Inkjet Printer Ink Service Module Foam Breaker

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Solution Overview

Problem

Continuous inkjet printers face issues with foam formation in the ink reservoir due to air entrainment during the return of ink from the print head, leading to ink overflow and pressure fluctuations, which existing solutions like anti-foaming agents or complex physical arrangements fail to adequately address.

Innovation Solution

A method involving a sub-chamber within the ink receiving chamber where the returning ink is slowed and its pressure reduced, causing air to be released before the ink overflows into the main chamber, with the foam settling on the surface and being separated from the ink circulation system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a jet pump is used to remove ink from the gutter, then ink removal efficiency is improved, but air entrapment in the ink increases

Engineering Contradiction:
Improveink removal efficiencyVSAvoidair entrapment
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A foam breaker component is introduced as an intermediary element between the jet pump and the ink reservoir. This foam breaker has a porous structure that allows air bubbles to escape from the ink stream while preventing liquid ink from being discharged. The foam breaker acts as a mediator that separates the air removal function from the ink circulation function, enabling efficient air venting without compromising ink delivery.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The foam breaker is constructed with porous material that has specific pore size and distribution. These pores are sized to allow air bubbles to pass through while blocking liquid ink. The porous structure provides a large surface area for air-liquid separation, enabling efficient foam breakdown and air venting while maintaining ink circulation integrity.

Inventive Principle:
Principle #31Porous materials

2Object-generated harmful factors

If anti-foaming agents are added to the ink, then foam formation is reduced, but ink adhesion and surface wetting properties deteriorate

Engineering Contradiction:
Improvefoam formationVSAvoidink adhesion and surface wetting
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The chemical approach of adding anti-foaming agents is replaced with a mechanical solution - the foam breaker component. This mechanical device physically breaks down foam structures and vents air bubbles through its porous structure, achieving foam control without introducing chemical surfactants that would compromise ink performance. The mechanical foam breaking mechanism preserves ink composition and its critical surface properties.

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

3Object-generated harmful factors

If a downwardly spiralling ramp is installed in the ink reservoir, then foam formation is reduced, but device complexity and space requirements increase

Engineering Contradiction:
Improvefoam formationVSAvoidreservoir structure complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The foam control function is segmented from the main ink reservoir system and implemented as a separate, modular foam breaker component. This component can be installed in the ink return line or circulation system without requiring modifications to the reservoir structure. The segmentation allows for simple installation and maintenance while achieving effective foam control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a complex three-dimensional spiralling ramp structure within the reservoir, the invention uses a two-dimensional porous surface (the foam breaker) that achieves foam control through its surface structure. This dimensional simplification reduces complexity while maintaining effectiveness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Effectively reduces foam formation and air entrapment in the ink, ensuring a stable ink supply by allowing air to be released and foam to settle on the surface, preventing its re-entrainment into the ink circulation system.

Implementation Method 1

The foam breaker may be porous and may prevent liquid from passing through whilst allowing gas to pass through

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 2

Jet pump action relies upon turbulence in a pump chamber between a nozzle and a throat in order to work effectively. This pump action has the effect of mixing air and ink efficiently as a by-product of the turbulence that is created

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 3

The removal of ink collected in the gutter is achieved by drawing the ink, along with air, through a return pipe located in the conduit. This is effected using a vacuum pump.

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP2640578B1Improvements in or relating to inkjet printers
Publication Date: 2015.08.19 DOMINO PRINTING SCIENCES
  • EP2640578B1 patent drawingFigure 1~2
  • EP2640578B1 patent drawingFigure 3~4
  • EP2640578B1 patent drawingFigure 5

AI summary

Method and Apparatus for Reducing Ink Foaming in a Continuous Inkjet Printer The invention provides a method of and apparatus for reducing foam formation in the returned ink in a continuous inkjet printer. The returned ink is subjected to deceleration and is reduced in pressure, preferably by being directed into a sub-chamber which reverses the direction of flow and provides an elevated edge over which the ink overflows. The de-aeration facility is preferably incorporated in an ink service module.