Oleophobic Membrane for Phase-Change Inkjet Printhead Bubble Venting

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Solution Overview

Problem

Inkjet printers using phase-change inks face issues with air bubbles forming due to freeze-thaw cycles, which obstruct ink jet pathways and result in printing inaccuracies and ink wastage during bubble removal processes.

Innovation Solution

An oleophobic membrane with a nanostructured surface and low-surface energy coating is integrated into the inkjet printhead, allowing air to vent while containing ink, thereby reducing bubble-related inaccuracies and ink wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If phase-change ink is used in inkjet printers, then printing capability is improved, but air bubbles form during freeze-thaw cycles which obstruct ink jet pathways

Engineering Contradiction:

Improveprinting capabilityVSAvoidink jet pathway obstruction

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

An oleophobic membrane is introduced as an intermediary component between the ink reservoir and the ink jet pathways. This membrane selectively allows air bubbles to pass through while blocking liquid ink, thereby removing bubbles without obstructing the ink flow pathways. The membrane acts as a mediator that resolves the contradiction by enabling bubble venting while maintaining ink flow integrity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The oleophobic membrane is designed with a porous structure that enables selective permeability. The pores are sized and configured to allow air bubbles to pass through while the oleophobic coating prevents liquid ink from penetrating. This porous structure resolves the technical contradiction by providing a pathway for bubble removal while maintaining ink pathway integrity.

Inventive Principle:

Principle #31Porous materials

2Manufacturing precision

If air bubbles are removed from ink flow channel, then printing accuracy is improved, but ink wastage occurs during purging processes

Engineering Contradiction:

Improveprinting accuracyVSAvoidink wastage

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The oleophobic membrane serves as a mediator that enables bubble removal without requiring purging operations. By continuously allowing bubbles to pass through while blocking ink, the membrane eliminates the need for periodic purging to remove bubbles, thereby preventing ink wastage while maintaining printing accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The oleophobic membrane provides continuous bubble removal throughout the printing process rather than requiring intermittent purging operations. This continuous action ensures that bubbles are removed as they form, maintaining consistent printing accuracy without the ink wastage associated with periodic purging cycles.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If oleophobic membrane is integrated into printhead, then bubble venting is improved, but device complexity increases

Engineering Contradiction:

Improvebubble venting capabilityVSAvoidprinthead structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The oleophobic membrane is implemented as a thin film or flexible structure that can be easily integrated into the existing printhead design. This thin film approach minimizes the increase in device complexity while providing effective bubble venting capability. The membrane can be positioned as a simple barrier layer within the ink flow channel without requiring complex mechanical structures.

Inventive Principle:

Principle #30Flexible shells and thin films

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

The oleophobic membrane effectively vents air bubbles from the ink flow channel, maintaining ink integrity and reducing the need for purging, thus enhancing printing accuracy and conserving ink and power.

Implementation Method 1

An oleophobic membrane with a nanostructured surface and low-surface energy coating is integrated into the inkjet printhead, allowing air to vent while containing ink

Methodology Applied

Scientific EffectOleophobic effect: Hydrophobe

Implementation Method 2

The oleophobic membrane includes a metal structure having a nanostructured surface and a low-surface energy coating disposed upon the metal structure

Methodology Applied

Scientific EffectSurface energy reduction: Surface Tension

Data Source

PatentUS9044943B2Inkjet printhead incorporating oleophobic membrane

Publication Date: 2015.06.02 XEROX CORP

AI summary

An inkjet printhead includes an oleophobic membrane arranged at a location that allows the oleophobic membrane to simultaneously vent air from an ink flow channel of the printhead and to retain ink within the ink flow channel. The oleophobic membrane includes a metal structure having a nanostructured surface and low-surface energy coating disposed on the metal structure.