Green Tech: Special Lamps Save Energy

Labels, forms, cards and lottery and raffle tickets are personalised by ink jet or laser printers. These inks must be completely dried or cured before the printed sheets are passed on for subsequent operations such as stacking, cutting, folding or gluing.

Depending on the type of ink used, UV or IR emitters are used for drying and curing and this inevitably takes place with some energy consumption. Today, it is well worth the effort to examine these processes scrupulously and find techniques which offer the best results at the greatest possible energy efficiency. At the IPEX exhibition in Birmingham, Heraeus Noblelight is showcasing emitters which can be matched precisely to the properties if the relevant coating system.

Infra-Red Emitters Improve Energy Efficiency

The Alito Color Group of Leyton, London achieved significant benefits through one simple change: They replaced their existing drier, which was fitted with near infrared (NIR), short wave emitters, with a Heraeus Carbon Infra-red (CIR) System. Carbon Infrared (CIR) emitters from Heraeus Noblelight are especially efficient at drying inkjet inks. This is due to the medium wave infrared radiation, which the carbon emitters transfer into the inks at high power.

Medium wave infrared radiation is absorbed extremely well by water-based inks. Carbon emitters combine high power and fast response times with the effective medium wavelengths.

Following successful tests, two carbon infra-red (CIR) were fitted in the existing drier frame. Each 24kW module matches a special 4¼ inch print head. As a result, it is now possible to realise the complete capability of the high speed print heads. Practical usage has shown that the print quality can be maintained even at the high print speeds. In addition, the new emitters require less energy than before and have a significantly longer operating life. This has greatly improved the machine energy efficiency.

UV Lamps with Intelligent Energy Supply

The emission spectrum of UV radiation is very important for the curing process. It must cause as many photons as possible to react with the coating, on one hand to cure the material completely and on the other to bind the coating with the substrate. Consequently, every curing process is complex and each coating system specifies its own individual curing parameters.

Some applications demand special testing and development work, such as processes which require a very high coating density with many pigments or inks. The chemistry of these coating systems requires longer wavelengths so that they can react with the UV light.

In addition, other special applications require light at wavelengths which are different from those emitted by the standard mercury spectrum. This is achieved by the use of metal halide additives in the lamps and when the lamp is operated, the metal halides evaporate. Consequently, their additional spectra are emitted so that the curing process can be significantly improved.
The majority of applications today use a conventional medium pressure mercury lamp which operates at the industrial standard of 120 W/cm. There was a demand for a reliable lamp with a long operating life and a good output throughout this life. Both these factors were important because today a lamp in a typical system needs to run for up to 3000 hours at a consistently good process speed.

This has been made possible through close collaboration with OEM partners, advances in lamp production have been best realised with the aid of intelligent energy supply and the development of cooling systems.

Controlled lamp cooling has allowed higher operating output power. The power was so chosen that not only can the curing take place but also the lamp can be held in standby at very much lower power than was possible previously. Considerable savings can be made. Some processes need specially developed lamps, such as small lamps (50mm arc length) and miniature lamps (15mm arc length). These are used in digital printing, where the lamp, together with the print head, travels over the surface of the print.

UV-LEDs – small, flexible and energy-saving.

With digital printing, where the lamp, together with the print head, moves over the surface of the print, every little saving in weight and size matters. Here, UV-LEDs are the innovation for the future. Their extremely small shape allows great flexibility in styling. UV-LEDs from Heraeus Noblelight are matched to the machine environment according to customer specifications. The individual components to meet the specifications are assembled from a modular construction system. As a result, even special solutions can be built. The package also includes all the associated peripheral components such as cooling, control and power supply.

An important factor governing the operating life of a UV-LED is the fact that all components belonging to the system are harmonically matched to each other. Thermal management plays the most important role in this.

The LED special light sources help to save energy. Because they instantly switch on and off, energy is consumed only on demand, when it is needed, without impairment of the performance of the LEDs. LED technology stands for “solid state lighting”, a robust, solid and above all resilient technology.

The new “Optoelectronics” business division of Heraeus Noblelight GmbH profits from the core competence of the Heraeus Organisation in the manufacture of UV-LED modules and systems. In a complete development and production line, LED chips are processed in so-called “chip-on-board” technology and measured and tested in our in-house, accredited measurement laboratory. As a result, customer-specific system solutions can assembled and offered to meet special requirements.

Heraeus Noblelight offers the complete palette of special emitters for printing ink curing from UV to IR, carries out tests with relevant materials and advises on the optimum selection of emitters to suit particular processes.

Heraeus has more than 40 years experience with special emitters, working both with end customers and with OEMs and carries out practical tests with customer own materials in its own application centres to establish optimal and customer specific process solutions.

Heraeus Noblelight GmbH with its headquarters in Hanau and with subsidiaries in the USA, Great Britain, France, China, Australia and Puerto Rico, is one of the technology and market leaders in the production of specialty light sources. In 2008, Heraeus Noblelight had an annual turnover of 92.5 Million € and employed 735 people worldwide. The organisation develops, manufactures and markets infrared and ultraviolet emitters for applications in industrial manufacture, environmental protection, medicine and cosmetics, research, development and analytical laboratories.

Heraeus, the precious metals and technology group headquartered in Hanau, Germany, is a global, private company with over 155 years of tradition. Our businesses include precious metals, sensors, dental products, biomaterials, quartz glass, and specialty lighting sources. With product revenues approaching € 3 billion and precious metal trading revenues of € 13 billion, as well as over 13,000 employees in more than 110 companies worldwide, Heraeus holds a leading position in its global markets.

Further Information:

Readers:
Heraeus Noblelight GmbH
Reinhard-Heraeus-Ring 7
D-63801 Kleinostheim
phone +49 6181/35-8545, fax +49 6181/35-16 8545
E-Mail hng-infrared@heraeus.com
Press:
Dr. Marie-Luise Bopp / Juliane Henze
Heraeus Noblelight GmbH,
phone +49 6181/35-8547, fax +49 6181/35-16 8547
E-Mail marie-luise.bopp@heraeus.com