LED has become dominant in many UV curing applications

The UV curing sector is a versatile part of the coatings industry. In the last years especially the UV LED technology had a huge impact on the sector. We spoke with Charles Bourrousse  and Frédéric Taché from Sartomer about their views on the technology.

How prevalent is UV LED technology?
Today, the perceived advantages of UV LED, including increased productivity, higher quality and a more environmentally friendly technology, has enabled UV LED curing to become major and even dominant in many UV curing applications, as well as to turn traditional processes to UV. The most important fields where the use of UV LED technology has increased, are wood coatings and printing inks, to the point where some lines are now “full” LED.

More recently, the development and marketing of low migration systems specifically developed for use with LED has resulted in a greater acceptance across all sectors of the coating and printing industry in EU where indirect food contact is critical. Moreover, the reduction in heat generated during the curing process has enabled thin film, thermo-sensitive plastic substrates to be employed. This has helped in the rapid development in the flexible packaging applications.

Further progression of UV LED will be based on the development of new wavelength lamps and/or more adapted photoinitiator packages. As a key supplier to the UV industry, Sartomer continues to develop & recommend market leading solutions for the highest surface cure performance.

What are remaining challenges (related to the UV curing technology in general)?
Any technology will always entail new technical challenges to maximize performance: adhesion, outdoor stability, durability, low migration. New visual or sensorial effects are also a key driver for future developments. We expect to see growing interest in sustainable and compliant formulation approach from the market players, guided by influential brand owners recommendations. REACH compliance is also a key subject we are addressing with our customers to ensure a smooth market continuity.

Finally, additive manufacturing is a major area of development today, for which we make the most of our UV curing technology knowhow & experience to provide our customers with the highest quality & performance 3D printing solutions.

What are the latest developments in raw materials for UV-curable adhesives?
The electronic market is driving the demand for new products in the field of UV curable adhesives. UV curing is a key technology because it enables a quick and clean process. The high performance UV cured adhesives will provide low viscosity systems enabling high barrier properties, optimal light transmission, low yellowing and good flexibility. This is the ideal solution for the Light Optically Clear Adhesives (LOCA) used in all our smartphones and tablets.


Flexo Innovation

Each element of the process continues to advance, meeting the needs of an evolving industry.

With so many stories of digital press launches and installations dominating the label industry news feed, to some, flexography has become an afterthought. However, despite the inroads digital printing has made in recent years – and they are indeed significant – the majority of PS labels and packaging printed around the world are done so via flexography. In fact, it’s really not even close.

There are several reasons why the tried and true flexo print method has been the backbone of the label industry for decades. As the name of the process suggests, flexo is flexible. Its versatility plays a pivotal role in its adoption and success. Flexo attributes that set it apart from competing technologies such as offset, litho, gravure and digital, include high press speeds, low equipment and maintenance costs, low cost of consumables, suitability for medium to long runs and ease of integration with other printing processes.

Furthermore, flexo’s flexibility allows the process to continue to evolve, with suppliers responsible for every element in the process working in lockstep to keep moving forward into the future.

Flint Group Narrow Web has recently announced developments in the up-and-coming UV LED flexo and shrink sleeve sectors, as well as addressing the extended gamut trend.

“We knew from interviews with clients specializing in the short-run shrink sleeve market, that they want a UV dual-curable ink with better adhesion and increased curing speed to boost productivity and reduce yield losses,” states Kelly Kolliopoulos, global marketing director for Flint Group Narrow Web. “Our experience in LED and conventional mercury curable ink system technology, combined with our understanding of the shrink market, enabled our R&D team to develop this best-in-class system.”  She concludes, “EkoCure XS combines the latest ink chemistry, including novel binders, that provide perfect cure and sufficient flexibility of the cured ink, allowing the adhesion to remain fool-proof – especially after post shrink processing is completed. The full range of Pantone shades and opaque white are available.”


Finding Opportunities in Industrial Printing Applications

Is there a business opportunity for the commercial printing segment in industrial printing applications? The most reliable answer at this point is a definite maybe. But, a market that’s been described by many pundits as “ready to pop for a long time” is definitely worth exploring.

When printing stops being printing for its own sake, it’s time to recognize it for what it actually is: industrial printing.

Another way to delineate industrial printing is by application. Broadly speaking, points out Josh Hope, senior manager of 3D Printing & Engineering Projects, Mimaki USA, industrial printing is putting ink onto “anything that isn’t paper,” but often in small batches that don’t scale up to true “industrial” quantities. He advises printers to look at the printable objects they are outsourcing for clues to the kinds of industrial printing they might be able to do in-house.

At Fujifilm Dimatix, says Timothy Rosario, senior project manager, Fujifilm Inkjet Technology, “we define ‘industrial printing’ by the various substrates we are printing on, including sandpaper, waterproof seam tape, cement board, drywall, house wrap and insulation.” This gives a sense of the role industrial printing can play in non-traditional markets such as homebuilding, where Fujifilm Dimatix has introduced an LED-UV solution, the StarFire SG1024 industrial inkjet printing system, for printing construction materials.

Flatbed UV inkjet printers that can accommodate solid objects, as well as flat substrates, work best. Hope says that Mimaki’s UJF Mark II (MkII) Series LED-UV tabletop printers are tailor-made for late-stage customization of phone cases, USB drives, skateboards and other items produced in small batches. With its 4˝ inkjet head height, the Ricoh Pro T7210 UV flatbed — the device that printed cinder blocks at the SGIA Expo — has been used to image bar stool seats and guitars, according to Dollard.

Unlike in traditional production, the printing isn’t the dominant technique, but one of a number of steps in a complex sequence of events. In industrial printing, “print adds value within a bigger process,” says Tom Molamphy, business development manager of the Industrial Inkjet Ink Div. at Agfa Graphics.

Molamphy points out that while there are industrial applications for Agfa devices such as the Jeti Tauro hybrid LED-UV inkjet printer, wide-format equipment generally isn’t geared for the high-speed, single-pass performance that industrial printing on an industrial scale requires. As a supplier of industrial inks, Agfa is working with printhead manufacturers and system developers to push wide-format inkjet further in this direction.

Article Resources

AWT Labels & Packaging installs 10-color Mark Andy P5

AWT Labels & Packaging has installed a new Mark Andy P5 press, its third of the model since August 2014.

The 17in, 10-color machine is equipped for rotary screen, cold foil, film package, full chill system, LED curing, and rail for the turn bar and unwind/rewind units. It also features a QCDC system, which allows for die change overs in less than two minutes.

Ted Biggs, vice president of manufacturing at AWT Labels & Packaging, said: ‘The new P5 gives us the additional capacity and capabilities we need to continue to pursue our targeted markets. We are also expanding our use of LED curing technology. This is a very exciting and busy time for all of us at AWT as we continue to grow.’


DPI Group adds Agfa Jeti Titan HS and Jeti Ceres from Agfa Graphics Canada

The DPI Group (Groupe DPI, Drummondville, Quebec) has installed an Agfa Jeti Titan HS as well as an Agfa Jeti Ceres, taking its wide-format and visual communications solutions to an entirely new level of quality, speed and productivity. DPI specializes in commercial display, interior décor, installations and signage solutions – including posters, backlit displays, banners, vehicle wraps, decals, promo flags and tents, tradeshow display solutions, and much, much more.

The Jeti Ceres is a 3.2-metre roll-to-roll UV LED inkjet printer that delivers extremely high print quality up to 10.5 feet wide. With speeds up to 2002 ft²/hr., it’s capable of unattended printing and offers six colours plus optional white and/or primer. Configurable with an optional dual roll and back-up camera, the Jeti Ceres can print on mesh and porous substrates without a liner. It’s powered by Asanti automated workflow software that was created specifically for sign and display applications. The printer is also ideal for high-volume printers looking to reduce operational costs.

The Jeti Titan HS (High Speed) is a flatbed, 3-metre-wide, 6-colour UV inkjet system that can reach speeds of up to 160 square metres per hour (1,722 ft.2/hr.) in Express Mode. The system, which can include a flat-to-roll printing option, can output resolutions of up to 720 x 1,200 dpi. It’s ideal for higher-volume or fast-turnaround jobs and is designed to guarantee the highest accuracy in drop placement. Its 7-picolitre droplet size makes it possible to achieve photo-realistic image quality with fine text down to 4 point, positive and negative. The Jeti Titan HS “works like POP viewed at close range, or for the high-level art, fashion and cosmetics markets,” said the OEM. It also features a precision moving table built on a robust steel frame for seven-day/three-shift endurance.


CJ Graphics adds two UV-LED printers

Toronto-based commercial printing company CJ Graphics has installed two Jeti ultraviolet-curing (UV-curing) light-emitting diode (LED) wide-format printers—a Tauro H2500 and a Ceres RTR3200—manufactured by Agfa Graphics in Mississauga, Ont.

The 2.5-m (100-in.) wide ‘hybrid’ Tauro features an automatic board feeder (ABF) and an integrated roll-to-roll (RTR) system, to handle both rigid and flexible media. It can reportedly reach speeds up to 275 m2 (2,960 sf) per hour.

The 3.2-m (126-in.) wide Ceres is faster, reportedly reaching speeds up to 186 m2 (2,002 sf) per hour, but is only intended for flexible substrates. Both printers run on Agfa’s Asanti workflow software.

“These wide-format printers provide the power to answer our clients’ demands for high quality and consistency,” says Jay Mandarino, president and CEO of the CJ Group of Companies. “They will enjoy faster turnaround and rich results, even on unlined mesh and porous substrates.”


UV LED Technology on the Horizon for Wide Web Applications

Ideal for laminating adhesives, coatings and inks

UV LED curing technology presents numerous opportunities for wide web applications. Although most applications on the market today are in digital inkjet, screen, narrow web flexographic and sheet-fed offset printing, and structural bonding, Phoseon Technology sees growing interest in UV LED for wide web applications.

UV LED laminating adhesives is an area of focus for Phoseon. The benefits of UV LED laminating include an immediate cure and a long pot life — also known as working life, or the period that chemicals remain usable when mixed. In addition, using laminating adhesives, as opposed to solvent-less adhesives, enables the laminated web to be slit, converted and filled immediately after the laminator with no controlled environment post-cure processing time requirements.

The wide web market currently uses traditional UV curing systems for protective varnish, silicone release and functional coatings, but businesses are starting to invest time and resources into developing UV LED solutions for their coating applications.

“Companies have started to integrate UV LED curing into their wide web coating lines because of the benefits and growing level of interest in the use of UV LED sources within this application space,” says Jennifer Heathcote, director of business development at Phoseon Technology. “While it is likely some applications may not yet be viable for LED today, there are several coating lines that are successfully being converted, and this trend is expected to grow in the coming years.”

In addition, wide web UV applications that were never achievable with conventional arc or microwave systems due to the large degree of heat transfer, are becoming possible with LED, thus expanding the total UV curing market.

Most of the UV LED formulation work over the past 10 years has been in the areas of inks, adhesives and over-protective varnishes. Many coatings companies are just now starting to evaluate UV LED curing systems for use in curing b-stage, functional, and hard coat chemistry.

“The fact that UV LED coating formulations are garnering attention suggests the latest improvements in the technology are making it increasingly viable — technically and economically — for use in wide web coatings applications,” Heathcote says. “UV equipment suppliers have achieved success in designing and producing UV LED curing systems in short head lengths, and these designs are rapidly being extended to longer lengths.”

Heathcote says that while there are upfront costs to begin using, or switching to, UV LED curing for wide web printing, companies often quickly recoup their investment. UV LED curing systems have no moving or consumable parts, virtually eliminating downtime for maintenance and repairs.


Poland’s Tom Druk invests in Bobst M5X in-line UV LED flexo press

Poland-based label converting company Tom Druk has invested in a Bobst M5X in-line UV LED flexo press to boost its operations.

Bobst sold the M5X inline UV LED flexo press featuring 10 colors to Tom Druk at Labelexpo Europe 2017.

Fully equipped with UV LED curing technology and Digital Flexo 3.0, the Bobst M5X press will complement the Tom Druk’s existing Bobst narrow-web inline flexo and multi-process printing and converting lines.

Tom Druk CEO Tomasz Wolak said that firm has invested in the new Bobst technology to increase turnaround speed, deliver consistent high quality and a sensible reduction of waste.

Wolak added: “We want to make sure we can continuously extend the range of substrates we can handle, as well as the added-value finishing applications that are required today by the high-end label industry, such as laminating, cold stamping, holograms, lacquering, as well as all sorts of die-cutting shapes.”

Bobst said it has already delivered and installed a 6-color machine to Tom Druk about 10 years ago, followed by the installation of a second 8-color and third 10-color presses.

Wolak added: “We were impressed by the machine performance highlighted by the demonstrations on the M5X.

“Furthermore, BOBST offers the REVO 7-color extended color gamut and digital flexo process, which we are considering to equip the M5X with in the near future.”

The optimized configuration of the M5 line, Bobst M5X is designed to handle a full range of substrates from unsupported film to self-adhesive stock, through to paper, laminate tubes, alu-foil and light cardboard.

Tom Druk offers variety of label types and shapes including decorative and security labels, foil labels, bottle wrappers and multi-layer coupons. It serves variety of market segments including cosmetics, food, beverages, pharma, automotive and electronics.


Fujifilm to Launch Illumina Retrofittable LED UV Curing System

The kit, which was launched in the US earlier this year, enables most traditional UV and water-based flexo presses to be converted to LED UV curing, boosting productivity and environmental performance while reducing costs and waste.

The LED UV curing lamp system is designed to operate with Fujifilm’s new 300 Series flexo inks, which are compatible with all plates designed to work with UV-based inks.

Combined, the manufacturer said the Illumina and 300 Series inks bring the benefits of LED UV curing to traditional flexo presses through a simple conversion process which takes two days or less to complete.

According to Fujifilm, the Illumina’s compact design means the unit will fit easily onto most UV flexo presses of any width, and will also mount directly onto any water-based flexo press without the need to add an extra roller, as is required by some other LED retrofit systems.

The Illumina is said to produce less heat than other LED technologies, with the kit’s design enabling a potential energy saving of up to 90% compared with conventional UV curing lamps.


UV LED Technology Best Option for Low-Migration Printing

Phoseon Technology believes it’s just a matter of time before UV LED cured low-migration inks, coatings and adhesives are widely adopted across global markets.

Low migration is a term used to describe the entire process of applying and curing specially formulated inks used in packaging such that there is minimal to no migration through the packaging materials and into the product. Low migration — also known as food safe process — is not exclusive to food packaging; it also extends to other products such as pharmaceuticals, cosmetics and pet products where uncured or migrating inks can negatively impact the product’s composition or odor.

Since 2004, EU Framework Regulation EC 1935/2004 requires low migration for all food packaging. While there are a variety of processes that can reduce migration levels, Phoseon Technology’s revolutionary UV-LED curing technology offers superior process stability and consistency, both top requirements for low-migration printing.

“The UV output of LED curing equipment is much more stable over time compared with conventional mercury based systems. This results in greater process control when used to crosslink inks, coatings and adhesives in low-migration processes,” said Jennifer Heathcote*, global business development manager at Phoseon Technology.

UV LED curing is becoming increasingly more viable for decorating applications spanning printed labels, flexible and shrink films, rigid containers, and carton and corrugated board. In addition to its quick-drying capabilities, UV LED curing creates less heat transfer to the substrate, thereby, eliminating or significantly reducing any damage to the print surface.

“That’s a critical benefit, especially when printing on heat-sensitive plastic films often used in food packaging,” said Heathcote.

Heathcote notes that while there are upfront costs to switch to UV LED curing for food safe process printing, companies often quickly recoup their investment. UV LED curing technology has no moving or consumable parts which significantly reduces down-time for maintenance and repairs. UV LED systems last longer and can reduce energy consumption by up to 70 percent compared with traditional arc lamps. In addition, UV LED curing does not contain mercury, which is used in conventional lamps, making for a safer environment and workplace.