FDM 3D Printing Research Articles

Study on the hot isostatic pressing post-treatment of FDM-3D printed continuous carbon fiber reinforced composites

Study on the hot isostatic pressing post-treatment of FDM-3D printed continuous carbon fiber reinforced composites

Simulation of temperature distribution in 3D printing heated chamber on orientation and temperature variations with ABS material

Currently, the use of 3D printing is growing rapidly. Uneven temperature distribution in the printing chamber causes problems such as warpage, shrinkage, geometric accuracy, and decreased mechanical properties. The proper environmental temperature is needed to produce a good part. The heated chamber is needed to regulate the temperature during the printing process. Simulation of CFD is carried out, knowing the temperature distribution inside the heated chamber. Simulations and experiments were carried out with variations in temperature of 70 °C, 80 °C, 90 °C, and 100 °C with an airflow rate of 3 m/s. The correlation of temperature distribution in a chamber between simulation and experiment was investigated. Experiments on FDM 3D Printing with 70 × 30 × 30 mm3 ABS material dimensions. Meanwhile, variations in printing orientation on the x, y, and z-axes. The results show a fit correlation between simulation and experiment. The temperature in a heated chamber has increased and the temperature distribution is even during the printing process, along with increasing temperature variations from the heater. The heat flux distribution shows different temperature variations in each part build orientation. Therefore, the orientation and temperature rise of the chamber play a pivotal role in quality.

3D printed curved shape solar evaporator in producing distillate

3D printed curved shape solar evaporator in producing distillate

SYSTEM IDENTIFICATION AND VIBRATION ANALYSIS OF ROTATING BEAM WITH LATTICE STRUCTURES

Today, lattice-structured materials are used in many engineering applications. Research and applications including lattice structures focused on obtaining lightweight components with the optimal distribution. In literature, studies on obtaining vibration models of the beams with lattice structures are limited. In this study, vibration models of rotating beams with lattice structure were obtained by using system identification methods. Beams used in the experimental phase of this study were produced using FDM 3D printer. Three types of lattice structure such as triangular, hexagonal, and square rotated were used. Lattice-based generative design program nTopology was used for the design of the beams. The experiments were carried out using a setup that includes a servo system and a wireless accelerometer. It was proved that the obtained models successfully represent the vibration behavior of the rotating beams. The success of the vibration models of the rotating beams was compared and discussed using tables and figures.

Determining the effect of porosities on the hydrogen adsorption capacity of 3D printed PEEK

Determining the effect of porosities on the hydrogen adsorption capacity of 3D printed PEEK

Development of a cyber physical production system framework for 3D printing analytics

Development of a cyber physical production system framework for 3D printing analytics

Development of Diclofenac Sodium 3D Printed Cylindrical and Tubular-Shaped Tablets through Hot Melt Extrusion and Fused Deposition Modelling Techniques.

The present study aimed to develop 3D printed dosage forms, using custom-made filaments loaded with diclofenac sodium (DS). The printed tablets were developed by implementing a quality by design (QbD) approach. Filaments with adequate FDM 3D printing characteristics were produced via hot melt extrusion (HME). Their formulation included DS as active substance, polyvinyl alcohol (PVA) as a polymer, different types of plasticisers (mannitol, erythritol, isomalt, maltodextrin and PEG) and superdisintegrants (crospovidone and croscarmellose sodium). The physicochemical and mechanical properties of the extruded filaments were investigated through differential scanning calorimetry (DSC), X-ray diffraction (XRD) and tensile measurements. In addition, cylindrical-shaped and tubular-shaped 3D dosage forms were printed, and their dissolution behaviour was assessed via various drug release kinetic models. DSC and XRD results demonstrated the amorphous dispersion of DS into the polymeric filaments. Moreover, the 3D printed tablets, regardless of their composition, exhibited a DS release of nearly 90% after 45 min at pH 6.8, while their release behaviour was effectively described by the Korsmeyer-Peppas model. Notably, the novel tube design, which was anticipated to increase the drug release rate, proved the opposite based on the in vitro dissolution study results. Additionally, the use of crospovidone increased DS release rate, whereas croscarmellose sodium decreased it.

Assessment of laparoscopic intracorporeal intestinal anastomosis training using simulation-based 3D printed models: exploring surgical performance and learning curves.

Intestinal anastomosis is a clinical procedure widely used to reconstruct the digestive tract, but authentic laparoscopic intracorporeal intestinal anastomosis（LIIA） models are lacking. However, three-dimensional (3D) printing can enable authentic and reusable models. In this paper, a novel cost-effective 3D-printing training model of LIIA is designed and the authenticity and validity of the model are tested. An FDM 3D printing and assembled lab model were built to test LIIA. Fifteen surgeons were required to perform LIIA, and their operation score and time were recorded and analyzed. Five experts were invited to assess the face and content validity of the models. A study was also performed to further evaluate and validate the learning curve of surgeons. The difference in Modified anastomosis objective structured assessment of technical skills (MAOSATS) scores between the expert, intermediate and novice groups were significant (64.1±1.8: 48.5±1.7: 29.5±3.1, P < 0.001). In addition, the operation time of the procedure was statistically different for all three groups (21.5±1.9: 30.6±2.8:70.7±4.0, P < 0.001). The five experts rated the face and content validity of the model very highly, with the median being four out of five. Surgeons who underwent repeated training program showed improved surgical performance. After eight training, the novices' performance was similar to that of the average level of untrained intermediates, while the operation scores of the intermediates were close to that of the average level of experts. In this study, it is found that the LIIA model exhibits excellent face, content and construct validity, repeated simulation training of the LIIA training program improved the surgeon's operative performance, so the model is considered one of the effective methods for LIIA training and assessment of surgical quality in the future and for reducing healthcare costs.

In-situ formation of nanoparticles from drug-loaded 3D polymeric matrices

The in-situ formation of nanoparticles from polymer-based solid medicines, although previously described, has been overlooked despite its potential to interfere with oral drug bioavailability. Such polymeric pharmaceuticals are becoming increasingly common on the market and can become even more popular due to the dizzying advance of 3D printing medicines. Hence, this work aimed to study this phenomenon during the dissolution of 3D printed tablets produced with three different polymers, hydroxypropylmethylcellulose acetate succinate (HPMCAS), polyvinyl alcohol (PVA), and Eudragit RL PO® (EUD RL) combined with plasticizers and the model drug naringenin (NAR). The components' interaction, dissolution behavior, and characteristics of the formed particles were investigated employing thermal, spectroscopic, mechanical, and chromatographic assays. All the systems generated stable spherical-shaped particles throughout 24h, encapsulating over 25% of NAR. Results suggest encapsulation efficiencies variations may depend on interactions between polymer-drug, drug-plasticizer, and polymer-plasticizer, which formed stable nanoparticles even in the drug absence, as observed with the HPMCAS and EUD RL formulations. Additionally, components solubility in the medium and previous formulation treatments are also a decisive factor for nanoparticle formation. In particular, the treatment provided by hot-melt extrusion and FDM 3D printing affected the dissolution efficiency enhancing the interaction between the components, reverberating on particle size and particle formation kinetics mainly for HPMCAS and EUD RL. In conclusion, the 3D printing process influences the in-situ formation of nanoparticles, which can directly affect oral drug bioavailability and needs to be monitored.

Development of mobile smart material-handling system

Development of mobile smart material-handling system

Topological optimization of vice jaws model for pipe clamping

This paper presents a model of the clamping vice jaw that is being developed for clamping the aluminium pipes. This model will be used on an available power hack for cutting the pipes to the desired length for further processing. In order to increase the stiffness to weight ratio of a given model, and thus optimize the material usage, the Topology Optimization method is implemented. The geometry of the jaw needs to adjust to the shape of the pipe, so it does not deform it when the clamping force is applied, and also be made from a material softer than aluminium, so that it does not damage the surface of the pipe. These conditions make the jaws a good candidate to manufacture by FDM 3D printing technology, from frequently used ABS material. As this process is a method of Additive Manufacturing, Topology Optimization benefits it not only in material usage but also in production time and cost. The presented procedure has a general character and as such can be applied to many mechanical parts, especially those made by Additive Manufacturing technologies.

FDM 3D프린팅 기반 VR컨트롤러용 맞춤형보조기기의 제작

VR controllers, which are key devices for implementing VR technology, play a role as a mediator that connects users and VR environments by detecting users' movements. VR users come into contact with VR controllers based on their own physique and senses, and the usability of VR devices can be improved by applying custom assistive devices to existing standardized VR controllers. As part of the process to improve the usability of VR devices, the focus of this study is on improving the assembly and production process efficiency of custom assistive devices that are compatible with VR controllers. To produce prototype custom assistive devices and make modifications, a small-scale production method for multiple items is required, and 3D printing is one of the flexible production systems that satisfies this requirement. In this study, (1) tensile tests were conducted on PLA material used to make custom assistive devices for VR controllers to determine their mechanical characteristics, and (2) for the safety design of the lever applied to the VR controller and body The required cross-sectional area was identified. And (3) modifications were made to the prototypes to improve their assembly and production process efficiency. Through this research, we confirm the suitability of developing custom assistive devices for VR controllers based on FDM 3D printing and propose their practical use.

Recycling of iron oxide waste by carbothermic reduction to utilize in FDM 3D printing materials

Iron oxide scale generally forms on low-carbon steel surfaces during the hot rolling processes andproduces as solid waste more than 100 thousand tons per year. The utilization of the iron oxide scaleis one possible way to reduce the production cost for steel plants and promote environmental protection. Acrylonitrile-Butadiene-Styrol-Copolymer (ABS) is widely used as engineering plastic for automotive parts because of its high strength and wear resistance. The recycling of iron oxide waste as reinforcement particles for enhancing the tensile strength of ABS composite was studied. The iron oxides were recycled by carbon powder at a high temperature between 1150℃ to 1350℃ up to 120 min. After the reduction process, the reduced iron from an optimal condition with the iron-rich fraction was ground to powder. Afterward, the 0.3 vol% to 1.3 vol% powders were mixed with ABS polymer powder and formed as composite filaments for additive manufacturing (FDM 3D printing). The tensile strength of pure ABS filament increased to 37.16 ± 2.37 MPa when added recycled iron powders. The regular distribution and 13.68 ± 9.78 µm of recycled-iron particle sizes on the ABS matrix were investigated and correlated to the mechanical properties.

Thermal stability of UPy-based polyurethane in granular FDM 3D printing

Granular fused deposition modeling (GFDM) 3D printing is a convenient and effective fabrication technique for personalized polyurethane scaffolds. The residence time of polyurethane in the heating chamber is crucial to its thermal stability. In this work, a biodegradable shape memory polyurethane containing a soft segment of poly(D,L-lactic acid) and a hard segment with pendant 2-Ureido-4[1H]-pyrimidone (UPy) units (UPy-p-PDLLA-SMPU) was successfully printed at 130°C by using GFDM 3D printing. Subsequently, the effects of residence time at 130°C chamber on the thermal stability of UPy-p-PDLLA-SMPU were investigated by using 1H NMR, WAXD, ATR-FTIR, GPC and DSC. It is found that the urethane and urea groups demonstrate divergent thermal stability with a dependence on the steric hindrance. Specifically, the urethane groups and the urea groups with negligible steric hindrance first start thermal degradation after a residence time of 1 h, resulting in an initial degradation ratio of 7.9% and 4.1%, respectively. After 3 h residence, they further thermally degrade to reach a degradation ratio of 25.2% and 14.6%, respectively. Correspondingly, the Mn decreases from 48 kDa to 42 kDa after 1 h residence and then to 31 kDa after 3 h residence. In brief, it is acceptable to finish the GFDM 3D printing of UPy-p-PDLLA-SMPU within 1 h at 130°C. These findings provide a guidance to select appropriate parameters for the GFDM 3D printing and add new thermal degradation mechanism to UPy-based supramolecules.

K-Means Module Division Method of FDM3D Printer-Based Function–Behavior–Structure Mapping

Product performance, function, cost, and the level of module generalization are all significantly influenced by product modular design, but different goods require different division indicators and techniques. The purpose of this study is to provide a set of appropriate modular division techniques for FDM 3D printers. This research offers an ecologically friendly module division index and uses module clustering as the module division principle in accordance with the current industrial development trend and the fundamental requirements of FDM 3D printer consumers in the current market. The K-means algorithm is used to use the Jaccard similarity coefficient as the metric of similarity of the DSM clustering process to realize the module division of the FDM 3D printer after studying the function–behavior–structure mapping model of the 3D printer. Additionally, the elbow method–cluster error variance and average contour coefficient evaluation systems were built, respectively, in order to verify the viability of the FDM 3D printer module division method and obtain the best module division results. By analyzing these two systems, it was discovered that when the FDM 3D printer was divided into three modules, the in-cluster error variance diagram obviously had an inflection point, and the average profile coefficient and other modular approaches that need to be adjusted to their respective goods can use this division method as a theoretical foundation and point of reference.

Evaluation of a design for a three‐dimensional‐printed artificial bone structure

AbstractIn this work, artificial bones composed of hydroxyapatite (HA)/polyacrylonitrile (PAN) and polylactic acid (PLA) were prepared as a potential replacement for natural bone. The cylindrical specimens included an auxetic system with artificial osteons. HA/PAN and PLA were used to fabricate composite filaments by fused deposition modeling three‐dimensional (3D) printing, and the obtained filaments were applied to produce reentrant artificial bone materials. Scanning electron microscopy was used to analyze the scaffold morphology and functional groups. Energy‐dispersive X‐ray spectroscopy was used for elemental analysis. The compressive properties of the samples were studied to determine the optimal scaffolding prototype. Compressive tests were also performed to assess the behavior of the cellular structure from a mechanical perspective. Finally, ANOVA and residual plots were used to investigate the contributions of the design elements, predict the y‐coordination of the stress values, and evaluate the printing orientation. The results indicated that the auxetic cells influenced the bone macrostructure, which displayed different stiffness characteristics in one working direction. Polymeric solution biomaterials based on HA/PAN and PLA biopolymers have enormous potential as high‐performance liquid synthetic organic polymers for light‐supported extrusion‐based 3D printing. PLA/HA scaffoldings with outstanding medical conversion capability may be used as biomaterial composites for bone deficiency restoration.Highlights Composite filaments for FDM 3D printing were used to manufacture reentrant artificial bone. A replacement method was utilized to determine the porosity of the scaffolds. Mechanically, this cellular structure was evaluated using compressive studies. SEM was used to assess scaffold morphology, functional categories, and elements. Create biodegradable constructions using as little material as possible.

Poly(3-hydroxybutyrate) (PHB) and Polycaprolactone (PCL) Based Blends for Tissue Engineering and Bone Medical Applications Processed by FDM 3D Printing.

In the presented work, poly(3-hydroxybutyrate)-PHB-based composite blends for bone medical applications and tissue engineering are prepared and characterized. PHB used for the work was in two cases commercial and, in one case, was extracted by the chloroform-free route. PHB was then blended with poly(lactic acid) (PLA) or polycaprolactone (PCL) and plasticized by oligomeric adipate ester (Syncroflex, SN). Tricalcium phosphate (TCP) particles were used as a bioactive filler. Prepared polymer blends were processed into the form of 3D printing filaments. The samples for all the tests performed were prepared by FDM 3D printing or compression molding. Differential scanning calorimetry was conducted to evaluate the thermal properties, followed by optimization of printing temperature by temperature tower test and determination of warping coefficient. Tensile test, three-point flexural test, and compression test were performed to study the mechanical properties of materials. Optical contact angle measurement was conducted to determine the surface properties of these blends and their influence on cell adhesion. Cytotoxicity measurement of prepared blends was conducted to find out whether the prepared materials were non-cytotoxic. The best temperatures for 3D printing were 195/190, 195/175, and 195/165 °C for PHB-soap/PLA-SN, PHB/PCL-SN, and PHB/PCL-SN-TCP, respectively. Their mechanical properties (strengths ~40 MPa, moduli ~2.5 GPa) were comparable with human trabecular bone. The calculated surface energies of all blends were ~40 mN/m. Unfortunately, only two out of three materials were proven to be non-cytotoxic (both PHB/PCL blends).

3D printing of polylactic acid/boron nitride bone scaffolds: Mechanical properties, biomineralization ability and cell responses

Polylactic acid (PLA) has been widely utilized as a bone scaffold material; however, it exhibits inadequate mechanical performance, biomineralization, and cell response, leading to limitations in its practical application. In this study, we utilized boron nitride (BN) nanosheets with favorable mechanical and biological properties to improve the performances of PLA, and prepared PLA/BN composite scaffolds by FDM 3D printing technology. Then, the PLA/BN composite scaffolds with varying BN contents (0–4 wt%) were investigated in terms of microstructure, mechanical performance, biomineralization, and cell response. The results showed that the FDM printed PLA/BN scaffolds have an orderly and interconnected porous structure. The mechanical tests showed that the tensile and compression properties (strength and modulus) increased first and then decreased with the content of BN gradually increasing from 0 wt% to 4 wt%, with the optimum mechanical properties occurring at 1 wt%, as an appropriate content of BN could be well-dispersed in the PLA matrix with forming a good interfacial bond, while an excessive content of BN would lead to obvious agglomeration. The simulated body fluid (SBF) soaking experiments showed that BN improved the biomineralization of PLA scaffolds through promoting the formation and deposition of apatite on the scaffold surface by accelerating ion exchange. Besides, an appropriate content of BN promoted the adhesion, proliferation, and osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). These results indicated that BN could be used as a versatile filler for improving the comprehensive performances of polymers, especially for bone tissue engineering.

Applying a Combination of Cutting-Edge Industry 4.0 Processes towards Fabricating a Customized Component

3D scanning, 3D printing, and CAD design software are considered important tools in Industry 4.0 product development processes. Each one of them has seen widespread use in a variety of scientific and commercial fields. This work aims to depict the added value of their combined use in a proposed workflow where a customized product needs to be developed. More specifically, the geometry of an existing physical item’s geometry needs to be defined in order to fabricate and seamlessly integrate an additional component. In this instance, a 3D scanning technique was used to digitize an e-bike’s frame geometry. This was essential for creating a peripheral component (in this case, a rear rack) that would be integrated into the frame of the bicycle. In lieu of just developing a tail rack from scratch, a CAD generative design process was chosen in order to produce a design that favored both light weight and optimal mechanical behaviors. FDM 3D printing was utilized to build the final design using ABS-CF10 materials, which, although being a thermoplastic ABS-based material, was introduced as a metal replacement for lighter and more ergonomic component production. Consequently, the component was manufactured in this manner and successfully mounted onto the frame of the e-bike. The proposed process is not limited to the manufacturing of this component, but may be used in the future for the fabrication of additional peripheral components and tooling.

Dimension synthesis of a 2T2R curved layer FDM 3D printer

3D printing or Additive Manufacturing (AM) is significant in various applications. The authors’ previous research indicates that higher-degree-of-freedom (DOF) 3D printers have the potential for curved layer printing and multi-direction AM. Hence, this paper focuses on designing a novel 2T2R FDM 3D printer. Performance-chart-based design methodology (PCbDM) has been used for multiple parameters optimization problems due to its reliability, globality, and intuition. While its limitation is the number of optimization parameters less than four. The printer’s print head is attached to a planar parallel 1T1R mechanism (4R1P, 3R1P, and passive P). Objectives and requirements require the print head to move over a more considerable distance with a constant swing range and proper pressure angle. So, the 4R1P five-bar (virtual double-rocker, crank-rocker, and rocker-crank) has been investigated to facilitate PCbDM. Meanwhile, one DOF remote center of motion (RCM) mechanism has been integrated for decoupling motion control. Finally, the selected parameters are verified by comparing the numerical and simulation results and experiments. Besides, this novel 3D printer’s initial feasibility of flat and curved layer printing is studied with several printed parts to give qualitative analyses. This early-stage work generally intends to investigate the dimension synthesis and show the resulting 2T2R-type rotary 3D printer’s initial feasibility for curved printing. The research can help people understand how to carry out the dimension synthesis of 4R1P and a novel mechanism with multi-chain with the help of Grashof criteria to reduce the design space dimensionality.