Fusion Deposition Research Articles

3D printed bilayer tablet with dual controlled drug release for tuberculosis treatment.

In this study Fusion Deposition Modelling (FDM) was employed to design and fabricate a bilayer tablet consisting of isoniazid (INZ) and rifampicin (RFC) for the treatment of tuberculosis. INZ was formulated in hydroxypropyl cellulose (HPC) matrix to allow drug release in the stomach (acidic conditions) and RFC was formulated in hypromellose acetate succinate (HPMC - AS) matrix to allow drug release in the upper intestine (alkaline conditions). This design may offer a better clinical efficacy by minimizing the degradation of RFC in the acidic condition and potentially avoid drug-drug interaction. The bilayer tablet was prepared by fabricating drug containing filaments using hot melt extrusion (HME) coupled with the 3D printing. The HME and 3D printing processes were optimised to avoid drug degradation and assure consistent deposition of drug-containing layers in the tablet. The in-vitro drug release rate was optimised by varying drug loading, infilling density, and covering layers. Greater than 80% of INZ was released in 45 mins at pH 1.2 and approximately 76% of RFC was releases in 45 mins after the dissolution medium was changed to pH 7.4. The work illustrated the potential application of FDM technology in the development of oral fixed dose combination for personalised clinical treatment.

Peel test experimentation on polycarbonate-based aluminium using fusion deposition modeling technique

Additive manufacturing is the process of fabrication of components with precise geometric shapes. In additive manufacturing, Fusion Deposition Modeling (FDM) was an effective method to fabricate metal and non-metals. It was one of the fastest methods used in the manufacturing of prototypes. The polycarbonate (PC) has more attractive properties such as high strength, toughness, and high-temperature resistance. It was added to the aluminium 7068 alloys through the fusion deposition modeling technique. The adhesive strength between polycarbonate and aluminium were found through the peel test. The adhesive strength was measured with the change of peel angle, speed, and peeling force. The maximum adhesive strength and optimal factors were analyzed through the Taguchi method. The contribution of factors on peel strength or adhesive strength was determined through variance analysis.

Overview of the use of 3D printing in forensic medicine

AbstractIn forensic medicine the use of so-called 3D printing is a niche application, whereas developments elsewhere in this field are rapidly advancing worldwide. The most common and widespread technology is fusion deposit modelling with polylactic acids (PLA). Although the equipment and materials may be relatively inexpensive and 3D printing relatively fast, the resulting end products tend to also have negative properties, such as poor durability and mechanical anisotropy, which may be an issue depending on the application. In forensic medicine, applications in the field of weapons technology and biomechanical models are realistic and 3D printing is already being used for demonstrations at court hearings and in teaching and also as a technique for building spare parts or accessories. Having a low-cost option for rapid prototyping on-site is particularly useful for the development phase. For finished 3D designs more expensive manufacturing options with a choice of materials with significantly broader mechanical or thermal properties are available. As the technology is undergoing major changes, one should carefully consider whether to enter the field oneself, buy own hardware, use a 3D printing service or seek cooperation possibly with a nearby partner.

Characterization of novel 3D printed plastic scintillation dosimeters

We propose a new methodology for the fabrication and evaluation of scintillating detector elements using a consumer grade fusion deposition modeling (FDM) 3D printer. In this study we performed a comprehensive investigation into both the effects of the 3D printing process on the scintillation light output of 3D printed plastic scintillation dosimeters (PSDs) and their associated dosimetric properties. Fabrication properties including print variability, layer thickness, anisotropy and extrusion temperature were assessed for 1 cm3 printed samples. We then examined the stability, dose linearity, dose rate proportionality, energy dependence and reproducibility of the 3D printed PSDs compared to benchmarks set by commercially available products. Experimental results indicate that the shape of the emission spectrum of the 3D printed PSDs do not show significant spectral differences when compared to the emission spectrum of the commercial sample. However, the magnitude of scintillation light output was found to be strongly dependent on the parameters of the fabrication process. Dosimetric testing indicates that the 3D printed PSDs share many desirable properties with current commercially available PSDs such as dose linearity, dose rate independence, energy independence in the MV range, repeatability, and stability. These results demonstrate that not only does 3D printing offer a new avenue for the production and manufacturing of PSDs but also allows for further investigation into the application of 3D printing in dosimetry. Such investigations could include options for 3D printed, patient-specific scintillating dosimeters that may be used as standalone dosimeters or incorporated into existing 3D printed patient devices (e.g. bolus or immobilization) used during the delivery of radiation therapy.

Polymer Selection for Hot-Melt Extrusion Coupled to Fused Deposition Modelling in Pharmaceutics.

Three-dimensional (3D) printing offers the greatest potential to revolutionize the future of pharmaceutical manufacturing by overcoming challenges of conventional pharmaceutical operations and focusing design and production of dosage forms on the patient’s needs. Of the many technologies available, fusion deposition modelling (FDM) is considered of the lowest cost and higher reproducibility and accessibility, offering clear advantages in drug delivery. FDM requires in-house production of filaments of drug-containing thermoplastic polymers by hot-melt extrusion (HME), and the prospect of connecting the two technologies has been under investigation. The ability to integrate HME and FDM and predict and tailor the filaments’ properties will extend the range of printable polymers/formulations. Hence, this work revises the properties of the most common pharmaceutical-grade polymers used and their effect on extrudability, printability, and printing outcome, providing suitable processing windows for different raw materials. As a result, formulation selection will be more straightforward (considering the characteristics of drug and desired dosage form or release profile) and the processes setup will be more expedite (avoiding or mitigating typical processing issues), thus guaranteeing the success of both HME and FDM. Relevant techniques used to characterize filaments and 3D-printed dosage forms as an essential component for the evaluation of the quality output are also presented.

Journal Vol – 15 No -7, July 2020 Journal > Journal > Journal Vol – 15 No -7, July 2020 > Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Journal Vol – 15 No -7, July 2020 Journal > Journal > Journal Vol – 15 No -7, July 2020 > Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Bone Compatibility on Different Porosity of PEEK Printed by Addictive Manufacturing of Fused Deposition Modeling inVitro

Bone Compatibility on Different Porosity of PEEK Printed by Addictive Manufacturing of Fused Deposition Modeling inVitro

Preparation of Hydrophobic Surface on PLA and ABS by Fused Deposition Modeling.

In the fields of agriculture, medical treatment, food, and packaging, polymers are required to have the characteristics of self-cleaning, anti-icing, and anti-corrosion. The traditional preparation method of hydrophobic coatings is costly and the process is complex, which has special requirements on the surface of the part. In this study, fused deposition modeling (FDM) 3D printing technology with design and processing flexibility was applied to the preparation of hydrophobic coatings on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) parts, and the relationship between the printing process parameters and the surface roughness and wettability of the printed test parts was discussed. The experimental results show that the layer thickness and filling method have a significant effect on the surface roughness of the 3D-printed parts, while the printing speed has no effect on the surface roughness. The orthogonal experiment analysis method was used to perform the wettability experiment analysis, and the optimal preparation process parameters were found to be a layer thickness of 0.25 mm, the Grid filling method, and a printing speed of 150 mm/s.

Investigation of Heated Nozzle Temperature in ABS Specimens Fabricated Based on Fiber Bragg Grating During Fused Deposition Modeling Process

The quality of the acrylonitrile-butadiene-styrene specimens are influenced by the inhomogeneous distribution of temperature caused by the heated nozzle temperature. To analyze the influence of the heated nozzle temperature, the specimens fabricated with fiber Bragg gratings are discussed. The specimens fabricated based on fiber Bragg gratings are suitable for real-time temperature monitoring and shrinkage deformation detection.

Protocols for 3D-printing pieces by fused deposition modeling for research purposes: from modeling to post-printing treatment

Additive manufacturing or 3D-printing is a revolutionary technique for prototyping and building objects for final use. Since the first registers at ~1890 the improved technology has boosted the applications of such technique, decreasing its market price. The most affordable 3D-print technique is Fuse Deposition Modeling (FDM), which is based on a layer-by-layer deposition of a fused polymer on a cooled table. Although FDM has been used by industrials, students and researchers, there are few published protocols dealing with small challenges and daily problems. Here we use a basic object to detail pre- and post-printing steps. This technical note offers the reader tools to model, print and treat the 3D-object. We point out basic challenges, such as positioning the objects on the virtual table of the slicing software, that may lead towards undesirable printed pieces. The protocols described here do not cover the uncountable possibilities of 3D-printing by FDM, but surely help researchers and industrials to start working with it. DOI: http://dx.doi.org/10.30609/JETI.2020-8625

Mechanical characterization of additive manufacturing composite parts

Additive Manufacturing is a novel manufacturing method in which the part is produced layer by layer from a 3D CAD model. In this work, we present the mechanical characterization of Fusion Deposition Modeling (FDM). Composite parts made by a nylon matrix with two kinds of fiber reinforcements: carbon fiber or fiberglass. From the obtained microstructure, we perform a division of the composite part in regions, and individual stiffness matrices are encountered by either using a linear elastic isotropic model, for the case of solid matrix filling, or an orthotropic linear elastic model based on micromechanical results. Then, a volume average stiffness method is employed to perform the characterization of the whole part. The theoretical results are compared with the experimental data, showing good agreement for both cases. This research allows the prediction of the structural behavior of additive manufacturing 2composite parts.

Frictional characteristics of Fusion Deposition Modeling (FDM) manufactured surfaces

Purpose Additive manufacturing (AM) is a promising alternative to the conventional production methods (i.e., machining), providing the developers with great geometrical and topological freedom during the design and immediate prototyping customizability. However, frictional characteristics of the AM surfaces are yet to be fully explored, making the control and manufacturing of precise assembly manufactured mechanisms (i.e., robots) challenging. The purpose of this paper is to understand the tribological behavior of fused deposition modeling (FDM) manufactured surfaces and test the accuracy of existing mathematical models such as Amontons–Coulomb, Tabor–Bowden, and variations of Hertz Contact model against empirical data. Design/methodology/approach Conventional frictional models Amontons–Coulomb and Tabor–Bowden are developed for the parabolic surface topography of FDM surfaces using variations of Hertz contact models. Experiments are implemented to measure the friction between two flat FDM surfaces at different speeds, normal forces, and surface configuration, including the relative direction of printing stripes and sliding direction and the surface area. The global maximum measured force is considered as static friction, and the average of the local maxima during the stick-slip phase is assumed as kinematic friction. Spectral analysis has been used to inspect the relationship between the chaos of vertical wobbling versus sliding speed. Findings It is observed that the friction between the two FDM planes is linearly proportional to the normal force. However, in contrast to the viscous frictional model (i.e., Stribeck), the friction reduces asymptotically at higher speeds, which can be attributed to the transition from harmonic to normal chaotic vibrations. The phase shift is investigated through spectral analysis; dominant frequencies are presented at different pulling speeds, normal forces, and surface areas. It is hypothesized that higher speeds lead to smaller dwell-time, reducing creep and adhesive friction consequently. Furthermore, no monotonic relationship between surface area and friction force is observed. Research limitations/implications Due to the high number of experimental parameters, the research is implemented for a limited range of surface areas, which should be expanded in future research. Furthermore, the pulling position of the jaws is different from the sliding distance of the surfaces due to the compliance involved in the contact and the pulling cable. This issue could be alleviated using a non-contact position measurement method such as LASER or image processing. Another major issue of the experiments is the planar orientation of the pulling object with respect to the sliding direction and occasional swinging in the tangential plane. Practical implications Given the results of this study, one can predict the frictional behavior of FDM manufactured surfaces at different normal forces, sliding speeds, and surface configurations. This will help to have better predictive and model-based control algorithms for fully AM manufactured mechanisms and optimization of the assembly manufactured systems. By adjusting the clearances and printing direction, one can reduce or moderate the frictional forces to minimize stick-slip or optimize energy efficiency in FDM manufactured joints. Knowing the harmonic to chaotic phase shift at higher sliding speeds, one can apply certain speed control algorithms to sustain optimal mechanical performance. Originality/value In this study, theoretical tribological models are developed for the specific topography of the FDM manufactured surfaces. Experiments have been implemented for an extensive range of boundary conditions, including normal force, sliding speed, and contact configuration. Frictional behavior between flat square FDM surfaces is studied and measured using a Zwick tensile machine. Spectral analysis, auto-correlation, and other methods have been developed to study the oscillations during the stick-slip phase, finding local maxima (kinematic friction) and dominant periodicity of the friction force versus sliding distance. Precise static and kinematic frictional coefficients are provided for different contact configurations and sliding directions.

Protocols for 3D-printing pieces by fused deposition modeling for research purposes: from modeling to post-printing treatment

Additive manufacturing or 3D-printing is a revolutionary technique for prototyping and building objects for final use. Since the first registers at ~1890 the improved technology has boosted the applications of such technique, decreasing its market price. The most affordable 3D-print technique is Fuse Deposition Modeling (FDM), which is based on a layer-by-layer deposition of a fused polymer on a cooled table. Although FDM has been used by industrials, students and researchers, there are few published protocols dealing with small challenges and daily problems. Here we use a basic object to detail pre- and post-printing steps. This technical note offers the reader tools to model, print and treat the 3D-object. We point out basic challenges, such as positioning the objects on the virtual table of the slicing software, that may lead towards undesirable printed pieces. The protocols described here do not cover the uncountable possibilities of 3D-printing by FDM, but surely help researchers and industrials to start working with it.
 
 DOI: http://dx.doi.org/10.30609/JETI.2020-8625

Effect of Maleinized Linseed Oil (MLO) on thermal and rheolological properties of PLA/MWCNT and PLA/HNT nanocomposites for additive manufacturing

Purpose This paper aims to describe the influence of maleinized linseed oil (MLO), when used as a lubricant, on the thermal and rheological properties of PLA/MWCNTs (polylactic acid/multi-walled carbon nanotubes) and PLA/HNT (halloysite nanotubes) nanocomposites, as a reference for application in 3D printing processes. Design/methodology/approach Nanocomposites were obtained by melting in a twin-screw extruder, mixing PLA with MWCNTs and HNTs in different percentages of 0.5, 0.75 and 1 Wt.% for subsequent mixing by the same process with 5 phr MLO, for application in additive manufacturing, as analyzed by means of differential scanning calorimetry (DSC), capillary rheometry, melt flow rate (MFL) and field emission scanning electron microscopy (FESEM). Findings The results obtained for thermal characterization by using DSC indicate the non-variation of glass transition temperature Tg = 62 ± 2°C and a melting temperature (Tm) around 170°C. Crystallization temperature dropped by approximately 12°C, which should be kept in mind during the transformation processes. The values obtained by capillary rheometry indicate that the material’s viscosity is reduced by the influence of the MLO plasticizer’s lubricant effect on the PLA’s molecular structure. The melt flow index values confirm a rise of approximately 46% in the flow index and back up the capillary rheometry results. The values obtained were as follows: PLA/0.5 Wt.% MWCNT/MLO 5 phr 54.07, PLA/0.75 Wt.% MWCNT/MLO 5 phr 53.46, PLA/1 Wt.% MWCNT/MLO 5 phr 51.84y PLA/0.5 Wt.% HNT/MLO 5 phr 61.8, PLA/0.75 Wt.% HNT/MLO 5 phr 68.3 and PLA/1 Wt.% HNT/MLO 5 phr 71.2 g/10 min. Apart from the nanocharge distribution, the information obtained from the FESEM shows the existence of a cluster, which could have been avoided by more energetic stirring during the nanocompound manufacturing process. Social implications This paper presents an analysis of the insertion of plasticizer in nanocomposites for the application in additive manufacturing processes in fusion deposition modelling (FDM) system. Originality/value This is a novel original research work.

Investigations on acute angle parts fabricated fusion deposition modelling parts volumetric shrinkage and surface roughness

This research paper focuses on analysing the two important quality determents namely surface roughness and volumetric shrinkage of fusion deposition modelling (FDM) parts with the selected process parameters, print speed, layer thickness and angle of inclination. These response factors are determined using minimum number of experiments designed by face centered central composite design (FCCCD) of response surface methodology (RSM). The test specimens fabricated using FDM machine and measurements have conducted to estimate surface roughness and volumetric shrinkage. The output responses are numerically modelled using analysis of variance (ANOVA) and presented as a function of three input process parameters.

Optimization of significant factors for improving compressive strength of ABS in Fused Deposition Modeling by using GA & RSM

The current research work is focused on optimization of FDM 3D printer input factors for compressive strength of ABS fabricated parts. It is a carbon chain copolymer thermoplastic possessing high impact strength and rigidity. Response Surface Methodology (RSM) and Genetic algorithm (GA) integrated with each other to optimize the input factors. Five factors viz. Layer thickness (LT), Build Orientation (BO), Raster angle (RA), Raster width (RW) and Air gap (AG) have been studied and modeled for compressive strength utilizing RSM. In present experimentation, quadratic model has been suggested for compressive strength. Build Orientation is most significant factor that imparts considerable effect on compressive strength as compared to other factors. Finally, GA-RSM, a popular hybrid evolutionary approach is used to optimize the factors.

Topology Optimization for Multipatch Fused Deposition Modeling 3D Printing

This paper presents a hybrid topology optimization method for multipatch fused deposition modeling (FDM) 3D printing to address the process-induced material anisotropy. The ‘multipatch’ concept consists of each printing layer disintegrated into multiple patches with different zigzag-type filament deposition directions. The level set method was employed to represent and track the layer shape evolution; discrete material optimization (DMO) model was adopted to realize the material property interpolation among the patches. With this set-up, a concurrent optimization problem was formulated to simultaneously optimize the topological structure of the printing layer, the multipatch distribution, and the corresponding deposition directions. An asynchronous starting strategy is proposed to prevent the local minimum solutions caused by the concurrent optimization scheme. Several numerical examples were investigated to verify the effectiveness of the proposed method, while satisfactory optimization results have been derived.

A Heterogeneous Infill Technique for Fused Deposition Modeling

Fused Deposition Modeling (FDM) is one of the most commonly employed Additive Manufacturing technologies worldwide. FDM parts are composed by layers of thermoplastic materials deposited through the controlled movement of one or more extrusion heads. Material deposition is usually performed in two distinct steps, the first involving the construction of the layer’s boundary and the second concerning the inner structure or infill. In the present paper an infill technique for the fabrication of parts with heterogeneous internal structure is proposed. To achieve this, the layer area is subdivided into sections which are covered by deposition paths of appropriate length according to material mapping information. Two path construction approaches are employed: one for establishing deposition paths for inner sections and another for drawing paths of peripheral sections. In order to test the effectiveness of the approach several test cases, involving relatively complex layer shapes and material distribution schemes are examined.

The use of statistical techniques to study the machine parameters affecting the properties of 3D printed cotton/polylactic acid fabrics

Textile materials have been combined with polymers using 3D printing technology, thus producing structures with novel properties. The aim of this study was to use statistical methods to determine the effect of 3D printing machine parameters on the mechanical properties of cotton fabrics combined with polylactic acid. Polylactic acid was printed on a cotton fabric using an Athena Fused Deposition Modelling 3D printer. The effect of extrusion temperature, printing speed, fill density and model height on adhesion force before and after washing was investigated. A study of the tensile strength was also undertaken using a central composite rotatable design and regression analysis. The experimental data were used to develop regression models to predict the properties of the cotton/ polylactic acid structures. The model for adhesion force before washing yielded a coefficient of determination (R2) value of 0.75 and an optimum adhesion force of 50.06 N/cm. The model for adhesion force had an R2 value of 0.84 and an optimum adhesion force of 42.91 N/cm and showed that adhesion force reduced after washing. Adhesion forces before and after washing were both positively correlated to extrusion temperature. However, they reduced with an increase in printing speed and model height. A positive correlation exists between tensile strength and temperature, while a negative correlation exists between tensile strength and printing speed and model height. From the results of this study, it was concluded that 3D printing parameters have an effect on the properties of the structures.

Design and fusion deposit modelling of radial flow centrifugal pump

Fusion Deposit Modeling (FDM) is a 3D Printing method which builds layer–by-layer of a component by the melting and deposition of plastic through the moving nozzle. Any complex shape which is not possible by convention fabrication technique can be fabricated using this technique. Moreover, this technique allow the innovator to develop the prototype much faster than the convention method. The complex shape prototype that chosen in this work is the radial flow centrifugal pump and it is the most common and widely used kinetic energy pump. The digital model of the centrifugal pump was prepared using the solidworks. The different component of the centrifugal pump like impeller, casing, suction and shaft also modeled and assembled. The design details of the impeller of the pump and casing is arrived after careful design calculation and it is prepared in such a way to have more efficiency of converting energy in the impeller. The impeller blades, shape, number of blades are arrived based on the total head and discharge. These impeller, suction, casing and shaft all are fabricated by using the FDM of 3D printer using ABS Plastic. The design plays a major role in preparing the centrifugal pump impeller and other components. The fabricated component should be matched accurately while assembly. Moreover, the components fabricated using the rapid prototyping solve the purpose when compare to the other conventional methods. Moreover this FDM technique is successfully benefited in manufacturing light weight prototype, tooling and creating customized design. However, the quality of prototype developed through this technique is relatively lower than the other formative or subtractive technique. This challenges in this technique is addressed by analyzing the microscopic structure of the ABS plastic and presented in this paper.