DoseGuard Laboratory Unit

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.

High powered variant of GEW’s E2C lamphead, designed for low migration and/or high-speed print applications.

E2C HP comprises a standard E2C UV lamp cassette housed in a larger casing to enable more air cooling and thus higher running power, up to 180W/cm. Perfect for low migration or high speed print applications up to 80cm wide, it boasts the same reliability and patented reflector designs contained in GEW’s most popular E2C product.

E2C HP still supports printing on the widest range of heat-sensitive materials because our actively air-cooled reflectors reduce heat transfer to the substrate. It also boasts GEW’s famous quick-change cassette design enabling a new lamp to be fitted in under 2 minutes with only 1 hex key tool required.

GEW’s LED bench-top lab unit allows fast, accurate UV LED irradiation of samples or radiometers and can be specified with different wavelengths as required.

GEW’s LED lab unit utilises a high precision linear drive to pass a sample tray under the UV LED array.

Variable speed control ensures highly repeatable testing up to 100m/min with UV power adjustable in set increments and LED array height adjustable up to 25mm.

A simple magnetic hinged tray carries print samples or can accommodate an EIT radiometer for precise UV power measurement.