External Rack for Flexographic Printing Roller Positioning
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Solution Overview
Problem
Flexographic printing machines face increased makeready times and costs due to waste generation during roller position adjustments, as existing methods rely on measuring defective printed images and ignore factors like ink modulus and color splitting behavior.
Innovation Solution
An external rack for a flexographic printing machine with an inking device, anilox roller, and format cylinder, using a special test color and sensor device to record ink film changes, allowing for optimized roller positioning without waste by measuring ink transfer under realistic conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the distance between cylinders is adjusted by measuring the printed image on the printing material, then the roller position can be optimized, but waste is inevitably generated during the adjustment process
Solution Approach 1:
The patent uses a sensor device to create an optical copy/representation of the ink film on the anilox roller surface, allowing measurement of ink transfer characteristics without requiring physical printing material. The sensor detects reflectivity changes that correspond to ink film thickness variations, providing a non-contact measurement method that eliminates waste while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the mechanical printing process with an optical measurement system. Instead of physically printing and measuring the printed image, the sensor device optically detects the ink film properties on the rotating anilox roller surface, substituting mechanical printing action with optical detection to achieve the same measurement goal without material consumption.
2Measurement precision
If rollers are stopped and held stationary for color stripe measurement, then contact pressure can be measured, but makeready time increases
Solution Approach 1:
The patent transitions from static measurement to dynamic measurement by detecting ink film changes on the rotating anilox roller surface. The sensor device captures reflectivity data during rotation, allowing contact pressure and ink transfer characteristics to be measured while the roller is in motion, thereby eliminating the need to stop and hold rollers stationary and reducing makeready time.
Solution Approach 2:
The patent enables continuous measurement during roller rotation rather than intermittent measurement during stationary holds. The sensor device continuously detects ink film properties as the anilox roller rotates, maintaining productive operation throughout the measurement process and eliminating idle time associated with stopping and positioning rollers for measurement.
3Measurement precision
If a color stripe is created on the second roller during adjustment, then contact pressure can be measured, but the color stripe reduces print quality at the start of printing
Solution Approach 1:
The patent uses optical sensing to create a non-contact copy of the ink film distribution on the anilox roller surface. The sensor device detects reflectivity patterns that correspond to ink film thickness and contact pressure variations without physically transferring ink to create visible color stripes, thereby maintaining measurement accuracy while preserving print quality.
Solution Approach 2:
The patent replaces the mechanical ink transfer process that creates visible color stripes with an optical detection system. The sensor device optically measures ink film properties on the rotating anilox roller without requiring actual ink transfer to the printing material or creation of visible color stripes, eliminating the harmful effect on print quality while maintaining measurement capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces makeready times by optimizing roller positioning based on real-time ink film changes, ensuring accurate ink transfer and minimizing waste during print job changes.
Implementation Method 1
a sensor device being provided, by means of which, depending on the working distance between the anilox roller and the format cylinder, printing process data about the change in the ink film within a zone on the anilox roller can be recorded
Data Source
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AI summary
The invention relates to an external rack for a flexographic printing press (15) for determining printing process data. To reduce the setup times of a flexographic printing press (15) when changing print jobs, the rack comprises an inking unit (6), an anilox roller (7), and a format cylinder (8). The inking unit (6) is supplied with a special test ink (29) for transfer to the surface of the anilox roller (7). The format cylinder (8) is designed to receive test ink (29) from the anilox roller in a contact area (10). A sensor device (17, 19) is provided by means of which, depending on the working distance between the anilox roller (7) and the format cylinder (8), printing process data about the change in the ink film within a zone on the anilox roller (7) can be recorded. This zone is located downstream of the contact area (10) and upstream of the inking unit (6) in the ink transport direction.and wherein a communication device is provided which transmits the printing process data from the sensor device (17, 19) to the flexographic printing machine (15).