What Industry Trends are Driving Developments in UV LED Curing Technology?

Sustainability

All the major brands require environmentally sustainable processes from printers and converters. These requirements significantly impact the development of UV curing technology. The environmental benefits of UV LED curing are numerous. With traditional UV curing processes, the tremendous heat associated with mercury UV lamps requires a lot of electricity to operate. Upgrading to UV LED curing can reduce energy bills up to 85% overnight with a return on investment in well under one year.

Flexographic/Digital Integration

Integrating Flexographic and digital into one system is becoming a common trend in the printing industry. Hybrid industrial printing systems combine flexographic analogue printing with inkjet printing on a single-pass production line. This setup leverages the benefits offered by both printing technologies. A combined flexo-digital printing system gives printers two production tools in virtually the same footprint. UV LED curing easily supports both digital and flexographic processes, offering one technology for the whole print flow.

Industry 4.0 Manufacturing

We are now in the fourth industrial revolution, also referred to as Industry 4.0. Characterized by increasing automation and the employment of smart machines and smart factories, informed data helps to produce goods more efficiently and productively across the value chain.

By collecting more data from the factory floor and combining that with other operational data, a smart factory can achieve information transparency and better decisions.

Customers increasingly require process control via real-time monitoring of UV LED curing lamps to better support Industry 4.0 manufacturing. Many of them are running & dark factories that have no lights and no humans during processing, so 24x7 remote performance monitoring is key. Even in facilities with human operators, customers want to be notified about curing issues immediately to minimize downtime and scrap.

Expansion of Low Migration Inks

As safety requirements of packaged food products with printed inks are becoming increasingly stringent, these strict requirements will drive the market trends. Expanded awareness pertaining to hazardous effects because of ink migration in food, cosmetics, pharmaceuticals, and cosmetic items will impact printing processes.

The popularity of low migration UV LED curable inks continues to grow and is expected to gradually replace the conventional UV inks. The UV output of LED curing equipment is much more stable over time compared with conventional mercury-based systems. This results in greater process control when used to crosslink inks, coatings, and adhesives in low-migration processes. UV LED offers superior process stability and consistency, both top requirements for low-migration printing.

Expansion of Printed Substrates

We will see a continuing expansion of printing substrates in industrial printing processes. UV LED technology allows users to cure a variety of heat-sensitive substrates that have previously been unusable with traditional UV arc lamps.

Increasing Press Speeds

Due to increased press speeds, more power is required from the UV-curing light source. Having enough power is crucial to the curing process. This is where peak irradiance and energy density (dose) come into play. A minimum threshold of irradiance is needed to start the polymerization process, and then a dwell time of dose is needed to finish the curing process.

Both high irradiance and energy density are required for a successful cure.

Peak irradiance, also called intensity, is the radiant power arriving at the surface area and is instrumental in penetrating and curing the ink or coating. Peak irradiance can be affected by the output of the UV LED light source, the use of reflectors or optics to concentrate or contain the rays in a tighter surface impact area, and the distance of the source from the cure surface.

Energy density, also called dose or radiant energy density. Energy density is the measure of energy arriving at a surface per unit area during a defined period (called the dwell time or exposure time). A sufficient amount of energy density is necessary for a full cure. Energy density is a factor of irradiance and exposure time and is managed by varying the speed or time that the substrate is under the UV LED lamp and the intensity of the light source.

Phoseon UV LED curing units support a wide variety of curing length requirements to fit all the print widths. For example, a 9″ web application would use a 225mm length product while a 2″label process would utilize a 50mm or 75mm product. These products scale end-to-end to provide greater flexibility and service options.

Expanding Ecosystem

Regarding ink development, almost all new ink materials are developed for LED technology. Every major ink company has Phoseon UV LED curing products used in their lab for testing new materials. UV LED companies need to work very closely with raw material and ink suppliers, OEMs (Original Equipment Manufacturers), and end users to support evolving and growing technology and future development.