Additive Manufacturing Process Monitoring via Negative Structure Imaging
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Solution Overview
Problem
Existing additive manufacturing monitoring processes face challenges in providing an easy line-of-sight to the component or build zone, especially with excess uncured resin and highly reflective materials like loaded ceramic resins, which are difficult to image optically.
Innovation Solution
The method involves using an imaging apparatus to evaluate the negative image of a cured layer in remaining uncured resin, allowing for control of the additive manufacturing process by producing an image of the negative structure defined by uncured resin and utilizing this image to monitor and adjust the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If imaging apparatus is used to monitor the cured layer, then process monitoring capability is improved, but line-of-sight accessibility and imaging quality deteriorate due to excess uncured resin and highly reflective materials
Solution Approach 1:
Instead of imaging the cured layer directly, the patent images the negative structure formed by uncured resin that remains after curing. This inverted approach allows the imaging apparatus to capture the geometry of the cured layer indirectly through the pattern of remaining uncured resin, solving the line-of-sight and reflectivity problems.
Solution Approach 2:
The uncured resin acts as an intermediary medium that preserves the negative impression of the cured layer geometry. By imaging this intermediary negative structure rather than the cured layer itself, the system overcomes the difficulties of direct imaging caused by excess resin and reflective surfaces.
2Measurement precision
If imaging apparatus is used to evaluate the cured layer, then quality monitoring is improved, but measurement accuracy deteriorates due to highly reflective ceramic resins
Solution Approach 1:
The patent inverts the imaging target from the reflective cured ceramic layer to the non-reflective uncured resin that remains after curing. This negative structure imaging approach eliminates the harmful reflectivity effect while preserving the ability to monitor layer geometry and detect defects.
3Ease of operation
If direct imaging of the component is used, then process monitoring is simplified, but detection reliability deteriorates due to excess uncured resin obscuring the view
Solution Approach 1:
The patent extracts the useful information (geometry pattern) from the uncured resin itself rather than trying to see through it. By treating the uncured resin as the imaging target rather than as an obstacle, the system achieves both operational simplicity and detection reliability.
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 approach enables effective inline or online quality and process monitoring, detecting machine and build failures, allowing for potential corrections or stopping the build if necessary, and providing early estimates of part quality to inform decisions on inspection, repair, or scrapping.
Implementation Method 1
using an imaging apparatus to produce an image of the negative structure
Implementation Method 2
Exposure to the radiation cures and solidifies the pattern in the resin
Data Source
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AI summary
A method is provided for controlling an additive manufacturing process in which a layer of resin is deposited on a build surface (26) and selectively cured via selective application of radiant energy so as to define the geometry of a cross-sectional layer of the component (65), such that uncured resin remaining on the build surface (26) after curing defines a negative structure (80) of the layer being cured. The method includes: using an imaging apparatus (18) to produce an image of the negative structure (80); evaluating the image of the negative structure (80) and controlling at least one aspect of the additive manufacturing process with reference to the image of the negative structure (80).