13 patents in this list

Updated: May 25, 2024

Using bigger layers increases the likelihood of noticeable ridges and defects resulting from the standard layer-by-layer deposition procedure. Because of this, 3D-printed items may become less aesthetically pleasing and perhaps less suitable for use in specific contexts.

 

This page examines several methods for giving 3D-printed objects a smoother surface finish.

1.  Multi-Energy Beam 3D Printing for Smooth Surface Finish

LAYERWISE NV, 2023

A 3D printing system that uses multiple energy beams to improve the surface finish of 3D printed articles. The system has a printer with a motorized build plate, a powder coater, and multiple energy beam units. The beams scan over different regions of the build plate that overlap. This allows smoother transitions between beams compared to using a single beam. The overlapping regions reduce surface artifacts caused by switching beams. The system also offsets the layers slightly in the Y-axis to further smooth transitions.

2.  Smoothing Internal Surfaces of 3D Printed Metal Parts using EDM

HAMILTON SUNDSTRAND CORPORATION, 2023

A method to smooth and improve the internal surface finish of metal components produced by additive manufacturing techniques like 3D printing. The method involves using Electrical Discharge Machining (EDM) with an in-situ electrode and graphite additive. The graphite is injected into the component's internal cavities. An electrode is then inserted into the cavities, and EDM is performed using graphite as the dielectric medium. The electrical discharges remove irregularities from the cavity surfaces and convert them into smoother finishes.

US11745278B2-patent-drawing

3.  Electrochemical Machining for Smoothing Internal Surfaces in 3D Printed Parts

General Electric Company, 2023

A method for machining a workpiece with complex internal geometries to improve the interior surface finish. The method uses electrochemical machining (ECM) with an electrode placed within the internal passage. An electrolyte is circulated in the gap between the electrode and the workpiece. The voltage applied between the electrode and workpiece dissolves material from the interior surface to smooth it. The electrode can be removed after machining. This enables access and finishing of complex internal geometries that conventional ECM cathodes cannot reach.

US11745279B2-patent-drawing

4.  Laser Re-melting for Improved Surface Finish in Metal 3D Printing

NATIONAL CHENG KUNG UNIVERSITY, 2023

Optimizing the parameters of a laser re-melting step after laser powder bed fusion (L-PBF) additive manufacturing to reduce the surface roughness of metal parts. The method uses simulation to find the best laser power, scanning speed, and hatching spacing for re-melting based on the initial surface roughness. A model predicts the post-re-melting roughness and iteratively adjusts parameters until the target roughness is reached. By virtually testing re-melting parameters before applying them to parts, the process can be optimized to reduce surface roughness without trial-and-error experimentation.

5.  Producing Smooth 3D Printed Parts via Relief Layer Application

Océ Holding B.V., 2021

Generating a three-dimensional object with a smoother outer surface from a polygon mesh representation. The method involves determining a polygon mesh resembling the object, finding the surface difference between the mesh and the desired object, defining a relief layer based on that difference, and printing/folding the relief layer onto the mesh to improve the smoothness of the resulting 3D object.

US11084214B2-patent-drawing

6.  Multi-Pass Laser Sintering for Smooth Finish in 3D Printing

EOS GmbH Electro Optical Systems, 2021

Improving the surface quality of 3D printed objects, particularly reducing roughness and porosity compared to conventional laser sintering. Producing smoother object surfaces by selectively scanning and solidifying surface regions multiple times before inner regions when building each layer of a 3D printed object. This allows more controlled melting and fusion of the surface material to create smooth, glossy finishes without requiring post-processing.

US11045876B2-patent-drawing

7.  Achieving Smooth Surface Finish in 3D Printing by Adjusting Powder Density and Feed Rate

Shigeki Yamada, Hiroyuki Hara, 2006

A method for 3D printing complex objects with smooth surfaces. It uses an adjustable powder feed rate and particle size differentiation to create varying powder densities between the inner and outer regions of the printed layers. By using higher-density powders and lower feed rates for outer layers, the technique prevents excess powder from sticking to the outer surface of the printed object.

8.  Support Structure Molding for Obtaining High-Resolution Surface Finish in 3D Printed Objects

Robert L. Zinniel, John Samuel Batchelder, 2006

A method for building a high-resolution, rapidly manufactured, three-dimensional object. The method involves jetting a first material to form a plurality of layers that define an increment of a support structure. Then, a second material is extruded to form a three-dimensional object, with the support structure supporting the object. The interior surface of the support structure acts as a mold to shape the object, resulting in a high-resolution interior surface.

US20060158456A1-patent-drawing

9.  Tunable Polishing Pad for 3D Printed Surface Finishing

APPLIED MATERIALS, INC., 2023

A polishing pad with tunable performance is created by sequentially forming layers of different polymer compositions to create a polishing surface with tunable properties for planarizing substrates. The layers can include porosity-forming agents that degrade in aqueous solution to create voids. The pad can have regions with different compositions, hardness, porosity, contact angle, and thermal diffusivity. This allows precise customization of local polishing characteristics like material removal rate, friction, and slurry transport. The layering enables performance tuning.

10.  Production of Titanium Alloy Powder for Enhanced Surface Quality in 3D Printing

SHENYANG UNIVERSITY OF TECHNOLOGY, 2023

An improved method to produce titanium alloy powder optimized for 3D printing. The method involves gradually reducing gas atomization pressure and increasing the feeding speed of the titanium alloy electrode while atomizing the metal. This hierarchical control reduces collision probability between droplets, improving surface quality while maintaining fine powder yield.

US20230234131A1-patent-drawing

11.  Multi-Fluid 3D Printing for Better Surface Quality

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

3D printing method using multiple fluids for additive printing of objects with improved surface quality and post-processing ability. The method involves selective application of different fluids including fusing agents with radiation absorbers, reactive agents to modify the build material, and detailing agents for finishing. The combination allows targeted coalescing of the build material layers during printing and chemically treating the surface afterwards.

US20230226754A1-patent-drawing

12.  Electrochemical Finishing for 3D Printed Metal Parts

Faraday Technology, Inc., 2023

Surface finishing method to achieve a desired surface finish on additively manufactured metal parts with minimal material removal. The method involves using sequenced pulse reverse waveform electrochemical finishing to decrease the surface roughness of an additively manufactured metal part to a desired final surface roughness. The waveform is tuned through multiple iterations to progressively smooth the part surface while minimizing material removal.

US11702759B2-patent-drawing

13.  Vapor Smoothing Process for 3D Printed Parts

Robert L. Zinniel, 2011

Smoothing the surfaces of 3D printed objects produced by rapid manufacturing techniques, like stereolithography, using vapor smoothing. The process involves placing the printed object in a sealed chamber containing a vaporizable solvent. The solvent vapor partially reflows the surface material of the object, reducing the layered appearance. The object is then moved to a separate drying chamber to remove any solvent residue.

Request the PDF report with complete details of all 13 patents for offline reading.

Due to developments in post-processing methods such as adjustable polishing pads and electrochemical machining, as well as optimization of printing parameters and materials, 3D objects can now have a flawless surface finish. This gives 3D printing new applications in a variety of industries.