Inkjet Head Cleaning Sequence to Prevent Pigment Aggregation

Solution Overview

Problem

Existing inkjet head cleaning methods using organic solvent liquids disrupt the ink dispersion state, leading to pigment aggregation and discharge abnormalities due to solvent infiltration.

Innovation Solution

A method involving two cleaning liquids, where the first liquid maintains ink dispersion and the second liquid dissolves foreign matter, using solvents compatible and incompatible with the ink, respectively, followed by removal of residual liquids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cleaning liquid containing a solvent different from the ink solvent is used to remove foreign matter, then the cleaning effectiveness is improved, but the ink dispersion state collapses and pigment aggregates

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidink dispersion state

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The cleaning process is divided into two distinct stages: first using a cleaning liquid with the same solvent as the ink to remove foreign matter while maintaining ink dispersion, then using a cleaning liquid with a different solvent to remove water-soluble precipitates. This segmentation allows each cleaning liquid to perform its specific function without causing pigment aggregation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first cleaning liquid acts as an intermediary that protects the ink dispersion state while enabling the removal of foreign matter. By using a cleaning liquid with the same solvent as the ink, it creates a compatible environment that prevents pigment aggregation during the cleaning process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If a cleaning liquid with the same solvent as the ink is used, then the ink dispersion state is maintained, but water-soluble precipitates cannot be effectively removed

Engineering Contradiction:

Improveink dispersion stateVSAvoidremoval of water-soluble precipitate

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The cleaning process is divided into two distinct stages: first using a cleaning liquid with the same solvent as the ink to remove foreign matter while maintaining ink dispersion, then using a cleaning liquid with a different solvent to remove water-soluble precipitates. This segmentation allows each cleaning liquid to perform its specific function without causing pigment aggregation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The solvent type parameter of the cleaning liquid is changed between two different cleaning liquids. The first cleaning liquid uses the same solvent as the ink to maintain dispersion stability, while the second cleaning liquid uses a different solvent to effectively remove water-soluble precipitates.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If multiple cleaning liquids are used sequentially, then both foreign matter and water-soluble precipitates can be removed, but the cleaning process complexity increases

Engineering Contradiction:

Improvecomprehensive cleaning effectivenessVSAvoidcleaning process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cleaning process is divided into two distinct stages: first using a cleaning liquid with the same solvent as the ink to remove foreign matter while maintaining ink dispersion, then using a cleaning liquid with a different solvent to remove water-soluble precipitates. This segmentation allows each cleaning liquid to perform its specific function without causing pigment aggregation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cleaning device is designed to handle multiple cleaning liquids through a universal supply system that can switch between different liquid types. The discharge surface cleaning unit can process both the first and second cleaning liquids using the same structural components, reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Prevents pigment aggregation and maintains ink dispersion, ensuring stable ink discharge by effectively removing foreign matter without disrupting the ink's state.

Implementation Method 1

cleaning the inkjet head using a first cleaning liquid capable of maintaining a dispersion state of ink

Methodology Applied

Scientific EffectSolvation: Solvation

Implementation Method 2

cleaning the inkjet head using a second cleaning liquid capable of dissolving a water-soluble precipitate

Methodology Applied

Scientific EffectSolvation: Solvation

Data Source

PatentUS12479208B2Method for cleaning inkjet head and cleaning device

Publication Date: 2025.11.25 KONICA MINOLTA INC

AI summary

In a method for cleaning an inkjet head, the inkjet head is cleaned using a first cleaning liquid capable of maintaining a dispersion state of ink and a second cleaning liquid having a solvent different from the ink.