Additive manufacturing of polymer-based structures by extrusion technologies

Abstract Extrusion-based additive manufacturing (AM) enables the fabrication of three-dimensional structures with intricate cellular architectures where the material is selectively dispensed through a nozzle or orifice in a layer-by-layer fashion at the macro-, meso-, and micro-scale. Polymers and their composites are one of the most widely used materials and are of great interest in the field of AM due to their vast potential for various applications, especially for the medical, military, aerospace, and automotive industries. Because architected polymer-based structures impart remarkably improved material properties such as low density and high mechanical performance compared to their bulk counterparts, this review focuses particularly on the development of such objects by extrusion-based AM intended for structural applications. This review introduces the extrusion-based AM techniques followed by a discussion on the wide variety of materials used for extrusion printing, various architected structures, and their mechanical properties. Notable advances in newly developed polymer and composite materials and their potential applications are summarized. Finally, perspectives and insights into future research of extrusion-based AM on developing high-performance ultra-light materials using polymers and their composite materials are discussed.

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Additive manufacturing of hydroxyapatite and its composite materials: A review

Journal of Micromechanics and Molecular Physics ◽

10.1142/s2424913020300029 ◽

2020 ◽

Vol 05 (03) ◽

pp. 2030002

Author(s):

Chunze Yan ◽

Gao Ma ◽

Annan Chen ◽

Ying Chen ◽

Jiamin Wu ◽

...

Keyword(s):

Tissue Engineering ◽

Additive Manufacturing ◽

Composite Materials ◽

Computer Aided Design ◽

Mechanical Performance ◽

Three Dimensional ◽

Research Field ◽

Manufacturing Processes ◽

Layer By Layer ◽

Tissue Engineering Scaffolds

Hydroxyapatite (HA) is a promising biomaterial for tissue engineering scaffolds due to its similar performance and composition to natural bone. However, the brittleness and poor toughness of pure HA limit its clinical application. Therefore, a lot of HA composites have been prepared to improve their mechanical performance. Fabricating complex and customized tissue engineering HA scaffolds have a very high requirement for manufacturing processes. It is difficult to fabricate ideal HA porous structures for artificial bone implants using traditional manufacturing processes, such as plasma spraying–sintering, and injection forming. Additive manufacturing (AM) could make three-dimensional physical parts with complex structures directly from computer-aided-design (CAD) models in a layer-by-layer way, and therefore show unique advantages in fabricating bone tissue engineering scaffolds with complex external shape and internal microporous structures. This paper reviews the state of the art for the preparation and AM process of HA and its composite materials, and raises the prospects for this research field.

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Effect of Structural Parameters on the Deformational Behaviors of Multiply 3D Layer-by-Layer Angle-Interlock Para-Aramid Fabric for Fiber-Reinforcement Composite

Journal of Composites Science ◽

10.3390/jcs4040145 ◽

2020 ◽

Vol 4 (4) ◽

pp. 145

Author(s):

Mulat Alubel Abtew ◽

Francois Boussu ◽

Pascal Bruniaux ◽

Carmen Loghin ◽

Irina Cristian

Keyword(s):

Mechanical Performance ◽

Structural Parameters ◽

Three Dimensional ◽

Layer By Layer ◽

Warp Yarn ◽

Plane Shear ◽

Technical Application ◽

Recovery Percentage ◽

Materials Used ◽

Interlock Structure

Materials used in the technical application including composite reinforcements and ballistic fabrics should show not only good mechanical performance but also better deformational behaviors. Meanwhile, three dimensional (3D) warp interlock fabrics have been widely employed in such applications to substitute the two dimensional (2D) fabrics because of their enhanced through-the-thickness performance and excellent formability. The deformational behaviors of such 3D warp interlock fabrics have been also influenced by various internal and external parameters. To understand and fill this gap, the current paper investigates the effects of the warp yarn interchange ratios inside the fabric structure on the formability behaviors of dry 3D warp interlock p-aramid fabrics. Four 3D warp interlock architecture types made with different binding and stuffer warp yarn interchange ratios were designed and manufactured. An adapted hydraulic-driven stamping bench along with hemispherical punch was utilized for better forming behavior analysis such as in-plane shear angle and its recovery, material drawing-in and its recovery, deformational depth recovery, and required stamping forces. Based on the investigation of various formability behaviors, the formability of (3D) warp interlock fabrics were greatly influenced by the binding and stuffer warp yarns interchange ratio inside the 3D warp interlock structure. For example, preform 3D-8W-0S exhibited a maximum deformational height recovery percentage of 5.1%, whereas 3D-4W-8S recorded only 0.72%. Preform 3D-8W-4S and 3D-8W-8S revealed 1.45% and 4.35% recovery percentages toward the deformational height at maximum position. Besides, sample 3D-4S-8W revealed the maximum drawing-in recovery percentage of 43.13% and 46.98% in the machine and cross direction, respectively, around the preform peripheral edges. On the contrary, samples with higher binding warp yarns as 3D-8W-0S show the maximum drawing-in recovery percentages values of 31.21% and 34.99% in the machine and cross directions respectively.

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3D Printing of High Viscosity Reinforced Silicone Elastomers

Polymers ◽

10.3390/polym13142239 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2239

Author(s):

Nicholas Rodriguez ◽

Samantha Ruelas ◽

Jean-Baptiste Forien ◽

Nikola Dudukovic ◽

Josh DeOtte ◽

...

Keyword(s):

Mechanical Properties ◽

High Performance ◽

New Technologies ◽

Three Dimensional ◽

High Viscosity ◽

Layer By Layer ◽

Silicone Elastomers ◽

Uv Curable ◽

Octet Truss ◽

Tunable Mechanical Properties

Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.

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Data-Driven Intelligent 3D Surface Measurement in Smart Manufacturing: Review and Outlook

Machines ◽

10.3390/machines9010013 ◽

2021 ◽

Vol 9 (1) ◽

pp. 13

Author(s):

Yuhang Yang ◽

Zhiqiao Dong ◽

Yuquan Meng ◽

Chenhui Shao

Keyword(s):

High Resolution ◽

High Performance ◽

Sampling Design ◽

Three Dimensional ◽

Measurement Data ◽

Data Driven ◽

Surface Measurement ◽

Smart Manufacturing ◽

Future Research ◽

3D Surface

High-fidelity characterization and effective monitoring of spatial and spatiotemporal processes are crucial for high-performance quality control of many manufacturing processes and systems in the era of smart manufacturing. Although the recent development in measurement technologies has made it possible to acquire high-resolution three-dimensional (3D) surface measurement data, it is generally expensive and time-consuming to use such technologies in real-world production settings. Data-driven approaches that stem from statistics and machine learning can potentially enable intelligent, cost-effective surface measurement and thus allow manufacturers to use high-resolution surface data for better decision-making without introducing substantial production cost induced by data acquisition. Among these methods, spatial and spatiotemporal interpolation techniques can draw inferences about unmeasured locations on a surface using the measurement of other locations, thus decreasing the measurement cost and time. However, interpolation methods are very sensitive to the availability of measurement data, and their performances largely depend on the measurement scheme or the sampling design, i.e., how to allocate measurement efforts. As such, sampling design is considered to be another important field that enables intelligent surface measurement. This paper reviews and summarizes the state-of-the-art research in interpolation and sampling design for surface measurement in varied manufacturing applications. Research gaps and future research directions are also identified and can serve as a fundamental guideline to industrial practitioners and researchers for future studies in these areas.

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Direct Patterning and Spontaneous Self-Assembly of Graphene Oxide via Electrohydrodynamic Jet Printing for Energy Storage and Sensing

Micromachines ◽

10.3390/mi11010013 ◽

2019 ◽

Vol 11 (1) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Bin Zhang ◽

Jaehyun Lee ◽

Mincheol Kim ◽

Naeeung Lee ◽

Hyungdong Lee ◽

...

Keyword(s):

Graphene Oxide ◽

Energy Storage ◽

Self Assembly ◽

High Performance ◽

Three Dimensional ◽

Chemical Properties ◽

Layer By Layer ◽

Energy Storage Devices ◽

Laminar Structure ◽

Jet Printing

The macroscopic assembly of two-dimensional materials into a laminar structure has received considerable attention because it improves both the mechanical and chemical properties of the original materials. However, conventional manufacturing methods have certain limitations in that they require a high temperature process, use toxic solvents, and are considerably time consuming. Here, we present a new system for the self-assembly of layer-by-layer (LBL) graphene oxide (GO) via an electrohydrodynamic (EHD) jet printing technique. During printing, the orientation of GO flakes can be controlled by the velocity distribution of liquid jet and electric field-induced alignment spontaneously. Closely-packed GO patterns with an ordered laminar structure can be rapidly realized using an interfacial assembly process on the substrates. The surface roughness and electrical conductivity of the LBL structure were significantly improved compared with conventional dispensing methods. We further applied this technique to fabricate a reduced graphene oxide (r-GO)-based supercapacitor and a three-dimensional (3D) metallic grid hybrid ammonia sensor. We present the EHD-assisted assembly of laminar r-GO structures as a new platform for preparing high-performance energy storage devices and sensors.

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Evaluation of Parts Produced by a Novel Additive Manufacturing Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.315.63 ◽

2013 ◽

Vol 315 ◽

pp. 63-67 ◽

Cited By ~ 1

Author(s):

Muhammad Fahad ◽

Neil Hopkinson

Keyword(s):

Additive Manufacturing ◽

Rapid Prototyping ◽

Manufacturing Process ◽

High Speed ◽

Three Dimensional ◽

Coordinate Measuring Machine ◽

Layer By Layer ◽

Nylon 12 ◽

Measuring Machine ◽

End Use

Rapid prototyping refers to building three dimensional parts in a tool-less, layer by layer manner using the CAD geometry of the part. Additive Manufacturing (AM) is the name given to the application of rapid prototyping technologies to produce functional, end use items. Since AM is relatively new area of manufacturing processes, various processes are being developed and analyzed for their performance (mainly speed and accuracy). This paper deals with the design of a new benchmark part to analyze the flatness of parts produced on High Speed Sintering (HSS) which is a novel Additive Manufacturing process and is currently being developed at Loughborough University. The designed benchmark part comprised of various features such as cubes, holes, cylinders, spheres and cones on a flat base and the build material used for these parts was nylon 12 powder. Flatness and curvature of the base of these parts were measured using a coordinate measuring machine (CMM) and the results are discussed in relation to the operating parameters of the process.The result show changes in the flatness of part with the depth of part in the bed which is attributed to the thermal gradient within the build envelope during build.

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Predictions of the Mechanical Performance of Leaf Fiber Thermoplastic Composites by FEA

International Journal of Applied Mechanics ◽

10.1142/s1758825121500666 ◽

2021 ◽

Author(s):

Faris M. AL-Oqla

Keyword(s):

Composite Materials ◽

Cantilever Beam ◽

Mechanical Performance ◽

Natural Fiber ◽

Fiber Composite ◽

Fiber Composites ◽

Fiber Types ◽

Natural Fiber Composites ◽

Pull Out ◽

Structural Applications

The available potential plant waste could be worthy material to strengthen polymers to make sustainable products and structural components. Therefore, modeling the natural fiber polymeric-based composites is currently required to reveal the mechanical performance of such polymeric green composites for various green products. This work numerically investigates the effect of various fiber types, fiber loading, and reinforcement conditions with different polymer matrices towards predicting the mechanical performance of such natural fiber composites. Cantilever beam and compression schemes were considered as two different mechanical loading conditions for structural applications of such composite materials. Finite element analysis was conducted to modeling the natural fiber composite materials. The interaction between the fibers and the matrices was considered as an interfacial friction force and was determined from experimental work by the pull out technique for each polymer and fiber type. Both polypropylene and polyethylene were considered as composite matrices. Olive and lemon leaf fibers were considered as reinforcements. Results have revealed that the deflection resistance of the natural fiber composites in cantilever beam was enhanced for several reinforcement conditions. The fiber reinforcement was capable of enhancing the mechanical performance of the polymers and was the best in case of 20 wt.% polypropylene/lemon composites due to better stress transfer within the composite. However, the 40 wt.% case was the worst in enhancing the mechanical performance in both cantilever beam and compression cases. The 30 wt.% of polyethylene/olive fiber was the best in reducing the deflection of the cantilever beam case. The prediction of mechanical performance of natural fiber composites via proper numerical analysis would enhance the process of selecting the appropriate polymer and fiber types. It can contribute finding the proper reinforcement conditions to enhance the mechanical performance of the natural fiber composites to expand their reliable implementations in more industrial applications.

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Design and Analysis of Hybrid Fused Filament Fabrication Apparatus for Fabrication of Composites

Current Materials Science ◽

10.2174/2666145414666210412150641 ◽

2021 ◽

Vol 14 ◽

Author(s):

Aniket Yadav ◽

Piyush Chohan ◽

Ranvijay Kumar ◽

Jasgurpreet Singh Chohan ◽

Raman Kumar

Keyword(s):

Additive Manufacturing ◽

Composite Materials ◽

Design Process ◽

Low Cost ◽

Matrix Material ◽

Fabrication Process ◽

Layer By Layer ◽

Fused Filament Fabrication ◽

Composite Manufacturing ◽

Tool Paths

Background: Additive manufacturing is the most famous technology which requires materials or composites to be fabricated with layer by layer deposition strategy. Due to its lower cost, higher accuracy and less material wastage; this technology is used in almost every sector. But in many applications there is a need to alter the properties of a product in a certain direction with the help of some reinforcements. With the use of reinforcements, composite layers can be fabricated using additive manufacturing technique which will enhance the directional properties. A novel apparatus is designed to spray the reinforcement material into the printed structures in a very neat and precise manner. This spray nozzle is fully automated, which works according to tool-paths generated by slicing software. The alternate deposition of layers of reinforcement and build materials helped to fabricate customized composite products. Objective: The objective of present study is to design and analyze the working principle of novel technique which has been developed to fabricate composite materials using additive manufacturing. The apparatus is numerically controlled by computer according to CAD data which facilitates the deposition of alternate layers of reinforcement and matrix material. The major challenges during the design process and function of each component has been explored. Methods: The design process is initiated after comprehensive literature review performed to study previous composite manufacturing processes. The recent patents published by different patent offices of the world are studied in detail and analysis has been used to design a low cost composite fabrication apparatus. A liquid dispensing device comprises a storage tank attached with a pump and microprocessor. The microprocessor receives the signal from the computer as per tool paths generated by slicing software which decides the spray of reinforcements on polymer layers. The spraying apparatus moves in coordination with the primary nozzle of the Fused Filament Fabrication process. Results: The hybridization of Fused Filament Fabrication [process with metal spray process has been successfully performed. The apparatus facilitates the fabrication of low cost composite materials along with flexibility of complete customization of composite manufacturing process. The anisotropic behaviour of products can be easily controlled and managed during fabrication which can be used for different applications.

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Increasing Part Accuracy in Additive Manufacturing Processes Using a k-d Tree Based Clustered Adaptive Layering

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4028586 ◽

2014 ◽

Vol 136 (6) ◽

Cited By ~ 14

Author(s):

Neeraj Panhalkar ◽

Ratnadeep Paul ◽

Sam Anand

Keyword(s):

Additive Manufacturing ◽

Computer Aided Design ◽

Three Dimensional ◽

Layer By Layer ◽

Adaptive Slicing ◽

Stl File ◽

Build Time ◽

Standard File Format ◽

Aided Design ◽

Profile Errors

Additive manufacturing (AM) is widely used in aerospace, automobile, and medical industries for building highly accurate parts using a layer by layer approach. The stereolithography (STL) file is the standard file format used in AM machines and approximates the three-dimensional (3D) model of parts using planar triangles. However, as the STL file is an approximation of the actual computer aided design (CAD) surface, the geometric errors in the final manufactured parts are pronounced, particularly in those parts with highly curved surfaces. If the part is built with the minimum uniform layer thickness allowed by the AM machine, the manufactured part will typically have the best quality, but this will also result in a considerable increase in build time. Therefore, as a compromise, the part can be built with variable layer thicknesses, i.e., using an adaptive layering technique, which will reduce the part build time while still reducing the part errors and satisfying the geometric tolerance callouts on the part. This paper describes a new approach of determining the variable slices using a 3D k-d tree method. The paper validates the proposed k-d tree based adaptive layering approach for three test parts and documents the results by comparing the volumetric, cylindricity, sphericity, and profile errors obtained from this approach with those obtained using a uniform slicing method. Since current AM machines are incapable of handling adaptive slicing approach directly, a “pseudo” grouped adaptive layering approach is also proposed here. This “clustered slicing” technique will enable the fabrication of a part in bands of varying slice thicknesses with each band having clusters of uniform slice thicknesses. The proposed k-d tree based adaptive slicing approach along with clustered slicing has been validated with simulations of the test parts of different shapes.

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