16 patents in this list

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In additive manufacturing, layer defects can compromise both structural integrity and dimensional accuracy. Recent data shows that interlayer bonding issues, thermal stress-induced warping, and incomplete curing account for up to 60% of part failures, with deviation tolerances as small as 50 microns making the difference between acceptance and rejection in precision applications.

The fundamental challenge lies in maintaining consistent layer properties while managing the complex thermal and mechanical interactions that occur as new material bonds to previously deposited layers.

This page brings together solutions from recent research—including dual-cure photopolymer systems, in-situ quality monitoring techniques, statistical defect detection models, and optimized powder distribution methods. These and other approaches provide practical strategies for achieving reliable layer adhesion and preventing common defects during the build process.

1. 3D Printing Method Utilizing Tacky Polymer Substrate for Metal Layer Formation

HEWLETT-PACKARD DEVELOPMENT COMPANY, L.P., 2023

3D printing metal objects without warping or cracking by using a tacky polymer substrate. The process involves spreading a layer of metal particles over a polymer substrate with low thermal conductivity and melting the unmasked metal with pulsed light to form each layer of the object. The polymer substrate reduces lateral heat transfer during melting, preventing warping and cracking.

2. Layer Inspection System with Pixel-Level Defect Probability Analysis Using Statistical Learning Model for 3D Printing

Carl Zeiss Industrielle Messtechnik GmbH, 2023

Using a statistical learning model to inspect camera images of each layer during 3D printing to detect layer defects early and correct them before building on top. The model provides defect probabilities for each image pixel. If defects are found, the layer is reworked.

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3. 3D Printing Method Using Photopolymer Composite Ink with Dual-Cure System and Inorganic Fillers

Mighty Buildings, Inc., 2023

3D printing of parts with improved mechanical properties and reduced warping. The method involves using a photopolymer composite ink with a dual-cure system that enables complete curing of each layer in a 3D printed object. The composite consists of a polymer matrix, inorganic fillers, and a combination of photo and thermal initiators. The dual-cure initiators allow the composite to be partially cured by UV light after each layer is printed and then fully cured by heat. This prevents uncured resin from accumulating stress and warping the part.

4. In-Situ Mechanical Excitation and Response Measurement System for Defect Detection in Additive Manufacturing

Siemens Energy Global GmbH & Co. KG, 2023

In-situ quality testing of additively manufactured components during production to detect defects like cracks or delamination and prevent fabrication of flawed parts. The process involves mechanically exciting constructed layers of the component and measuring the mechanical response. If the response deviates from a tolerance range, indicating flaws, the production is halted. Excitation can be done using vibrations or oscillations and measurement can use pickups or sensors.

5. Additive Manufacturing System with In-Line Layer Measurement and Deviation Detection

Shibaura Machine Co., Ltd., 2022

Additive manufacturing system that can detect and prevent defects during 3D printing to improve the quality of the printed objects. It does this by incorporating an in-line measurement unit that measures each layer as it is printed. The system then compares the layer measurements against reference data of a known good object to detect any deviations that could indicate an internal defect. This allows defects to be caught and corrected during the printing process rather than after completion.

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6. Selective Laser Melting System with Layer Imaging and Adaptive Laser Parameter Adjustment

Central University of Technology, Free State, 2016

Selective laser melting (SLM) additive manufacturing system that monitors layer-by-layer manufacturing of a product and adjusts control parameters during manufacturing to correct defects. It captures images of each layer before adding the next layer and then analyzes the images to identify irregularities. If found, it adjusts the laser parameters for the next layer to avoid defects like balling.

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7. 3D Printer Powder Loading System with Chamber-Based Compaction and Transfer Mechanism

Hewlett-Packard Development Company, L.P., 2023

A loading system for 3D printers that reduces mounding and increases the uniformity of powder layers. The system has a loading chamber positioned over the supply container. Powder is dispensed into the chamber and compacted to increase uniformity. The chamber floor is then lowered into the supply container, transferring the compacted powder. This loading process helps distribute the powder more evenly throughout the container compared to filling it directly.

8. Layer-by-Layer Inspection and Material Deposition Correction System for 3D Printing

INSTITUT DE RECHERCHE TECHNOLOGIQUE JULES VERNE, 2022

Inspecting parts during 3D printing to identify and repair defects as they occur. The method involves inspecting each layer after deposition to detect defects and repairing any defects by adding material before continuing to the next layer. The inspection can use techniques like scanning, imaging, or sensing to identify defects like voids, gaps, or misplaced material. It allows defects to be corrected in real time during manufacturing rather than after completion.

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9. Structured Light-Based Monitoring and Control System for Powder Deposition and Melting in Additive Manufacturing

Reliance Precision Limited, 2022

Monitoring and controlling powder deposition and melting quality in additive manufacturing to improve 3D printing accuracy and reliability. The method involves projecting structured light onto each powder layer before and after melting, imaging the light patterns to detect defects, and using the feedback to influence subsequent deposition and melting correctively.

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10. Additive Manufacturing System with Real-Time Defect Analysis and Layer Correction Mechanism

Sentient Science Corporation, 2022

A feedback-based correction system for additive manufacturing defects that helps repair defects on the fly during 3D printing. The system involves using real-time defect analysis during printing to scan each layer for defects and then sending correction commands to the printer to fix issues before moving on to subsequent layers.

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11. Photonic Sintering-Based Self-Alignment Method for Multilayer Printed Metal Patterns

National Research Council of Canada, 2021

A simple and reliable technique to enable high precision self-alignment of printed metal layers in multilayer printable electronic devices. The technique uses photonic sintering of metal nanoparticle inks to align the metal patterns. A first metal layer is printed on a transparent substrate and acts as a mask. A second metal layer is printed over a functional layer. Intense light pulses are then applied from the back of the substrate to partially sinter exposed particles, leaving aligned metal patterns. The unexposed particles are washed away.

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12. Layer-by-Layer Electromagnetic Acoustic Transducer Scanning for Anomaly Detection in Additively Manufactured Components

THE BOEING COMPANY, 2020

Non-destructively inspecting additively manufactured components layer-by-layer during manufacturing using an electromagnetic acoustic transducer (EMAT) to detect anomalies like cracks and residual stress. The EMAT scans over each layer of the component being formed with an additive manufacturing head, collecting acoustic data that indicates quality. The data is compared to reference images and analyzed to detect defects.

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13. 3D Printing Method with Adaptive Radiation Dose for Voxel Curing Compensation

Netherlands Organization for Applied Scientific Research TNO, 2020

A 3D printing method to compensate for defects caused by incomplete curing of voxels in each layer. The method involves selectively exposing the layer of uncured material based on layer data, then verifying the layer for regions of insufficiently cured material. The radiation dose is adapted for contiguous voxels in the next layer to compensate for the defects.

14. Layerwise 3D Printing Defect Correction via Real-Time Optical Beam Modulation

Lawrence Livermore National Security, LLC, 2019

A manufacturing technique to dynamically correct layerwise 3D printing defects. It uses optical beams to heat and modulate the material surface in real-time during printing. Optical beams are used to control light valves and electric field modulators that modify the energy and electric fields acting on the material surface. This allows localized surface melting and shaping to correct defects, planarize surfaces, remove impurities, and add features during printing. The beams can be tuned independently to address the modulators.

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15. Layer-by-Layer Defect Elimination in 3D Printing via In-Situ Laser Melting and Selective Material Removal

Moog Inc., 2017

A method to eliminate defects like surface roughness and sub-surface voids in 3D printed objects during the printing process itself instead of removing them after printing. The method involves partially melting each layer with a laser then removing the layer while it's still in the powder bed. This selectively removes just the layer material at the interface with the unfused powder, effectively eliminating roughness and voids that typically form there.

16. Data Model for Additive Manufacturing with Irregular 3D Volume Regions and Oblique Layer Interfaces

CARL FRUTH, 2013

A data model for additive manufacturing of components to reduce distortion. The model divides the component into irregular 3D volume regions, each of which extends over multiple build layers. The regions have oblique interfaces that intersect the layers at different positions. This disrupts the layer-by-layer building process and reduces distortion by breaking up stresses. Control parameters like fill pattern and energy input can be set separately for each region or layer within regions.

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Request the PDF report with complete details of all 16 patents for offline reading.

Ranging from sophisticated material handling methods to real-time flaw detection and rectification. These innovations show the progress being made to raise the uniformity and dependability of parts that are 3D printed. Future 3D printing results should be even higher quality as these techniques are developed and used.