For Fused Deposition Modeling Research Articles

3D-printed gradient conductivity and porosity structure for enhanced absorption-dominant electromagnetic interference shielding

The application of 3D printing for the development of electromagnetic interference (EMI) shielding materials is currently constrained by a limited range of material options and design schemes. In this work, we developed conductivity-modulated polylactic acid (PLA)-MXene composite filaments for fused deposition modeling (FDM) 3D printing, demonstrating excellent printability and durability. Utilizing these filaments, we propose a design scheme focused on absorption-dominant EMI shielding materials. Our design features non-conductive PLA with larger pores at the incident surface, transitioning to layers with increasing conductivity and decreasing pore sizes. This gradient structure minimizes reflection by providing impedance matching and enhances absorption by extending the propagation path of EM waves through multiple reflections and scattering within the pores. Additionally, interfacial polarization effects between air, PLA, and MXene nanoflakes strengthen the absorption mechanisms. Both simulation and experimental results confirm that the combined gradient conductivity and pore size structures significantly improve EMI shielding effectiveness (EMI SE) and absorptivity, achieving an EMI SE of 65 dB and an absorptivity of 0.76 in the X-band. Our findings underscore its potential to create adaptable, high-performance EMI shields suitable for complex geometries and reducing secondary interference.

A critical review of composite filaments for fused deposition modeling: Material properties, applications, and future directions

This review paper provides a comprehensive analysis of recent advancements in the development and application of composite filaments for fused deposition modeling (FDM) 3D printing technology. Focusing on the integration of various materials such as nano-fillers, fibers, and bio-based polymers into polylactic acid (PLA) and other thermoplastics, this study delves into how these composites enhance mechanical, thermal and functional properties of the printed objects. We critically assess studies that investigate the impact of raster orientation, filler content, and material composition on tensile, bending, and impact strength, as well as on the thermal stability and degradation behavior of composite filaments. The review highlights key findings from the literature, including the optimization of filament formulations to achieve superior mechanical performance, improved thermal resistance, and specific functional characteristics suitable for a wide range of applications from biomedical to structural components. Moreover, this paper discusses the challenges associated with composite filament production, including material compatibility, dispersion of nano-fillers, and the need for printer hardware adjustments. Future directions for research in the field are identified, emphasizing the potential for new material combinations, sustainability considerations, and the development of filaments designed for specific industrial applications. An effective way to better meet designers’ expectations for qualified materials is composite filaments. This review focuses on how these elements can be applied to improve both product design and functionality. A guide is presented in choosing composite filaments that can meet the features expected from the designed product.

Ternary Blends of Polypropylene Copolymer, Polyethylene and Thermoplastic Polyurethane for Fused Deposition Modeling Three-Dimensional Printing Technology: Preparation, Printing and Properties.

A set of filaments for fused deposition modeling (FDM) three-dimensional (3D) printing was developed from the ternary blends of polypropylene random copolymer (PPR or P), high density polyethylene (HDPE or E), and thermoplastic polyurethane (TPU or T), formulated with different weight ratios of polymers, i.e., 80:20:0, 70:20:10, 60:20:20, and 50:20:30, respectively, and coded as P80E20T0, P70E20T10, P60E20T20, and P50E20T30, respectively. The blend composition was optimized to obtain both high-quality filaments with low ovality and FDM-fabricated objects with minimized warpage and good interlayer bonding. The crystallization and crystalline morphologies of individual polymers in the blend filaments were comprehensively analyzed by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarized light optical microscopy (PLOM). It was found that HDPE acted as crystalline nuclei for PPR crystallization; PPR appeared to crystallize more readily at a slightly higher T c with somewhat greater crystallinity. Meanwhile, TPU explicitly restricted the crystallization of both polyolefins; decreases in both the size and growth rate of their spherulites were observed. The PLOM and SEM results indicated that the surface morphology of the ternary blends was not absolutely phase-separated; an increasing number of TPU droplets inherently imbedded at the boundary of the polyolefin aggregate phase when a higher TPU quantity was integrated. Consequently, the warpage deformation and layer interfusion of the as-printed articles were most remarkably improved when P50E20T30 was used. Nonetheless, the incorporation of relatively flexible TPU material into the PPR-based filaments inevitably reduced their mechanical performance; the flexural strength and modulus of the highest-quality 3D-printed P50E20T30 object were fairly decreased by approximately 25% and 12%, respectively.

Physical and mechanical properties of fused deposition modelling PLA/carbon dot nanocomposites

This study explores the incorporation of carbon dots (CDs) into polylactic acid (PLA) filaments to improve their mechanical properties for fused deposition modelling (FDM). Known for their adjustable photoluminescence, high quantum yield, low toxicity, and biocompatibility, CDs are integrated into PLA at various concentrations (0.1, 0.3, 0.5, 0.7, 1.0, 3.0, and 5.0 wt%). Samples reinforced with 0.1–0.7 wt% CDs exhibit a tensile modulus ranging from 3.55 to 4.0 GPa and a tensile strength from 30 to 35 MPa. Meanwhile, those with 3.0 wt% achieve a higher tensile modulus (4.3 GPa) and strength (55 MPa), albeit with noted manufacturing challenges. The inclusion of 5.0 wt% CDs compromises the filament manufacturing process, resulting in a reduced tensile stress of 27 MPa, lower than pristine PLA, and exhibiting micro defects after 3D printing. Fluorescence analysis during tensile testing indicates that lower CD concentrations reduce fluorescence, while higher concentrations increase it, suggesting a correlation with the mechanical response. PLA reinforced with 0.5 wt% CDs not only offers improved mechanical properties but also facilitates easy manufacturing, showing promise for creating both solid and lattice 3D-printed products.

Novel 3D printing filaments: PLA and zinc carbonate basic composites for laser-assisted thermal decomposition

Additive manufacturing (AM), also known as 3D printing, has revolutionized the production of complex geometric structures across various industries. This study presents an innovative approach by integrating zinc carbonate basic (ZCB) precursor with polylactic acid (PLA) to develop composite filaments for fused deposition modeling (FDM) 3D printers. The resulting filaments undergo surface transformation into zinc oxide (ZnO) through high-power laser irradiation. Thermal analysis (TGA-DSC) and Fourier-transform infrared spectroscopy (FTIR) were used to confirm the decomposition of ZCB ([ZnCO₃]₂·[Zn(OH)₂]₃) into ZnO during the thermal decomposition stages. The study successfully extruded a composite filament containing 10% of ZCB, which worked adequately in 3D printing. The printed parts were analyzed through tensile tests (based on ASTM D638-5 standard), showing a notable difference in mechanical behavior between the commercial filament PLA and the composite filament (PLAC10). Laser irradiation of these samples facilitated a targeted conversion to ZnO, verified through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The integration of zinc oxide within the printed structures enhances structural stability and provides surfaces enriched with ZnO, a metal oxide with widely reported applications. Furthermore, an irradiated 3D-printed sample demonstrated chemo-resistive properties upon carbon monoxide (CO) exposure, underlining its potential as a gas sensor and confirming its semiconductor nature. This approach provides a cost-effective and efficient way to develop innovative devices with integrated functional materials.

Flow Analysis and Shear Rate Comparison of Counter-rotating and Co-rotating Intermeshing Twin-screw Extruders for Filament Extrusion of Polypropylene-based Biocomposites

This study investigates and compares the performance of counter-rotating and co-rotating intermeshing twin-screw designs in filament extruder machines. The research sought to determine whether the counter-rotating intermeshing design with its opposite flow direction offers advantages over the co-rotating intermeshing design in terms of flow analysis and shear rates. Flow analysis was conducted to examine the velocity of the polypropylene-based biocomposite material inside the barrel. Shear rate data was obtained by evaluating the relationship between shear rate and screw speed to assess the stability and maximum shear rate of the twin-screw extruders. The results revealed that the counter-rotating intermeshing twin-screw extruders exhibited higher shear rates and more consistent pressure compared to the co-rotating intermeshing design. The superiority of the counter-rotating extruder was attributed to its opposite flow direction and distinct thread shapes, facilitating efficient material compression and improved dispersion of polymer-based biocomposite materials. The study suggested the potential for further exploration and refinement of the counter-rotating intermeshing twin-screw extruder design, particularly in producing polypropylene-based biocomposite filaments for Fused Deposition Modeling (FDM) machines.

Production of Composite Zinc Oxide-Polylactic Acid Radiopaque Filaments for Fused Deposition Modeling: First Stage of a Feasibility Study.

Three-dimensional printing technologies are becoming increasingly attractive for their versatility; the geometrical customizability and manageability of the final product properties are the key points. This work aims to assess the feasibility of producing radiopaque filaments for fused deposition modeling (FDM), a 3D printing technology, starting with zinc oxide (ZnO) and polylactic acid (PLA) as the raw materials. Indeed, ZnO and PLA are promising materials due to their non-toxic and biocompatible nature. Pellets of PLA and ZnO in the form of nanoparticles were mixed together using ethanol; this homogenous mixture was processed by a commercial extruder, optimizing the process parameters for obtaining mechanically stable samples. Scanning electron microscopy analyses were used to assess, in the extruded samples, the homogenous distribution of the ZnO in the PLA matrix. Moreover, X-ray microtomography revealed a certain homogenous radiopacity; this imaging technique also confirmed the correct distribution of the ZnO in the PLA matrix. Thus, our tests showed that mechanically stable radiopaque filaments, ready for FDM systems, were obtained by homogenously loading the PLA with a maximum ZnO content of 6.5% wt. (nominal). This study produced multiple outcomes. We demonstrated the feasibility of producing radiopaque filaments for additive manufacturing using safe materials. Moreover, each phase of the process is cost-effective and green-oriented; in fact, the homogenous mixture of PLA and ZnO requires only a small amount of ethanol, which evaporates in minutes without any temperature adjustment. Finally, both the extruding and the FDM technologies are the most accessible systems for the additive manufacturing commercial apparatuses.

Decoupling Geometry from Surface Finish by Parameterizing Texture Directly in G-code for Fused Deposition Modeling (FDM) Printing

Decoupling Geometry from Surface Finish by Parameterizing Texture Directly in G-code for Fused Deposition Modeling (FDM) Printing

Sustainable improvement in the polylactic acid properties of 3D printing filaments: The role of bamboo fiber and epoxidized soybean oil‐branched cardanol ether compatibilizer

AbstractPolylactic acid (PLA) is the prevailing raw material for fused deposition modeling (FDM) 3D printing filaments, offering benefits such as a low printing temperature, minimal shrinkage, and biodegradability. However, this material has challenges such as poor toughness, low heat deflection temperature, susceptibility to moisture‐induced thermal degradation, and high costs. This study addressed these concerns by incorporating natural bamboo fiber (BF) into PLA, elevating heat the deflection temperature and lowering the material costs. Additionally, a synthesized branched structure compatibilizer, in the form of epoxidized soybean oil‐branched cardanol ether (ESOn‐ECD), enhanced the toughness of PLA, the bonding strength between PLA and the BF surface, and the flowability of high‐fiber composites during processing and printing. The mechanical, thermal, and rheological properties were assessed, demonstrating the promising processing performance of PLA/BF/ESO3‐ECD. The fully biobased composite exhibits strength, toughness, good processability, excellent 3D printability, and durability, implying substantial potential in FDM 3D filament production.Highlights Bio‐based PLA/bamboo fiber/ESO3‐ECD FDM 3D printing filaments were developed. The excellent nucleation ability of the bamboo fibers enhances the crystallization rate and crystallinity of PLA. The epoxy values and branching degree of ESOn‐ECD are crucial for its effective modification.

Performance of bioresorbable peptide incorporated polymers produced for fused deposition modelling (FDM)

The use of biomaterials in additive manufacturing (AM) of medical devices has gained significant attention over the years, especially in areas such as wound care and orthopedics. This study aims to investigate the performance of bioresorbable peptide-incorporated polymers produced for fused deposition modelling (FDM) process. Herein, we report FDM 3D Printing process of bioactive polymers comprising polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA) or polylactic acid (PLA) or blended with peptide–containing brush copolymers bearing similar synthetic polymer side chains. Mechanical, thermal and rheological properties of the materials were carried out and we report that the incorporation of bioactive polymers into these biodegradable polymers does not result in significant changes to glass transition temperature, melt temperature, tensile properties of the base polymers. However, it was observed that flexural and rheological properties altered significantly. This study provides an insight into the thermomechanical performance of bioresorbable peptide-incorporated polymers for FDM utilization which allows for their use potential in medical device fabrication.

Recent development of poly (lactic acid) blends with a thermoplastic elastomer compatibilised for fused deposition modelling (FDM) 3D printing

Recent development of poly (lactic acid) blends with a thermoplastic elastomer compatibilised for fused deposition modelling (FDM) 3D printing

Silk-inspired architectured filament with enhanced stiffness and toughness for Fused deposition modelling (FDM)

Architectured materials, those capable of manipulating the spatial configurations of two or more material phases, have recently gained substantial attention, primarily due to their unprecedented material properties (e.g., exceptional strength-to-weight ratio and intriguing negative Poisson's ratio). Most architectured materials draw inspiration from the microstructure of natural solutions. One of fascinating examples are spider silk and cocoon silk. Their multimaterial core-shell fibrous structure exhibits remarkable mechanical properties—high stiffness, strength, and toughness. In this study, silk-inspired dual-phase Core-Shell Architectured Filament (CSAF), which combines a rigid Polylactic Acid (PLA) core with a soft Thermoplastic Polyurethane (TPU) shell, was developed as feedstock for additive manufacturing. The mechanical testing of dual-phase CASF printed samples reveal intriguing results. Notably, the optimized CASF in this study, whose volume fraction of rigid core was set as 52 %, was observed a substantial improvement of the printed specimens in initial stiffness and energy absorption capacity—up to a remarkable 14-fold increase in initial stiffness and a ∼9 % enhancement in energy absorption when compared to the pure TPU filament. To gain a deeper understanding of the synergistic effects arising from geometrical and material configurations on the structure's damage mechanism, a theoretical model of this core-shell structure was developed. Computational models have been built to validate theoretical model, and the results from finite element analysis are in excellent agreement with experimental results. These discoveries offer valuable insights to enhance mechanical performance of the feedstock for additive manufacturing.

Influence of Hydroxyapatite Particle Size on the Flowability of PLA/HA Filament

Advanced bioactive ceramic materials, Hydroxyapatite (HA) and Polylactic Acid (PLA) are common in bone regeneration implants. As demand for customised implant products increases, research increasingly focuses on developing composite filament manufacturing technology. However, creating PLA/HA composite filament faces challenges, including clumping HA particles and uneven flowability. The brittleness of the filament properties makes it unsuitable for Fused Deposition Modelling (FDM) printing, causing inconsistent extrusion and reduced filament strength. The purpose of this study is to compare the effectiveness of microHAs (m-HAs) and nanoHAs (n-HAs) in the production of filament composite fibers, based on the flowability assessment. The particle size of the micro-HA was reduced to nano by a ball mill process using 4 mL ethanol and the ball-powder ratio of 5:1, which was verified by the particle size analyzer. The feedstock comprises 79.5 wt.% PLA, 19.5 wt.% HA and 1 wt.% impact modifier (IMK) was mixed and rheological tested (130 ℃ to 150 ℃, shear rate: 20-1000 s-1) to achieve pseudoplastic behaviour (n<1). The rheological tests showed that both feedstocks exhibited pseudoplastic behaviour (n<1) across all temperatures studied. The properties of the feedstock were observed by scanning electron microscopy (SEM), and tensile tests evaluated the filament strength. The investigation found that nano-sized HA filament has 24% higher strength than micro-sized PLA/HA filament.

Influence of SiC and ZnO Doping on the Electrical Performance of Polylactic Acid-Based Triboelectric Nanogenerators.

Polylactic acid (PLA) is one of the most widely used materials for fused deposition modeling (FDM) 3D printing. It is a biodegradable thermoplastic polyester, derived from natural resources such as corn starch or sugarcane, with low environmental impact and good mechanical properties. One important feature of PLA is that its properties can be modulated by the inclusion of nanofillers. In this work, we investigate the influence of SiC and ZnO doping of PLA on the triboelectric performance of PLA-based tribogenerators. Our results show that the triboelectric signal in ZnO-doped PLA composites increases as the concentration of ZnO in PLA increases, with an enhancement in the output power of 741% when the ZnO concentration in PLA is 3 wt%. SiC-doped PLA behaves in a different manner. Initially the triboelectric signal increases, reaching a peak value with enhanced output power by 284% compared to undoped PLA, when the concentration of SiC in PLA is 1.5 wt%. As the concentration increases to 3 wt%, the triboelectric signal reduces significantly and is comparable to or less than that of the undoped PLA. Our results are consistent with recent data for PVDF doped with silicon carbide nanoparticles and are attributed to the reduction in the contact area between the triboelectric surfaces.

Composite PCL Scaffold With 70% β-TCP as Suitable Structure for Bone Replacement

The purpose of this work was to optimise printable polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) biomaterials with high percentages of β-TCP endowed with balanced mechanical characteristics to resemble human cancellous bone, presumably improving osteogenesis. PCL/β-TCP scaffolds were obtained from customised filaments for fused deposition modelling (FDM) 3D printing with increasing amounts of β-TCP. Samples mechanical features, surface topography and wettability were evaluated as well as cytocompatibility assays, cell adhesion and differentiation. The parameters of the newly fabricated materila were optimal for PCL/β-TCP scaffold fabrication. Composite surfaces showed higher hydrophilicity compared with the controls, and their surface roughness sharply was higher, possibly due to the presence of β-TCP. The Young's modulus of the composites was significantly higher than that of pristine PCL, indicating that the intrinsic strength of β-TCP is beneficial for enhancing the elastic modulus of the composite biomaterials. All novel composite biomaterials supported greater cellular growth and stronger osteoblastic differentiation compared with the PCL control. This project highlights the possibility to fabricat, through an FDM solvent-free approach, PCL/β-TCP scaffolds of up to 70 % concentrations of β-TCP. overcoming the current lmit of 60 % stated in the literature. The combination of 3D printing and customised biomaterials allowed production of highly personalised scaffolds with optimal mechanical and biological features resembling the natural structure and the composition of bone. This underlines the promise of such structures for innovative approaches for bone and periodontal regeneration.

Fused Deposition Modeling of Isotactic Polypropylene/Graphene Nanoplatelets Composites: Achieving Enhanced Thermal Conductivity through Filler Orientation.

High-performance thermally conductive composites are increasingly vital due to the accelerated advancements in communication and electronics, driving the demand for efficient thermal management in electronic packaging, light-emitting diodes (LEDs), and energy storage applications. Controlling the orderly arrangement of fillers within a polymer matrix is acknowledged as an essential strategy for developing thermal conductive composites. In this study, isotactic polypropylene/GNP (iPP/GNP) composite filament tailored for fused deposition modeling (FDM) was achieved by combining ball milling with melt extrusion processing. The rheological properties of the composites were thoroughly studied. The shear field and pressure field distributions during the FDM extrusion process were simulated and examined using Polyflow, focusing on the influence of the 3D printing processing flow field on the orientation of GNP within the iPP matrix. Exploiting the unique capabilities of FDM and through strategic printing path design, thermally conductive composites with GNPs oriented in the through-plane direction were 3D printed. At a GNP content of 5 wt%, the as-printed sample demonstrated a thermal conductivity of 0.64 W/m · K, which was 1.5 times the in-plane thermal conductivity for 0.42 W/m · K and triple pure iPP for 0.22 W/m · K. Effective medium theory (EMT) model fitting results indicated a significantly reduced interface thermal resistance in the through-plane direction compared to the in-plane direction. This work shed brilliant light on developing PP-based thermal conductive composites with arbitrarily-customized structures.

Development of 3D Printing Filaments from Recycled PLA Reinforced with Nanoclay

This study focused on the development of 3D printing filaments suitable for fused deposition modeling (FDM) by recycling expired polylactic acid (PLA) filaments. The 3D printing filaments were processed into pellets by incorporating montmorillonite (MMT) nanoclay into the expired PLA filaments through twin-screw extrusion with varying concentrations of 1%, 3%, and 5 wt.%. These composite pellets were reprocessed to filaments through a filament extruder with a diameter of 1.75 mm. These filaments underwent different characterization techniques to test its mechanical and thermal properties. The thermal properties showed increasing values in the glass transition temperature, crystallization temperature, and melting temperature with a decrease in the specific heat upon incorporating increasing amount of MMT nanoclay. Furthermore, thermogravimetric analysis (TGA) showed a positive impact with better thermal stability when the MMT content was incorporated. In terms of mechanical properties, the study showed that the addition of 1 wt% MMT nanoclay, provided an increase in both the tensile strength and elastic modulus comparable to the virgin 3D printing PLA filament.

Effect of Nano-Alumina (Al<sub>2</sub>O<sub>3</sub>) Loading on the Thermo-Mechanical Properties of Poly(Lactic Acid) for Fused Deposition Modeling 3D Printing Applications

This research focused on the development of filament composite materials for fused deposition modeling (FDM) 3D printing applications. The main objective of this study was to fabricate and characterize poly (lactic acid) (PLA) filaments with varying amounts of alumina (Al2O3) nanopowder (0, 2.5, 5.0, and 10.0 wt.%). The resulting PLA/Al2O3 filament blends were produced using hot-melt extrusion. The filament blends were subjected to different characterization techniques and mechanical testing. The results indicate that the thermal stability of the filaments increased with increasing filler content. Furthermore, PLA with 5.0 wt.% nanoAl2O3 exhibited 55.84%, 66.14%, and 45.84% improvement in tensile strength, elastic modulus, and toughness, respectively.

Polyvinyl Alcohol, a Versatile Excipient for Pharmaceutical 3D Printing.

Three-dimensional (3D) printing in the pharmaceutical field allows rapid manufacturing of a diverse range of pharmaceutical dosage forms, including personalized items. The application of this technology in dosage form manufacturing requires the judicious selection of excipients because the selected materials must be appropriate to the working principle of each technique. Most techniques rely on the use of polymers as the main material. Among the pharmaceutically approved polymers, polyvinyl alcohol (PVA) is one of the most used, especially for fused deposition modeling (FDM) technology. This review summarizes the physical and chemical properties of pharmaceutical-grade PVA and its applications in the manufacturing of dosage forms, with a particular focus on those fabricated through FDM. The work provides evidence on the diversity of dosage forms created using this polymer, highlighting how formulation and processing difficulties may be overcome to get the dosage forms with a suitable design and release profile.

Direct ink writing of polymer matrix composite with carbon for driving a flexible thermoelectric actuator of shape memory polymer

Carbon nanomaterials and polymer composites that possess excellent electrical and mechanical properties for soft robots have been investigated over decades in multidisciplinary research fields. As considering the incorporation of carbon into polymer composite, several major concerns include the electrical conductivity, elastic module, and manufacturing flexibility that can enable them to satisfy various functions such as actuation and sensing. In this paper, we report a comprehensive study on how to design and fabricate a soft gripper based on carbon polymer matrix composite and multilayer structure through multistep processes of 3D printing on paper. Using commercial conductive additives of graphene and carbon nanotube with polydimethylsiloxane (PDMS), a polymer matrix composite (PMC) was prepared for the ink of direct ink writing (DIW) with percolation conductivity. Additionally, a shape memory polymer (SMP) was utilized for fused deposition modeling (FDM) of a thermal actuator. Incorporating the DIW of PMC with the FDM of SMP on paper, a soft gripper with four fingers was designed and fabricated to show remarkable thermoelectrical actuation for grasping a 50 mm-diameter 10 g-weight spherical ball. In the future, it would provide an alternative approach for the fields of science and engineering, such as nanomaterials and nanotechnology, space applications, sustainable soft robots, and flexible autonomous systems.