Inert Gas Curing

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.

Fully air cooled, extreme high power lamp design perfect for web & industrial applications.

NUVA2 HP is the same NUVA2 cassette in a narrower format − the extra cooling available allows running up to 240W/cm, with maximum power decreasing as lamp length increases. Fully air-cooled, NUVA2 HP is available with a wide range of customisation options and is perfect for final cure inkjet applications (with iron-doped lamps) or high-speed web machines.

GEW’s patented reflectors are actively cooled to ensure that heat transfer to the substrate is minimised, whilst delivering the highest UV intensity and dose available. The quick-change cassette design ensures fast lamp changes with only 1 hex key tool required and all replaceable components are plug and play for easiest maintenance.

A quartz glass plate which is transparent to UV energy, fitted over the UV lamphead’s emitting window.

In the majority of cases it is best to have a direct path of radiation from the UV lamp to the target area to maximise the curing effect. However, in some cases, the application necessitates a quartz glass filter to be installed in the lamp’s emitting window.