Ink-Wetting Solution Selection via Capillary Rising Speed Ratio

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Solution Overview

Problem

The relationship between water-based inks and wetting solutions in ink-jet recording devices is unclear, making it difficult to select an effective combination for improving ink introduction into the ink-jet head, leading to printing failures.

Innovation Solution

A method is developed to select a combination of water-based ink and wetting solution based on the rising speed ratio through a capillary, where the wetting solution is introduced into the ink-jet head prior to the ink, using the formula Vi/Vs ≥ 2 to ensure effective ink introduction, with the capillary having an inner diameter of 0.1 to 1 mm and the wetting solution providing at least twice the rising speed of the ink alone.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If water-based ink is introduced into the ink-jet head, then print quality can be achieved, but the ability to introduce ink may be poor resulting in printing failures

Engineering Contradiction:
Improveprint qualityVSAvoidink introduction ability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by introducing a wetting solution into the ink-jet head before introducing the water-based ink. This pre-treatment modifies the surface properties of the ink passage to enhance ink introduction. The wetting solution is introduced first to prepare the ink passage, ensuring that when the ink is subsequently introduced, it can flow properly without printing failures.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a wetting solution is introduced into the ink-jet head before ink, then ink introduction ability is improved, but the relationship between ink and wetting solution is unclear making selection difficult

Engineering Contradiction:
Improveink introduction abilityVSAvoidselection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by establishing specific selection criteria based on the rising speed ratio (Vi/Vs ≥ 2) of ink through a capillary with the wetting solution versus without it. This quantitative parameter provides a clear guideline for selecting compatible ink and wetting solution combinations, transforming the previously unclear relationship into a measurable and selectable criterion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the complex trial-and-error selection process with a simplified measurement system using a capillary tube. Instead of testing various combinations empirically, the invention substitutes a mechanical measurement approach by observing ink rising speed in a capillary, providing an objective and straightforward method for selecting ink-wetting solution pairs.

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

3Stability of the object's composition

If physical properties such as viscosity and surface tension of water-based inks are the same, then ink composition may differ but ability to introduce ink into ink-jet head may still differ

Engineering Contradiction:
Improvedissolution stabilityVSAvoidink introduction ability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent introduces a wetting solution as an intermediary substance between the external environment and the ink-jet head's ink passage. This intermediary modifies the surface properties of the passage to facilitate ink introduction, bridging the gap between ink composition stability and introduction reliability. The wetting solution acts as a mediator that enables proper ink flow regardless of subtle compositional differences in the ink.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 improves the ability to introduce ink into the ink-jet head by ensuring the wetting solution enhances ink flow, reducing printing failures and optimizing ink-jet performance.

Implementation Method 1

one end of a capillary having an inner diameter of from about 0.1 to about 1 mm is dipped in a water-based ink so that the water-based ink rises inside the capillary

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS7824028B2Method for selecting water-based ink and wetting solution for ink-jet recording
Publication Date: 2010.11.02 BROTHER KOGYO KK

AI summary

Disclosed is a combination of a water-based ink and a wetting solution for ink-jet recording, which enables smooth introduction of the water-based ink into an ink-jet head. One end of a capillary having an inner diameter of from about 0.1 to about 1 mm is dipped in the water-based ink so that the water-based ink rises inside the capillary. A combination of a water-based ink and a wetting solution that satisfy the following formula (1) is selected:Vi/Vs≧about 2  (1)wherein Vs indicates a rising speed of the water-based ink at an intermediate position before and after the water-based ink rising when an inner wall of the capillary is in a dry state, and Vi indicates a rising speed of the water-based ink when an inner wall of the capillary is wetted with the wetting solution.