How does the curing of inks and coatings with LED technology actually work? What are the differences between this and systems which use conventional UV technology? When is it worth switching? IST METZ GmbH supplies both conventional UV systems with medium-pressure mercury discharge lamps and LED systems. The LED Tech Talk passed on extensive information about the "new" technology.
A brief welcome from Dirk Jägers, Managing Director of IST METZ GmbH, was followed by an explanation by Stefan Feil, Technical Marketing Manager, of the technical principles of LED UV technology. He also described the development of the market since the advent of the technology in 2008. UV light sources are currently used primarily in the spheres of disinfecting, medicine, measuring equipment, security and curing. According to the Yole market research institute, LED technology is expected to achieve a market share of around 30 per cent in 2016, a significant rise compared to previous years. The technology currently makes up the greatest proportion of adhesive curing and inkjet printing. Feil said that for the first time this year, partner company Integration Technology Ltd., with whom IST METZ has entered into a strategic alliance, sold an equal number of systems with UV lamps and with LEDs. He also addressed the possibility of saving energy, an issue which is often raised. The more highly reactive ink does mean that energy savings are possible in principle. A comparison between a conventional UV system and an LED system would have to take into account that this system also changes the chemistry of the inks. "An effective comparison needs to be made on the basis of a defined drying outcome, which in turn allows the necessary drying output to be derived. Standby/production times and average print format also have to be taken into account to make the result meaningful", continued Feil.
After that, Dr. Erich Frank, member of the Printing Inks Technical Committee of the Verband der deutschen Lack- und Druckfarbenindustrie e.V. (Industrial Association of German Coatings and Printing Inks), dealt with LED ink technology. He described the key difference from conventional UV inks as being the photoinitiators, which are adapted to absorb at wavelengths of >350 nm and thus to suit the emissions of the LED radiators. "Other ink components such as binders, reactive thinners, pigments and additives are largely comparable to those of other UV inks", continued Dr. Frank.
The brief presentations which followed gave the sales staff of IST METZ and Integration Technology the opportunity to introduce applications and advantages of the LED UV technology for the sheet-fed offset, rotary offset, flexographic and inkjet printing processes. The use of LED technology was later demonstrated on both a flexographic printing press and a sheet-fed offset printing press. The MBS-6 LED-prepared concept was used on the narrow-web flexographic printing press. Depending on the requirements of the print job, a conventional UV system can be replaced by an LED system.
The subsequent podium discussion, chaired by Klemens Ehrlitzer, Managing Director of the VskE (Verband der Hersteller selbstklebender Etiketten und Schmalbahnkonverter e.V. - German Association of Manufacturers of Self-Adhesive Labels and Narrow Web Converters), met with great interest. The speakers answered numerous questions, comparisons with conventional technology proving particularly popular. As a supplier of both kinds of system, IST METZ believes that it is necessary to weigh up and assess which individual solution is appropriate and this depends on the application in question. Whilst LEDs may still have potential for development at the moment, one thing is certain: both technologies have individual advantages depending on the application in question; these need to be taken into account when selecting the UV system.