UV LED offers significant advantages over traditional UV curing for direct printing applications, including smaller and lighter lamps, less maintenance and downtime, which translates into higher productivity rates, better adhesion on pigmented products, less scrap and higher quality end products at lower costs. The use of traditional UV lamps to cure inks on heat-sensitive substrates, such as plastic cosmetic objects, can result in deformation. UV LEDs allow high adhesion on covering inks, enabling strong colors on the more difficult substrates. Due to narrow, high UV-A wavelength, UV LEDs produce significantly less heat. The UV-A wavelength also allows for a more penetrative cure, which is an advantage when faced with thicker sections.

• Direct Printing Applications

• Screen printing on cosmetic plastic bottles and caps

• Screen printing on glass

• Screen printing on closures

• Screen printing on metal bottles

• Screen printing on sky sticks

Screen Printing on Bottles

Advantages of LED Compared to Mercury UV

• High UV-A wavelength will reduce heat-related damage to materials and substrates

• High UV-A is excellent for curing thick sections – allow high pigmented white Controllable power output

• Strong reduction of consumption

• Instant adhesion

• Instant on/off

• No UVC scattering light, protecting operators

• No ozone production

Mercury lamps run very hot, which can cause heat-sensitive printed materials to warp and wrinkle. Plus, mercury UV curing systems generate ozone that must be vented away from the work area. Using LEDs to cure UV inks doesn’t generate ozone – nor does it transfer a lot of heat to the printed surface.

UV LED lamps are solid-state semiconductor devices. They produce light by generating a voltage to join positive holes with negative electrons, emitting energy in the form of photons. The light is focused within a narrow spectrum of ultraviolet wavelengths. Phoseon LED curing units produce light only within the UV-A range, with wavelengths of 365 nm, 385 nm, 395 nm, or 405 nm.

Unlike mercury lamps that need time to warm up and typically run all day, LEDs provide energy instantly and can be switched on and off as needed. Print shop employees can turn off the LEDs every time they take a 15-minute break; some units are configured so the LEDs turn off between prints, providing further efficiency. LED curing units are expected to operate for more than 20,000 hours compared to less than 2000 hours for a mercury arc lamp.

UV LED curing systems are offered either in air-cooled or water-cooled packages to ensure that the LEDs operate at a consistent junction temperature (the highest operating temperature of the semiconductor) during production and withstand harsh production environments.

UV LED Inks

For UV LED curing to be successful, you need inks that are formulated to cure within the high UV-A wavelengths produced by the LED lamp. UV LED screen inks include photoinitiators that absorb the specified UV-A wavelengths needed to ensure a full cure at the desired speed.

Today, companies offer UV LED inks for specific applications, including bottle decorating, container printing, durable decals, membrane switches, and indoor and outdoor point-of-purchase graphics. Some UV LED screen inks are “dual-cure” formulations that also work with traditional mercury vapor curing systems.

Each new ink formulation must provide the desired curing performance at the speed of production and must also meet the adhesion and durability requirements of specific applications.

Are LEDs sustainable?

• No mercury! Mercury ban in manufacturing processes is growing globally.

• No greenhouse gases or ozone produced or needed to be evacuated from facility.

• Significantly reduced energy usage versus mercury UV and high-energy IR dryers.

Energy Savings

With traditional UV curing processes, the tremendous heat associated with mercury UV lamps required a significant amount of electricity to operate. By replacing the mercury UV LED lamps, with UV LED curing systems, Phoseon customers have experienced energy savings of up to 85 percent. Phoseon UV LED technologies provide energy savings of between 75 and 85 percent compared to prior drying systems. With the Phoseon lamps, there is no need for fume extraction units to remove the gases generated by mercury-vapor UV lamps.

Pollution Prevention

UV LED lamps offer better than 50 percent lower CO₂ emissions. UV LED lamps generate no ozone and offer the promise of eliminating toxic mercury in an entire category of industrial processes. With UV LED lamps, there is no need for fume extraction units to remove the harmful gases and Ozone generated by mercury-vapor UV lamps. With LED systems, converters can diversify their product lines and enter new markets without having to expand their floor space or expose employees to Volatile organic compounds (VOCs) harmful UV-C ozone. By removing its mercury stations and upgrading them with 13 Phoseon FireJet™ LED lamps (FJ200), Indeco can reduce over 67 Tons of CO₂ annually. They also do not need to reintegrate into the building the 23.5 Million cubic meters of air extracted every year to remove ozone and the heat produced by the mercury lamps.

Waste Reduction

Conventional mercury lamps have a very short lifetime and need to be replaced every 1000-1500 hours. LED curing lamps extend beyond 60,000 hours if maintained properly. Upgrading to UV LED technology eliminates these replacement costs, offering significant environmental benefits with the elimination of mercury. Phoseon is the only company in the industry which can say that we have a proven lifetime of more than 60,000 hours. 60,000 hours means, in UV LED terms, that we count only the ON time as turning lamps on and off is instant.

Operating expenses for a press with typical mercury vapor curing units, which generate plenty of heat, cost around $34,000 a year (and the mercury bulbs used eventually end up in a landfill). However, the cost for the same press installed with UV LED curing units adds up to an energy efficient $658 per year. Empire Screen Printing – USA

LED is the Only Sustainable Choice for UV Curing

Today, all the major brands are requiring their suppliers to deliver more sustainable printing practices. The environmental benefits of UV LED curing in the printing process are numerous and significant. Phoseon customers have experienced energy savings up to 85 percent with the implementation of UV LED curing systems. With traditional UV curing processes, the tremendous heat associated with mercury UV lamps required a lot of electricity to operate. The mercury lamps produce ozone, which is dangerous to breathe, especially in a constricted space like a print shop. Air exhaust systems are required to extract the toxic fumes from the presses. These exhaust systems can be eliminated with UV LED curing, making it a far more environmentally friendly process. Phoseon is the best choice with the most reliable products available and is the only company that focuses specifically on LED technology.

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