UV LED Curing Systems

OxyGuard is GEW’s next generation oxygen control system. It consists of an innovative new inert gas chamber and revolutionary control software for precision control of oxygen concentration. OxyGuard is ideal for low migration/odour printing, siliconisation and other high performance applications.

Closed loop control

OxyGuard features a radically improved closed loop control functionality. Oxygen set points are rapidly achieved and maintained to within ~±10%, even with different materials or coatings. Chamber O2 concentration and flow rates are clearly displayed on the HMI. The innovative control ensures no spikes of oxygen concentration, even during rapid machine acceleration. User adjustable warning and error bands are graphically represented on the HMI and can be outputted via digital I/O if levels are exceeded for an adjustable time period.

Job reporting

OxyGuard includes a means of recording live system curing performance data. Oxygen level (ppm), UV intensity and any warning and fault conditions that occur are recorded and timestamped.

For compliance or GMP (e.g. EC Regulation No. 2023/2006), data can be exported via GEW API for OEM integrations or via an email report, triggered via the HMI ‘Job logging’ function.

The benefits of OxyGuard

• Achieves precision oxygen ppm control with custom set points from 30-10,000ppm
• Closed loop control algorithm rapidly achieves set points and minimises inert gas usage
• Custom designed chambers support all GEW lamp models and widths, and any quantity of lamps per chamber
• Chambers can be on rollers, straight through web paths or mounted on conveyors
• A radically improved user interface makes operator monitoring and adjusting of the curing process easier than ever before
• Enhanced user-set alarm and warning outputs are available, to enable simple process compliance

How it works

Ambient oxygen reduces the effectiveness of UV curing in many inks and coatings. The OxyGuard system overcomes this, by reducing oxygen concentration at the point of curing. A chamber, with inlet and outlet slots, is constructed around the material and an inert gas, usually nitrogen, is pumped in to displace the air and maintain a target oxygen level. A quartz window in the chamber allows the UV lamp to be mounted outside the chamber and shine through to irradiate the ink / coating. Oxygen levels in the chamber are monitored by an oxygen sensor. A closed loop algorithm precisely adjusts the flow of inert gas to the chamber to maintain target oxygen ppm as the material moves through the chamber.

GEW excimer lamps produce vacuum ultraviolet radiation for a range of applications and can be seamlessly integrated onto machinery up to 2.55m wide.

GEW’s ExciRay lamp systems utilise dielectric barrier discharge (DBD) lamps to produce quasi-monochromatic vacuum ultraviolet radiation, typically at 172nm. This radiation is commonly used for mattification of surface coatings, modification of surface tension for improved adhesion or surface cleaning for semiconductor and medical industries.

UV LED modules are sub-assemblies incorporating tens or hundreds of roughly millimetre square LEDs arranged in a matrix of rows and columns. Multiple LED modules are arranged in various configurations within lamp head assemblies to span the desired UV emitting length and width.

The UV spectral output of an LED is relatively monochromatic compared to broadband mercury sources. The material structure of the LED semiconductor determines the exact UV output wavelength, which is fixed and unchanging for each individual diode. Typically, a UV LED module will contain many LEDs with very similar UV spectra and will be specified at a nominal peak wavelength (e.g. 395 ± 5nm).

All GEW LED modules are available with peak wavelengths of 365, 385, 395 or 405nm, with a range of market leading irradiancies to suit many different applications.

Contact us to discuss which option is right for you.