Deposition Modeling Research Articles

Pepgen-P15 delivery to bone: A novel 3D printed scaffold for enhanced bone regeneration

Pepgen-P15 is a combination of an organic hydroxyapatite matrix derived from bovine sources, combined with a synthetic peptide known as P-15. The interaction between α2β1 integrin and the P15 chain triggers both intracellular and extracellular signaling pathways, resulting in the production of growth factors. Three-dimensional (3D) printing has recently emerged as an innovative strategy for developing personalized therapies in bone tissue regeneration. In this research, various ratios of calcium magnesium silicate (bredigite) nanoparticles were used to modify 3D printed scaffolds made of xanthan gum and polycaprolactone (PCL) via fused deposition modeling (FDM). Scaffolds were subsequently treated with an alkaline solution, covered with graphene oxide, and finally, Pepgen-P15 was applied. the effects of xanthan gum were assessed using swellability and contact angle tests. The results indicated that, the prepared scaffolds exhibited suitable degradation rates, mechanical characteristics, and apatite formation. Alizarin red and alkaline phosphatase assays were also conducted to evaluate the scaffolds’ effectiveness in promoting bone cell differentiation during cell culture. Furthermore, the surface of the scaffold was examined to determine the amount of Pepgen-P15 loaded and released. According to the findings, the scaffold composed of 20 % bredigite and 0.3 % graphene oxide, coated with Pepgen-P15, demonstrate optimal mechanical properties, cell adherence, development, and proliferation. Typically, it is a good candidate for use in bone tissue engineering.

Copper-decorated covalent organic framework covalently modified 3D-printed nanocarbon electrodes for the determination of methotrexate

3D printing has emerged as a popular topic in electrochemistry due to its high flexibility in production. In this work, we used graphene/polylactic acid materials for the fabrication of 3D printed electrodes (3DEs) via fused deposition modeling (FDM). Subsequently, the synthesized novel copper-decorated covalent organic framework (Cu(II)@S-COF) was covalently bound on the 3DE by the Au-S bonding to construct the Cu(II)@S-COF@Au@3DE sensor. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle experiments were used to characterize the prepared 3DEs. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical performance of the prepared 3DEs. The sensor exhibited good electrocatalytic performance for detecting methotrexate (MTX). It was capable of accurately determining MTX in the range from 0.5 to 100 μM with a limit of detection (LOD) of 0.07 μM and a sensitivity of 0.1489 μA μM−1 cm−2. In addition, the sensor has recoveries from 97.33% to 101.09% for the detection of MTX in commercial tablets and urine samples, so it can be used to detect MTX in real samples successfully. This work opens a novel avenue for using metal-decorated COF materials in the field of electrochemistry.

Polypropylene Crystallinity Reduction through the Synergistic Effects of Cellulose and Silica Formed via Sol-Gel Synthesis.

This study focuses on the development of environmentally sustainable polypropylene (PP)-based composites with the potential for biodegradability by incorporating cellulose and the oligomeric siloxane ES-40. Targeting industrial applications such as fused deposition modeling (FDM) 3D printing, ES-40 was employed as a precursor for the in situ formation of silica particles via hydrolytic polycondensation (HPC). Two HPC approaches were investigated: a preliminary reaction in a mixture of cellulose, ethanol, and water, and a direct reaction within the molten PP matrix. The composites were thoroughly characterized using rotational rheometry, optical microscopy, differential scanning calorimetry, and dynamic mechanical analysis. Both methods resulted in composites with markedly reduced crystallinity and shrinkage compared to neat PP, with the lowest shrinkage observed in blends prepared directly in the extruder. The inclusion of cellulose not only enhances the environmental profile of these composites but also paves the way for the development of PP materials with improved biodegradability, highlighting the potential of this technique for fabricating more amorphous composites from crystalline or semi-crystalline polymers for enhancing the quality and dimensional stability of FDM-printed materials.

Osteochondral Regeneration With Anatomical Scaffold 3D-Printing-Design Considerations for Interface Integration.

There is a clinical need for osteochondral scaffolds with complex geometries for restoring articulating joint surfaces. To address that need, 3D-printing has enabled scaffolds to be created with anatomically shaped geometries and interconnected internal architectures, going beyond simple plug-shaped scaffolds that are limited to small, cylindrical, focal defects. A key challenge for restoring articulating joint surfaces with 3D-printed constructs is the mechanical loading environment, particularly to withstand delamination or mechanical failure. Although the mechanical performance of interfacial scaffolds is essential, interface strength testing has rarely been emphasized in prior studies with stratified scaffolds. In the pioneering studies where interface strength was assessed, varying methods were employed, which has made direct comparisons difficult. Therefore, the current review focused on 3D-printed scaffolds for osteochondral applications with an emphasis on interface integration and biomechanical evaluation. This 3D-printing focus included both multiphasic cylindrical scaffolds and anatomically shaped scaffolds. Combinations of different 3D-printing methods (e.g., fused deposition modeling, stereolithography, bioprinting with pneumatic extrusion of cell-laden hydrogels) have been employed in a handful of studies to integrate osteoinductive and chondroinductive regions into a single scaffold. Most 3D-printed multiphasic structures utilized either an interdigitating or a mechanical interlocking design to strengthen the construct interface and to prevent delamination during function. The most effective approach to combine phases may be to infill a robust 3D-printed osteal polymer with an interlocking chondral phase hydrogel. Mechanical interlocking is therefore recommended for scaling up multiphasic scaffold applications to larger anatomically shaped joint surface regeneration. For the evaluation of layer integration, the interface shear test is recommended to avoid artifacts or variability that may be associated with alternative approaches that require adhesives or mechanical grips. The 3D-printing literature with interfacial scaffolds provides a compelling foundation for continued work toward successful regeneration of injured or diseased osteochondral tissues in load-bearing joints such as the knee, hip, or temporomandibular joint.

Additive manufacturing and in vitro study of biological characteristics of sulfonated polyetheretherketone-bioactive glass porous bone scaffolds

Polyetheretherketone (PEEK), a high-performance special engineering plastic, has gradually been used in bone substitutes due to its wear resistance, acid and alkali resistance, non-toxicity, radiolucency, and modulus close to that of human bone. However, its stable biphenyl structure determines strong biological inertness, thus artificial interventions are required to improve the biological activity of fabricated PEEK parts for better clinical applications. This study developed a novel strategy for grafting bioactive glass (BAG) onto the surface of PEEK through sulfonation reaction with concentrated sulfuric acid (H2SO4), aiming to improve the bioactivity of printed porous bone scaffolds manufactured by fused deposition modeling (FDM) to meet clinical individual needs. In vitro biological study was conducted on sulfonated polyetheretherketone-bioactive glass (SPEEK-BAG) scaffolds obtained by this strategy. The results demonstrated that the optimal modification condition was a 4-hour sulfonation reaction with 1 mol/L concentrated H2SO4 at high temperature and high pressure. The scaffold obtained under this condition showed minimal cytotoxicity, and the Ca/P molar ratio, yield compressive strength, and compressive modulus of this scaffold were 2.94 ± 0.02, 62.78 MPa, and 0.186 GPa respectively. The hydrophilicity and the biomineralization ability of PEEK modified by the proposed strategy were substantially improved. The SPEEK-BAG bone scaffolds exhibited excellent biocompatible properties, suggesting that the sulfonation reaction and BAG effectively enhanced the proliferation and differentiation of osteoblasts. The presented method provides an innovative, highly effective, and customized strategy to improve the biocompatibility and bone repair ability of printed PEEK bone scaffolds for virous biomedical applications.

Characterization, generative design, and fabrication of a carbon fiber-reinforced industrial robot gripper via additive manufacturing

Robot grippers are crucial components across various industrial applications, requiring special design and production for obtaining the optimal performance. Conventional plastic injection moulding techniques fall short in achieving the specificity needed for these grippers. To address this challenge, current paper focuses on developing a robot gripper using carbon fiber-reinforced polyamide with a next-generation composite filament and employing the innovative Generative Design technique. In the work, we began by characterizing and optimizing the composite material specifications. Then, the tensile strength and fracture mechanics of standard samples based on printing parameters, applying Taguchi experimental design for optimization were evaluated. Analysis of Variance (ANOVA) was used for factor analysis to fine-tune the process. Using the Generative Design technique, we determined optimal geometries, which were then fabricated through Fused Deposition Modeling (FDM). As a result, the optimization efforts led to significant improvements i.e., tensile strength increased from 103.2 to 116 MPa, and the elasticity modulus from 8386 to 8990 MPa. In practical industrial applications, we achieved a reduction in material weight from 14 to 4 g, lowered production costs from $5.16 to $1.50, and cut production time from 58 to 28 min. This study presents a validated method for developing industrial products with reduced material usage and costs, promoting sustainable production practices.

Comparison of energy absorption characteristics of novel lattice structures inspired by Helleborus petticoat flower and fish scale pattern for different loading orientations

In the present work, arc-shaped, thin-strut-based structures were developed by taking inspiration from the cup shaped Helleborus petticoat flower and fish scale pattern. The designed structures have been additively manufactured with a fused deposition modeling process. In this work, one fish scale pattern inspired structure was developed and named FS structure, whereas two flower-inspired structures were developed and named FL4 and FL8 structures. The static compression tests were conducted to study stress-strain behavior of the proposed structures in two different orientations, viz. orientation:1 (along z-axis) and orientation:2 (along x-axis). Furthermore, the mechanical responses and energy absorption characteristics are comprehensively examined for the proposed structures in both orientations. The structures exhibited higher specific energy absorption (SEA) in orientation:1 compared to orientation:2. The increment in SEA is ∼29 % for FS, ∼298% for FL4, and ∼115% for FL8 structures in orientation:1 compared to orientation:2. Meanwhile, the proposed bio-inspired structures are capable of absorbing energies in the range of 0.06-0.47 MJ/m3, up to densification. Finally, SEA of proposed structures is compared with the SEA of other structures in the available literature.

Optimizing the grasping behavior of a soft robot's gripper

AbstractIn this study, smart composite materials based on 4D printing technology were used to determine the grasping ability of four‐claw gripper of soft robot. First, fused deposition modeling (FDM) is used to prepare polylactic acid (PLA) strips on the surface of a rectangular bamboo substrate to create a single‐claw gripper for a smart composite soft robot, while using stimulus (heat) to deform and recover its original shape. Here, the authors first evaluate the deformation and recovery angle of the single‐claw gripper of the smart composite soft robot, as well as various processing parameters such as heating temperature and time. This study then used FDM to print PLA ribbons on cross‐shaped bamboo sheets to design the four‐claw gripper of soft robot and its gripper technology was actuation type. Then, the four‐claw gripper of soft robot was used to grab the table tennis ball to test its grasping ability. Finally, four processing parameters (width of claw, pitch of PLA ribbon, heating temperature, and heating time) were applied to determine the grasping ability of the four‐claw gripper of soft robot. The optimal processing parameters for the grasping ability of the four‐claw gripper of soft robot were width of claw of 20.2 mm, pitch of PLA ribbon of 1 mm, heating temperature of 200°C, and the heating time of 15 s. The authors also applied the operation window of two processing parameters to discuss the success of the grasping ability of the four‐claw gripper of soft robot. The innovation of this study is the use of PLA/bamboo composite materials as the four‐claw gripper of soft robot and these materials are cheap, easy to obtain, and can be recycled naturally. This study uses a simple thermal stimulus to enable the four‐claw gripper of soft robot to easily grasp irregular objects.Highlights The innovative composite material of polylactic acid and bamboo fabricated by 3D printing. Width of claw and heating temperature are the key factors on grasping ability. Operating window of grasping ability appears on four‐claw gripper of soft robot.

Decentralized approach for incorporating waste wind turbine blades into 3D printing filaments using mechanical recycling

AbstractThe increasing awareness in environmental safety has led to rapid development in production of electricity using wind energy with wind turbines. The widespread deployment of wind turbines has outpaced the effective recycling of End‐of‐Life wind turbines. This study explores the potential of mechanically recycling decommissioned wind turbine blades (WTB) as reinforcement material in 3D printing processes. Utilizing mechanical grinding, materials were extracted from the waste blades and subsequently analyzed using Fourier transform infrared spectroscopy, Differential scanning calorimetry, and thermogravimetric analysis to determine optimal processing conditions. The reclaimed materials were then blended with recycled polypropylene through single‐screw extrusion to fabricate tensile test samples via Fused Deposition Modeling. The impact of print orientation on mechanical strength was examined at 0°, 45°, and 90° angles. Morphological analysis was conducted on the fractured specimens to assess the failure characteristics. The findings indicate that samples printed at a 90° orientation exhibited superior mechanical properties, suggesting a viable pathway for incorporating wind turbine waste into sustainable manufacturing cycles.Highlights A decentralized‐mechanical recycling technique to the waste WTB. The necessary material parameters for the operations employed in this study. Reinforced 3D printable filaments from waste WTB. Stronger reinforced filaments obtained from proper fiber alignment.

Experimental investigation of FDM manufacturing of 316 l stainless steel

Continuous research in the field of metal additive manufacturing has led to the need for constant improvement of manufacturing parameters especially in the case of FDM (Fused Deposition Modeling) manufacturing. In recent years, the main directions outlined for productivity and quality improvement were related to higher printing speed and the use of ironing-type processes. This article aims to study the manufacturing parameters of the dimensional accuracy and surface quality of FDM-manufactured 316L stainless steel. The degree of novelty is given by the application of the ironing process for the green part. A full factorial 33 experimental design was designed for this study, in which the factors studied were ironing angle, ironing speed, and layer spacing during ironing. The dimensional accuracy and surface roughness were analyzed by means of deviation measurement from CAD to the green part and final part after the sintering process. Using the design of experiments offers the possibility of applying the analysis of variance (ANOVA) which provides information about the degree of influence of each of the studied factors. The results obtained for the dimensional accuracy showed that the ironing direction had the biggest influence on the Z-axis shrinkage. Overall, approximately 6% shrinkage in the Z and Y directions was obtained while in the X directions, the shrinkage percentage was around 20%. Surface roughness showed an improvement with higher ironing speeds for the green part while for the sintered part the most significant factor was ironing spacing.

Analysis of emission of volatile organic compounds and thermal degradation in investment casting using fused deposition modeling (FDM) and three-dimensional printing (3DP) made of various thermoplastic polymers.

The study examined the degradation process of various types of polymers used to form models using the fused deposition modeling (FDM) and three-dimensional printing (3DP) methods and used in the investment casting method. Commercial filaments made of polylactide (PLA), acrylonitrile butadiene styrene terpolymer (ABS), high-impact polystyrene (HIPS), polyamide 12 (PA12), poly(methyl methacrylate) (PMMA), and polypropylene (PP) were used to produce gypsum molds. The assessment included organic volatile compounds (VOCs) released during mold heating and model degradation, which is characteristic of this technological process. The screening qualitative chromatographic analysis of decomposition products sampled from various points of the production hall made it possible to define potential threats related to the processing of selected polymers and the necessary preventive measures. Furthermore, passive diffusion-type samplers were used at the sampling stage of VOCs emitted to the gaseous phase to reduce nuisance and user interference. Studies have been completed to characterize the thermoplastic polymer degradation process. The coupled thermogravimetry (TGA) with analysis of gaseous products by infrared spectroscopy with Fourier transformation (FT-IR) has been used. The presented results are the first to compare and rate the use of this still-developing novel aspect of castings by the method of fused models.

Hygrothermal aging and durability prediction of 3D-printed hybrid fiber composites with continuous carbon/Kevlar-fiber and short carbon-fiber

Hybrid Fiber Reinforced Polymers (HFRP) have excellent mechanical properties. However, preparation with 3D-printing technology is prone to hydrothermal aging compared to conventional method. Currently, complex hygrothermal aging and degradation mechanisms of 3D-printed HFRP are still unclear. Thus, hygrothermal aging and durability prediction of 3D-printed HFRP with continuous carbon/Kevlar-fiber and short carbon-fiber are studied, which considers four typical stacking sequences. All experimental samples are manufactured by Fused Deposition Modeling (FDM) 3D-printing. The artificial accelerate aging testing is conducted on samples at different times, and then flexural testing is adopted to evaluate the residual mechanical properties and failure modes. The results show that the stacking sequence significantly influences the moisture absorption behaviors, and [OC4O2K4]S absorbed more moisture than [OK4O2C4]S. During the aging process, the flexural properties of the 3D-printed HFRP first decrease rapidly and then keep stable. Among them, [OK4O2C4]S have the fastest degradation but possessed the highest residual strength. OC8O4K8O possess the slowest degradation but have a lower residual strength. The morphologies and micro failure modes/mechanisms are analyzed to explain the significant mechanical degradation. Finally, the Arrhenius relationship is adopted to accurately predict and analyze the degradation evolution process of specimens. This work offers a novel perspective on the hygrothermal aging and durability of 3D-printed HFRP.

Enhancing precision in 3D printing for highly functional printing with high-speed vision

3D printing has revolutionized product design and manufacturing across various industries by enabling the creation of complex geometries with minimal waste. Despite its advancements, 3D printing still faces significant challenges, including spatial constraints and process control limitations. This paper introduces novel approaches to improve the functionality and precision of material extrusion 3D printers for the fused deposition modeling method, particularly for additional printing tasks such as printing on existing objects or continuing a print on a relocated object without prior knowledge of its position or even the environment is changed. We introduce a compensation system integrating a high-speed vision system for robot arms to address these challenges. Our system employs a three-step pose estimation process—fast point feature histograms (FPFH)-based, corner-based, and sub-pixel edge-based methods—to ensure high accuracy in restoring the position of printed pieces for additional printing tasks on a given object. Experimental results demonstrate substantial improvements in printing precision, with the system achieving sub-millimeter and sub-pixel accuracy. These advancements not only eliminate work area constraints but also enhance the adaptability and reliability of 3D printing processes.

Upcycling end-of-life carbon fiber in high-performance CFRP composites by the material extrusion additive manufacturing process

Each year, a significant amount of waste is produced from carbon fiber polymer composites at the end of its lifecycle due to extensive use across various applications. Utilizing regenerative carbon fiber as a feedstock material offers a promising and sustainable approach to additive manufacturing based on materials. This study proposes the additive manufacturing of recycled carbon fiber with a polyamide-12 polymer composite. Filaments of recycled carbon fiber-reinforced polyamide-12 (rCF-PA12) with different recycled carbon fiber contents (0%, 10%, and 15% by weight) in the polyamide-12 matrix are developed. These filaments are utilized for 3D printing of specimens by using various infill density parameters (80% and 100%) on a fused deposition modeling 3D printer. The study examined how the fiber content and infill densities influenced the flexural performance of the printed specimens. Notably, the part containing 15 wt% recycled carbon fiber (rCF) composites showed a significant improvement in flexural performance due to enhanced interface bonding and effective fiber alignment. The results indicated that reinforcing the printed part with 10% and 15 wt% recycled carbon fiber (rCF) improved the flexural properties by 49.86% and 91.75%, respectively, compared to the unreinforced printed part under the same infill density and printing parameters. The investigation demonstrates that the additive manufacturing-based technique presents a potential approach to use carbon fiber-reinforced polymers waste and manufacture high-performance engineering, economic, and environmentally friendly industrial applications with the complicated design using different polymer matrices.

Development and Comparison of Model-Based and Data-Driven Approaches for the Prediction of the Mechanical Properties of Lattice Structures

AbstractLattice structures have great potential for several application fields ranging from medical and tissue engineering to aeronautical one. Their development is further speeded up by the continuing advances in additive manufacturing technologies that allow to overcome issues typical of standard processes and to propose tailored designs. However, the design of lattice structures is still challenging since their properties are considerably affected by numerous factors. The present paper aims to propose, discuss, and compare various modeling approaches to describe, understand, and predict the correlations between the mechanical properties and the void volume fraction of different types of lattice structures fabricated by fused deposition modeling 3D printing. Particularly, four approaches are proposed: (i) a simplified analytical model; (ii) a semi-empirical model combining analytical equations with experimental correction factors; (iii) an artificial neural network trained on experimental data; (iv) numerical simulations by finite element analyses. The comparison among the various approaches, and with experimental data, allows to identify the performances, advantages, and disadvantages of each approach, thus giving important guidelines for choosing the right design methodology based on the needs and available data.

Finite Element Analysis of Leaf Spring Fabricated Via Fused Deposition Modeling (FDM)

An introduction to fused deposition modeling, or 3D printing technology, will be given in this chapter. The basic idea of additive manufacturing and its underlying scientific theory will be presented at the outset of this chapter as a novel and emerging industrial technology. The parameters used to predict the melt deposition of polymers and their basic interactions with the structural component qualities will also be covered in this chapter. The chapter will provide a brief description of the quality features of FDM products concerning the process parameters. The additive manufacturing process will involve layering material to produce three-dimensional (3D) parts using a class of manufacturing technologies known as additive manufacturing (AM). This substance will include composite, metal, polymer, or concrete materials. A manufacturing process will need to have the following three main elements to be designated as an AM technique: making visual 3D models with computers and computer-aided design (CAD), utilizing a variety of CAD tools such as AutoCAD, SolidWorks, CATIA, and others. Some of these programs will be either closed- source or open-source. For additive manufacturing to be successful, an engineer or artist working with several computers will need to be proficient in using multiple operating systems. With these CAD tools and user experiences, it will be possible to produce a variety of complex 3D product models. The amount of material a 3D printer will take and the time it will require will be important factors influencing the additive manufacturing process.

Fabrication of PEI/CF composite parts with multi-angle reinforced mechanical properties by a micro-extrusion foaming FDM process

The combination of fused deposition modeling (FDM) and foaming technology enables the fabrication of complex hierarchical and lightweight parts. However, this approach is hindered by a reduction in the mechanical properties of final parts. To this end, with the aim of addressing the challenge of the fabrication of 3D-printed parts with enhanced mechanical and lightweight features, a micro-extrusion foaming FDM process using CO2 as a blowing agent was hereby established, and the carbon fiber (CF) was selected as a reinforcing filler. Compared to pure polyetherimide (PEI) parts, the longitudinal tensile strength of the PEI/CF parts with 5.0 wt% CF added increased by 30.3 %, while the interfacial bonding strength of PEI/CF-5.0 foamed parts increased by 86.3 % compared to the unfoamed parts. Furthermore, the PEI/CF-5.0 foamed parts, weighing only about 1.7 g, could bear a load of a 60 kg human body in multiple directions. Additionally, focusing on the filler orientation and the enhanced interdiffusion and entanglement of polymer chains at interfaces, the reinforcement mechanisms of the foamed parts fabricated by micro-extrusion foaming FDM process were discussed. The micro-extrusion foaming FDM process demonstrated the capability to produce lightweight parts with enhanced mechanical properties, making it a promising technology for applications in the aerospace and military industries.

Broadband low-frequency noise attenuation with parallel U-shaped membrane resonators

The attenuation of noise at low frequencies has been the subject of extensive research in the last two decades. Employing membrane-type acoustic metamaterials (MAMs) is one of the most promising solutions due to their lightweight structure and ease of fabrication. This study fabricated a metamaterial with four U-shaped cavities supporting a thin elastic nitrile rubber membrane. We print the U-shaped cavities using fused deposition modeling (3D printing). The sound absorption coefficient (SAC) is calculated using numerical simulations. For SAC computation, an electro-acoustic model is developed that constructs an equivalent electrical circuit based on an impedance analogy. Furthermore, the findings of the numerical and analytical analyses are supported by the actual data acquired from the experiments. We have determined that the average sound transmission loss (STL) is 29.84 dB, and the average SAC exceeds 82% within the frequency range of 500 Hz to 1000 Hz. Due to its lightweight, subwavelength thickness, ability to attenuate broadband noise, and very simple fabrication, this metamaterial is suitable for use in aircraft, automotive industries, and room/building acoustics.

Investigation of The Effect of CNC Milling Cutting Process on The Tensile Test of PLA Samples Produced Using Two Different 3D Printers with The FDM Method

One of the most commonly used materials in additive manufacturing with the fused deposition modeling (FDM) method is polylactic acid (PLA) filaments. In 3-dimensional (3D) printed products, an external wall is also used in addition to the internal structure pattern. The exterior wall pattern differs from the interior structure pattern. The 3D products obtained by this method contain two different pattern structures, which is not desired when determining the mechanical properties. In this study, tensile test specimens were produced with two different 3D printers using 1.75 mm and 2.85 mm diameter PLA filaments. Some tensile test specimens were directly produced in ASTM D638-14 Type 1 dimensions and subjected to tensile testing. The rest of the specimens were produced in a rectangular shape with 19 mm x 165 mm dimensions and the side edges of those specimens, produced in rectangular shape, were cut with CNC milling to bring their dimensions to ASTM D638-14 Type 1. All tensile test specimens were manufactured with a thickness of 4 mm. The test specimens cut with CNC milling after 3D printing were compared with the specimens tested only by 3D printing. The effects of CNC milling cutting on the tensile test properties of specimens produced on two different 3D printers using 1.75 mm and 2.85 mm diameter PLA filaments were investigated. Consequently, it was observed that cutting the side edges with CNC milling eliminated irregularities caused by 3D printing due to the tensile stress in those areas and allowed for more regular and consistent fractures of test specimens. When compared with only the 3D-printed specimens, the elongation at break of the tensile test specimens whose side edges were cut with CNC milling resulted in 13.45% and 33.55% higher using 1.75 mm and 2.85 mm PLA filaments, respectively. It was determined that the toughness of the samples cut by CNC milling was higher than the test samples that were only 3D printed.

Development of ANN model for predicting mechanical properties of 3D printed PEEK polymer using FDM and optimization of process parameters for better mechanical properties

Additive manufacturing (AM) has evolved from a proven technology to a rapid prototyping tool with great potential. This technology is widely used in many industries such as automotive, aerospace, and medical; fused deposition modeling (FDM) is a popular 3D printing technique for producing PEEK (polyether ether ketone) parts, including implant prosthetic teeth. In this study, artificial neural network (ANN) modeling, parametric optimization, and experimental examination of PEEK 3D printing were conducted to enhance 3D printing processes. In this study, four critical process factors (infill density, layer height, printing speed, and infill pattern) influence the surface roughness, mechanical strength, and elastic modulus of the printed samples. Utilizing a 4–12–3 network design, this study demonstrates that an ANN model with an average error of less than 5% is optimal for all three responses. Furthermore, the study employed a teaching and learning based optimization algorithm (TLBO) and a non-dominated sorting genetic algorithm (NSGA) to optimize the printing process to obtain improved mechanical properties. The findings highlight TLBO’s ability to minimize surface roughness to 6.01 μm and NSGA’s capability to maximize the elastic modulus to 1253.35 MPa and ultimate tensile strength to 65.55 MPa. Microstructural studies supported the results obtained through parametric analysis and optimization.