Spain-based machinery supplier Comexi has adapted US firm QuadTech’s Colour Control with SpectralCam technology to support the flexible packaging industry.
The use of the technology can be extended from paper and label printing to the printing of flexible packaging.
The adaptation of the solution is a result of the collaboration between the two companies.
The new Colour Control with SpectralCam system provides automated precision for achieving colour targets, as well as faster and easier colour OKs, reduced makeready times and increased productivity.
As a 31-channel spectrophotometer, the new SpectralCam helps precisely measure spectral response over micro colour bars.
It then calculates L*a*b*, ΔE, Density and ΔDensity at full-press speeds.
The web stabiliser features ISO-conforming black and white reference tiles which move with the camera to deliver a consistent spectral response.
Short bursts of pressurised air are used to bring the substrate into close proximity with the ceramic backing tiles to provide accurate colour measurement.
Following this, the adaptive control methodology adjusts the press to maintain precise control over the four-colour process, extended gamut and spot colours throughout the run.
Also known as ‘extended gamut’ printing, Comexi’s Offset CI8 running seven-colour process prefers a spectral system that measures colour over a density measurement.
Comexi Offset technology research and development manager Adelbert Schoonman said: “Thanks to the collaboration between QuadTech and Comexi, we are working together to introduce a closed-loop colour control system that benefits operators and converters and will be of added value for flexible packaging printers using Comexi’s CI8 Offset technology and the whole flexible packaging industry.”
Ink fountains of offset presses have a wide range of narrow ink keys throughout their entire width.
The opening of each individual ink key can be remotely controlled by the press operator.
This can enable the operator to react on local or general colour variations as they are indicated by the colour measuring systems.
The closed-loop colour control system can make the operator’s corrections by automatically adjusting the ink keys based on data provided by the SpectralCam.
In combination with the web stabiliser system, the use of SpectralCam provides a stable and calibrated background for each measurement.