Ink Distribution Control for Printing Press Changeover

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Solution Overview

Problem

The challenge in printing presses, particularly rotary printing presses, is the inefficient and time-consuming process of changing over from one printing process to another, resulting in ink waste and uneven ink distribution across the printing material, which affects the quality of the subsequent print job.

Innovation Solution

An automated control method that calculates and adjusts the area coverage of ink distribution across multiple printing units, optimizing the changeover process by comparing actual and target ink densities, adjusting ink supply, and determining the number of sheets or images needed to achieve the desired ink coverage, minimizing ink waste and reducing downtime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the ink supply to the inking unit is completely shut off or interrupted when a final phase of a printing process is reached, then the changeover time is reduced, but the ink remaining in the inking unit causes uneven ink distribution and affects the quality of the subsequent print job

Engineering Contradiction:
Improvechangeover timeVSAvoidink distribution uniformity
Core Design Contradiction:
Loss of timeVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by calculating and setting the ink dose for a defined number of sheets or print images in advance, before the changeover is complete. The control device determines how many sheets can still be printed with the ink remaining in the inking unit, and pre-configures the ink dose for the subsequent printing process to ensure uniform ink distribution from the start of the new job.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback by continuously monitoring the ink layer thickness or area coverage during printing and comparing it with target values. The control device adjusts the ink dose based on this feedback to maintain uniform ink distribution, even during the transition between different printing processes.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the ink supply is not shut off and printing continues with the remaining ink, then uniform ink distribution is maintained, but ink waste increases and the changeover process becomes inefficient

Engineering Contradiction:
Improveink distribution uniformityVSAvoidink waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent applies partial action by shutting off the ink supply only for a defined, calculated number of sheets or print images, rather than completely stopping the printing process. This partial interruption allows the remaining ink to be used efficiently for a specific quantity of prints while preventing excessive ink waste and ensuring uniform distribution for the subsequent job.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter of ink supply duration by defining a specific number of sheets or print images for which the ink supply is shut off. This parameter change optimizes the balance between ink waste reduction and maintaining uniform ink distribution, transforming the changeover process from an inefficient continuous supply to a controlled partial interruption.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If manual adjustment of ink metering elements is performed during changeover, then ink distribution can be optimized, but the changeover process becomes time-consuming and labor-intensive

Engineering Contradiction:
Improveink distribution qualityVSAvoidchangeover duration
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies self-service by implementing an automated control device that calculates, determines, and adjusts the ink dose without manual intervention. The system automatically monitors ink layer thickness, calculates the optimal number of sheets for ink supply interruption, and adjusts the ink metering elements, eliminating the need for manual adjustment while maintaining high ink distribution quality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical adjustment of ink metering elements with an automated control system. The control device uses sensors to monitor ink layer thickness and automatically adjusts the ink dose, substituting human operation with an automated feedback-controlled mechanism that is both faster and more precise.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Loss of substance

If the ink layer thickness is reduced automatically after reaching a final phase of production, then ink waste is minimized, but the transition may cause uneven ink distribution if not properly controlled

Engineering Contradiction:
Improveink wasteVSAvoidink layer uniformity
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent uses feedback control by continuously monitoring the ink layer thickness during the transition and comparing it with target values. The control device adjusts the ink dose based on this feedback to maintain uniform ink distribution while minimizing ink waste, ensuring that the automatic reduction in ink layer thickness does not compromise print quality.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2396174B1Method for adjusting an area coverage and a corresponding method for execution in a printing press having a plurality of printing units
Publication Date: 2014.12.17 KOENIG & BAUER AG
  • EP2396174B1 patent drawingFigure 1
  • EP2396174B1 patent drawingFigure 2~4
  • EP2396174B1 patent drawingFigure 5~8

AI summary

The invention relates to a method for adjusting an area coverage wherein the area coverage is carried out by a volume of printing ink transferred to a print stock by an inking unit of a printing press, wherein an ink feed to the inking unit is at least disengaged in zones or interrupted in the inking unit upon reaching a final phase of a printing process previously carried out by the printing press, wherein the volume of printing ink remaining on the print stock after disengaging or interrupting the ink feed in the inking unit in the final phase of the printing process previously carried out by the printing press is transferred to the print stock until the area coverage made by the volume of printing ink transferred to the print stock equals a specified target value of area coverage for an impression of a subsequent printing process. The invention further relates to a corresponding method for execution in a printing press having a plurality of printing units.