Choosing the Right LED Wavelength 

Selecting the appropriate wavelength is a pivotal aspect in maximizing the efficiency of UV LED curing systems. While we covered wavelength selection in the previous blog, let’s explore this topic from a different perspective, focusing on how it directly impacts the efficiency of the curing process. 

Enhanced Curing Performance 

The right LED wavelength significantly contributes to faster and more efficient curing. By selecting the optimal wavelength, you can decrease curing time and improve the overall quality of the cure, ultimately maximizing efficiency. 

Customization and Optimization 

UV LED sources offer system designers the advantage of working with specific wavelengths or multiple wavelengths, allowing for greater customization and optimization of the curing system. This flexibility enables system designers to fine-tune the curing process to specific materials and applications, optimizing efficiency. 

Multi-Wavelength Systems 

In certain cases, the use of multi-wavelength systems can provide enhanced flexibility and efficiency. By incorporating various wavelengths, you can effectively address diverse curing needs, streamlining production processes and maximizing overall efficiency. 

Material Compatibility 

Matching the absorption characteristics of the materials with the appropriate wavelength ensures optimal energy transfer, maximizing efficiency and reducing energy waste. 

Proper LED Placement 

LED technology is fundamentally a more compact technology than traditional lamps due to the LED packing densities possible. A variety of LED array methods such as through hole (T-pack), surface mount or chip-on-board can be implemented for different LED packing densities. 

ProPhotonix utilizes Chip-on-Board LED technology in which the bare chip is placed in direct contact with the substrate allowing greater design flexibility, greater intensity and uniformity. For example, LED substrates can be designed on flexible substrates, spherical substrates or as in the COBRA Cure FX series, the LEDs can be placed with an asymmetric distribution so that a higher distribution of LEDs is located near the edges of a lamp to mitigate shadowing effects which also results in higher intensity. 

Optimal Cooling 

UV LED lamps typically require fan or water-cooled systems to guarantee reliable continuous operation over the entire operating temperature range although some low power lamps are available that rely solely on convection cooling. Fan– cooled systems do not require any ancillary equipment, but higher intensity fan-cooled systems may become bulky due to the requirement for bigger and/or more fans to regulate the temperature.  

In environments where there are airborne particulates, filters can be attached to the lamp’s openings to reduce the access of these particles into the inner workings of the UV LED lamp. ProPhotonix offers a range of direct air-cooled UV LED systems with the COBRA Cure FX series. 

Effective Optics 

Optical design of UV LED curing systems is important to ensure that your system works efficiently and that all of the output generated by the UV LED system reaches the target material and cures the correct surface area. If the optical design of the UV lamp is not optimized, under-curing or over-curing can occur. For example, in print applications, if the ink is over-cured, the process results could be banding and other issues. Conversely, inefficient design or poorly fitted optics can result in a significantly reduced light output onto the target area resulting in under-curing of the target material. 

Optical requirements can differ from one application to another. For this reason, ProPhotonix has an in-house optical engineering team that can develop an optimized illumination system to satisfy your requirements. 

Controlled Irradiance 

An inherent challenge with LED curing systems is to maintain the high irradiance over working distances due to the divergence of light from the LED source. Measurement of irradiance is essential in order to optimize cure conditions and maintain consistency in cure results. By implementing techniques to overcome light divergence, optimizing optical design, and utilizing dynamic power control, engineers and system designers can achieve consistent and controlled irradiance levels.  

Regular Maintenance 

UV LEDs do not generate excess heat and as such are a “cool” cure technology ideal for curing materials on heat-sensitive substrates such as wood or plastics that might be damaged by the high temperatures generated from traditional mercury lamps. Maintenance downtimes and the costs involved will be lower because of the extended life of LEDs providing less production downtime versus the changeout required by mercury lamps.  

Conclusion 

Operating efficiency of UV LED curing systems is improved as a result of the unique control capability of light uniformity, speed of flash and precise spectral output among other factors. Following several years of research and customer trials, ProPhotonix launched the COBRA Cure FX series. The product range, designed specifically for UV curing of inks, coatings, and adhesives, offers the flexibility to configure a UV LED curing system to specific application needs.  

It is important to remember that the inherent advantages of UV LED curing systems over traditional UV lamps are not only about improved performance and higher efficiency but also about environmental friendliness and safety. Our next blog post will dive deeper into the safety measures for UV LED curing systems. With 15 years of experience in UV LEDs, ProPhotonix’ UV LED Curing systems can help maximize system performance. We have also worked with customers to design and produce custom UV LED solutions for more than two decades. 

The post Maximizing the Efficiency of UV LED Curing Systems: Tips & Techniques appeared first on Prophotonix.

Customer Requirements

ProPhotonix recently partnered with a system integrator developing currency inspection systems used to inspect bills and sheets of bills. Visible, UV, and IR light are all used in currency inspection. For this particular application, the customer required a single, compact illuminator that had visible and NIR infrared in one source. The light was to be used specifically for the identification of taggants. In high-value materials such as currency and even pharmaceuticals and electronics, for example, the use of taggants is common. Taggants can be either absorbing or reflecting taggants and can be UV as well as IR. In this particular case, the system was being designed to inspect infrared taggants.

COBRA MultiSpec

Initially, ProPhotonix supplied a demo enabling the customer to test the unit in their system. Working with the customer, ProPhotonix configured a COBRA MultiSpec to address the application’s needs. ProPhotonix’ multispectral line light, COBRA MultiSpec, features Chip-on-Board LED technology enabling a compact form factor and can be configured with up to 12 wavelengths from 365nm to 1650nm. A three-color LED line light tailored to this application with two types of white LEDs, and one infrared at 855nm was quickly supplied to the customer.

In addition, in order to meet the customer’s challenging commercial targets, the electronics were optimized for this specific application. In the end, ProPhotonix was able to deliver a cost-effective solution and improve the customer’s overall system performance and affordability.

The Solution

Built using Chip-on-Board LED technology, the COBRA MultiSpec offers a compact solution for multispectral applications. The multispectral  LED line light can be tailored to address a wide range of applications.  System designers can further fine-tune the performance of their system via its user-friendly GUI.

The post Case Study: Multispectral Imaging in Currency Inspection appeared first on Prophotonix.

Compact, Light Form Factor – No Compromise on Performance

With COBRA Cure Mini, ProPhotonix has utilized its expertise in Chip-on-Board LED array design and mechanical engineering to deliver the optimum solution for applications where space and weight are restricted but higher intensity and dose levels are required. COBRA Cure Mini’s light head measures just 33.4mm x 57mm x 30mm (1.3” x 2.24” x 1.18”), with control electronics housed separately achieving a compact light-head module. Weighing less than 175gm (0.4 lb) the light-head is suitable for compact translation systems, providing ease of installation without any compromise on performance.

Maximized Intensity and Dose

In addition to its compact form factor, COBRA Cure Mini delivers extremely uniform, high-intensity UV light for a reliable cure. It has been designed to deliver maximum intensity and dose offering the high performance of our COBRA Cure FX1 UV lamp in a more compact package. COBRA Cure Mini delivers intensities up to 6W/cm² and a factory set dose of up to 9 J/cm² at 2mm offering users the flexibility to meet weight restrictions and available footprint without any performance trade-off.

Key Features: Compact (33.4 x 57 x 30mm) Form Factor Weight: <175g Intensities: Up to 6W/cm² at 2mm Dose: 9J/cm² at 2mm Illumination Area: 36 mm x 13.5mm Linear Intensity Control Options

Key Applications

• UV Curing of:
  • Inks
  • Coatings
  • Adhesives
• 3D Printing

In-house Engineering and Manufacturing

ProPhotonix builds the light engine used to power the COBRA Cure FX series in-house and has engineered each step of the design and manufacturing process to ensure that intensity, dose as well as lifetime are maximized in the COBRA Cure Mini.

Applications

COBRA Cure Mini offers an ideal solution for UV curing of inks, coatings and adhesives as well as 3D printing applications. In high-speed single and multi-pass printers, COBRA Cure Mini can minimize infrastructure requirements and contribute to system speed and delivering the high performance required by these applications.

The post New Compact, Low-Weight, UV LED Curing System appeared first on Prophotonix.

Intensity and Dose

COBRA Cure FX1 Max delivers intensities up to 6.4W/cm² and a factory-set dose of up to 7.8J/cm². This increased output has been achieved without any increase in the compact form factor design of COBRA Cure FX1. The charts below show the comparable intensity levels, at different working distances, for both the COBRA Cure FX1 and the new COBRA Cure FX1 Max lamps.

ProPhotonix utilizes Chip-on-Board LED technology in its COBRA Cure FX Series. Using this LED packaging method, ProPhotonix works with the bare LED chip to design and manufacture densely packaged LED arrays. With this latest release, ProPhotonix has utilized its expertise in Chip-on-Board LED array design and packaging to deliver the optimum solution for applications where space is restricted but higher intensity and dose levels are required.

A number of intensity profiles are available with the COBRA Cure FX1 Max. Read this post for more information on intensity profiles.

Form Factor

In many applications, space is a premium. At just 77 X 28 X 120mm, COBRA Cure FX1 Max retains the slim and compact footprint of COBRA Cure FX1 making it well suited to applications with limited available area.

Benefits of a UV LED Curing System

UV LED curing systems offer a more sustainable solution than traditional technologies with no mercury content or ozone emissions. Operational costs are lower as UV LED systems offer longer lifetimes, significant energy savings, and less downtime for maintenance. If you need a curing system for thin films or heat sensitive substrates, a UV LED solution may be preferable due to its cold cure technology.

Lifetime

ProPhotonix understands the importance of product lifetime, as one of the key advantages of selecting a UV LED Curing system, in ensuring repeatable performance in your system.  The Optical, Mechanical and Electronic engineers at ProPhotonix developed and optimized the design and manufacturing processes increasing the COBRA Cure FX1 Max’ intensity and dose without compromising on lifetime.

Applications

COBRA Cure FX1 Max’ combination of higher intensity and dose, as well as a compact form factor, make it ideal for UV curing in printing and 3D Printing applications as well as UV curing of coatings and adhesives.

For more information about the COBRA Cure FX1 Max:

Download the Datasheet

About the COBRA Cure FX Series

ProPhotonix has a long history of working with OEMs to provide optimized LED solutions for their systems and more than 15 years of experience working with UV LEDs. The COBRA Cure FX series incorporates this wealth of experience offering reliably, high performance along with ease of installation a number of unique features. Learn more about the COBRA Cure FX Series.

The COBRA Cure FX Series has been designed with multiple mounting options allowing the lamps to be set to the optimum working distance for the application. The COBRA Cure FX1 series is UL, CE and IEC certified.

The post New Compact High-Power UV LED Curing Lamp appeared first on Prophotonix.

In this post, we look at the software developed by ProPhotonix’ engineers to provide intensity control in UV LED curing lamps and highlight a number of useful features enabling the configuration of the lamps to suit your specific application needs.

Configurable Intensity

The COBRA Cure FX1 UV LED Lamp offers a variety of factory set intensity profiles, as standard, allowing users to specify the optimum intensity profile to suit their application needs. In addition, ProPhotonix’ engineers have developed software used in the COBRA Cure FX Series to correct for the non-linear response typical of LED technology ensuring a precise linear response and superior intensity and dose control.

Maximum intensity

The maximum intensity of a COBRA Cure FX1 lamp is factory set to ensure a long lifetime. Applications can vary in terms of intensity and lifetime requirements and the COBRA Cure FX Series is designed to offer the flexibility required to configure the lamp to your application.

Intensity, Dose, Lifetime: What does your application require?

The COBRA Cure FX1 delivers intensities up to 6W/cm². Some applications do not require this level of intensity but need high precision control at lower intensity levels. Instead of the maximum intensity of 6W/cm², COBRA Cure FX1 can be configured to output 2W/cm², for example, with more precise control at the 0 to 2 W/cm².

In other types of applications, intensity and dose are the main priority. In these instances, the COBRA Cure FX1 can be configured to higher intensity and dose levels to meet the application needs. Estimated lifetimes can be provided for these new settings.

Linear Response

ProPhotonix’ innovative software ensures further options are available to the user allowing them to select the intensity response to analog control to best suit their application needs.

In “Analog” mode the lamp remains off until 1V. At 1V the lamp instantly turns on at 10% intensity. The intensity then scales in precise linearity with a change in voltage up to 10V where it reaches 100% intensity.

The “Sustain” mode is useful in applications with lower intensity requirements as well as in calibration modes. This mode is particularly useful in noisy environments. In “Sustain” mode the lamp is off at 0V. From 0.1V to 0.99V the lamp is on at 10% intensity. The intensity then scales in precise linearity with a change in voltage from 1V up to 10V where it reaches 100% intensity.

COBRA Cure FX1

COBRA Cure FX1 UV LED Curing lamp incorporating its innovative proprietary software ensures users can configure many aspects of intensity control to suit their application requirements.

The post Intensity Control in UV LED Curing Systems appeared first on Prophotonix.

Optical Design of UV LED Curing Systems

Optical design of UV LED curing systems is important to ensure that your system works efficiently and that all of the output generated by the UV LED system reaches the target material and cures the correct surface area. If the optical design of the UV lamp is not optimized, under-curing or over-curing can occur. Poorly designed optics placed in a UV LED curing system can result in unnecessarily high intensity causing over-curing of the target. Over-curing of target materials affects the quality of the final product. For example, in print applications, if the ink is over-cured, the process results could be banding and other issues. Conversely, inefficient design or poorly fitted optics can result in a significantly reduced light output onto the target area resulting in under-curing of the target material.

Greater intensity is not always the goal with UV LED curing systems, but the direction of light and dose (energy density) are critical. As a result, it is important to have the optimum optical design for your application and to ensure that you work with a reputable lamp supplier with a rigorous quality management system in place.

Supplier Expertise

Achieving the optimum energy density in each application is a challenge for UV LED curing systems designers. If energy density is too high the material will be over-cured, too low and the material will not cure consistently if at all. For system designers, the first step is to determine the optimum energy density for your application.

A further challenge in optical design is in material selection. Exposure to such high levels of UV light can degrade traditional materials over time, reducing optical output. ProPhotonix has over 10 years of experience in supplying UV LED based systems and has a well-established, reliable supply chain. Our extensive quality control, lifetime testing and burn-in facilities ensure repeatable, quality UV solutions.

UV LED Systems Optical Options

Optical requirements can differ from one application to another. For this reason, ProPhotonix has built flexibility into the design of our UV LED systems. Each product in the COBRA Cure FX series is configurable allowing users to select the optimum optical set-up for their application.

The COBRA Cure FX series is available in highly collimated, angle reduced and natural emission profile configurations. The highly collimated version is typically a zero degree option. This configuration has a narrow illumination angle, which ensures low risk of curing at the print head. However, this configuration is not suitable for applications that require a wide curing profile.

An angle reduced profile is the second option. This configuration provides an optical output angle of forty degrees. While still a relatively narrow illumination angle ensuring low risk of curing at the print head, this option produces high dose levels and is suited to applications requiring a wide curing profile. The angle reduced profile is a popular option, as it provides a tighter angle than many systems, which results in reduced reflections in the system and significantly reducing the risk of unintended curing. As this configuration maintains high intensity levels, especially over wide working distance ranges, it is ideal for applications such as inkjet printing.

The final option is a natural emission profile which offers a sixty degree angle. This configuration has the highest level of dose at short working distances (<5mm) of the options presented in this post, but dose reduces significantly past 5mm. With a wider illumination angle there is an increased risk of curing at the print head. The type of system can be used in industrial applications such as ink curing, counterfeit detection and medical applications.

ProPhotonix Experience

ProPhotonix has over 15 years of experience working with UV LEDs. As an experienced LED system manufacturer, ProPhotonix is expert in working with complex requirements to provide the optimum solution for your system’s needs. Custom solutions are also available where we can adapt many of our existing systems to meet your specific requirements. For these types of applications, ProPhotonix has an in-house optical engineering team that can develop an optimized illumination system to satisfy your requirements.

The post Optical Design of UV LED Curing Systems appeared first on Prophotonix.

UV LED Curing Systems Lifetime

Perhaps the most well-known advantage of UV LED Curing systems over traditional technologies is that of lifetime. UV LEDs have an expected lifetime of 20,000 hours. The lifetime of traditional technologies such as mercury lamps can vary greatly but typically ranges from 500 to 2,000 hours. This relatively short time results in increased downtime and operational costs with traditional technologies.

Lamp Efficiency

Mercury lamps emit some of their energy as infrared light. In traditional lamps, only 20% of energy is emitted as UV. This can cause surface areas to be cured that were not intended to be cured and over-curing of some surfaces. Mercury lamps operate at very high temperatures which can damage heat-sensitive substrates. This may restrict the materials used when operating mercury lamps. In addition, in traditional systems the output of the lamp changes as the bulb ages. This can result in inconsistent curing. With LED systems, all the light emitted is ultraviolet, the light does not generate heat so is a “cold cure” technology and the LED curing lamp intensity can be controlled to ensure consistent output over the lifetime of the lamp.

Intensity Control

ProPhotonix has designed its UV LED curing systems to enable users to monitor and drive each individual LED segment. This ensures excellent intensity control over each segment. With the ability to control the intensity, ProPhotonix maintains uniformity across the lamp. The design also allows ProPhotonix to set the lamp to a specified intensity for the customer to ensure the lamp works to the customers’ specifications.

Conclusion

Compared to traditional technologies, UV LED systems offer many advantages. For more information on the advantages of UV LED curing systems, download the whitepaper.

The post Benefits of UV LED Curing Versus Traditional Systems appeared first on Prophotonix.

High peak irradiance and energy density are important factors in UV curing. To achieve this in UV LED based curing lamps, a large number of LEDs operating at high current and voltage levels is required. This process produces a lot of heat in the LEDs. To maximize lifetime, reliability and performance this heat needs to be removed from the LEDs as efficiently and as quickly as possible. If this heat is not removed the LEDs intensity can drop significantly, lifetime can reduce and the LEDs can become permanently damaged. To this end, good thermal design is critical. Local thermal management techniques including choice of LED chip, LED packaging technique, LED circuit board choice and design, adhesive choice etc. are beyond the scope of this post but are important factors that need to be considered by a reliable lamp manufacturer.

This post will look at the macro thermal design considerations for UV LED curing systems as these decisions are more end-user led than the local thermal management decisions. This blog will discuss the advantages and disadvantages of direct air cooling and liquid cooling as well as the systems offered by ProPhotonix.

Direct Air Cooling

In systems where direct air cooling is employed, a heat sink acts as a passive heat exchanger that transfers the heat generated by the LEDs to air via fan assisted cooling. The hot air is dissipated away from the lamp, thereby allowing regulation of the device’s temperature to optimal levels. These types of lamps are quick and easy to install and because they need no external accessories and are inexpensive in comparison to liquid-cooled options.

A consequence of using fan-assisted cooling is that higher intensity lamps need larger heat sinks, bigger fans, and/or a large number of fans to remove the heat. For applications, where the lamps are moved at speed along a rail this extra weight may be an issue. The heavier the lamp the more robust the rail is required to support the lamp leading to an increase in costs. For relatively quiet environments such as laboratories, larger fans increase noise levels. Due to the large heat sinks on some high-intensity versions, these lamps may not be suitable for applications where space is restricted. In fact, there is a point at which high-intensity requirements necessitate a heat sink size that is not practical. As a result, for very high intensity and dose applications, lamps based in liquid cooling are preferred.

Liquid Cooling

Liquid cooling is an efficient method of extracting heat, particularly in applications where high power densities are required over wide curing areas. Many liquid cooled systems are designed to be rugged and reliable enough to withstand tough operating environments. Liquid-cooled systems are very compact making them suitable for applications where available space is a concern. These systems are also noise-free.

The drawbacks of liquid-cooled solutions are that they are more complex to install and are more expensive due to the requirement for a chiller unit. For systems where multiple lamps are required, more than one liquid flow input and output point are needed to ensure the liquid is evenly and sufficiently cooled to pull heat from the LEDs. Multiple water-cooling points increase potential points of failure in the system. The need for chillers and liquid pipes requires extra infrastructure that, for certain applications, is not suitable from a cost and form factor point of view.

Systems Offered by ProPhotonix

ProPhotonix offers a range of direct air-cooled UV LED systems with the COBRA Cure FX series.

ProPhotonix also offers custom solutions where we can adapt many of our existing systems including liquid cooling options to meet your specific requirements. For more information on Specifying UV LED Curing Systems, download our whitepaper.

The post Thermal Management in UV LED Curing Systems appeared first on Prophotonix.