Ink Transfer Roller Characterization via Optical Spectral Analysis

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Solution Overview

Problem

The existing methods for determining the ink transport behavior of rollers in printing processes are complex and time-consuming, requiring extensive testing and adjustments to achieve the desired color impression, leading to increased machine downtime and costs.

Innovation Solution

A method and device that compare the ink transport behavior of a roller to be tested with a reference roller using optical measurements, applying a normalization factor to extrapolate ink transport data, allowing for more efficient selection and adjustment of rollers to achieve the desired color impression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If extensive testing and adjustments are performed to determine ink transport behavior, then the accuracy of color impression is improved, but machine downtime and costs increase

Engineering Contradiction:
Improvecolor impression accuracyVSAvoidmachine downtime
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses a reference roller with known ink transport characteristics to create a reference profile. Instead of extensively testing each individual roller, the system copies the reference profile and applies it to test rollers through comparison. This allows rapid assessment of ink transport behavior without repeating full testing procedures, significantly reducing measurement time while maintaining color impression accuracy.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent performs preliminary characterization of roller surfaces using optical properties (reflectance, absorbance) before actual printing tests. By pre-establishing the relationship between optical properties and ink transport behavior through a reference roller, the system can predict ink transport characteristics without extensive trial printing, thereby reducing machine downtime while ensuring accurate color reproduction.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If extensive testing and adjustments are performed to determine ink transport behavior, then the accuracy of color impression is improved, but costs increase

Engineering Contradiction:
Improvecolor impression accuracyVSAvoidprinting fluid consumption
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The patent creates a reference profile from a single reference roller that can be reused across multiple testing scenarios. Instead of consuming printing fluid for extensive testing of each roller, the system copies the reference profile and uses optical measurements to compare test rollers against it. This dramatically reduces printing fluid consumption while maintaining the ability to achieve accurate color impressions through minimal actual printing tests.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If multiple types of ink transport rollers are used to achieve different ink applications, then the versatility of printing is improved, but device complexity increases

Engineering Contradiction:
Improveprinting versatilityVSAvoidroller selection complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent characterizes different roller types by their optical parameters (reflectance, absorbance spectra) and establishes relationships between these parameters and ink transport behavior. Instead of managing complexity through physical roller variations, the system uses parameter-based characterization to differentiate roller types. This allows versatile printing capabilities to be achieved through software-based parameter matching rather than physical roller inventory management, reducing device complexity while maintaining adaptability.

Inventive Principle:
Principle #35Parameter changes

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 approach simplifies the process of determining ink transport behavior, reducing machine downtime and costs by enabling more accurate and efficient selection and adjustment of rollers, thereby improving the quality of printed images.

Implementation Method 1

the spectral intensity of the light remitted from a printed image

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

The paint application or the layer thickness can be characterized with a density measurement - which is carried out with a densitometer - in the absorption range of the reflectance spectrum of the paint

Methodology Applied
Scientific EffectAbsorption spectroscopy: Absorption Spectroscopy

Data Source

PatentEP2295248B1Method and device for finding the specific ink transfer behaviour of a ink transfer roller
Publication Date: 2013.07.31 WINDMOELLER & HOELSCHER GMBH
  • EP2295248B1 patent drawingFigure 1
  • EP2295248B1 patent drawingFigure 2
  • EP2295248B1 patent drawingFigure 3

AI summary

A method for determining the specific ink transport behavior of an ink-transporting roller (42a) for a printing ink (11) having a specific pigment composition is presented - in which the roller (42a) to be tested is inserted into a printing unit (8, 101) and the substrate is printed with printing ink of this pigment composition - in which the printing is carried out at least at a number N of mixing ratios of the pigment composition to the ink mixture, - and in which at least a part of the printed image (9) produced using the roller (42a) to be tested is examined with an optical measuring device (4), whereby test data are obtained.The following are considered novel and inventive: - a control device (3) compares the test data with data on the ink transport behavior of an arbitrary roller (42b); - the ink transport data used for the arbitrary roller (42a) are data obtained by means of printing with at least one number M of pigment composition to blend ratios greater than the number N; - and that extrapolation data are obtained from the comparison which extrapolate the ink transport behavior of the roller (42a) to be tested. An apparatus is also presented and applied for.