The Color Control with SpectralCam system brings significant advantages for standard applications on various flexible films. The two global enterprises have made progress on increasing brand owners’ awareness about the benefits of this technology.
Early on, Comexi and its Offset Business Unit team recognized the clear advantages that the closed-loop Color Control system brings to press operators and converters in the flexible packaging printing industry. As flexible packaging printing typically runs reel-to-reel, it is not possible for press operators to take a printed sample for exact color check. That was one of the main requirements that the two companies recognized, and this drove the implementation of Color Control with SpectralCam for flexible packaging printing.
QuadTech’s system brings automated precision for achieving color targets. Spectral-based, closed-loop color control means faster, easier color OKs, reduced makeready time and enhanced productivity. The innovative SpectralCam is a 31-channel spectrophotometer that accurately measures spectral response over micro color bars, then calculates L*a*b*, ΔE, Density and ΔDensity…all at full press speeds. The patented web stabilizer uses ISO-conforming black and white reference tiles—a constant, known backing—that moves with the camera to provide consistent spectral response. Short bursts of pressurized air are used to bring the substrate into close proximity with the ceramic backing tiles for precise color measurement.
Patented adaptive control methodology adjusts the press to maintain accurate control over four-color process, extended gamut and spot colors throughout the run. On Comexi’s Offset CI8 running seven-color process, also known as “extended gamut’ printing, a spectral system that measures color is preferred over a density measurement. SpectralCam is QuadTech’s third-generation spectrophotometer.
Broadening flexible packaging market
“It is a pleasure to collaborate with one of the most technologically innovative companies in the flexographic, offset and gravure printing industries”, says QuadTech President Karl Fritchen. “Comexi’s reputation and commitment to innovation is perfectly aligned with QuadTech’s vision and expertise. Both companies continually invest in the development of pioneering technologies and solutions for the market”.
“We are continuously investing in development, research, knowledge and innovation”, affirms Comexi CEO, Mr. Jeroen van der Meer. “We have become a market-reference in this field and we are really glad that the strategic collaboration with QuadTech has resulted in the development of new technologies that broaden the sector, its possibilities, and facilitates customers’ day-to-day production”.
Manager of R&D for Comexi’s Offset Technology, Mr. Adelbert Schoonman, explains the main challenges that the closed-loop Color Control system addresses: “All printing processes have their deviations during a print run. It is of great help for each printer when they can monitor, automatically correct, and regulate the quality of the colors during the process”. In today’s flexible packaging industry, there are various systems on the market that simply measure color or density inline, and then show the color variations in a graphical or numerical way to the printer. These systems do not then “close the loop” by also automatically making color adjustments. Also, when required, the printer can react on the provided information during the run, for example by making adjustments to viscosity, temperature or pressure”. In comparison to flexographic and gravure technologies, offset printing technology offers an additional parameter that can be used in order to control color consistency automatically, without operator intervention.
Automatic adjustments
Ink fountains of offset presses have a range of narrow ink keys across their entire width. The opening of each individual ink key can be remotely controlled by the operator, in this way the operator can react on local or general color variations, as they are indicated by the color measuring systems. The “closed-loop“ Color Control system can make the press operator’s corrections by automatically adjusting the ink keys based on data provided by the SpectralCam. As Mr. Schoonman explains: “In the paper printing industry, closed-loop control systems are standard equipment with a long history of proven performance and, nowadays, are standard equipment on many heat-set and cold-set web presses. However, the characteristics required in the flexible packaging printing, such as measuring through a transparent film, and the different characteristics of packaging films—like clarity, gloss or matte finishes, background or spot colors—makes closed-loop color control for flexible packaging much more challenging”.
With SpectralCam in combination with the advanced web stabilizer system that assures a stable and calibrated background for each measurement, QuadTech and Comexi deliver an important part of the required solution. “Thanks to the collaboration between QuadTech and Comexi, we are working together to introduce a closed-loop color 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”, states Mr. Schoonman.
Comexi and QuadTech will continue efforts focused on creating new developments that bring advantages for standard applications on various flexible films, and are working with brand owners to combine the use of color patches in flexible packaging designs to increase their understanding and awareness and, at the same time, to create a broader acceptance of this innovative technology in the flexible packaging market.
