Adhesives, consumer electronics, metal finishing, industrial plastics, industrial wood finishing, graphic coatings and inks, and field-applied decorative coatings are a few of the markets that have embraced radiation curing as a mainstream production technology.  The extent and complexity of the market is continuing to grow, as more manufacturing applications find they can benefit from its capabilities. As a result, the industry association, RadTech Europe (RTE), was challenged to considerably expand the scope of its biennial conference this year, which took place in Munich, Germany in October.

The event program featured more than 70 presentations, in concurrent subject-specific sessions, and brought together more than 350 industry professionals from across the supply chain – including some 50 end user participants. For the convenience of this extended attendee profile, the event took place over two days rather than the usual three days.

With so much interest in the technology from potential new professionals in UV/EB curing, it made sense to add an introductory “Academy Session” on the first day to deliver a sound understanding of  the science, markets, manufacture, and applications for UV, EB, and LED. 

Hosted by RadTech Europe ex-President David Helsby, the day-long session proved a popular feature. He explains, “Originally described as a specific course for newcomers to the industry, its content was expanded to provide, in the individual course sessions, a  reference or refresher course on each particular topic for all comers. The introductory sessions on formulation and basic chemistry were attended by no less than 30 participants – proof of an audience outside the technology mainstream who wanted to gain an understanding.”

The session concluded with a lively 30-minute roundup and question and answer session with the audience, featuring RTE president Paul Kelly, program chair, and ex-RTE president Dawn Skinner, and Helsby – who, between them have over a century of experience in the radiation curing industry.

During the conference’s plenary opening session, an in-depth market overview was provided by David Engberg of specialty chemicals company Perstorp (SE).  Based on RTE’s annual market survey, it confirmed that the global market for formulated products – now at an estimated 630kT in total – is continuing to grow around the world, with Asia growing annually at 3.6%, North America at 3%, and Europe at 2.1%.  He also identified extant technology and application splits, and provided a regulatory update on inks and coatings and REACH. The concurrent, subject-defined sections followed, enabling delegates to choose to follow the topics of particular interest to them.    

Valuable features of the agenda were two market-specific end user sessions – in-depth seminars on the key topic of food packaging, and on the growing focus on metal coating – both of which focused on the practical business of utilizing UV/EB technologies.  
The full-day seminar on food packaging topics encompassed a review of the chemistry by Daniel Kunz of BASF; of the market, by Perstorp’s Engberg;  and of the important UVFoodSafe industry initiative, which promotes the use of UV technology in indirect food applications, by Jonathan Sexton, Sun Chemical.  Andreas Grabitz of Eurofins talked about current regulations  and, with Nick Ivory of Sun Chemical, went on to host a regulatory panel discussion on this topic. A panel discussion on related equipment followed, bringing together panelists Im Rangwalla, ESI, Thomas Efsen of Efsen Engineering, and Rob Karsten of Phoseon.

Later, Ivory went on to discuss the activities of EuPIA, the European Printing Ink Association, and Efsen discussed the important issue of monitoring the UV dose, and Werner Weit, Constantia Teich (AT) presented the converter’s perspective.

The subsequent day’s end user seminar focused on metal coating – a growing and wide-ranging market today. Xavier Drujon of Sartomer went into the relevant chemistry, and Phoseon’s Karsten and Sage Schlissel of PCT EBI reviewed related equipment.   Two end users from multinational companies then went on to recount their particular views and experiences — Elena Uta of leading steel manufacturers ArcelorMittal, and Gianni Mirone of Metlac, manufacturers of coatings for protecting and decorating metal food and beverage packaging.

Health and safety issues
Of course, health and safety issues are a prime concern and were the subject of an extended main conference session, which covered the emerging status of EEU REACH legislation (from Martin Klatt, BASF; an overview of RoHS mercury exemptions, by Roumiana Kamenova-Santos of Lightning Europe; and the implications of Brexit, which were discussed by the British Coatings Federation’s Ellen Daniels.  US developments in the HSE arena were also covered by Michael Gould, RAHN USA. Werner Veit of Constantia detailed the company’s methods for safely using radiation curing, and Eurofins’ Grabitz covered the EU food contact agenda.

In the conference mainstream, the first major specialist session was devoted to studying advances in polymerisation in composite materials – a subject which included a study of achieving full control of polymer properties during on-demand free radical photopolymerization of fiber-reinforced polymers by a team from the Université de Haute Alsace, and by Mathias Köhler of the Fraunhofer Institute for Applied Polymer Research – on UV-LED curing and UV-LED-cured release liners for a new nap-core production process.

Advances in raw materials for UV and EB processes were the topic of the second session, in which Sartomer’s Xavier Drujon outlined the company’s recommendations for high-performance EB-curing systems and compared UV and EB curing of oligomers and monomers, while Willy Du of Wraio Chemicals detailed self-initiating UV-curable acrylate monomers, and Liza Marasinghe of Sartomer talked on methacrylate oligomer resins for high-performance applications.

Advances in coatings and materials were enumerated in the third and fourth sessions.  Reactive layer functionalization of UV-curable coatings, water-based radiation-curable dispersion with improved adhesion, and hydrolysis resistance on plastics, were the topics explored in turn by Sonja Neuhaus of the Fachhochschule Nordwestschweiz, Elodie Siband of Allnex, and Perrine Theil of Elkem Silicones. Sartomer’s Chris Orilall talked on energy-curable pressure sensitive adhesives, from the basics to “smart” and resealable adhesive types. David Ivarsson of Efsen Engineering looked at how to establish, maintain and automatically control the process window in UV/LED curing, and Petra Lenz and Niklas Kircher of BYK Chemie focused on wetting and dispersion additives required to meet the colour requirements of different ink types.

Advances in 3D printing with UV technology were the next session topic. The formulation of components to meet specific property requirements were addressed by Sean Des Roches of Rahn Group’s USA Tehcnical Labortory;  advances in (meth)acrylic systems for additive manufacturing by Noémi Fellée of Sartomer; the effects of newly-developed (meth)acrylate resins on impact strength in 3D printing by David Robitalle, Dymax; and the health and safety implications of using DLP technology in 3D printing by Ing Florian Garnich, Henkel.

Requirements for measuring and monitoring UV and EB processes were covered in the sixth session. Mid-infrared laser spectroscopy for in-situ monitoring of curing reactions was discussed by Florian Eigenmann of Irsweep, while Ing Christiane Schuster of the Fraunhofer Institute introduced a versatile dosimetry system based on radiation-sensitive ceramic. Robin Wright of Wright Way UV Consulting spoke on a photodiode-free approach to LED lamp radiometry; and Thomas Efsen of Efsen Engineering looked at developments in inline UV monitoring.

Developments in sustainable raw materials were the subject of the seventh session.  Dipl-Ing Nicolas Klikovits of TU Wien opened with a discussion of novel photopolymers created by UV-induced cationic-ring-opening polymerization. Jurgen van Holen of Allnex explained how new energy-curable products can extend the sustainable product offering for high-performance coatings.  From synthesis to material characterization, Aymeric Champion of the Université de Haute Alsace explored bio-based polyester acrylates for LED coating. New radiation-curable oligomers with a high renewable carbon content, offering solutions for 3D printing and coating,  were introduced by Rahn’s Andreas Möck.

EB and UV LED systems for printing and packaging were detailed in the eighth session. How low-voltage EB equipment is continuing to develop to meet the many challenges of the packaging market were discussed, in turn, by Thorsten Vehoff of Heraeus Noblelight, Dirk Exner of Phoseon, and Im Rangwalla of Energy Sciences Inc.

UV LED photoinitiators were also the subject of multiple conference sessions. Marika Morone of IGM Resins showed how the driving forces of photoinitiator research – application improvement, technology development, and toxicology issues – are bringing new polycyclic photoinitiators to the forefront. Expert speakers addressed two sessions on advances in the chemistry of photopolymerization, as well.

The program also featured the presentation of the established RadTech Awards during the opening plenary session and an extensive supplier tabletop exhibition – an excellent opportunity for networking, which was not only explored by participants during the lunch and coffee breaks, but also the site of the after-work party on the first evening.  

Reviewing the event as a whole, RTE president Paul Kelly of Luxsit said, “It is our strategy to focus the energy of RadTech Europe on market conversion (in favor of UV/EB curing technology), education and the opportunity for exchange of knowledge and experience between established professionals. This year’s program well reflected these three key pillars of our ambition.”  

Program organizer Dawn Skinner added, “This year’s turnout has confirmed that our biennial conference remains an important part of our industry, in that it combines solid content with the aspects of connecting expertise and peer networking.”