62 patents in this list

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Layer adhesion remains a critical challenge in additive manufacturing, with delamination failures occurring at interfacial bonds that typically achieve only 20-80% of bulk material strength. These weak interfaces arise from insufficient molecular diffusion between layers, thermal gradients during solidification, and residual stresses that can exceed 10 MPa in some polymer systems.

The fundamental challenge lies in achieving molecular-level bonding between successive layers while maintaining dimensional accuracy and processing speed.

This page brings together solutions from recent research—including cross-layer mechanical anchoring systems, multihydrazide adhesion promoters, controlled thermal management during layer fusion, and stress-relieving substrate designs. These and other approaches focus on practical methods to enhance interlayer strength without compromising print quality or production efficiency.

1. Method for 3D Printing Multi-Layer Structures with Interlayer Cavities Filled by Transverse Rivets

DANA ITALIA S.R.L., 2023

A method for 3D printing multi-layer structures with improved interlayer adhesion to prevent delamination. The method involves creating cavities that cross multiple layers during printing and then filling the cavities with a second material to form rivets perpendicular to the layers. The rivets compress the surrounding layers as they cool and contract, increasing adhesion.

2. 3D Printed Green Body with Multihydrazide-Enhanced Layer Bonding

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

Improving the tensile strength of 3D printed green bodies to prevent damage during transportation and handling prior to fusing. The method involves selectively applying an adhesion promoter containing multihydrazide compounds like adipic dihydrazide to the binder fluid used in 3D printing. The multihydrazide adhesion promoter enhances the bonding between layers of particulate build material when forming the green body.

3. Layered Object Fabrication Method Utilizing Sub-Glass Transition Temperature Heating for Enhanced Interlayer Adhesion

SEIKO EPSON CORPORATION, 2021

Method for manufacturing a three-dimensional shaped object with high adhesion between layers without using solvents. The method involves shaping a first layer, cutting it, heating it to a temperature below the resin's glass transition temperature, and then shaping subsequent layers on top. The heating step increases adhesion between the layers.

4. 3D Printer Head with Nozzle-Integrated Layer Texturing Protrusions

SIGNIFY HOLDING B.V., 2019

Printing head for 3D printers that improves adhesion between layers of printed objects. The nozzle of the head includes a texturing member that protrudes from the main surface of the printed layer. These protrusions increase the contact surface area between layers, improving adhesion strength. The textured layer interfaces lock together better when subsequent layers are printed on top. The protrusions can be clamping features that grip the next layer.

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5. Method for Enhancing Interlayer Adhesion in Fused Material Extrusion via Temperature Differential Extrusion

SABIC GLOBAL TECHNOLOGIES B.V., 2018

A method to improve interlayer adhesion in 3D printed objects made by fused material extrusion, e.g., FDM. The method involves extruding adjacent layers at different temperatures. The temperature difference between layers should be at least 5°C. This sequence of alternating temperatures enhances bonding between layers to improve the overall strength of the printed object. The layers are fused together after extrusion to form the final article.

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6. Additive Manufacturing Feedstock with Removable Capsules for Interlayer Void Formation

Empire Technology Development LLC, 2017

A feedstock for additive manufacturing that enables strong interlayer bonding in 3D printed objects. The feedstock contains removable capsules that, when extracted after printing, leave voids on the surface of the solidified layer. The voids are then filled by the next layer's material, forming mechanical interlocks between layers. This provides enhanced adhesion compared to regular printing.

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7. Additive Manufacturing System with Molten Polymer Interfacial Layers for Inorganic Layer Adhesion

XEROX CORPORATION, 2025

Additive manufacturing method and system that uses a polymer interfacial material to improve adhesion between printed inorganic layers during 3D printing. The method involves printing a polymer layer between inorganic layers to separate them and prevent sticking. The polymer is kept molten during printing at temperatures above its melting point to enable good wetting and adhesion between the inorganic layers. This allows printing complex shapes with interfaces between dissimilar materials like metals, oxides, and salts without support structures. The polymer interfacial layer can be removed after printing.

8. Method for Enhancing Mechanical Properties of 3D-Printed Resin Sheets via Combined Heating and Compression

KURARAY CO., LTD., 2025

A method to improve the mechanical properties of resin sheets produced by 3D printing by post-processing the sheets. The method involves heating and compressing the printed resin sheet under pressure. This step fuses the resin blocks together, increasing contact area and polymer entanglement. This improves the mechanical properties of the resin sheet compared to just printing or just post-processing steps like heating or compressing alone.

9. Integrated Device with Ultrasonic Rolling, Powder Spreading, and Compaction Sections for Additive Manufacturing

China University of Mining and Technology, 2025

Integrated device for additive manufacturing with ultrasonic rolling, powder spreading, and compaction to improve surface finish and reduce roughness compared to conventional additive manufacturing techniques. The device has an ultrasonic rolling section, powder spreading section, and compaction section. After powder spreading, ultrasonic rolling flattens the powder, then compaction compresses it. This smooths the powder layer for better adhesion and reduces surface roughness. The device is integrated into an additive manufacturing platform that lifts and lowers to alternate layers.

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10. Direct Extrusion of Thermoplastic Structures onto Fiber-Reinforced Composite Surfaces

VICTREX MANUFACTURING LTD, VICTREX MFG LTD, 2024

Directly printing thermoplastic structures onto composite parts made of fiber-reinforced thermoplastic prepreg tape or sheet. The method involves extruding molten thermoplastic feedstock through a printing head onto the composite part at a temperature higher than the matrix polymer melting point. The first layer melts and bonds the composite, then subsequent layers build the structure. The printed layers fuse together and co-mingle with the matrix polymer, creating a strong melt bond. This allows complex shapes to be formed on prepreg without needing additional adhesives or molds.

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11. Gradient Nesting Material with Core-Cladding Layer Interface Polymerization for Enhanced Interlayer Adhesion

GUANGZHOU YOUSU 3D TECH CO LTD, GUANGZHOU YOUSU 3D TECHNOLOGY CO LTD, 2024

Gradient nesting material for 3D printing with improved interlayer adhesion. The material consists of a core layer and a cladding layer. Polymerization occurs at the interface between the layers. The core layer contains a second polymer, a polymerization aid, and catalyst. The cladding layer contains a first polymer. The polymerization aid enables chemical bonding between the polymers at the interface, improving adhesion and preventing delamination. This allows 3D printing of dissimilar materials with better mechanical properties in all directions.

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12. Method for Producing Substrate Laminates with Cured Low Modulus Bonding Layer

Mitsui Chemicals, Inc., 2023

Manufacturing method for substrate laminates with reduced voids and misalignment issues. The method involves applying a curable bonding material to the substrate surfaces, curing it to form a low modulus (10 GPa or less) bonding layer, then bonding the substrates through that layer. This prevents void formation and misalignment compared to using uncured bonding material.

13. Method for Layer Bonding in Additive Manufacturing Using Transparent Substrate and Flexible Pressure Media

Sakuu Corporation, 2023

An improved method for layer-to-layer bonding in additive manufacturing ensures reliable, uniform bonding of new layers to previously processed layers. The method involves using a transparent substrate between the new uncured layer and the previously cured layer and curing the new layer by applying energy through the substrate to simultaneously cure and bond the new layer to the stack. A flexible pressure conveyance media is then applied to the substrate to uniformly compress the new layer onto the stack during curing.

14. Composite Structure with Interwoven Belts and Interlocking Posts for Enhanced Through-Thickness Integrity

Boeing Company, THE BOEING CO, 2023

Composite structures with improved through-thickness toughness and crack resistance. The structures have interwoven belts with posts that interlock between belts to provide continuity through the thickness. The belts have a two-dimensional mesh with filaments in orthogonal directions. The posts extend from the mesh and interlock between belts to create a three-dimensional network. This network provides interlocking interfaces between adjacent layers that prevent crack propagation through the thickness. The belts can be positioned between layers of fiber bundles during composite fabrication to toughen the structure.

15. Method for Forming Double Network Structure in 3D Printed Polydicyclopentadiene Using Mixed DCPD and Epoxy Monomer Solution

Sun Yat-sen University, SUN YAT-SEN UNIVERSITY, 2022

Method to improve bonding between layers of 3D printed polydicyclopentadiene (DCPD) devices. The method involves using a mixed solution containing both DCPD and a liquid epoxy monomer as the 3D printing material. During printing, the DCPD front-end polymerizes and cures at lower temperatures than the epoxy monomer. After printing, heat treatment causes the epoxy monomer to thermally polymerize and form a second network inside the DCPD layers, providing interlayer bonding. This double network structure significantly improves the interlayer bonding strength of 3D printed DCPD devices compared to using just DCPD.

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16. 3D Printing Method with Interlocking Layer Embedding for Enhanced Shear Resistance

NANJING UNIV OF SCIENCE & TECHNOLOGY, NANJING UNIVERSITY OF SCIENCE & TECHNOLOGY, 2022

A 3D printing technique to improve the strength of printed parts in the thickness direction. The technique involves embedding adjacent layers of the printed structure into each other. This creates interlocking connections between layers that improves shear resistance compared to conventional layer-by-layer printing. The embedding is achieved by modifying the printing path to overlap adjacent layers during deposition. This allows the filament to be extruded into the gaps between layers of the previous print pass. The interlocking structure created by embedding adjacent layers helps prevent separation and shear failure in the thickness direction.

17. Method for Integrating Toughness Films in 3D Printed Fiber-Reinforced Resin Composites

WU SIYUAN, 2022

Method to improve the interlayer performance of 3D printed fiber-reinforced resin composites by adding toughness films between the layers. The method involves fused deposition printing tough resin filaments between the fiber-reinforced resin layers to form thin films. This creates multi-phase interfaces that enhance strength and toughness. The toughness films can be made from short fiber, particle, nanotube, graphene, or high-toughness resins. The shape, position, thickness, and type of the films can be customized for different applications. Auxiliary heating and hot pressing are used to improve bonding strength. This allows targeted local or global reinforcement and toughening of printed parts.

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18. Additive Manufacturing Method Utilizing Thermally Activated Flowable Photocurable Composition

Henkel AG & Co. KGaA, 2022

Method for performing additive manufacturing using a photocurable composition to form a three-dimensional part. The method involves providing a non-flowable photocurable composition in a reservoir, heating it to a temperature to make it flowable, and then exposing it to radiation to initiate polymerization. This allows the formation of a photoplastic material with improved properties compared to existing photopolymers.

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19. 3D Printing Method with Separate Curing for Laminated Structures Using Predetermined Distanced Objects

M O P CO LTD, MOP CO LTD, 2022

3D printing method to prevent interlayer mixing and rounding issues when forming laminated structures with different materials. The method involves providing separate objects and surrounding objects with a predetermined distance between them. This prevents mixing between layers during curing. The objects are formed by sequentially curing slurries. The surrounding objects are cured separately. The objects and surrounding objects can be separated after printing. This allows forming structures surrounded by different materials without mixing or rounding issues.

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20. Adhesive Layer with Cavity Structure for Stress Relief in 3D Printed Electronics on PCBs

Signify Holding B.V., SIGNIFY HOLDING BV, 2022

3D printing electronics directly onto printed circuit boards (PCBs) without bending them by using an adhesive layer between the PCB and the 3D printed structure. The adhesive layer has cavities or a grid structure to provide stress relief and improve adhesion. This allows 3D printing on PCBs without causing board deformation. The adhesion layer prevents bending by dispersing stresses across the PCB surface. The cavities or grid structure in the adhesive layer provide stress relief to further prevent PCB deformation during 3D printing.

21. 3D Printing Process for Reinforced Concrete Structures with Continuous Layer-Integrated Reinforcement Elements

22. 3D Printing of Semi-Crystalline and Amorphous Polymers with Low Curing Temperature for Enhanced Layer Adhesion

23. 3D Printing Filament Comprising High and Low Molecular Weight Polymer Blend for Enhanced Interlayer Bonding

24. Method for 3D Printing with High-Temperature Powder Bed and Adhesive Curing System

25. Manufacturing Method for Multilayer Structures Using Partially Cured Thermosetting Adhesive Films

In order to achieve better inter-layer bonds in 3D printed objects, these techniques involve novel material combinations and printing processes that go beyond the initial layer formation. This opens up new applications and produces stronger printed parts.

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