GEW UV systems: 25 years and beyond

What does an industry-leading manufacturing company do when it turns a quarter of a century old? Over 25 years of GEW, there have certainly been plenty of successes to acknowledge: market-leading UV technology, innovative designs, technological breakthroughs (and a few moments of hardships to overcome).

But the story so far not only tells us what has been achieved, it is also a hint at the direction in which the company will travel in the years to come.

Malcolm Rae, managing director at GEW, is assertive: “As a specialist UV systems manufacturer GEW is and has been actively engaged in researching the potential of UV LEDs for many years, but is also committed to further innovate mercury arc lamp technology for label printing, coating and industrial applications.”

In 25 years of GEW, the company has developed several pioneering technology advances with the aim of providing printers, coaters and converters with the most advanced UV curing technology in the industry.

Energy management

Energy management is a prime consideration in the design of GEW UV systems. As every component in any system generates a loss, the cumulative effect of several weak links in the chain can considerably lower the efficiency of an entire system. In UV lamps a considerable amount of heat is generated as a side-effect of UV production when converting electrical power to UV light.

Excess heat generated by the system can be reduced by correct geometry and careful material design. Inadequate heat management and poor reflector configuration can add more losses by preventing the optimum output. GEW’s reflector designs use dichroic reflector surfaces and GEW lampheads with their patented airflow and perfect cooling of the glass reflectors from behind have the most advanced cooled reflector on the market.

Further significant improvements can be achieved by reducing secondary sources of losses such as during burn-in or in stand-by mode.

Optimising existing resources and available technology are the keys to successful reduction of profit-gnawing wasted energy, time and materials while at the same time improving performance and production capacity. Eliminating wasted time will increase machine time availability and can reduce unit costs.

To this purpose the reduced start-up times of high efficiency arc lamp systems and the instant switch on and off capability of LED systems can drastically grow actual machine production time.

Remote preventive maintenance

GEW’s cassette-based lamp design minimises stoppage time by streamlining lamp changes. Indeed releasing a single Allen head bolt allows the lamp chassis to be removed from the casing and be replaced quickly and easily. Plug connectors ensure error-free, uncomplicated lamp changes and minimal press downtime.

Unplanned maintenance leading to machine downtime due to component failure can to a large extent be eliminated by making full use of GEW’s Embedded Service technology. RHINO powered UV systems are supplied, as standard, with the Embedded Service package which allows remote monitoring of the system running conditions over the internet, allowing the manufacturer’s service engineers to detect and correct out of tolerance parameters before they can develop into a fault. This type of remote preventive maintenance ensures the entire UV system operates at peak performance at all times thus avoiding inefficiencies, productivity drops and unplanned machine stoppages.

As a result GEW are now able offer all RHINO systems with a comprehensive 5-year warranty which gives users total peace of mind about their investment well into the critical payback period of their project.

Hybrid systems

In recent years the use of LEDs in UV curing systems has become more and more common. Reduced heat radiation, instant on-and-off switching and the absence of moving parts are some of the apparent advantages of LED UV systems; however these obvious benefits have to be offset against the higher initial cost and the particularities of this technology that so far prevent more widespread use of LEDs.

However, the implications of the transition towards UV curing inks and varnishes in a press fully equipped with LEDs are often technically and financially not fully understood to make such an investment. GEW have addressed the needs and concerns of printers by developing the first fully flexible and truly futureproof hybrid UV curing system.

And this ArcLED technology represents one of the standout developments in the past 25 years of GEW.

GEW’s ArcLED hybrid systems with RHINO power supply are compatible with both conventional mercury arc lamps and LEDs and thus allow for convenient switching from one technology to the other while leaving the operator the option to upgrade at any later stage without having to modify the power supply, controls or the interconnecting cables. The GEW hybrid system recognises which type of cassette is installed in the press and the RHINO ArcLED power supply automatically adjusts to operate LEDs or an arc lamp.

LED UV curing in the balance

LEDs are substantially more efficient than older UV systems but the differences compared to modern arc lamp systems in operation have to be closely looked at. The real energy advantage for LEDs is that they switch on and off instantly, not requiring the warm up and standby cycles of arc lamps. This reduces the non-production energy consumption significantly and can make LEDs an attractive energy saving alternative in environments with short production runs and high standby cycles.

The second important consideration is lifetime cost efficiency. Reliability and HALT (Highly accelerated life test) testing of LED arrays carried out in the GEW development lab have conclusively indicated a potential service length of over 20,000 hours even in adverse conditions, about seven to ten times longer than that of an arc lamp with 2 to 3,000 hours.

With similar power usage and efficiency, the unwanted heat produced by LEDs is also similar to an arc lamp. However, with LEDs most of this heat is absorbed by the heat sinks behind the light source, and in general only UV radiates down towards the substrate. With an arc lamp, both UV and heat are radiated in all directions and special reflectors are required to return the UV to the substrate and absorb as much of the heat as possible.

LEDs produce a narrow band of high intensity long wave UV, compared to the broad spectral output of arc lamps. This can penetrate thicker, heavily pigmented inks much better than UV from arc lamps, and helps support higher running speeds in what have traditionally been difficult applications. Some special low migration ink formulations also demonstrated faster running speeds when cured with UV LEDs.

In addition, the lack of short wave radiation means there is no ozone production, removing the need for extraction and saving significant air extraction costs. LEDs are solid state components and thus a highly accurate and infinitely controllable UV source. Converters can more reliably tune the power of the array to their requirements and control the UV output and product quality of their process more accurately than ever before.

In an industry where flexibility and speed are valued increasingly by the end customer, LEDs are a solution today for the cutting edge and specialist applications and are a future solution for all applications when efficiency, power and cost become competitive against existing arc technology.

The costs of LED inks and curing systems are likely to come down and the performance of both will increase further. Today LEDs are a more expensive alternative but if current trends continue, they will become an attractive proposition in the future. Considering that label converters will not want to duplicate their ink stocks with special LED-compatible formulations and have to master a new production process, demand for energy-efficient arc lamp systems will continue to grow.

Malcolm Rae explains: “At GEW we believe that the simplest solutions are the best. LEDs are the most straightforward and most effective solution for some printing applications, particularly for inkjet printing. We are committed to working with ink manufacturers to explore and develop the opportunities for LED curing in all sectors of the industry, but we remain equally committed to building on the strengths of proven, viable technology. GEW offers its customers experienced and objective advice on whether LEDs or arc lamps are best suited to their production scenario.

25 years of GEW

And Rae concludes: “Everyone at GEW has worked hard to ensure that its first 25 years in business have been successful and prosperous. Trying to delve into the future of UV curing technology is bound to be a challenge. GEW has the skills and the resources to meet that challenge.

Whilst 2016 saw the anniversary of 25 years of GEW, 2021 saw GEW pass its 30-year anniversary. You can find out more about this latest anniversary here.