Updated: Jul 31, 2019
I’ve always loved the fact that in UV curing no one ever really knows it all. The technology is very humbling, and no single person and no single company dominates everything. Success comes from collaborating throughout the supply chain in pursuit of suitable solutions for each application. It has always been a team effort, and the collaboration, necessary development, and newness of each application can be very exciting for those involved.
The practical uses for UV curing as well as the means of integration are as numerous as they are diverse. Applications span analog and digital inkjet printing, industrial and graphic coatings, and laminating and structural bonding adhesives. Some uses are purely decorative while others require functional properties. Both are employed in different ways throughout various stages of manufacturing to produce everyday disposable as well as durable consumer goods, light and heavy-duty industrial items, much of the product labels and rigid and flexible packaging in which goods are supplied, and commercial print. Using the correct UV curing system with proper integration and formulation for each application is critical as there is no one-size-fits-all UV solution.
The nature and shape of the surface to be cured, the formulation, the manufacturing process, and the material handling method collectively determine how close the UV system can be located and dictate how much UV energy must be delivered. Some UV curing systems are designed to be mounted within a ½” (13 mm) of flat substrates while others are capable of delivering sufficient output from several inches away (75 to 100 mm or more) onto parts or assemblies with shapely profiles. For some applications, photopolymerization is designed to occur slowly at low irradiance, taking many seconds or even a minute to reach full cure. For others, it is instant and requires both a higher irradiance and greater energy density to cure in tiny fractions of a second. Fully integrated systems often include power and controls, cabling, chillers and plumbing, lamp head brackets, shutters, shielding, exhaust, turn-key automation, nitrogen inertion, reflectors and/or optics, and material handling. Installations can be static or dynamic as well as benchtop and hand-held.
The many applications, formulations, and manufacturing line constraints across all the different markets drive a wide range of UV curing system designs. This includes lamp head lengths that are available in millimeters and inches as well as meters and feet and a diverse set of bulb types, wavelengths, peak irradiance settings, and energy density all of which must be delivered in the optimal combination needed to achieve full cure at the required maximum line speed. Conditions of installation range from climate-controlled, clean-room facilities on one end to those that tax UV system performance on the other such as filthy, high-temperature, high-humidity, industrial plants. With respect to heat transfer and airflow into or out of the UV system, it can be beneficial, a non-factor, or a detriment to the substrate, parts, equipment, and operator environment. As a result, conventional UV systems have been engineered over the years to be positively and negatively air-cooled, liquid-cooled, and liquid-filtered as needed.
Due to the need for complete solutions that deliver UV output in a wide range of configurations, UV system suppliers (arc and microwave) have historically focused on one, two, or three key applications or market segments. This does not mean companies do not sell outside their chosen markets because they do. It means that companies have achieved greater success and market penetration when they have focused development and engagement on a few key areas at a time. Doing so allows them to be more in-tune with the needs of the targeted customer base and ultimately design UV product offerings, ancillary system components, and total solutions to best meet those specific application needs. The more closely system suppliers have followed this strategy in the past, the stronger their competitive advantage became and the greater the barriers to entry for the competitors. The result was a smaller number of UV system suppliers that ultimately existed in any particular market segment.
Generally speaking, out of the dozens of UV system manufactures across all the various market categories, typically there are no more than three key suppliers that dominate each major segment. In some cases, these are global players, and in others, they are regional players. As newer UV system suppliers become more knowledgeable of market dynamics, they too come to the realization that they must have stronger relationships with co-suppliers and customers, be more engaged in the application development process, and supply an increasingly more complete package to win business. Those who don’t find their foray into the world of UV curing short lived or limited in growth potential.
Since the UV curing source is just one tool of many in a given manufacturing process, the ability to design, deploy, and integrate the tool properly is what separates true industry leaders from the rest of the pack. In time, the basic mechanics of each device, whether it be mercury arc lamps, microwave lamps, or UV LEDs, is somewhat streamlined across suppliers. What ultimately separates companies over the long term is their ability to tailor the curing source in form factor, UV output, and electrical and operator interface to the specific needs of each application, formulation, and market segment and help short-cut each client’s own development timeline and improve installation success. Without the supportive application knowledge, system suppliers always find it difficult to penetrate new markets, increasingly grow and protect market share in current markets, and transform markets not presently using UV technology.
When UV LED curing systems commercialized in the mid-2000s, they weren’t capable of much. They were clever for sure, but none of the necessary industry collaboration had taken place to make them a viable curing tool. Existing UV formulations originally developed for mercury lamps needed modified, and new LED formulations needed to be created. Integration had to be considered and then coordinated. The co-suppliers, machine builders, and end-user markets all required education, and the UV LED systems had to evolve in design to supply the correct UV output in the necessary form factor for the various applications and material handling methods. Most important, in order to justify switching, the new LED alternatives had to provide cure performance and benefits that made using them preferable to the conventional mercury lamp technology.
At the time, no one understood what UV LED output was required for each application or how much formulation modification was necessary. When the supply chain was asked what the UV LED systems should emit, they always described the output of a mercury lamp. Making a UV LED system perform like a mercury lamp fails to leverage the true potential of UV LED curing technology. As a result, without a clear map in hand, most suppliers entered a race to provide the highest irradiance and most reliable UV LED systems with little regard to what each distinct market segment truly required.
Since the earliest appearance of UV LED curing systems, the loose order of application feasibility has been spot cure and bonding adhesives followed by pinning and then full cure for digital inkjet sign printers and product decoration, screen and pad printing, sealants, digital inkjet label printers (pinning and/or full cure), sheetfed offset, fiber optics, wood fillers, narrow web flexo, 3D printing, wood top coats, mid and wide web converting, and large scale commercial digital inkjet. Today, UV digital inkjet for wide format sign and specialty product decoration has achieved about a 90% conversion from conventional UV curing to LED followed by spot cure adhesives at more than 50%. Doing so has taken 10 to 15 years of education, testing, and market penetration. Most other applications are still predominantly using conventional mercury lamps but with a growing rate of interest, adoption, and development activity in LED technology.
As with any new offering, the immediate revenue opportunities in the early days of UV LED were limited. As a result, companies battled for market share in a few high potential segments and collectively pursued a disproportionately large number of unrelated and undeveloped applications elsewhere regardless of whether they had viable UV LED solutions. Other than spot cure adhesives and UV digital inkjet, no one really knew which markets were going to gain the greatest traction with UV LED or which markets or companies were going to invest in the most development. There were also many naysayers, particularly in high line speed and industrial coatings applications, who felt UV LED would never be viable. Over time, skeptics have started shifting their beliefs as UV LED increasingly proves itself a credible alternative despite still needing further development in many segments.
As the years have progressed, the low hanging fruit of UV digital inkjet wide format printing has become saturated with UV LED system suppliers. This was due to a business strategy promoting off-the-shelf UV LED lamp heads with minimal application support and system integration from lamp suppliers. This shifted the purchasing power to the OEM machine builders who took ownership of the application development. When UV suppliers allowed OEMs to treat the UV LED lamp head as just one component in their BOM and drove them to engineer the power, controls, and integration themselves, it made it easy for the OEMs to switch suppliers of LED lamp heads in pursuit of lower cost options once the ink formulations were sufficiently optimized. This approach also lowered the barriers to entry for new competitors who also only needed to supply the lamp head. As a result, UV LED systems in the digital inkjet wide format sign market have quickly become commoditized. Meanwhile, other markets such as industrial converting where OEMs and end users have no interest in taking ownership of building the total solution or driving development of the formulations and integration have been content to continue using conventional mercury UV systems with little incentive to drive UV LED application development on their own.
UV LED system suppliers are quickly realizing that it is not in their best interest to pursue all UV LED curing markets simultaneously. The ever-growing portfolio of products becomes difficult to support, and products are often forced into markets where they are not an ideal fit in terms of output, form factor, and integration. The pursuit of everything may have made sense in the early days of UV LED, but it no longer does. Pursuing everything inhibits one’s ability to provide the necessary engagement and development activity for each distinct market segment and requires a very large engineering team, sales team, and business development team to support the required activity level. As a result, UV LED system suppliers across the global curing industry are increasingly zeroing in on areas where they can be most impactful and build long-term business strategies. They are starting to focus their sales, engineering, and development teams on a fewer number of markets and operating with leaner support staffs and a deeper knowledge of and engagement with the markets they are serving.
UV LED was always going to follow a similar market strategy as conventional electrode arc and microwave curing with roughly three key suppliers in each market segment. This recent strategy shift of UV LED curing system suppliers is good news for graphic and industrial curing as it should drive new applications across industries as suppliers will have a greater interest in developing the markets they target and not just trying to sell the products they have engineered. The more capable companies will also supply their targeted markets with the total solutions that customers actually require. This will reduce the inclination of OEMs and end users to treat the technology as a commodity purchased on price alone and instead place greater value in collaborative partnerships that drive new manufacturing and product innovations that solve production problems.
Cover Image: Courtesy of AMS Spectral UV