Laser Window Lock Chamber for Inert 3D Printing Maintenance

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Solution Overview

Problem

Current methods for cleaning and replacing laser windows in process chambers used for 3D printing technologies like Selective Laser Sintering and Direct Metal Printing are inefficient, as they require interrupting the manufacturing process to maintain a modified atmosphere, leading to contamination and instability due to thermal lensing caused by laser window absorption.

Innovation Solution

A device with a movable sealing plate and internal sealing ring creates a lock chamber around the laser window, allowing for cleaning or replacement while maintaining the modified atmosphere within the process chamber, using an external guide mechanism and inflatable seals to ensure a sealed environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the laser window is cleaned or replaced by opening the process chamber, then the laser window can be accessed for maintenance, but the modified atmosphere is lost and the process must be interrupted

Engineering Contradiction:
Improvelaser window maintenanceVSAvoidmanufacturing process continuity
Core Design Contradiction:
Ease of repairVSProductivity

Solution Approach 1:

The process chamber is segmented into two independent sealed chambers: the main process chamber and a lock chamber. The laser window is accessible from the lock chamber, allowing maintenance without opening the main process chamber. This segmentation enables independent access to the laser window while preserving the atmosphere in the main chamber.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lock chamber serves as an intermediary space between the operator and the main process chamber. It provides a transition zone where the laser window can be accessed, cleaned, or replaced without directly opening the main process chamber, thus preventing atmosphere loss and maintaining process continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of repair

If the laser window is cleaned or replaced by opening the process chamber, then the laser window can be accessed for maintenance, but the modified atmosphere must be recreated which is highly time-consuming

Engineering Contradiction:
Improvelaser window maintenanceVSAvoidatmosphere recreation time
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The process chamber is segmented into two independent sealed chambers: the main process chamber and a lock chamber. The laser window is accessible from the lock chamber, allowing maintenance without opening the main process chamber. This segmentation enables independent access to the laser window while preserving the atmosphere in the main chamber.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lock chamber is pre-prepared with its own atmosphere control system, including vacuum pumping and gas supply capabilities. This preliminary preparation allows the lock chamber to be sealed and pressurized independently before laser window maintenance begins, eliminating the need to recreate the atmosphere in the main process chamber during maintenance.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the laser window remains in place, then the process chamber remains sealed, but the laser window becomes contaminated causing thermal lensing and process instability

Engineering Contradiction:
Improveprocess chamber sealingVSAvoidmelting process stability
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The laser window is made dynamically accessible through the lock chamber mechanism. The sealing plate can be moved to seal the opening in the outer wall, allowing the laser window to be removed, cleaned, or replaced while maintaining the seal of the main process chamber. This dynamic system allows the laser window to be maintained without compromising the sealing reliability of the process chamber.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lock chamber serves as an intermediary space between the operator and the main process chamber. It provides a transition zone where the laser window can be accessed, cleaned, or replaced without directly opening the main process chamber, thus preventing atmosphere loss and maintaining process continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If gas flow systems are built into the laser window, then contamination is limited, but the laser window still becomes contaminated requiring cleaning or replacement

Engineering Contradiction:
Improvelaser window contaminationVSAvoidgas flow system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The laser window is extracted from the main process chamber environment and placed in the lock chamber. This extraction allows the laser window to be removed, cleaned, or replaced without affecting the main process chamber. The gas flow systems can be removed with the laser window, simplifying the overall system by eliminating the need for integrated gas flow systems in the laser window itself.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Enables the cleaning or replacement of the laser window without disrupting the manufacturing process, maintaining the modified atmosphere and preventing thermal lensing, thus improving the stability and quality of the 3D printing process by minimizing residual porosity and surface roughness.

Implementation Method 1

The device features an inflatable seal that is deflated to allow movement of the sealing plate and inflated to seal the opening between the lock chamber and process chamber

Methodology Applied
Scientific EffectInflation:

Implementation Method 2

the laser window allows a laser beam from a laser source located outside of the process chamber into the process chamber

Methodology Applied
Scientific EffectLaser transmission: Laser

Implementation Method 3

the process chamber must first be placed under a vacuum to remove all oxygen

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3412385B1Method and device for cleaning and/or replacement of a laser window of a process chamber
Publication Date: 2023.04.12 LAYERWISE
  • EP3412385B1 patent drawingFigure 1~3
  • EP3412385B1 patent drawingFigure 4~5

AI summary

Method for cleaning and/or replacement of a laser window (1) of a process chamber (3), in particular a process chamber (3) for layered construction of a 3D object by means of a laser, and device with a laser window (1) and where this laser window (1) provided to the process chamber (3), having at least an opening (4) featuring the laser window (1), where the laser window (1) is movable with respect to the opening (4)wherein a sealing plate (6) is provided extending in the process chamber (3) and movable between an open position and a closed position, where in the closed position of the sealing plate (6) a lock chamber (8) is created around the opening (4) and an inlet (11) and an outlet (10) extend into the lock chamber (8) for supply of the modified atmosphere in this lock chamber (8).