Flexo and UV Flexo Inks

By Steve Katz | March 30, 2009

Ink manufacturers conduct extensive R&D in order to improve upon the wide range of products available to flexo printers.

Ink has been around for thousands of years. Historians point out that ink even pre-dates paper, its primitive formulas designed to darken the surfaces of raised stone hieroglyphics. The first inks were often mixtures of natural items like soot, animal gelatin, and extracts from a variety of vegetation. But ink has come a long way since its inception, and along with paper and adhesive, it's a key ingredient in the construction of a pressure sensitive label.

With the aid of the company's software, an ink technician in the Graphic Resource Center at Color Resolutions International custom formulates an ink for a shrink sleeve application.
Label printing has evolved to the point where converters using the flexographic process have a myriad of options when it comes to design and style. Along with these choices, today's converter also has other factors in mind such as price, performance, and environmental concerns. Selecting the right ink for the job at hand is an important task, and the aforementioned considerations are all taken into account. Thankfully, there's a plethora of flexo and UV flexo inks available, and those that manufacture and supply these products conduct extensive R&D while working closely with customers to ensure satisfaction.

Color Resolutions International

Color Resolutions International (CRI), located in Fairfield, OH, USA, is an international packaging ink company focused on water based and UV curing flexo inks for printing pressure sensitive labels and security tags, as well as flexible packaging, envelopes, folding cartons and corrugated. One of CRI's niches lies in its role in creating custom formulations for its customers.

According to George Sickinger, president and CEO, CRI has two core responsibilities as a supplier of inks to the label industry. "The first is to develop ink systems that resolve today's ever evolving and complex issues. We consistently invest funds into our R&D division so that we can stay one step ahead of where the industry is headed, recognizing that when a customer invests in new methods, we need to be right there with them, ready to supply inks that will work with their operations.

"The second responsibility is to offer the technical expertise that necessarily goes hand in hand with providing inks. In any printing operation, there are at least four variables at play: the ink, the press, the substrate and the operating conditions," Sickinger says.

CRI takes a hands-on approach in custom formulating inks for its customers. Activities include pressroom visits and investigations into a converter's printing methods. "We begin with a complete audit of our customers' pressrooms so that we know their specific needs and can formulate inks to minimize their job-to-job press adjustment," Sickinger says.

The company has a broad range of flexographic products for the narrow web industry. Its Label Choice inks are water based flexo inks designed to run on a wide variety of films that are to be laminated or overprinted. The ProTherm system is a water based ink that has been specially developed for use on direct thermal paper substrates. Sickinger says it provides exceptional resolubility, which translates to minimum plate washes and easy press cleanup.

CRI's Profector inks can be overprinted or laminated, and work well on coated paper and films. This system can also be used for shrink wrap applications. "It delivers high intensity colors that print clean all day long while assuring the converter that their product will be scuff resistant, water resistant, and stay that way for the life of the label," Sickinger says.

LabelCure is among CRI's UV flexo ink systems that can be used on both paper and top coated films for narrow web presses. Sickinger says, "These inks are low viscosity, and demonstrate very low plate swell. The inks can also be overprinted or laminated. LabelCure can also be used for many shrink wrap applications."

CRI's strengths are twofold, Sickinger stresses, "We possess the processing know-how to develop inks for today's market, and we have outstanding customer support capabilities to think through tough issues on the spot. We don't simply ship our products out the door and walk back to our office; we visit our clients' production facilities, roll up our sleeves, and get to work."




Eckart Effect Pigments, with US headquarters in Painesville, OH, USA, specializes in metallic printing inks. The company's products are key components in the converting of special effects labels.
"In today's economic climate, brand owners are actively looking for ways in which to promote their products and are continually looking to distinguish themselves from the competition," says Robert Hulston, technical service manager, North America. "Innovation is the key to success, and Eckart takes this into account when introducing products to the marketplace."

Hulston talks about an example of Eckart's newer products, one that he says was developed for improved flexo printing and uses the latest in water based metallic ink technology with an emphasis on ease of use. "ROTOSTAR Aqua FP06 series pigment and binder technology exhibits the most brilliant effect with superior press-side handling. Its attributes include 'high brilliance' with 'high coverage,' the ability to use fine line aniloxes, improved trapping, the latest technology in foam control, and excellent intercoat adhesion with topcoats," he says.

On the UV side, Eckart features ULTRASTAR UV and ULTRASTAR Solvent based inks, products based on vacuum metalized pigment dispersions. Examples of the ULTRASTAR Solvent based series include FX-1604 and FX-1805. "A relatively new member to the ULTRASTAR family of products and designed for improved coverage and printability with fine line aniloxes, the FX-1604 has been printed successfully at high speeds and on extended production runs, therefore proving its ease of use press side. FX-1805 has been developed specifically for those more difficult to adhere to substrates," Hulston says.

Eckart's PLATINSTAR for shrink applications
Additionally, Eckart offers ULTRASTAR UV Silver, a UV curable metallic ink also based on vacuum metalized pigment dispersion technology for flexo printing. "An interesting feature is that it becomes brighter as the amount of time between printing and curing increases. It gives the brightest results when applied on smooth, high gloss paper substrates and films," Hulston says.

The company recently introduced PLATINSTAR, a product that bridges the gap between ROTOSTAR and ULTRASTAR, and Hulston feels that it's a great example of what innovative ideas can produce. "Based on our new Advanced Silver Dollar technology, GX-2901 has been developed with shrink sleeve specifically in mind. It has the ability to maintain its brilliance when subjected to over 40 percent shrink. It gives a cost effective way of printing where a superior finish is required over ROTOSTAR and keeping the cost lower than the ULTRASTAR. It's got excellent printability, brilliance, adhesion and ease of use for the printer."


Flint Group Narrow Web

Flint Group Narrow Web, based in Sweden with US headquarters in Plymouth, MN, USA, offers several ink products that are manufactured using both water based and UV flexo technology.

Water based products popular among label converters include Hydrofilm, a water based flexo ink for film and water based shrink applications; and Hydrokett, water based flexo ink for paper. Deanna Whelan, customer relations and marketing manager, Packaging and Narrow Web Division, says these water based inks are readily available and ordered on a regular basis by roughly 90 percent of the company's customer base.

Mike Buystedt, general manager, Midwest, says, "Both Hydrofilm and Hydrokett have excellent press stability and are low maintenance – exhibiting low viscosity, low foaming, and extreme ease of use; printers can expect improved productivity with less waste. These water based inks exhibit excellent color strength and superior printability."

The Hydrofilm inks can also be used in water based shrink applications. "Many customers use Hydrofilm as their single water based ink system for both paper and film. Our customers in South America have chosen to use only Hydrofilm because the performance is so much better than other water based products in the region. And, as it can be used for both paper and film, they are able to purchase one technology for both applications," Whelan says.

On the UV flexo side, Flint Group Narrow Web offers customers its Flexocure Sigma, UV flexo inks for both paper and film labels, and Flexocure XS, UV flexo inks for shrink applications. The UV flexo inks are also readily available and ordered by roughly 40 percent of the company's customer base.

Buystedt says the Flexocure XS line offers the same advantages as the Flexocure Sigma in a "shrink ink." He says, "These inks provide excellent 'shrinkability,' providing more than 70 percent shrink with no deteriorating of the printed image." Both of the UV flexo inks are VOC free and are comprised of environmentally friendly raw materials.

Flint Group's R&D has also led to changes and improvements in UV flexo inks, particularly in how the inks today are now much thinner with lower viscosity. "In the past, it was very difficult to get a high strength ink with a low viscosity product. But you can actually pour Flexocure Sigma out of a jug container," Buystedt says. "Also, printers can now run 1.25 to 2.0 bcm anilox for process colors, and 2.5 to 3.0 for line colors. This was not an option in the past, it was necessary to run coarser line anilox for similar results."


Graphic Sciences

Graphic Sciences is a US based ink manufacturer with corporate headquarters in Portland, OR, and several manufacturing and blending facilities throughout the country.

According to Jeff Ashburn, VP sales and marketing, the company has spent several years working with label converters with a focus on developing products to address specific challenges. "During this time we have listened closely to our customers' concerns and have used their input to drive our R&D efforts. Our most popular product line, Stable Flex, was developed as a direct result of this input. Our Stable Flex product line offers superior pH stability making it virtually maintenance-free on longer press runs," he says.

Stable Flex, Ashburn points out, is formulated to print on a vast array of substrates allowing customers to minimize their inventory levels and better utilize what they have on-hand. He says, "Recent enhancements to this product line have been made to further maximize pigment efficiency as it relates to the interaction of ink to substrate. As new packaging technologies evolve, Graphic Sciences continues to refine our products to meet specific performance requirements while remaining dedicated to helping our customers improve their bottom line."


INX International

INX International, Schaumburg, IL, USA, offers converters its INXFlex line of UV flexo inks. These inks are formulated to provide minimal plate swell, clean color and high strength, working effectively with fine anilox (up to 1800 line screen). The product line was developed for tag and pressure sensitive label, in-mold and shrink applications.

"INXFlex UV flexo inks are optimized for maximum press speeds when run at normal ink densities. They are designed to run on virtually all flexo presses, and have the unique ability to perform under a multitude of print applications including shrink, outdoor bags, and IML applications; all with one ink system. Additionally, both our INXFlex UV flexo white, and our rotary screen white, provide industry leading performance, and complements the INXFlex UV system," says Jonathan Graunke, director of Energy Curable Systems for INX International.



Siegwerk, an international ink manufacturer with North and Central American headquarters in Des Moines, IA, USA, has a variety of products available for label customers depending on their specifications and printing conditions. The majority of the flexographic inks required by the company's label printing customers are water based.

Manuel Rivas, director of technology, describes three of Siegwerk's flexo ink offerings: "LABELPLAST has good adhesion to a variety of standard substrates. It also has excellent print quality. CWE Series is an ink that does an excellent job of keeping graphics tight. And the CWS Series has found great success in North and South America for water based shrink label applications," he says.

In order to commercially answer the requirements of UV flexo printers, Siegwerk offers its SICURA line of UV products. There are product lines within the SICURA family of inks for printers using flexo, offset or letterpress printing methods. Two commercial flexo options include the 39-5 Series which Rivas says is the work-horse of Siegwerk's commercial UV flexo offerings. He says, "This ink system has good printability, high functionality at a variety of press speeds and also has an excellent cure profile."

Rivas takes note of what he feels are much publicized misconceptions about UV technology, and believes that education is a key in getting the facts straight. "With recent bad publicity centering on ITX, BPA, and outdated information about the state of the technology, Siegwerk, along with other suppliers and associations, has been working to correct the misconceptions regarding the safety of the UV technology. And we accomplish this through customer trainings and by participating in articles such as this," he says.


Uvitec Printing Inks

Uvitec Printing Inks, located in Lodi, NJ, USA, manufactures UV curable inks and coatings primarily for the graphic arts industry, and labels make up a large part of its business in addition to the company's folding carton, flexible packaging and other customers.

Uvitec's popular products among its label customers include its cold foil laminating adhesives, inks for shrink sleeve applications, inks for autoclave applications, four color process inks, matte and specialty coatings.

Robert Waddington, general manager for Uvitec, says durability is a key attribute of Uvitec's products. "The shrink ink system will shrink without cracking or losing its bond with the substrate, and the autoclave ink system will not shift color during the autoclave process. The cold foil laminating adhesive will enable printers to print down to five point type cleanly without breaks, and the process inks are low viscosity and can be poured right out of the jugs and are strong enough to be used with high line anilox rollers."

Waddington says that the company has taken measures to overcome some of the market and economic challenges that they've been faced with. "Rising raw material costs haveput pressure on us, as customers are asking for reductions in price. In order to meet this specific challenge, we will arrange volume discounts for our customers and in certain cases we'll offer lower cost alternatives for some ink systems."

Waddington says that in the last year Uvitec has introduced a variety of new products, a result of its research in looking for solutions to some of its recent challenges. "We have been forced to look at new raw material vendors for our inks, and in doing so we have found that we've improved the performance of our inks and have presented several new ink products over the course of the last year," he says.


Water Ink Technologies' ink pigments

Water Ink Technologies

Water Ink Technologies, Lincolnton, NC, USA, manufactures both flexo and UV flexo inks. The company offers a multitude of ink products for a variety of applications.

According to Kurt Hudson, general manager, UV Division, the company's popular UV ink products include multi-function white inks (rotary screen, flexo, shrink, etc.), screen from flexo technology, specialty ultra-low odor coatings, high performance inks, and low migration inks.

Hudson says that due to the shrinking of label margins, printers are seeking ways to differentiate and improve, and inks are an area where that can be achieved. He says, "Renewable content inks and coatings, low migration inks and ultra-low odor coatings provide 'green' and healthier differentiation at very low additional cost. High performance inks allow for entry into difficult markets and in some cases reduce label construction costs by replacing more expensive functional label components. Multi-purpose products preserve profit by keeping inventory costs down."

Hudson emphasizes the label printer's focus on cost as a significant market driver, but points out that you get what you pay for. " 'More for less' has been the five year mantra driving UV flexo ink development. More color, more fluidity, more consistency, more health sensitive, etc. – at lower and lower cost, is the expectation," he says, adding that focusing on cost comes with choices and (usually negative) consequences.

A Water Ink chemist conducts an ink viscosity test.
"Cheap ink is cheap ink. Lower lightfastness, dirty colors, lower chemical and water resistance (no, a varnish cannot always compensate) and lower line color strength are all byproducts of a price per pound driven mentality. Label printers sell labels by the count, not by the pound. A focus on color yield, consistency, print quality and press efficiency keeps printers competitive. Inks that provide these features support the core operating principles of profitability. Any study of true cost supports this fact. Why else do printers spend millions on new, efficient equipment with shops full of older, paid-for, reliable (enough) equipment? It's because they are smart and are dialed into the true profit drivers," Hudson says.

Tony Blakley, technical manager, focuses on the company's water based products and what he sees as the market drivers. "Converters want strong, clean printing and stable water based inks for paper and film, as well as exceptional performance on shrink films. We have the products to meet those needs," he says.

Water Ink Technologies takes into account the variables at play when working with customers, and Blakley says the company tailors products to meet customers' needs. He says, "There is tremendous variation in press room conditions, particularly aniloxes. It is very difficult for ink manufacturers to compensate for this variation in its products. Water Ink Technologies works with customers, both water and UV, to correlate press room activities and ink properties in order to improve efficiencies for both parties."

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