
by Melissa Donovan
UV curing is a pivotal part of the direct to print process and advancements like the introduction of LED only make the technology more attractive. Lamp or arc curing continues to be used as it fills some of the gaps that LED has yet to bridge.
Above: Hönle LED Powerline Focus on a sheetfed printing machine.
Bob Waddington, product line leader – curing and drying, BW Converting, foresees LED systems capturing a larger market share as their capabilities improve, but “arc systems will likely remain indispensable for specialized, high-precision needs.”
The two technologies—lamp and LED—are complementary. “The coexistence of arc lamp and LED systems ensures that manufacturers have the flexibility to choose the most appropriate technology for their processes, reinforcing the continued demand and relevance of UV arc lamp systems alongside the growing adoption of LEDs,” believes Eugene Mikhaylichenko, director of sales and marketing, Uvitron International.
Recognizing the need for both UV lamp and LED curing, some vendors’ lamp-based systems are designed to make changeover to LED uncomplicated. These allow users to slide out one lamp type and insert another without major modifications. Hybrid systems, which are a mix of UV lamps and LED lights, installed on one piece of equipment, are also becoming popular.
Working Side by Side
While UV LED technology is advancing, it isn’t taking the place of UV lamps.
Each type offers distinct advantages and limitations, states Volker Selg, director sales (business unit curing), Hönle. “Their coexistence stems from complementary strengths, catering to varied industrial needs.”
Selg notes advantages of UV LED technology as energy efficiency, instant on/off functionality, lower operating temperatures, and a longer lifespan. UV lamps feature a broader wavelength range, higher peak intensity for certain applications, and a greater flexibility in curing specific materials.
There is a critical need for UV lamps, or more specifically mercury arc systems, according to Waddington. “This is especially true in applications requiring UVB and UVC wavelengths, such as sterilization. Current LED diodes lack the irradiance, and in some cases the wavelengths needed for these tasks, and predictions suggest it could take another four to six years for this technology to mature in those ranges.”
UV LED technology has made significant strides but is currently limited in terms of wavelength output, particularly below 365nm in industrial applications. “High-power LED systems that can compete with traditional UV lamps are still under development. For applications requiring full surface coverage or required anti-scratch properties, traditional UV lamps remain essential,” notes Mark VandenBosch, technical sales, IST America.
UV lamp systems provide advantages in packaging and low-migration printing. “For instance, certain photoinitiators required for low-migration applications are not yet available for LEDs. Moreover, arc systems allow for more affordable and versatile coatings, which remain critical in regions with stringent regulations, like Europe. In these cases, arc systems often serve as the go-to solution for coatings, while LEDs are more commonly used for inks,” shares Waddington.
“Many varnishes, coatings, and special colors still require conventional UV curing, but for mainstream inks UV LED is very much a viable alternative. Bearing in mind the many production advantages of working with UV LED, added to the significant energy cost savings it brings, the adoption of LED is rising rapidly,” admits Duncan Smith, marketing manager, GEW (EC) Limited.
While UV lamps offer a broader wavelength range, UV LED emits light at narrow, very specific wavelengths. This is why energy efficiency is so high, the targeted wavelengths enable precise energy delivery. “The use of UV LEDs is advantageous for applications where thermal management is crucial, such as curing heat-sensitive substrates or optimizing energy consumption in environmentally conscious production processes. Additionally, the longer operational life and instant on/off capability of LEDs contributes to reduced maintenance and energy costs,” explains Mikhaylichenko.
Despite the advancements and growing adoption of UV LED systems, Mikhaylichenko believes the market for arc lamp systems isn’t wavering. “Arc lamp technology continues to be critical for applications requiring broad-spectrum UV output, which is essential for curing complex materials and a wider range of photoinitiators. The coexistence of these technologies allows manufacturers to tailor their curing processes precisely.”
Switch to LED
UV lamp systems are designed to easily accept LED lights. Users can slide out one lamp type and insert another without major modifications.
According to Selg, the transition from lamp to LED is possible due to modular frameworks. “These frameworks include replaceable lamp housings, drivers, and power supplies that accommodate future upgrades to LED technology without requiring a complete system overhaul. This future proofing approach is increasingly popular in industrial printing.”
For example, GEW’s patented interchangeable ArcLED technology enables the use of a conventional UV arc lamp or LED array on the same print unit, by changing the cassette. “Both arc and LED cassettes are compatible with GEW’s RHINO power supply unit (PSU) and fit in the same housing, to enable fast and easy changeover. The only tool required to change a cassette is a hex key. The RHINO PSU enables any combination of curing technologies to be used, by instantly and automatically switching the supply to either DC power for LEDs or high-voltage AC power for arc lamps. The entire process is operator controlled,” explains Smith.
IST’s UV lamp systems are designed for easy upgrades to LED technology in preselected positions. “This allows users to transition to LEDs seamlessly when production requirements or preferences evolve,” notes VandenBosch.
Besides a modular system, there is another option—a fully integrated product range, as offered by Uvitron. “Our systems are purpose engineered with key components, including high-voltage power supplies, lamp housings, and precision control electronics, seamlessly built into a unified unit. By optimizing every component specifically for either arc lamp or LED technology, we eliminate the compromises often associated with modular setups. Our systems are engineered to deliver precise, consistent curing results, maintaining optimal UV intensity, spectral distribution, and thermal stability across all applications,” explains Mikhaylichenko.
Waddington notes that while the changeout can be simplified, the technologies are fundamentally different. “Arc lamps operate using electrodes and a quartz tube filled with argon and mercury, while LEDs use semiconductor diodes to emit light. As a result, while the physical installation can be simplified, the lamp heads and other critical components must still be fully replaced.”
Meredith Stines, president, American Ultraviolet, also points to the power supplies and cooling as differing between lamp and LED systems.
Hybrid Approach
Hybrid UV curing systems—which allow both lamp and LED technologies to be used interchangeably—do exist.
Hybrid configurations share common components like power supplies, connectors, and mounts, says Waddington, and then the lamp heads are interchangeable. “This hybrid approach allows users to transition between the two technologies as needed without requiring an entirely new system. There are nuances to this hybrid setup and we suggest potential customers speak with us to iron out the details on optimal setup of the system,” he cautions.
The ability to switch between technologies provides greater flexibility and cost efficiency. “For example, certain hybrid systems include dual-slot configurations for easy integration of either lamps or UV LEDs,” shares Selg.
Smith notes that some GEW ArcLED users choose not to remove all the arc cassettes when upgrading to LED, which provides them with the flexibility to continue working with lamp systems to cure varnishes, coatings, and special colors.
Hybrid systems, such as the IST MBSc and its compact variant MBScx, support interchangeability with Modulux LED systems. These systems provide flexibility for production setups that demand a combination of traditional UV and LED technologies, according to VandenBosch.
A Practical Bridge
Hot-swappable systems allow users to alternate between UV lamps and LED without downtime.
Interchangeable solutions are a way to “future proof” a machine, says Smith. “Interchangeable lamp cassettes mean that a user can future-proof their machine—even if they have an all-arc UV system now, it can easily be upgraded to LED in the future. Similarly, the user can change back from LED to arc UV on any or all print/coating stations, according to whatever is best for the job in hand.”
“In industrial printing, these systems are currently preferable because they indeed do offer adaptability to different materials like inks and curing needs. Additionally, they reduce long-term operational costs by integrating LEDs for energy-intensive jobs and retaining lamps for specialized tasks,” explains Selg.
While hot-swappable systems are available, VandenBosch believes “their adoption depends largely on the industry’s job structure. LED curing is gaining traction in applications with high-value, low-coverage inks, while end-of-press varnish curing typically relies on traditional plasma lamps. Furthermore, evolving regulatory requirements—such as those addressing migration and odor—necessitate high-energy curing solutions. Ultimately, the decision will hinge on the development of ink systems that are compatible with these technologies.”
Hönle believes swappable solutions only “bridge technology until the full range of suitable LED curable materials are available,” admits Selg.
“Once LEDs can fully cover the UVB and UVC ranges, they are expected to replace arc systems across application requirements. Until then, hot swappable systems offer flexibility for printers and converters who want to utilize both technologies,” agrees Waddington.
Conversely, Mikhaylichenko isn’t seeing a lot of demand for hot-swappable systems at this time, as Uvitron customers have a clear preference for either UV arc lamp or LED technology based on their specific curing requirements. “Most of our clients are focused on optimizing their processes with the technology that best fits their materials and production environments, rather than seeking interchangeability between the two.”
Symbiosis
At this time, the coexistence of UV lamp and LED technologies is necessary. UV LED isn’t yet tailored to meet all the needs that UV arc lamp technologies can, so they must work together to achieve this.
“Hybrid approaches enable flexible manufacturing setups where both arc lamp and LED systems can be integrated based on the requirements of specific applications. This symbiosis provides industries with the ability to balance energy efficiency, curing speed, and material compatibility, ensuring optimal performance across diverse curing environments,” states Mikhaylichenko.
Keeping this in mind, it goes without saying that UV LED and lamp technologies’ coexistence is highly advantageous. Visit industrialprintmagazine.com in February to learn more about UV LED and arc lamp curing technologies in our latest webinar. IPM
Feb2025, Industrial Print Magazine