Cold Foil Inline Vision Registration Calibration across Shift Operations
Cold foil inline vision systems maintain registration across shifts by matching strobe sensor geometry to substrate thermal growth and adhesive rheology changes.
Web Tension Registration
Mechanical Alignment
Coordination of the pulling force on a moving roll of paper ensures that printed images and die cuts land in the correct position. Maintaining web tension registration requires a complex system of motors and brake rollers that respond to changes in the material. Paper is an elastic medium that stretches or shrinks depending on the moisture it absorbs from the air or the ink.
Process Control
Load cells and ultrasonic sensors provide constant feedback to the press computer to adjust the speed of the rollers. If the tension is too high, the paper may tear or permanently deform. If it is too low, the web will wander from side to side or sag, causing the print to go out of alignment.
Consistent tension is the foundation of high quality printing and converting on all reel-fed machines.
Material Stability
Different paper grades have different levels of elasticity, meaning that the settings for a thin tissue will not work for a heavy linerboard. Operators must understand the tensile properties of the stock they are using to set the initial tension parameters. Successful registration results in a product where the design is centered and all functional elements like tear strips work correctly.