RadTech 2020 Covers Latest in Energy Curing

By David Savastano, Editor | 03.09.20

Speakers offer insights into new technologies for coatings and inks.

Driven by numerous environmental and performance benefits, the use of UV, UV LED and EB is on the rise in numerous industries, including coatings, graphic arts and industrial markets. RadTech International North America, The Association for Ultraviolet and Electron Beam Technologies’ biennial show, RadTech UV+EB 2020, is focusing on opportunities in the field of energy curing.  
 
This year’s conference, held at Disney Coronado Springs in Orlando, FL, opened March 9, with Technical Conference tracks, Exhibit Theater programs and more. RadTech’s Mickey Fortune said that despite the challenges brought on by the coronavirus, including some speakers and exhibitors dropping out, RadTech 2020 is doing well.
 
“Our attendees understand that there are some difficulties due to travel bans, but the exhibitor floor is busy and the sessions are packed. The vibe of the conference has been fantastic,” said Fortune.
 
Applications I opened with Bob Lin of Evonik Corporation, who covered “Novel Approaches to Improve Scratch Resistance in UV Coatings.” 

Lin cited a study by ResearchandMarkets that showed that the market size of abrasion resistant coatings is projected to grow from $8 billion in 2019 to $11.1 billion in 2024, at a CAGR of 6.5%.The major driving factors for the market are stringent EU and US regulations regarding VOC emission.
 
“Abrasion resistance is the behavior of a surface to withstand a mechanical removal,” Lin said. “Testing methods include Taber abrader, Crockmeter, Martindale, Martens Hardness and Taber shear tester.” He highlighted Evonik’s Nanosilica 153 and Slip 496, which he said showed the best results.

“Advancements and Challenges in ‘Easy-to-Clean’ Coatings was the topic of a talk by 
Kristy Wagner of Red Spot Paint and Varnish.
Wagner noted that there are more requirements for coatings nowadays.
 
“Automotive coatings are expected to last longer,” Wagner reported. “There are increasing coating demands – anti-fingerprint, anti-glare and anti-reflective for touch screens, anti-ice for safety, and easy to clean coatings, which are critical for sensors.”
 
“Increasing hydrophobicity and oleophobicity seems to improve cleanability of a coating,” Wagner added. “Formulation and processing can be critical to achieving optimum results. Formulation adjustment may be necessary to maintain high contact angles. The question is whether omniphobiicity contributes to easy to clean coatings.”

Marcus Hutchins of allnexclosed Applications 1 with “High-Performance UV Curable Resin for Automotive Coatings.”Hutchins said that there are more than 30,000 parts in an automobile, and a lot of them are coated parts. 
 
“UV radiation penetrates the complete coating layer to get full polymerization and optimized performance. Rapid cure saves energy, time and production space,” Hutchins noted. “UV is excellent for heat sensitive plastics, and also achieves harsh automotive specifications with enhanced chemical, abrasion and weathering resistance.”
 
The Applications II segment was up next, beginning withMichael J. Dvorchak, Dvorchak Enterprises LLC, who discussed “Aerospace UV Cured Coatings; Yesterday, Today & Tomorrow.” Dvorchak gave a comprehensive overview of V projects with aerospace, including early requirements from the US Air Force for “72 hours dry to fly” requirement for a 2K polyurethane topcoat. “These potentially save 89 to 100.5 hours per aircraft – that’s significant,” Dvorchak said.
 
Dvorchak added that 2011 saw the first attempt with UV LED for topcoats, and noted that almost all are military projects. 
 
“One of the most important limiting factors for the UV cure aerospace technology is the design and size of the UV light for curing the paint of the aircraft,” said Dvorchak. “The future is bright for this technology, especially when you see the incredible foundation that exists for UV cure aerospace coatings. The DCM 3D UV cure technology has the potential to obtain a 2% reduction in aviation fuel used and would reduce the annual CO2 emissions by 20 million tons annually.” 

“Organic-Inorganic Hybrid Coatings for High-Performance Protective Coating Applications” was covered byVijay Mannari of Eastern Michigan University. 

Mannari noted that the pretreatment layer is critical. 
 
“Two families of epoxy silane and urea silane precursors were developed based on modifying materials,” Mannari observed. “We experimented with these UV-initiated Sol-Gel pretreatment. It is possible to deposit OIH pretreatment (coatings) on metal substrate using UV cure. Both PLA and PLB are suitable. PLA gives denser films with better corrosion resistance. Epoxy silane system with PLA catalyst works the best, significantly better than conventional system. We can eliminate the need for post-curing with PLA. The UV Sol GeL process offers significant technological and environmental benefits.”

Jonathan Shaw of allnexclosed Applications II with “Paper Upgrade - A Path to Realistic Looking Substrates.”

“Printed paper and foil are used to upgrade inexpensive substrates,” Shaw said. “Grains can be generated by physical means. Inks can generate the color and help with the grain. Physically drying UV-polyurethane dispersions PUD will seal the surface and can be handled prior to UV cure. UV-PUDs can be selected for clear or pigmented systems. One benefit of an all-UV PUD systems is that all coating layers can be applied and then one cure step will suffice for all layers.” 
 
The Printing & Packaging section looked at the role of UV and EB inks in packaging. Elliot Coulbeck of Lubrizol Ltd. led off the segment with “Multi-functional Dispersants for UV Inks.” He discussed a new prototype dispersant from Lubrizol.
 
“Our new prototype is giving good let down compatibillty and color strength,” Coulbeck noted. “We have improved solubility and increasing performance on a range of pigments. We are tackling challenging pigments, and seeing better stability on PY 13 and PR571. The prototype also has extremely fluid physical form.” 
 
Imtiaz Rangwalla, Energy Sciences Inc., followed with an excellent talk on “Recyclable Packaging Options with Electron Beam Curing Technology.” Rangwalla began by asking what the industry can do to improve recycling.
 
“What can we do as suppliers to help recycling of plastic,” Rangwalla said. “The flexible packaging market is close to $32.3 billion in North America, and is 19% of the total packaging market. It is steadily growing.’
 
Rangwalla noted that inks are 6% of $17.5 billion of flexible packaging materials, while films and resins are the vast majority of costs at 70%. He then discussed the interest multinational CPGs are showing.
 
“PepsiCo says that sustainable plastics vision is rooted in three pillars – reduction of plastic use, increasing recycling rates and reinventing packaging,” he said. He added that in California, producers will have to prove that amount of packaging recycled is 30% by 2026. 
 
The goal is to flexible packaging recyclable. “You may need a top layer of EB PV or MDOPE or BOPE,” Rangwalla observed. “Through the use of EB to increase heat resistance of the top ply PE film, a sufficient temperature gradient could be created between the top ply printed film and bottom ply, increasing sealing speed. EB gives a lot more flexibility to packaging. EB treated laminates can be recycled. An option can be to EB cure flexo or gravure inks and EB crosslink the film to make PE/PE recyclable similar laminates.”

Julie Cross, Domino Printing Sciences, was next up with“Food Packaging Compliant Inks and Set-Off Migration,” which due to travel restrictions, Cross delivered by video. Cross focused on set-off migration, noting that materials must be manufactured in accordance of Good Manufacturing Practices so they do not transfer constituents to food in quantities that endanger human health, change taste and other aspects. 
 
“Development of a food packaging compliant ink is considerably more difficult for inkjet compared to analog inks,” Cross observed. “Printhead technology requires significantly lower viscosity.”
 
Domino designed inks that were formulated to be compliant with Swiss Ordinance and Nestle Guidance, but to be food packaging compliant, a functional barrier was still required. 
 
“Migration can still occur when inks are food packaging compliant,” Cross concluded. “Extra curing may be required to achieve sufficient cure to prevent set-off migration and it is possible on a hybrid digital/flexo press.”

“Attainable Sustainable: Using Electron Beam Technology in Compostable Flexible Packaging,” the final talk of the Printing & Packaging session, was led by Karl Swanson and Sage Schissel of PCT Ebeam and Integration, LLC.
 
Swanson noted that according to Smithers Pira, the global packaging market was $975 billion in 2019.  Interestingly, sustainable packaging is growing 25% to 30% per year. 
 
“Some of the current issues in packaging are consumer driven, such as the need to maintain product safety, respond to shorter runs, and fast delivery,” Swanson reported. “Sustainability is a key trend for major CPGs, and electron beam can make it possible. Electron beam can eliminate a layer of lamination, downgauge film, uses no photoinitiators or solvents, with less energy consumption and material waste. EB has a smaller footprint and works with digital printing allows print on demand. Using polyethylene with surface printing with an OPV as a final layer, it is compatible with recycling of PE.”