has also highlighted the need for a secure supply chain. Sun Chemical, for example, has kept its focus on Asia, as many materials are sourced from regions such as China and India. Although Sun Chemical monitors these regions regularly, COVID-19 has forced the company to monitor purchase orders and supply positions daily, which was even more present when the situation was rapidly changing.
“Sun Chemical’s global footprint allows us to respond to these shifts and support our customers with a reliable supply. In addition, Sun Chemical’s portfolio supports essential businesses and has focused its efforts to support these areas during COVID-19,” says Dennis Sweet, vice president – NWTL, Commercial, Rycoline and Distributors at Sun Chemical. “The largest operational challenges have been to keep pace with evolving regional regulations and developing effective screening and disinfection protocols. Sun Chemical’s excellent Environmental Health and Safety department has worked tirelessly to assist the labs and plants achieve compliance and more importantly, maximize protection.”
The evolution of flexo inks is currently on full display, with ink sets featuring high performance under harsh demands. “Flexo inks have evolved in the past 10 years by moving from slower UV flexo presses to exceeding speeds of 600 fpm with newer presses,” says Andrew Wasserman, managing partner, Cyngient. “And the addition of combination presses that include UV LED curing lamps have had a big impact as well. We have seen some older flexo ink technology with higher viscosity and slower cure that still exists and creates problems for cure and poor adhesion for narrow web converters, which have newer, higher speed presses.”
“In general, flexo inks today are stronger, lower viscosity, much more operator friendly,” says Ed Dedman, flexo technical support manager at Zeller+Gmelin. “They are able to run at much higher speeds than in years past, and in many cases, available at a much lower cost of use than ever before.”
“We see an increase in industry standards, especially with regards to consumer and employee safety,” says Dave Hiserodt, head of Narrow Web Business Unit at Siegwerk. “We expect the demand for low migration solutions to further increase worldwide.”
Ink suppliers have been faced with several challenges along the way. There have, and will continue to be, compliance concerns, especially as labels must adhere to certain low migration mandates. Additionally, ink manufacturers must also deal with the predicament of working with their customers from afar – be it through conference calls, Zoom or socially-distanced plant visits.
The strict demands on inks have forced suppliers to engineer products that are optimized for the entire workflow – from prepress to post-press. INX International Ink Co. has found that energy-curable inks are more popular for their increased strength and require less maintenance on press than typical water-based inks. They especially provide for a much higher print quality, notes Jim Krstulic, national account manager – Envelopes, and product manager – Tag and Label, for INX International Ink Co.
“Both water-based and energy curable inks must continue to evolve in order to keep up with the technological advances being made with plates, sleeves, screening processes and anilox rolls, as well as the presses themselves,” states Krstulic.“Water-based inks, in particular, must improve and increase pigment strength, transfer properties, press stability and overall resolubility. This is due to the higher line plate screens being used more frequently in today’s industry.”
Flexo inks must also be optimized for any number of coatings and adhesives required by the label. “As market awareness on issues surrounding the migration of compounds on food packaging continues to increase concerns in the global marketplace, the demand for low migration inks and coatings in the label industry has increased,” says Sweet. “It is important for package printers and brand owners to understand the issues surrounding migration in food packaging, especially in three important aspects: Knowing what low migration ink and coating products are available, understanding proper process implementation and control, and the testing required.”
These inks must adhere to a wide range of substrates, as well. “Fujifilm’s latest UV LED hybrid inks have the broadest adhesion range of any ink to date,” says Tom Pokorny, director of product marketing at Fujifilm Graphic Systems. “Adhesion to shrink film is the key to shrinkability and flexibility so these inks perform exceedingly well on shrink films and the new flexible substrates. In addition, a specialty last down shrink white for applications over glass bottles is receiving strong market acceptance by eliminating trapped air bubbles under the sleeve that has been commonplace until now.”
In terms of working remotely, the industry has dealt with new challenges. “Our sales to the label and packaging segment have actually grown this year,” states Dedman. “Our biggest challenge these days is the way the pandemic has impacted our sales and technical activities. In an industry where business was most often built and supported through personal and professional relationships, this has significantly challenged our sales force to find new ways of engaging with their customers and prospects.”
Industries served have played a major role in converters’ ability to adapt, too. “The printers that focus on food, pharmaceutical or flexible packaging for food have seen double digit growth in ink purchases over the last eight months, while our customers that focus more on the retail and industrial sides of the industry have been impacted negatively,” notes Phillips. “For the most part, our liquid ink volumes have remained consistent throughout the pandemic.”
However, many companies are doing their best to adapt to this new normal. “Supporting customers from a technical perspective has been a new challenge, as on-site visits from the technical team have understandably been limited,” cites Pokorny. “We have adapted with virtual meetings and Facetime support. We are finding, in some cases, support has actually improved as both customers and suppliers have adapted to the phone or virtual support and get immediate feedback instead of waiting for an on-site visit.”
Drive for sustainability
While sustainability has always been a popular topic in the label and packaging industry, adherence to these practices has been inconsistent throughout the years. Suppliers, converters and brands are currently echoing the need to improve their carbon footprint. Many brands and CPGs are now requiring their suppliers to put sustainable measures into practice.
“Last year alone, Sun Chemical, in combination with its parent organization, DIC Corporation, spent over $100 million in R&D, much of which was focused on sustainable solutions,” states Sun Chemical’s Sweet. “That focus on R&D and industry partnerships led to our launch of SunVisto AquaGreen water-based inks, which are formulated with the highest level of bio-renewable resin content the industry has to offer.”
Siegwerk has taken several sustainable initiatives, as well. The supplier recently launched a deinkable UV flexo varnish and offset inks to improve recyclability. Plus, Siegwerk has created a flexographic printing ink system for flexible sheets that received Material Health Certification Gold from Cradle to Cradle Certified with partners Werner & Mertz and Mondi.
“Sustainability and creating a circular economy are hot topics in the industry right now,” states Siegwerk’s Hiserodt. “Inks and coatings play an important, enabling role for the realization of these solutions, as they support the reduction, reuse and recycling of packaging. Siegwerk already has a strong track record in customer-specific ink development projects for circular packaging solutions that either increase recyclability, allow composting, or reduce the need for plastic use and other non-renewable raw materials.”
INX International Ink Co. expanded its Green Team group in 2019, which has resulted in a series of successful initiatives. Most are focused on the goals and targets of customers who are prioritizing recyclable or renewable packaging. The company intends to develop products for circularity, with minimal impact on the environment.
While sustainable endeavors can be a challenge, Cyngient’s Wasserman believes that collaboration is critical in making that first step. “Sustainability in the broad sense has been challenging for smaller, independent narrow web converters that don’t have the resources to keep up with the ever-changing regulations that impact the narrow web industry. We as ink, coating and adhesive manufacturers have taken a proactive approach to sustainability. We work with our raw material suppliers to ensure we comply with US and EU standards with the manufacturing of our products. After we have selected our raw material, it’s evaluated by our Ph.D. chemist and team for compliance and performance while adhering to industry sustainability guidelines.
“We believe in a proactive approach to sustainability with our raw material selection and maintain clear communication with our customers to ensure we meet their clients’ requirements,” Wasserman adds.
Flint Group’s Vieira states that the industry must make a conscious effort to improve its environmental practices. “Whether we are working on raw material sources, our internal processes, or through to the end of life of every package our inks reside on, we can do better,” he says. “This continuous improvement cycle is a necessity for our inks. Whether the customer base is consolidating, or within a customer site working to consolidate, it will continue. That puts a strain on our products to work in more applications, between more customer sites and technologies, and across more geographies.”
As Sun Chemical’s Sweet adds, companies can work with associations and third-party entities to validate whether or not their ink manufacturers are in fact offering products that are more sustainable.
Improved technology will no doubt highlight the future of this industry.
Cyngient has seen the direction in which the label industry is heading, and the company’s products have been tailored to meet those demands. Cyngient has focused on high performance flexo inks that address the needs for speed, flexibility and increased adhesion to film substrates.
“PUREmatte, a newly launched matte coating for shrink sleeve, was developed to address industry needs such as low odor, enhanced abrasion resistance, press stability and lower migration,” explains Cyngient’s Wasserman. “HYPERcolor cold foil adhesives combine an ink and adhesive, offering the ability to reverse print silver cold foil with an expanded gamut of colors on shrink sleeves without the need for special colored cold foil. Our Hi-def UV LED flexo inks are performance-based, with a focus on printing on various films where ink adhesion and flexibility are needed for shrink sleeves and prime labels. In addition, we have also introduced a full line of adhesives and coatings that address the multi-layer peel and reseal label market and film-to-film bonding.”
Flint Group has analyzed ink from a color control perspective. The company has launched Vivo Color Solutions, which is a software system that provides ink formulations based on color inputs. It is capable of cutting press downtime associated to color matching by 50% but relies on supplied ink to be consistent. As a result, Flint Group has improved its color consistency to a Delta E of less than 1.0 to support customers’ color control, the company says.
Fujifilm’s newest narrow web flexo ink offerings include UV LED hybrid inks. The company recently launched a set of extended life pigments colors, fluorescents, a special last down white for shrink sleeves in glass bottle applications and a host of brighter and cleaner clears and whites.
Additionally, Fujifilm has developed the sustainable LED system called Illumina. “The combination of the Illumina curing system and the 300 Series UV LED hybrid inks allow for the lowest energy consumption of any drying or curing system on the market and significantly reduces substrate waste,” says Pokorny. “It is the only system that eliminates the need for large chilling systems altogether, as well as the benefit of all LED systems that eliminate the need for exhaust systems.”
At hubergroup, the company has developed Chromis Screen Plus and Temp-o-grip II Plus water-based systems specifically for optimization on most narrow web substrates and applications, eliminating the need for multiple ink series. Additionally, the NewV Flex inks have been engineered for fast cure and low viscosity on paper, film, folding carton and shrink sleeve applications. “The Chromis Screen Plus ink system has been developed for clean printing with low volume bcm anilox rolls on paper, film, and thermal transfer applications which covers a majority of most narrow web print shop applications,” says hubergroup’s Phillips. “While the Temp-o-grip II Plus inks offer the same benefits above, as well as thermal direct applications. Both systems have been designed to minimize inventory in print shops.”
INX International Ink Co.’s newest product has been timely, given its predilection for food packaging. “INXhrc natural-based inks are the perfect sustainable choice, and offer a 20-30% lower CO2 footprint compared to standard aqueous inks, and allow brand owners the opportunity to reduce their regulatory risk,” states INX’s Krstulic. “We’ve also had good feedback from printers and converters who have experienced improved production efficiencies, including better ink mileage and lower resource consumption and waste. All told, INXhrc has replaced over four million pounds of petro-based chemicals, waxes and additives, and reduced CO2 emissions by more than six million pounds since being introduced to the North American market two years ago.”
INX sees a continued shift to energy curable inks. “With lower overall press maintenance and an exceptional increase in print quality, I see energy curable inks as a replacement for traditional water-based ink technologies,” adds Krstulic. “Energy curable inks are sensitive to heat and light, so the formulation process will be ongoing in order to counter the many unknowns that will appear on the press floor.”
Siegwerk anticipates the continued interest in sustainability, and the company has established circular goals it plans to reach by 2025. The company’s latest product launches have come with that in mind.
“The circular economy is currently – and will be – the biggest topic for the future,” says Siegwerk’s Hiserodt. “As a global ink manufacturer, Siegwerk is actively cooperating with CE initiatives as we are committed to increasing the recyclability of printed packaging with our inks and coatings, addressing the needs of circular packaging solutions – today and in the future.”
Sun Chemical offers a wide range of products in the flexo inks space. Some of the latest offerings include SunVisto AquaGreen, MX12 Dispenser, and Solar Wave. MX12 Dispenser is an offering from the Sun Chemical Dispenser Program, which allows printers to decrease their operational costs and expenses by up to 35%, the company says. With this dispenser, printers can mix only what they need, thereby reducing waste and excess inventory.
SolarWave is a range of UV LED curing flexo inks that enable environmental improvements within industrial processes, resulting in lower energy consumption and minimized energy costs from production. The inks demonstrate all the capabilities of conventional UV flexo inks when cured under suitable UV LED curing systems.
Zeller+Gmelin has launched several UV LED coatings to meet specific market needs. They include a set of gloss and matte bacteriostatic coatings, curable by both LED and mercury UV, which provide a surface that resists bacterial and microbial growths.
“All of our UV/LED flexo products are designed for multiple applications and are used daily across the industry for most every application you can imagine, from shrink sleeves and PS labels to in-mold labels, rigid packaging and folding cartons,” says Dedman. “If you can imagine an application that needs to be printed, there’s an excellent chance our inks will work.”
By John Pogatschnik, product manager, Flint Group
UV LED curable inks are being adopted by label converters at an accelerating pace. A major factor in the increasing speed of adoption is the introduction of “Dual Cure” inks, which are capable of curing under both UV LED lamps, as well as mercury lamps. They can also be run in conjunction with mercury lamp-cured inks on the same press during an extended changeover period.
This technological shift means that changing to UV LED curing does not have to be a disruptive, major capital investment process. Rather, UV LED curing technology (ink and lamps) can be introduced over time. The converter has the freedom to upgrade the press one station at a time, reducing the initial expenditure and minimizing risk while immediately delivering the benefits of UV LED curing.
The performance advantages
UV LED curing brings strong cost, environmental and performance advantages. First, UV LED systems use less energy and may last up to 20,000 hours compared to the 2,000-hour life of mercury lamps. No exhaust systems are required for ozone removal, also reducing heat management and maintenance time and costs.
UV LED lamps cure from the bottom of the ink layer upwards, meaning better anchorage at the ink/substrate interface. Combined with reduced curing times, this can lead to faster press speeds, increased productivity and more reliable results. At Flint Group, we have seen UV LED flexo inks performing at 1,000 fpm, and we validate inks at test speeds of up to 750 fpm.
Additionally, UV LED lamps can be turned on and switched off without the need for warm-up and cool-down times, yielding more potential production time. The absence of cool-down time eliminates the need for lamp shutters to prevent damage to substrates.
Environmental and safety benefits include avoidance of mercury use, ozone creation and excessive heat generation through infrared emissions.
The use of Dual Cure inks allows printers to reap all these benefits as soon as the first UV LED lamp is installed.
Minimizing risk with a gradual switch
Phasing in UV LED technology spreads the investment over time. Ideally, stations would be converted during quieter periods so as not to interfere with overall productivity in the way a total refit would. A gradual transition also makes training easier as not all operators would have to be trained at once.
In a phased introduction, conventional UV ink stocks can be back filled with Dual Cure inks ahead of any equipment changes. This avoids costs of disposing redundant inks or a lengthy, disruptive shutdown associated with an all-at-once changeover to UV LED curing.
All of these endeavors are about managing risk, converting at a rate comfortable with the converter, and maintaining production through a transition period.
Our strategy has been to reformulate our range of narrow web inks so that they can be cured effectively using mercury or UV LED lamps – whatever the application. The Dual Cure range has a carefully developed mix of photoinitiators for optimum results under either curing process. Since the chemistry of Dual Cure inks is similar to that of mercury-cured inks, it is possible to run the different inks on different stations without compromising image quality.
Offered under our EkoCure brand, Dual Cure inks are formulated at the same strength as their conventional counterparts, simplifying color matching. Ink series are available for major narrow web applications: labels and tags, shrink sleeves, and food packaging.
Starting by using Dual Cure inks on a press’ black station shows how changing a single color can bring immediate gains. Because of light absorption, curing the color black can limit the press speed. Curing, as mentioned, from the bottom up under the UV LED lamp overcomes this challenge, potentially yielding an instant boost to productivity.
Our R&D team continues to optimize the range of Dual Cure inks and coatings, and works with customers to address a specific application. Examples include tactile and metallic effects, for strengthening brand recognition in the retail environment.
In our experience, successful transitions to UV LED are “evolution” rather than “revolution.” Gradually switching to Dual Cure inks, with printing lines upgraded in logical phases that allow for learning along the way, enables continuity of business and minimizes disruption.