However, for the manufacturer, this can present real challenges, as very often these manufacturing steps can be costly and energy-demanding.
Infrared heat dries, UV radiation cures – tests in our Application Centre help to define the necessary parameters.
Copyright Heraeus Noblelight, Hanau 2014
Heraeus Noblelight is showing application-focused UV lamps, infrared emitters and systems for coating curing at the PaintExpo exhibition in Karlsruhe in April. Examples of applications will show when and where a combination of UV and IR can be beneficial and what parameters must be observed.
Infrared transfers energy to materials without contact, generates heat where it is required and consequently is especially efficient in the drying of varnishes or the melting of powder coatings. In a UV curing process, polymerization, photo-initiators are activated by intensive UV light and cured in a fraction of a second.
As a result, the material is cured very quickly and the surface is dry, wear-resistant and can be subjected to further processes immediately. In some applications, the curing can be optimized and carried out more efficiently by a combination of infrared heat with UV radiation. These applications include high quality surface coatings and surfaces which must be scratch resistant.
Plastic surface are given a scratch-free coating, to impart a mirror finish. Fingerprint-resistance prevents smearing of the highly polished surfaced by fingerprints, hand cream or suntan lotions. Such coatings are often UV coatings, which need UV radiation to initiate the cross-linkage. This cross-linkage reaction occurs more efficiently at higher temperatures and can be further optimized by pre- or post-heating. For this reason, some plastic components such as radio fascias, gear sticks or lipstick casings are often pre-heated with infrared. This provides an improvement in the coating properties.Infrared Emitters Provide Very Efficient Curing of Coatings on Many Materials
IR heating is also ideal for web substrates such as paper, textiles and foils, where IR heat dries coatings within seconds. IR heat dries large three dimensional objects such as engine blocks or metal housings faster than some hot air systems, as metal is a very good conductor of heat and infrared emitters transfer large amounts of energy in a very short time.
UV Lamps Cure in Seconds in a Targeted Fashion
UV radiation allows UV paints, lacquers and adhesives to cure very quickly. In contrast to conventional coatings UV formulations contain little or no solvents. In a UV curing process, polymerization, photo-initiators are activated by intensive UV light. Chemical compounds are then broken down and then cross link to form new compounds. In fractions of a second, the cross-linked system is dry and abrasion-proof and is suitable for further processing.
Today, there are already light sources doped with Gallium or mercury. Their wavelengths determine the point of the curing: in the depth of the coating or on the surface. The optimum curing process is affected by different factors. The emission spectrum and intensity of the UV light source, the carrier material and ambient temperature, the nature and thickness of the material to be cured, the process speed, the distance between the material and the UV light source and, naturally, the chemical composition of the coating system must all be taken into consideration. UV light sources, precisely matched to the process, improve reliability as well as process speed, reduce the material loading and save both costs and energy.
When Should a Combination of Infrared Heat and UV Technology Be Considered?
Heat improves the mobility of molecules and so improves the curing reaction. Many processes introduce only a little heat into the coating materials, sometimes when the process runs very fast. This can be detrimental to the adhesion and stability of the coating.
UV curing is a chemical cross-linking process. By pre-heating the substrate with infrared radiation there is better adhesion and cross-linking of UV coatings. It has been shown to be beneficial to heat materials in a targeted fashion before the UV cross linking.
Infrared heat is also used to drive solvents from high gloss UV coating before curing. This is especially important with modern, water-based wet coatings. Here infrared heat is used to vaporize the water, so that the following UV radiation can cross-link the coating optimally.
A combination of IR and UV should then be considered when excellent quality is demanded or energy needs to be saved. By the innovative combination of infrared heat with UV technology the energy efficiency of the coating curing is improved on one hand and the cross-linking of UV coatings is optimized on the other hand.
The precious metals and technology group Heraeus headquartered in Hanau, Germany, is a global, family company with over 160 years of tradition. Our businesses include precious metals, materials and technologies, sensors, biomaterials and medical products, quartz glass, and specialty lighting sources. With product revenues of € 4.2 billion and precious metal trading revenues of € 16 billion in 2012, Heraeus has around 12,200 employees in more than 100 companies worldwide and holds a leading position in its global markets.
Heraeus Noblelight GmbH with its headquarters in Hanau and with subsidiaries in the USA, Great Britain, France, China and Australia, is one of the technology- and market-leaders in the production of specialist light sources. In 2012, Heraeus Noblelight had an annual turnover of 92.5 Million € and employed 715 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 measurement techniques.
Heraeus Noblelight acquired the Fusion UV Systems Group, headquartered in Gaithersburg, Maryland, USA, on 31 January 2013.
For further information, please contact:Technical: Heraeus Noblelight GmbH
Dr. Marie-Luise Bopp | Heraeus Noblelight GmbH
Energy-self-sufficient remote terminal unit permits wireless mobile plant monitoring
09.10.2015 | Siemens AG
Open cloud platform boosts digital service business for industrial customers
09.10.2015 | Siemens AG
Nondestructive material testing (NDT) is a fast and effective way to analyze the quality of a product during the manufacturing process. Because defective materials can lead to malfunctioning finished products, NDT is an essential quality assurance measure, especially in the manufacture of safety-critical components such as automotive B-pillars. NDT examines the quality without damaging the component or modifying the surface of the material. At this year's Blechexpo trade fair in Stuttgart, Fraunhofer IZFP will have an exhibit that demonstrates the nondestructive testing of high-strength automotive body parts using 3MA. The measurement results are available in a matter of seconds.
To minimize vehicle weight and fuel consumption while providing the highest level of crash safety, automotive bodies are reinforced with elements made from...
The MICADO camera, a first light instrument for the European Extremely Large Telescope (E-ELT), has entered a new phase in the project: by agreeing to a Memorandum of Understanding, the partners in Germany, France, the Netherlands, Austria, and Italy, have all confirmed their participation. Following this milestone, the project's transition into its preliminary design phase was approved at a kick-off meeting held in Vienna. Two weeks earlier, on September 18, the consortium and the European Southern Observatory (ESO), which is building the telescope, have signed the corresponding collaboration agreement.
As the first dedicated camera for the E-ELT, MICADO will equip the giant telescope with a capability for diffraction-limited imaging at near-infrared...
Self-driving cars will be on our streets in the foreseeable future. In Graz, research is currently dedicated to an innovative driver assistance system that takes over control if there is a danger of collision. It was nature that inspired Dr Manfred Hartbauer from the Institute of Zoology at the University of Graz: in dangerous traffic situations, migratory locusts react around ten times faster than humans. Working together with an interdisciplinary team, Hartbauer is investigating an affordable collision detector that is equipped with artificial locust eyes and can recognise potential crashes in time, during both day and night.
Inspired by insects
An interdisciplinary team of researchers has built the first prototype of a miniature particle accelerator that uses terahertz radiation instead of radio...
At present, tiny magnetic whirls – so called skyrmions – are discussed as promising candidates for bits in future robust and compact data storage devices. At...
01.10.2015 | Event News
30.09.2015 | Event News
17.09.2015 | Event News
09.10.2015 | Earth Sciences
09.10.2015 | Life Sciences
09.10.2015 | Life Sciences