Sheet-Fed Offset Inking With Color-Feedback Control

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Solution Overview

Problem

In sheet-fed offset printing, insufficient pressure between the blanket and impression cylinders leads to poor print quality, characterized by incomplete ink coverage, resulting in waste due to unsatisfactory print consistency.

Innovation Solution

A method involving continuous monitoring of inking values using a colorimeter, with a computer-assisted evaluation to adjust printing settings, specifically altering the distance between the blanket and impression cylinders to maintain optimal ink application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the pressure between the blanket cylinder and impression cylinder is increased to improve ink coverage, then inking quality improves, but the risk of stencilling, emulsification, and fogging increases

Engineering Contradiction:
Improveinking qualityVSAvoidstencilling, emulsification, fogging
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent implements continuous monitoring of inking quality using colorimeters and optical inspection systems, with automatic feedback control that adjusts printing pressure and ink application in real-time. This closed-loop system maintains optimal inking quality while preventing excessive pressure that causes stencilling, emulsification, and fogging.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts multiple parameters including printing pressure, ink film thickness, and cylinder speed to optimize inking quality. By changing these parameters within optimal ranges rather than maximizing pressure, the system achieves complete ink coverage without causing harmful effects like stencilling and emulsification.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If more printing ink is used to increase ink film thickness and compensate for insufficient pressure, then inking coverage improves, but the risk of stencilling and emulsification increases

Engineering Contradiction:
Improveinking coverageVSAvoidstencilling, emulsification
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The system uses colorimeters and optical inspection systems to continuously measure inking quality and provides feedback control that adjusts ink application and pressure. This prevents excessive ink accumulation that would cause stencilling and emulsification while ensuring complete coverage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Instead of simply increasing ink quantity, the system optimizes multiple parameters including ink film thickness, pressure, and cylinder speed to achieve proper inking coverage through balanced parameter adjustment rather than excessive ink application.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If continuous monitoring and adjustment of inking values is implemented, then print quality consistency improves, but device complexity and operational cost increases

Engineering Contradiction:
Improveprint quality consistencyVSAvoidmonitoring and control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs colorimeters and optical inspection systems that provide continuous feedback on inking quality, enabling automatic adjustment of printing parameters. This feedback mechanism ensures consistent print quality while the automation reduces manual intervention requirements.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-monitoring and self-adjustment of inking quality through automated color measurement and pressure regulation, reducing the need for manual quality control and minimizing operational complexity despite continuous monitoring.

Inventive Principle:
Principle #25Self-service

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

Enhances print quality by reducing waste through consistent ink coverage, achieved by optimizing the inking process with minimal ink film thickness adjustments.

Implementation Method 1

the inking value on the printing substrate sheet serving as a reference sheet is determined in a printed area using a colour measuring device

Methodology Applied
Scientific EffectOptical measurement: Absorption (EM radiation)

Data Source

PatentEP4624160A1Method for optimizing the inking of printed sheets in offset printing
Publication Date: 2025.10.01 HEIDELBERGER DRUCKMASCHINEN AG
  • EP4624160A1 patent drawingFigure 1
  • EP4624160A1 patent drawingFigure 2
  • EP4624160A1 patent drawing

AI summary

The invention relates to a method for optimising the colouring of printing material sheets in an offset printing unit of a sheet-fed printing press, in which the colouring is continuously monitored by determining the colouring values ​​using a colour measuring device and the printing supply is controlled and, if necessary, adjusted on the basis of an evaluation of the colouring values ​​by a computer.