3D Printing Nozzle Clogging Prevention via Position-Based Flushing

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Solution Overview

Problem

Three-dimensional printing systems face nozzle clogging issues due to high temperatures in the build area, which can cause the agent to dry out or boil in the fluid ejection device, leading to system failures and reduced device lifespan.

Innovation Solution

A method of controlling the fluid ejection device to flush agent through the nozzles when it unintentionally stops over the hot build area, using techniques like spitting or priming to cool down the device and prevent clogging, while also detecting the device's position to avoid agent dispersion on unintended areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the fluid ejection device remains stationary on the hot build area during system failure, then the device can maintain its position for continued operation, but the agent dries out and clogs the nozzles

Engineering Contradiction:
Improvedevice operation continuityVSAvoidnozzle clogging
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs a preliminary flushing action by ejecting agent through the nozzles before complete drying occurs. The controller detects the stationary condition and initiates flushing cycles that prevent agent crystallization and nozzle clogging, maintaining device reliability without requiring movement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The flushing operation maintains continuous agent flow through the nozzles while the device remains stationary. By continuously ejecting small amounts of agent, the system prevents complete drying and maintains nozzle patency, allowing the device to remain operational without movement.

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If the fluid ejection device flushes agent continuously to prevent clogging, then nozzle reliability is maintained, but agent is wasted and evaporation increases

Engineering Contradiction:
Improvenozzle clearanceVSAvoidagent evaporation and waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The controller implements periodic flushing cycles rather than continuous flushing. Agent is ejected in intermittent pulses through the nozzles, sufficient to prevent clogging but minimal enough to reduce evaporation losses and conserve agent material.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes the ejection parameters by controlling the frequency, duration, and volume of flushing cycles. By adjusting these parameters dynamically based on device position and operational state, the system maintains nozzle clearance while minimizing agent loss through evaporation and waste.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the device detects stationary position to prevent clogging, then flushing can be initiated, but the detection system becomes more complex

Engineering Contradiction:
Improveclogging preventionVSAvoidposition detection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The position detection system leverages existing multi-functional sensors already present in the 3D printing system. The same sensors used for tracking device movement during normal operation are utilized to detect stationary conditions, eliminating the need for separate dedicated detection hardware.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The controller continuously monitors device position feedback from existing sensors and uses this information to trigger flushing operations when stationary conditions are detected. The feedback mechanism allows the system to respond automatically to position changes without requiring complex additional detection systems.

Inventive Principle:
Principle #23Feedback

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 effectively prevents nozzle clogging and extends the lifespan of the fluid ejection device by maintaining a cooling effect and reducing agent evaporation, ensuring continuous operation and preventing contamination outside the build area during system failures.

Implementation Method 1

flushing agent through at least one nozzle of the fluid ejection device... may produce a cooling effect on the fluid ejection device

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

the high temperature may push the fluid ejection device surface temperature beyond a boiling point of the agent and boil agent inside the nozzles and adjacent fluidics

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

boil agent inside the nozzles and adjacent fluidics

Methodology Applied
Scientific EffectBoiling: Boiling

Data Source

PatentEP3468776B1Flushing a fluid ejection device
Publication Date: 2021.06.09 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3468776B1 patent drawingFigure 1
  • EP3468776B1 patent drawingFigure 2

AI summary

A fluid ejection device controller for controlling a fluid ejection device of a three dimensional printing system has a processor and a memory. The memory includes executable instructions that when executed by the processor causes the fluid ejection device controller to control a motion of the fluid ejection device to print agent onto a layer of build material in a build area; and to flush agent through at least one nozzle of the fluid ejection device in response to detecting, by the fluid ejection device controller, an erroneous stopping of the motion of the fluid ejection device and the fluid ejection device being positioned on top of the build area.