Fused Filament Fabrication Process Research Articles

An improvement in the mechanical properties of polypropylene/ethylene-propylene-diene monomer/titanium dioxide nanocomposite obtained by fused filament fabrication

In the present research, the PP/EPDM/TiO2 nanocomposite was fabricated using the fused filament fabrication process to improve the mechanical properties of the obtained samples. For this purpose, first the response surface methodology was used to investigate the effect of TiO2 content, nozzle temperature and printing speed on the responses of tensile strength and elongation. Then, the desirability function method was applied to find the optimal condition of the process parameters. The fracture surface of the tensile samples was also studied by scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis to find a relationship between the microstructure and mechanical properties of the fabricated samples. The results indicated that the highest elongation of samples (144.9%) was attained at a TiO2 content of 4 wt%, while the tensile strength of samples was maximized (24.6 MPa) at a TiO2 content of 2 wt% due to fine dispersion of the nanoparticles. An increase in the nozzle temperature from 200 to 225°C led to an enhancement in the tensile strength (11.2%) and elongation (15.7%) of samples because of the good viscosity of the filament, whereas the tensile strength (6.6%) and elongation (11.1%) of samples were decreased with the increase of nozzle temperature from 225 to 250°C because of the thermal degradation of filament. Moreover, when the printing speed raised from 20 to 40 mm/s, the tensile strength initially improved by 2.7% and then decreased by 1.2%, but the elongation continuously decreased by 6.3%. Nevertheless, the concurrent enhancement of the tensile strength and elongation has been obtained at a TiO2 content of 2.5 wt%, nozzle temperature of 227°C and printing speed of 28 mm/s.

The Development of a 3D-Printed Compliant System for the Orientation of Payloads on Small Satellites: Material Characterization and Finite Element Analysis of 3D-Printed Polyetherketoneketone (PEKK)

This article focuses on the development of a 3D-printed 2-degree-of-freedom (DOF) joint for the payloads’ orientation on small satellites. This system is a compliant mechanism, meaning that this monolithic system composed of cross-axis flexural pivots (CAFPs) produces complex movements through the elastic deformation of its structure. Using fused filament fabrication (FFF), a demonstrator made of Polyetherketoneketone (PEKK) is printed to determine its potential compatibility with space conditions. Focusing on a segment of the joint, the CAFP, this study aims for an enhancement of its mechanical behavior through the study of its printing direction and the creation of an accurate finite element model of this compliant mechanism. First, material characterization of 3D-printed PEKK is achieved through differential scanning calorimetry tests of the filament and flexural and tensile tests of specimens printed in different printing directions. Then, these data are used to perform a finite element analysis of different CAFP designs and compare their mechanical response of their 3D-printed twin using digital image correlation software. Finally, the CAFP structures were observed by X-ray tomography. The results show that printing direction greatly influences both flexural and tensile strength. Voids induced by the FFF process could impact the mechanical behavior of 3D-printed parts as the simple CAFP design has a better test/model correlation than complex ones. This could influence its resistance to space environment.

A Novel Powder Addition Method for Improving Tensile Strength of Polylactic-Acid Prepared by Using Fused Filament Fabrication (FFF)

Although Fused Filament Fabrication (FFF) technology has gained popularity and is used extensively since the last decade, the low mechanical properties of the resulting product have been recognized as the major limitation of this technique. The anisotropic nature of the printed products due to the layered structure and many cavities that are present inside the printed parts are among the main causes of this problem. In this study, the powder addition reinforcement (PAR) method had been developed by introducing reinforcing powder into the polylactic acid (PLA) as the base material during the printing process so that nozzle clogging can be avoided and powders can be placed between the layers. In this work, iron oxide nanoparticles (Fe2O3) were used as a reinforcing powder. The addition of this powder was carried out by using two methods, namely brushing and compressed air-assisted techniques. The results showed that the compressed-air assisted technique demonstrated better results in terms of mechanical properties. In this case, the tensile strength of the composite with the compressed-air assisted technique was higher by 28.95% than that of the PLA and by 5.53% - 25.2% than that of the brushing method. Finally, this study showed that the compressed air-assisted method is the potential to be developed in the future as a powder addition reinforcement technique in the FFF process.

Electrically conductive and flexible filaments of hot melt adhesive for the fused filament fabrication process

Fused filament fabrication technique is the most popular additive manufacturing that has received extensive attention, revolutionizing industrial production processes. In addition to the standard thermoplastic polymers, much emphasis is placed on developing electrically conductive functional filaments being the most interesting. While there are conductive filaments that are commercially available, the market lacks a wide range of flexible options. Hence, this paper presents innovative filaments based on the combination of thermoplastic hot melt copolyester adhesive (HMA) with multi-walled carbon nanotubes (MWCNT). The incorporation of carbon nanotubes into the HMA was carried out through a two-step process. First, a masterbatch of 10 wt. % MWCNT was diluted with pure polymer using a half-industrial twin-screw extruder to obtain concentrations in the range of 1–9 wt. %. Consequently, the nanocomposite pellets were extruded again into the form of filaments. The rheological analysis demonstrates that adding MWCNT to the HMA increases both the viscous and elastic behavior of the composites. The homogenously dispersed nanotubes in the polymer matrix led to electrical conductivity of 1.39 S/m for the filaments containing 10 wt. % MWCNT. They are also characterized by the stiffness and tensile strength of about 300 and 13 MPa, respectively. With high thermal stability up to 360 °C, low porosity, and high flexibility, the developed filaments are suitable for 3D printing. The printability of all filaments was confirmed, exhibiting lack of breakage during printing and visibly better quality of the parts with the higher nanotube content.

Assessing nozzle flow dynamics in fused filament fabrication through the parametric map α−λ

Polymer rheology profoundly influences the intricate dynamics of material extrusion in fused filament fabrication (FFF). This numerical study, which uses the Giesekus model fed with a full rheometric experimental dataset, meticulously examines the molten flow patterns inside the printing nozzle in FFF. Our findings reveal new insight into the interplay between elastic stresses and complex flow patterns, highlighting their substantial role in forming upstream vortices. The parametric map α–λ from the Giesekus model allowed us to sort the materials and connect the polymer rheology with the FFF nozzle flow dynamics. The identification of elastic instabilities, the characterization of flow types, and the correlation between fluid rheology and pressure drop variations mark significant advancements in understanding FFF processes. These insights pave the way for tailored nozzle designs, promising enhanced efficiency and reliability in FFF-based additive manufacturing.

The Effects of Manufacturing Techniques on the Mechanical Performance of an Auxetic Structure Manufactured by Fused Filament Fabrication and Multijet Fusion Processes

Additive manufacturing is increasingly becoming potential for short‐run part production. The aim of this work is to explore the mechanical properties of a hybrid auxetic structure fabricated by multijet fusion (MJF) and fused filament fabrication (FFF). The experimental measurements indicate that robust specimens with high‐dimensional accuracy are successfully achieved using MJF process. In the case of the FFF process, the walls–walls and walls–cylinders areas (connecting areas) suffer large pores, indicating poor printing quality. The 3D printed specimens via FFF process reveal smooth plateau stress, while plateau stress with high peaks is observed when the MJF specimens are compressed along the Y‐axis. Moreover, specimens manufactured by the MJF process reveal the highest specific energy absorption (SEA) per unit volume and per unit mass. The calculated values of SEA are 2.1 and 2.5 J g−1 (for specimens fabricated by MJF) in which they significantly outperform the SEA (0.495 and 0.480 J g−1) of those manufactured by the FFF process. Furthermore, the trend of auxetic features (negative Poisson's ratio) has not been affected by the manufacturing processes. This study sheds light on the influence of fabrication methods on the mechanical properties of cellular materials especially their ability to absorb energy.

Gradual error detection technique for non-destructive assessment of density and tensile strength in fused filament fabrication processes

Fused filament fabrication (FFF) is a widely used additive manufacturing process for producing functional components and prototypes. The FFF process involves depositing melted material layer-by-layer to build up 3D physical parts. The quality of the final product depends on several factors, including the component density and tensile strength, which are typically determined through destructive testing methods. X-ray microtomography (XCT) can be used to investigate the pore sizes and distribution. These approaches are time-consuming, costly, and wasteful, making it unsuitable for high-volume manufacturing. In this paper, a new method for non-destructive determination of component density and estimation of the tensile strength in FFF processes is proposed. This method involves the use of gradual error detection by sensors and convolutional neural networks. To validate this approach, a series of experiments has been conducted. Component density and tensile strength of the printed specimens with varying extrusion factor were measured using traditional destructive testing methods and XCT. The cumulative error detection method was used to predict the same properties without destroying the specimens. The predicted values were then compared with the measured values, and it was observed that the method accurately predicted the component density and tensile strength of the tested parts. This approach has several advantages over traditional destructive testing methods. The method is faster, cheaper, and more environmentally friendly since it does not require the destruction of the product. Moreover, it facilitates the testing of each individual part instead of assuming the same properties for components from one series. Additionally, it can provide real-time feedback on the quality of the product during the manufacturing process, allowing for adjustments to be made as needed. The advancement of this approach points toward a future trend in non-destructive testing methodologies, potentially revolutionizing quality assurance processes not only for consumer goods but various industries such as electronics or automotive industry. Moreover, its broader applications extend beyond FFF to encompass other additive manufacturing techniques such as selective laser sintering (SLS), or electron beam melting (EBM). A comparison between the old destructive testing methods and this innovative non-destructive approach underscores the possible fundamental change toward more efficient and sustainable manufacturing practices. This approach has the potential to significantly reduce the time and cost associated with traditional destructive testing methods while ensuring the quality of FFF-manufactured products.

Effect of meta-structure on mechanical properties of polyvinylidene fluoride composite-based 3D printed intramedullary pins

Some studies have outlined the use of 3D-printed polyvinylidene fluoride (PVDF) composite-based solid intramedullary (IM) pins with tunable mechanical (tensile, compressive, flexural, and torsional) properties for orthopedic applications. But hitherto little has been reported on the effect of meta-structure induced in 3D-printed IM pins for canines from the mechanical properties’ viewpoint. This study highlights the design, fabrication, and testing to mimic actual loading conditions in the canine femur bone on novel IM pin with meta-structure employed in different length zones (30%, 40%, and 50% of total gauge length) prepared by fused filament fabrication (FFF) of PVDF composite. The IM pin (of length 150 mm) has square threads (pitch 2 mm) at the distal end (ɸ7 mm, up to 60 mm in length), and V threads (pitch 1.5 mm) at the proximal end (ɸ6 mm, up to 30 mm in length). The IM pin was fabricated at the best setting (of the FFF process) suggested by the multifactor optimization (at nozzle temperature (Nt) 235°C, printing speed (Ps) 60 mm/s, and raster angle (RA) 45°). The result suggests that for the solid IM pins prepared at the optimized settings the observed elongation, peak load (PL), and break load (BL) during tensile and compressive loading were 4.83 mm, 968.40 N, 958.20 N, and 14.19 mm, 412.80 N, 371.52 N respectively. Whereas for 50% meta-structure the observed elongation, PL, and BL during tensile and compressive loading were 14.49 mm, 405.49 N, 90.20 N, and 13.23 mm, 243.20 N, 218.88 N respectively. For both tensile and compression loading (in this case study), better elongation was noticed for the FFF-based IM pin with 50% meta-structure and hence recommended for implantation in the canine femur bone. The results are also supported by scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) based surface characteristics of the fracture sites.

The Tensile, Thermal and Flame-Retardant Properties of Polyetherimide and Polyetherketoneketone Processed via Fused Filament Fabrication.

Polymer materials are increasingly widely used in high-fire-risk applications, such as aviation interior components. This study aimed to compare the tensile, thermal, and flame-retardant properties of test samples made from ultra-performance materials, polyetherimide (PEI) and polyetherketoneketone (PEKK), using the fused filament fabrication process (FFF). The tensile tests were performed for these materials at different raster angles (0, 45, and 90°). The thermomechanical tests were done in the axial, perpendicular, and through-thickness directions to the extruded filaments. The impact of printing parameters on the flame retardancy of 3D-printed samples was investigated in vertical burn tests with varying specimen thicknesses and printing directions. Experimentally, it was testified that PEKK had better isotropic behaviour than PEI for mechanical performance, thermal expansion, and fire-resistant properties, which are essential in fabricating intricately shaped products.

Monitoring of extrusion filament state for fused filament fabrication: A super-resolution image monitoring approach based on degradation pattern learning

Extrusion filament is the fundamental unit of the fused filament fabrication process (FFF). Its state stability directly affects the product quality. Therefore, a reliable method is required to monitor the state of the extrusion filament. This work presents an innovative approach involving super-resolution algorithms for conveniently monitoring the state of the extrusion filament during the printing process using cost-effective cameras. Firstly, this work captures high-resolution images during the printing ending and low-resolution images during the printing processing. Secondly, a generative adversarial network (GAN) is employed to adaptively learn the degradation patterns in the printing environment. Subsequently, the trained generator of the GAN is used to construct pixel-level paired super-resolution training dataset. The work then utilizes this dataset to train a super-resolution model, getting a specialized super-resolution model for the degradation patterns specific to the printing scenario. Finally, this super-resolution model is employed to enhance the resolution of the images captured during the production process, resulting in improved performance in downstream image-related tasks.

Effect of autoclaving on the dimensional stability and surface characteristics of 3D printed PVDF composite-based implants

In the past decade, a lot of work has been reported on the use of polyvinylidene fluoride (PVDF) based thermoplastic composites as energy storage devices, and implant materials. But hitherto little has been reported on the dimensional stability and surface characteristics of 3D-printed PVDF composites after autoclaving for implant applications. In this study, the effect of autoclaving on surface characteristics (Shore-D hardness, surface roughness (Ra), morphological characteristics), and dimensional stability of 3D printed PVDF-hydroxyapatite (HAp)- chitosan (CS) composite has been reported for implant applications. The signal-to-noise (S/N) ratio approach was used to ascertain the best setting of process parameters for 3D printing by fused filament fabrication (FFF) process. This study suggests that the best setting for the FFF process, for the 3D printing of PVDF composite (90%PVDF-8%HAp-2%CS) are the nozzle temperature (NT) of 225°C, raster angle (RA) 0°, and printing speed (PS) 40 mm/s, resulting in Shore-D hardness 48.5 HD (before autoclaving) and 55.0 HD (after autoclaving), dimensional deviation 0.01 mm (after autoclaving). The results are supported by scanning electron microscopy (SEM) and Fourier transmission infrared (FTIR) spectroscopy analysis.

Experimental and Numerical Study of Printing Strategy Impact on the Mechanical Properties of Sustainable PLA Materials.

This article is focused on a mechanical properties investigation of three types of sustainable poly lactic acid materials manufactured using the fused filament fabrication process. The purpose of this work was to study the impact of printing strategies on the mechanical properties and predict mechanical behavior under tensile loading using finite element analysis. The testing of mechanical properties was conducted according to the ISO 527 standard. The numerical simulations were conducted in Simufact Forming 2022 software. Analysis of the experimental data showed a dependance of mechanical properties on the used printing strategy. The Clear PLA samples printed in the XY plane exhibited a 43% reduction in tensile strength and a 49% reduction in elongation compared to samples printed from the same material in YZ plane. The experimental results show the influence of the printing orientation on the mechanical properties of 3D-printed samples.

Effects of Microstructural Arrangement on the Mechanical Behavior of 3D Printed Polyamide

This study aims to relate the microstructural arrangement, in particular the symmetry materialized by filament sequencing in the fused filament fabrication process, to the mechanical behavior of printed polyamide. Dog-bone structures were printed using various printing temperatures ranging from 250 °C to 280 °C, which were combined with part orientation including vertical, horizontal, and lateral configurations and raster angles (0°, 15°, 30°, and 45°) that represent the in-plane and out-of-plane symmetrical arrangement of the filament. Mechanical testing was conducted on both as-received filaments and printed structures to derive the effects of filament arrangement symmetry and process-generated defects on mechanical loss. In addition, a microstructural analysis using scanning electron microscopy was used to share more light on the filament arrangements and their consequence on the deformation mechanisms with respect to the printing conditions. The results showed that the 3D printed polyamide-based materials exhibited remarkable tensile performance with strain stiffening behavior and large elongation at break due to their particular filament layout. Among the considered printing conditions, the part orientation was found to have the largest influence on the tensile behavior, which modulates the behavior from complete restoration of the filament performance to mechanical loss.

Effect of process parameters on mechanical properties and wettability of polylactic acid by fused filament fabrication process

Abstract Fiber-reinforced composites have changed additive manufacturing into a sustainable manufacturing paradigm with the capacity to produce items with outstanding mechanical performance. The fused filament fabrication (FFF) process is the latest in advanced digital fabrication techniques used for fabricating polymer material using additive layer deposition. In this study, the results of mechanical and vibration tests were used to examine the impact of process variables such as layer thickness (0.08 mm, 0.25 mm, and 0.64 mm), infill density (20 %, 40 %, 60 %, and 80 %), and infill pattern (rectilinear, triangular, and hexagonal). The novelty of this work is to correlate the contact angle measurement with the mechanical properties of the 3D-printed specimens. The adhesion behaviour of the 3D printed parts is examined by measuring the contact angle from the wettability test. From the findings, it was observed that the infill density and layer pattern play a significant role in the interlayer adhesion, as evident from the contact angle measurement.

Optimization of Dual Extrusion Fused Filament Fabrication Process Parameters for 3D Printed Nylon-Reinforced Composites: Pathway to Mobile and Transportation Revolution

<div>Nylon polymer with an optimal blend of Kevlar, fiberglass, and high-speed, high temperature (HSHT) Fiberglass offers improved characteristics such as flexural strength, wear resistance, electrical insulation, shock absorption, and a low friction coefficient. For this reason, the polymer composite manufactured by combining HSHT, Kevlar, and fiberglass with nylon as base material will expand the uses of nylon in the aerospace, automotive, and other industrial applications related to ergonomic tools, assembly trays, and so forth. The proposed work was carried out to investigate the continuous fiber reinforcement (CFR) in nylon polymer using a dual extrusion system. Twenty experimental runs were designed using a face-centered central composite design (FCCD) approach to analyze the influence of significant factors such as reinforcement material, infill pattern, and fiber angle on the fabricated specimen as per American Society for Testing Materials (ASTM) standards. The tensile strength, percentage elongation, and surface roughness of each test specimen (ASTM) have been investigated using the universal testing machine (UTM) and a surface roughness tester. A set of regression equations connecting process input factors and output features have been derived using the response surface methodology (RSM). In addition, the MOGA-ANN method is employed to achieve the multi-response targets. The results show that the best tensile strength and surface roughness are achieved with a 64.5-degree fiber angle, fiberglass CFR, and a triangular infill pattern, while the best balance and optimal response are achieved with a 49.2575-degree fiber angle, a rectangular fill pattern, and fiberglass reinforcement using the MOGA-ANN evolutionary hybrid algorithm. With MOGA-ANN, the least surface roughness of 1.43158 microns, maximum tensile strength, and percentage elongation of 37.869 MPa and 51.05% were attained at these parameters, and the same has been validated experimentally.</div>

High Vacuum Capable Fused Filament Fabrication 3D Printer, Part II: High-Temperature Polymers Suitable for In-Space Manufacturing

The ability to additively manufacture structures on-orbit has the potential to fundamentally alter the traditional paradigm for how large spacecraft are constructed and launched into space. The space environment presents several unique challenges for additive manufacturing, including the need to operate in a vacuum. This paper presents the design, analysis, and test results for a passively cooled fused filament fabrication (FFF) 3D printer capable of manufacturing parts out of engineering-grade thermoplastics in the vacuum of space. Four high-temperature materials were successfully printed in high vacuum, including polyetherketoneketone, carbon-nanotube–polyetherketoneketone, polyetherimide, and carbon-nanotube–polyetherimide. Over 100 test coupons were printed in a vacuum and tested to confirm the feasibility of applying the FFF process in this environment. Lessons learned were documented throughout the vacuum printing test campaigns and are discussed here. This paper is part of a two-part series. Part I presented results for using a low-temperature hotend capable of printing hobby-grade materials in high vacuum and documented initial findings and lessons learned. Part II presents the results for a high-temperature hotend capable of printing engineering-grade plastics that are suitable for on-orbit manufacturing. The combined results of the two papers in this series can be used to inform future on-orbit additive manufacturing.

On digital twinning of fused filament fabrication for tensile properties of polyvinylidene fluoride composites-based functional prototypes

In the last two decades, several studies have been conducted for the process parametric optimization of fused filament fabrication (FFF) with a variety of thermoplastic composites, especially for mechanical properties. But hitherto less has been conveyed, on the development of dynamic reduced order models (ROMs) for digital twining (DT) of tensile properties (of 3D printed implants/scaffolds) with novel thermoplastic-based composites. In this study, for the generation of dynamic ROM (for hybrid analytics), the signal-to-noise (S/N) ratio was used to ascertain the best settings of parameters for tensile properties of polyvinylidene fluoride (PVDF) composite. The study suggests that the best setting of the FFF process, for the 3D printing of PVDF composite (90% PVDF, 8% hydroxyapatite (HAp), and 2% Chitosan (CS) (for maximizing the tensile properties as per ASTM-D638-Type-V) are nozzle temperature (NT) of 235°C, raster angle (RA) 45°, printing speed (PS) of 60 mm/s respectively resulting in peak load (PL) 394.87 N, peak stress (PSt) 33.92 MPa, Young’s modulus (E) 2.606 MPa. For a modulus of toughness (MOT) of 0.484 MPa, the best settings are NT 230°C, RA 90°, and PS 50 mm/s. The results are supported by the morphological analysis.

Automating life cycle assessment for additive manufacturing with machine learning: Framework design, dataset buildup, and a case study

Additive Manufacturing (AM) has been regarded as a technology with disruptive potential, offering the possibility of substantial reductions in the environmental footprint. The predominant approach to quantitatively evaluate AM’s environmental impacts relies heavily on the knowledge-intensive and time-consuming Life Cycle Assessment (LCA) methodology. To enable a faster design iteration cycle and alleviate the knowledge requirements of LCA modeling, the availability of an automated LCA tool could mark a remarkable leap forward in further enhancing AM's environmental performance. An emerging solution to achieve this goal is the combination of Machine Learning (ML) with LCA, the effectiveness of which has been initially demonstrated outside the AM domain. To explore the feasibility of predictive LCA for AM, this paper proposes a novel data-driven framework that integrates ML, product-process codesign, and LCA to support the environmental impact prediction of AM. The efficacy of the proposed methodology is demonstrated by taking the Fused Filament Fabrication (FFF) process as a case study. This work introduces three main contributions to the research community. First, a training dataset comprising 200 data entries, where each entry encompasses 5 design features, 7 process features, and 18 environmental impact categories is constructed. Second, through a two-stage process involving correlation analysis and an ML preliminary study, the initial 12 design-process parameters are refined to 7 key influential features. Lastly, the refined set of features and 7 different ML algorithms are employed to develop a data-driven LCA (DD-LCA) model for the FFF process. Notably, the Extreme Gradient Boosting (XGBoost) and Multi-Layer Perceptron (MLP) algorithms demonstrate good performance with a prediction accuracy of 98% and a root mean square error (RMSE) of 0.029. The developed model exhibits good generalizability when tested on new data. The paper concludes by addressing its limitations and outlining future research work.

Characterization of the Metal Fused Filament Fabrication Process for Manufacturing of Pure Copper Inductors.

This work presents a comprehensive investigation into the optimization of critical process parameters associated with metal fused filament fabrication (Metal-FFF) for the production of copper-based components. The study focused on three different commercial and one self-manufactured filament, each with unique chemical compositions. These filaments were systematically optimized and the density was characterized for all processing steps, as well as the electrical conductivity on the specimen scale. Remarkably, two of the studied filaments exhibited exceptional properties after sintering with forming gas (up to 94% density and 55.75 MS/m electrical conductivity), approaching the properties measured for established manufacturing methods like metal injection molding. Finally, the research was extended to component-scale applications, demonstrating the successful fabrication of inductors with integrated cooling channels. These components exhibited water tightness and were used in induction hardening experiments, validating the practical utility of the optimized Metal-FFF process. In summary, the results show great promise in advancing the utilization of Metal-FFF in industrial contexts, particularly in the production of high-performance copper components.

Anisotropic and elastoplastic mode‐I fracture toughnesses of three additively manufactured polymers fabricated via material extrusion and powder bed fusion

AbstractTwo types of additive manufacturing (AM) techniques, fused filament fabrication (FFF) and selective laser sintering (SLS), were employed to fabricate specimens from three widely used AM polymers: polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polyamide (PA): the first two using FFF and PA using SLS. The single‐edge notch bending (SENB) test was employed to measure the mode‐I fracture toughnesses of bulk and AM specimens in three directions relative to the printing direction. Unlike their bulk counterparts, AM polymers exhibited anisotropic fracture toughness. The degree of anisotropy in FFF‐PLA was much larger than FFF‐ABS and SLS‐PA. The smallest fracture toughness value for each AM polymer was achieved along the transverse printing direction. Different AM techniques affect fracture toughness differently. For instance, FFF is shown to increase PLA's plastic deformation, while SLS reduces PA's ductility. The decrease in fracture toughness is consistently observed when transitioning from bulk polymers to AM ones, reaching as much as 75%. This study provides insights into the fracture toughness of AM parts made via popular plastics, which are crucial for designing structural parts using FFF and SLS processes.