Applications

A wide range of applications can take advantage of the many benefits that UV LEDs bring. From spot curing to small- and large-area curing requirements in medical, electronic, industrial, automotive, and optical fiber manufacturing, UV LED solutions can offer greater flexibility than lamp-based curing solutions.

The gaps that previously existed between traditional lamp solutions and UV LED-based curing systems have certainly been narrowed. Whether it is performance, cost, or availability of formulations that are compatible with UV LEDs, the technology has unquestionably made considerable advances to allow U LED curing solutions for adhesives to become commercially viable.

Healthcare

UV curing has gained a reputation for guaranteeing high speed, consistent and reliable manufacturing, which makes it the ideal process for producing medical devices. In recent years, the materials used for these devices have demanded processes that do not create thermal stress in the articles (primarily due to the advent of disposable products). UV curing is also known as “cold” processing, as it does not reach temperatures which could degrade plastics. Great importance has also been attributed to the development of products to be cross-linked with this technology, such as PSAs (Pressure Sensitive Adhesives) on transdermal treatments and UV adhesives for medical products such as syringes, draining tubes, dialysis and endoscopy machines, filters, angioplasty accessories and hearing aids. Functional UV coatings are employed for products such as catheters, flow regulators, transdermal treatment systems and blood test strips. These coatings result in enhanced

biocompatibility, faster sterilisation processes and considerable increases in chemical and mechanical resistance. Finally, when used to print or decorate small items such as syringes or catheters the application of UV inks creates an extremely durable and resistant print.

Photovoltaics

Besides wind and geothermal energy, photovoltaic power is considered to be one of the most promising sources of renewable energy.  Photovoltaic devices work according to the capacities of specially-treated semiconductors, which convert solar energy into continuous-current electricity.  Research in this field has made significant progress and is focused on increasing the energy efficiency of photovoltaic devices while reducing production and maintenance costs.

The UV curing process is employed for various aspects of solar panel production.  This has resulted in production line improvements by reducing production cost, as mentioned, while maintaining the high quality and performance of the finished product. A notable example is the printing of circuits with UV-curable conductive inks.  These inks can be printed onto the energy-absorbing sheet of the photovoltaic cell in a roll-to-roll format, creating a very efficient UV process.

Automotive

The automotive industry has quickly recognised the significant added value of UV technology due to its particularly low environmental impact, improved quality of the finished product and high productivity. Thanks to superior chemical and mechanical properties such as wear, abrasion and corrosion, functional UV coatings are now commonly used in the automotive industry, on both interior and exterior components of cars and motorcycles. UV curable coatings and adhesives are used for plastic hub caps, BMC reflectors and polycarbonate lenses for headlights, interior and exterior trims and mouldings, brake disks, bearings, rotors and other mechanical components. In all of these applications, UV technology uses chemistries with low or no VOCs and the process is faster compared to conventional

thermal drying techniques. Another recent and innovative application is vacuum or physical vapour deposition (PVD) technology, which is used to transfer thin layers of metal (i.e. chrome and aluminium).  This coating technology, used in combination with UV primers and top coats, has significantly improved productivity and the chemical/mechanical performance of the finished products.  But most importantly, the environmental impact has been drastically reduced by producing plastic

automotive components with this technology.  In the past, metal finishes were obtained using the old, highly polluting process of chrome electro-plating, which requires baths of hex or trivalent chrome. The use of UV technology in this manner has improved the performance of the finished products, expanded the areas of application to all types of plastic materials, and most importantly has eliminated the release of toxic substances into the environment.

Packaging

UV curing technology and the development of related products reached a level of excellence never before achieved in the printing and packaging industry. UV decorations on metal and plastic food or cosmetics containers, polyurethane containers, glass bottles, tins and polystyrene containers are now renowned for their high definition and high level of chemical/mechanical resistance. UV technology is especially beneficial when used for the decoration of plastic containers made from thermo-sensitive polymers such as PVC, PET and PC, in which the absence of excess heat due to the speed of the UV cross-linking process prevents damage to the polymers.

One of the most impressive aspects in the field of UV decoration and printing is the rapid drying time combined with the excellent mechanical and chemical durability of the UV curable inks. These inks have significantly contributed to the development of multicolour, in-line printing presses which apply multiple colours directly onto the product, thereby reducing process times and costs while providing a flawless result. Last but not least, overprint varnishes (OPV) are UV coatings applied on printed paper or film to improve the gloss of the printed substrate and protect it against scratching or discolouring

Consumer electronics

The growth of the mobile phone market, not only in terms of numbers but also product performance, has found a natural response to UV technology. UV coatings can be both decorative and functional and are now used worldwide on the external casings and displays of mobile phones. Special UV coatings are applied in order to create the most sophisticated touch screen displays on mobile phones and computers, giving better protection against scratches, abrasion, staining and fingerprints. These coatings can also improve anti-glare performance, prevent eye fatigue and ensure good image quality. Elsewhere in the electronics industry, UV curing is used in the assembly of micro-components and can offer processes with improved precision and speed. UV curing is also used to protect small electronic components in mobile phones. This type of coating, known as conformal coatings takes a few seconds to cure and is carried out directly on the assembly line. It not only improves the end product but also significantly reduces production space requirements and production time.The growth of the mobile phone market, not only in terms of numbers but also product performance, has found a natural response to UV technology. UV coatings can be both decorative and functional and are now used worldwide on the external

casings and displays of mobile phones. Special UV coatings are applied in order to create the most sophisticated touch screen displays on mobile phones and computers, giving better protection against scratches, abrasion, staining and fingerprints. These coatings can also improve anti-glare performance, prevent eye fatigue and ensure good image quality. Elsewhere in the electronics industry, UV curing is used in the assembly of micro-components and can offer processes with improved precision and speed. UV curing is also used to protect small electronic components in mobile phones. This type of coating, known as conformal coatings takes a few seconds to cure and is carried out directly on the assembly line. It not only improves the end product but also significantly reduces production space requirements and

production time.

Furnishing

UV technology has been used to decorate and protect wooden components since the early 1980s. The growth of this market has resulted in the development of a series of innovative coating products suitable for cross-linking with UV radiation. The new products are either 100% solid (no VOCs) or water-based, and together with the undisputed benefits of this technology, they have helped to significantly reduce environmental emissions. UV coatings for wood – transparent, opaque or glossy – can be used to give a highly protective and aesthetic finish to wooden flooring, doors, furniture and frames. In recent years the introduction of vacuum or physical vapour deposition (PVD) technology, in combination with UV primers and top coats, has enabled the development of new types of chrome-like decoration processes. These innovative chrome and gold-plating effects are particularly interesting for shower cabin aluminium frames, bathroom plastic and metal components, taps and fittings. The UV/PVD chroming technology enables the production of 100% recyclable products with improved technical characteristics, and the products are easier to clean and more resistant to moisture, corrosion and aggressive modern detergents. As for other applications (such as the automotive and consumer electronics sectors), the UV/PVD process releases no harmful substances into the environment or the workplace. This results in a sustainable and greener process than the baths of hex or trivalent chromium used in the conventional, but highly-polluting chrome plating process.

Optical Fibres

Optical fibres are extremely fine threads of flexible, transparent glass with a circular cross section.  While optical fibre is employed in a number of industries, its main use is for telecommunication cables.  It consists of an inner “core” and an outer “cladding”, both essentially composed of silica (SiO2) which is the main constituent of everyday glass. UV technology is an essential component in the ultra-high speed production of optical fibres.  Since the fibre is so thin (125μm diameter), it requires an external polymer coating before it can be processed.  The coating makes the fiber flexible, resistant to mechanical stress, and enables

it to be properly inked and cabled. UV technology has made another fundamental contribution to his field:  The use of colour-coded UV inks to mark and identify the finished optical fibre.  Since the UV-cured inks are resistant to chemical attack, they are not degraded by the cabling gels used during the production of optical

fibre cables.