Compact, hermetically sealed electron beam emitters open up new possibilities for in-line process integration. Photo courtesy of Advanced Electron Beams, Wilmington, MA.
Dubbed “RadTech Europe ’07: UV/EB - The Natural Choice” by its organizers, the November event in Vienna was greeted by nature itself dumping snow on attendees trying to get in and out of Austria. But if the weather was brisk, so was activity at the conference, which has become a notable forum for ultraviolet (UV) and electron beam (EB) suppliers to gather every two years and check the pulse of technology and measure its progress.
“Every electron beam manufacturer in the western hemisphere is here,” commented Josh Epstein, product manager for Advanced Electron Beams of Wilmington, MA. And indeed the conference was successful at drawing nearly 600 delegates from 36 different countries.
The Global Potential
Reminding visitors of the host city’s magic and artistic beauty, the plenary session kicked off with lyrics of Wien, Du Stadt Meiner Träume (“Vienna, City Of My Dreams” by Rudolf Sieczynski) before heading into more serious topics of sustainability and the growth of UV/EB technology globally.David Harbourne, president of Fusion UV Systems, in presenting “UV/EB Market trends in North America: A Global Perspective,” observed that “industrial coatings are depended upon to overcome the most extreme environmental conditions, extremes of temperature, moisture, humidity, chemicals, fumes, scratches and abrasions, while maintaining the integrity and appearance of a multitude of products that we encounter in everyday life. It is in this harsh, demanding and rapidly changing environment, in which the consequences of failure (financial and product/corporate reputation) are very high, that UV/EB curing is becoming the manufacturing process of choice for protecting the substrate, while simultaneously protecting the environment.”
According to Harbourne, a number of drivers will continue to affect both the users and suppliers of UV/EB equipment and materials. These drivers include the following (not ranked in order of timing or impact):
- The shift in global manufacturing from North America to the BRIC nations (Brazil, Russia, India and China) will continue to impact industrial production in the USA. In the short term, it is primarily China, followed by Russia, which are having the most impact; however, both India and Brazil also have the capability and resources to become centers of global manufacturing.
- The recent transition from “natural” substrates, such as wood, metal and glass, to composites, plastics and other substrates, such as PLA (polylactic acid) films for packaging, has motivated the suppliers of UV/EB curing processes to deliver curing systems that provide superior performance on heat-sensitive substrates, while meeting energy conservation requirements.
- The increasing costs of energy and raw materials have made UV/EB curing more competitive with conventional drying/curing processes, but in some cases it also has jeopardized the value proposition typically associated with UV curing. The prices of some clear coating formulations have increased by as much as 70% within the past 18 months. In some instances, these increases have been offset by the availability of lower cost raw materials and photoinitiators from China, but management of these complex cost issues will continue to be a challenge for the foreseeable future.
- The ongoing development of new synergistic technologies, such as nanotechnology, that can be combined with UV/EB formulations to enhance the already high performance of UV/EB cured products (improved scratch/scuff abrasion resistance, barrier properties, solvent and water resistance) will enable the technology to expand current applications and to enter others not previously considered as potential UV/EB applications.
- While perhaps not considered “new,” the continuing developments of UV processes and equipment for curing three-dimensional complex shaped substrates is enabling this technology to be used applications that were not previously considered suitable for the “line-of-sight” restricted uses of UV curing. The uses of robotics and dual-cure UV systems have been the main drivers of the market change.
- Environmental regulations mandating the reduction in emissions of hazardous air pollutants (HAPs), volatile organic compounds (VOCs) and carbon dioxide (CO2), when coupled with popular demands to lower pollution levels from consumers/users of UV cured products, have resulted in significant pressure being applied to many industries to rethink the method by which they produce their products. Several very large global corporations have based their future corporate business strategies on being environmentally proactive.
- “Sustainability,” once just a buzzword and a politically correct platform, has now become a requirement for many major packaging consumers in North America. Wal-Mart and Dell Computer are two examples of companies that have mandated that their suppliers of packaging films switch from the current polyethylene terephthalate (PET) films made from non-renewable raw materials to PLA films made from renewable resources such as corn and cut grass.
“The aim of equipment suppliers must be a further reduction of energy consumption and an increase in energy efficiency,” said Jaegers. “The question is to what extent can the electrical power of a UV curing system be reduced to achieve the same curing results? The aim in the future is to cut this energy requirement in half. And I would not propose this if I did not think it were achievable.”
RadTech Europe presented the Paul Dufour Best Paper Award to Dr. Jan Weikard of Bayer MaterialScience AG, Germany, for his work titled “The New Frontier: Waterborne UV Coatings for Plastics.”
Awards and Recognition
RadTech Europe presented the Paul Dufour Best Paper Award to Dr. Jan Weikard of Bayer MaterialScience AG, Germany, for his work titled “The New Frontier: Waterborne UV Coatings for Plastics.” Weikard compared the chemistry, application and performance characteristics of new waterborne UV systems with existing solventborne UV or thermosetting coatings. Examples included high-gloss clearcoats on basecoats, pigmented single-layer coatings with good adhesion on various plastic substrates, and soft-touch coatings.“With a new generation of waterborne UV-curing polyurethane dispersions, it is possible to formulate coatings for plastics with performance characteristics that until now could only be realized by two-component polyurethane systems or solventborne UV systems,” explained Weikard.
The plenary session concluded with awards for innovative commercial applications of UV/EB technology. In the automotive category, Wörwag Coatings won the RadTech Europe Innovation category with a UV clearcoat for a thermo-formable plastic substrate for making automotive body parts. Recognition in the Printing and Packaging sector was given to Crea Printing Industries of Belgium for PP + 3D®, a 3D-lenticular printing method of producing a production box that uses 100%-UV printing inks. And the Industrial Coatings and Adhesives award was presented to Dietmar Dengler of Delo Industrial Adhesives (Windach, Germany) for its cationic UV-curing edge sealant for organic light-emitting diodes (OLEDs).
Finally, in a touching expression of sentiment, Luc Nuijten was awarded the association’s first RadTech Europe in recognition of his outstanding efforts in the promotion of UV and EB technology. Nuijten, who has been involved with the coatings industry for more than four decades, championed the European UVITECH project, one of the earliest efforts to provide data on the safe use and environmentally friendliness of UV/EB technology. This work set the stage for the subsequent development of the UV and EB protocols. He was also instrumental in ensuring that the UV/EB technology would be recognized as a technology qualifying for the ECO-label. Luc worked to prevent implementation of a mercury ban for UV lamps that would have been detrimental for the UV industry. Nuijten’s latest work concerned investigating the de-inking and recyclability of UV coated paper.
Technical Advances
The main technical conference, always the heart of the RadTech Europe event, was well organized into three concurrent sessions. A total of 53 papers covered topics ranging from health and safety, equipment, graphic arts, and wood, automotive and metal applications, to innovations in chemistry, equipment and new synthetic routes.In his paper “UV-Curable Electrically Conductive Flexo Ink,” Rudie Oldenzijl of Acheson Electronic Materials in the Netherlands reported on Acheson’s effort to develop a UV-curable conductive ink for flexography that has the right properties after UV curing to function as an RFID antenna. Oldenzijl reported some success in that the developed UV-curable electrically conductive ink had a resistance of < 0.020 Ohm/square/25 micron after UV curing and a heat treatment that was close to the target goal. A few beta site tests have shown that it is possible to use this ink as antenna material for an RFID tag.
New, energy efficient techniques using solid-state sources such as LEDs and semiconductor light matrices (SLMs) were discussed as well, with a paper by Alex Schreiner, the past director of R&D for Phoseon Technology. And Dr. Bernd Brandl of IST Metz, a European-based manufacturer of arc lamp systems, presented the paper “UV LEDs: Survey of a New Emerging Technology.” How and where can LEDs compete today with mercury medium pressure gas discharge lamps at this stage were the questions posed by Brandl and Dirk Jaegers of IST in their talk, “Quo vadis LED?”
A well-attended paper on “Photoinitiator-Free Daylight Curing of Maleimide Functional Coatings” was presented by Leo G.J. van der Ven, Keimpe J. van den Berg, and Edith Benningshof-Hulsbos of Akzo Nobel Car Refinishes. This paper described a new “robust daylight-curing clearcoat” based on isocyanate/thiol chemistry. The authors proposed that such a system eliminates the need for the dangerous shortwave UV sources that are impractical in the refinish shop.
Advances in equipment were abundant. Kevin Joesel of Fusion UV Systems detailed successes in curing three-dimensional parts with a variety of techniques, including reciprocating lamps and work done with robotic UV curing, in his paper “Direct-to-Metal UV Coatings Applications for UV Curing.”
Tunja Jung of Ciba Specialty chemicals, Basel, Switzerland updated the audience on Ciba’s continued progress in commercializing the PlasmaCure process.
Dr. Klemens Rother of Cadfem GmbH presented results of the company’s work with Fraunhofer IPA in developing a system that uses sophisticated computer modeling programs to help position and optimize the uniform curing of complex 3D objects such as car bodies when many fixed lamps are required. The system can be used in combination with other process tools that model the thermal drying and spray application process to provide a completely automated view of coating and curing for automobiles.
Other presentations pointed to the influence of developing nanotechnology in UV formulations. For example, Frank Bauer of the Leibniz Institute for Surface Modification discussed his work with the firm of Cetelon Nanotechnik. The resulting system creates a matte effect with gloss levels down to 0.5 units (at 60) as well as a soft-touch feeling while maintaining a high abrasion resistance. Bauer concluded that matted nano/micro-hybrid composites provide a very natural visual appearance and seem to be suitable for durable parquet and PVC flooring applications.
In addition to these presentations, an impressive roster of 31 poster papers were presented at the conference from a wide range of academic institutions, including 10 papers from the local Vienna University of Technology in Vienna on topics ranging from new photoinitiators to the surface grafting and metallization of polypropylene.
A Promising Future
“Over the past years, the UV/EB technology has proven to offer a sustainable edge, and all market reviews also foresee a continuous, above average growth for the coming years,” noted Philippe Goethals, president of Radtech Europe. “Today, the UV/EB technology is an established technology with evidenced features and thus ‘The Natural Choice.’”For more information about RadTech Europe, visit www.radtech-europe.com.
