Terephthalate Glycol Research Articles

Parametric Study of Functional Components Obtained by Additive Manufacturing Fused Filament Fabrication

Fused Filament Fabrication (FFF) is a growing additive manufacturing technology for various applications in the engineering field. The mechanical properties of 3D printed materials in FFF technology depends on various parameters and the literature suggests that infill pattern and infill density are the parameters that most affect the mechanical properties of 3D printed parts.These factors have direct influence on the time of production and amount of material used. In this work it was analyzed the influence of infill parameter on stiffness of the final parts, considering the printing time and amount material used. For this purpose, the Taguchi method was used and then the statistical method of ANOVA to calculate the influence of each parameter.Test specimens were printed according to ASTM Standard D790 dimensions, in Polyethylene terephthalate glycol (PETG). The specimens were printed in the same position on the printing bed to reduce as much as possible the influence of external factors on the results. A visual and dimensional inspection of the specimens was carried out for further analysis. The best combination between production and stiffness, with 350 MPa/mm, was obtained with 15% infill density, concentric pattern, 45º orientation, with 4 perimeters path, layer thickness of 0.1 mm and speed of 45 mm/s. The results obtained allow us a broader view of how to save 3D printing time and the amount of material consumed during the production of a part.

A Coherent Assessment of the Compressive Strain Rate Response of PC, PETG, PMMA, and TPU Thermoplastics in MEX Additive Manufacturing.

In this study, we successfully address a significant research and engineering gap by quantitatively assessing the impact of varying compressive loading rates on the mechanical behavior of four popular thermoplastic polymers in material-extrusion-based (MEX) 3D printing. Raw powders of polycarbonate (PC), polyethylene terephthalate glycol (PETG), polymethyl methacrylate (PMMA), and thermoplastic polyurethane (TPU) were processed through melt extrusion, and the filaments were used to 3D-print the test samples. For completeness, thermogravimetric analysis and a compressive test following the ASTM-D695 standard were conducted. Ultimately, the compressive strength and yield stress, the compressive modulus of elasticity and toughness, and the maximum compressive sensitivity index were thoroughly documented. Specimens were tested in strain rates from 1.3 mm/min to 200 mm/min. The compressive strength (40% for the PMMA) and stiffness (29% for the TPU) increased with the increase in the strain rate in all polymers tested. PC had the highest strain rate sensitivity. Significant variations in deformation and fracture modes were observed and thoroughly documented throughout this study. Our findings can be useful in industrial engineering as valued design optimization input parameters in various applications involving the above-mentioned polymeric materials.

Additive manufacturing of continuous carbon fiber-reinforced silicon carbide composite by fused filament fabrication and precursor infiltration pyrolysis

Continuous fiber reinforced silicon carbide composites (Cf/SiC) are known for their advantages such as high strength, high modulus, high thermal conductivity, and low density. In this paper, we propose an integrated Cf/SiC preparation and processing process. The continuous carbon fiber-reinforced resin matrix composite green parts were processed by fused filament fabrication, and then ceramicized by precursor infiltration pyrolysis process. The processing parameters of the green parts, the performance of the green-part specimens, the phase evolution in the post treatment, and the performance of Cf/SiC samples were investigated. The infill line distance (ILD) had a huge influence on the mechanical properties of green parts and Cf/SiC. The bending strength of the green parts and the Cf/SiC specimens increased with the decrease in ILD. The maximum bending strength of 169.48 MPa and 155.83 MPa was achieved for the carbon fiber/polyethylene terephthalate glycol (Cf/PETG) and polylactic acid (Cf/PLA) green parts, respectively. The highest bending strength of 47.73 MPa of the Cf/SiC material was obtained with the Cf/PLA green parts, while the bending strength of 93.79 MPa was obtained for the Cf/SiC with Cf/PETG green parts. The increase in mechanical properties was believed to result from the pyrolyzed carbon brought by PETG and the increase of the equivalent fiber density within the single layer after a larger nozzle size was used.

Accelerated ultraviolet aging behavior and numerical simulation of ramie/carbon fiber reinforced polyethylene terephthalate glycol hybrid composites

Multi-fibers reinforced polymer hybrid composites can be designed to achieve excellent comprehensive performance through maximizing fibers physical and chemical properties. The accelerated ultraviolet (UV) aging behavior and mechanical degradation of natural ramie fiber (R) and carbon fiber (C) reinforced polyethylene terephthalate glycol (PETG) hybrid composites were investigated to broaden the industrial applications and understand the performance of ramie plant fiber products. The results show that the color and thermal properties of PETG matrix after UV aging have changed. The flexural properties of R/C laminated composites vary with the material types and layup sequences. The flexural modulus of the unaged [C/R/C/R]s and [C/C/R/R]s composites increase 1.2 and 1.0 times as compared with the unaged [R/C/R/C]s and [R/R/C/C]s. After 28 days of UV aging, the flexural strength retention rates of the [R/R/R/R]s, [R/R/C/C]s, [R/C/R/C]s, [C/R/C/R]s, [C/C/R/R]s and [C/C/C/C]s composites were 77.1 %, 79.2 %, 78.8 %, 81.7 %, 83 % and 87.4 %, respectively. The fracture strains of the R/C composites increase significantly after UV aging. The multiscale finite element model of the R/C composites is established to study the UV aging mechanism and predict the mechanical degradation. The knowledge gained in this work will be beneficial for the design and engineering application of plant fiber reinforced polymer hybrid composite materials.

Development of a novel cartridge for expansive cement application to hard rock breakage

ABSTRACT Expansive cement (EC) is generally a slurry that it is poured into vertical holes for surface rock breakage applications. This paper describes the development of a novel cartridge for extending EC applications from gravity-filled vertical holes to horizontal, uptilted, and wet boreholes. Four cartridge prototypes were made from low-cost and readily available plastics using three-dimensional printers. The performance of each cartridge was investigated in unconfined rock slab tests. The polylactic acid (PLA) cartridge was found to be superior to the thermoplastic polyurethane, polyethylene terephthalate glycol, and acrylonitrile butadiene styrene cartridges. Through partial heat containment, the PLA cartridge accelerated the EC hydraulic reaction and shortened the onset of rock destruction by 30% relative to vertical, gravity-filled EC. Finally, rock breakage with EC was demonstrated in an underground mine using PLA cartridges. This novel type of cartridge could not only suit various applications beyond the scope of the current EC surface applications but also significantly improve the rock fracturing efficiency of EC.

Topological design factor optimization in the development of periodic‐type honeycomb lattice structure on the carbon fiber reinforced polyethylene terephthalate glycol composite

AbstractIn most of the automobile and aerospace materials, cellular structures are extensively used due to their lightweight and high energy absorption capabilities. Naturally available animal bones and plant stems are light in weight due to their natural cellular structures. This may inspire various researchers for integrating the various lattice structures such as beam, planar, triply periodic minimal surfaces, and voronoi structures on the various structural materials. The development of lattice structures using 3D printing technology has opened up major attention towards fabricating lightweight components without any complications. In this study, the detailed crashworthiness responses such as compressive strength was optimized in terms of varying the topology‐related factors on the carbon fiber reinforced polyethylene terephthalate glycol (CF/PETG) composite. The experimentation was conducted concerning variable topology factors such as shell thickness, unit cell type, wall thickness (WT), unit cell orientation (UCO), skewing angle, and unit cell size. The model was examined and optimized by means of the Taguchi optimization technique. The crashworthiness response was analyzed using the compression test and moreover, this experimental response is used for the optimization processes. From the observation, the topology factors which contributed more for the higher compressive strength will be UCO of 65.47% and WT of 15.20%. Results of the regression study show that the R square value with concern to the compressive strength will be 92.74%. The optimized design parametric condition for CF/PETG composite established a higher compressive strength of 41.179 MPa, From the overall results, it is clear that the variation in the topology factors has developed a huge and favorable impact on the mechanical characteristics of the lattice‐structured CF/PETG polymer composite.Highlights Hexagonal Lattice structure incorporation on the carbon fiber reinforced PETG composite. Design optimization on the compressive properties. Taguchi optimization is performed on design‐based lattice structures. Unit cell orientation has higher percentage contribution on compressive strength.

Comparative Study Regarding the Design of a 3D Printed Hip Prosthesis

This work proposes the comparison of two models of 3D printed hip prostheses, using microscopic and chemical analysis, but also compression and bending testing. The comparison was made using a hip prosthesis designed in the Autodesk Inventor 2020 program and a model freely available on the Internet. The work includes some details about the virtual prototyping of prostheses and results from the chemical analysis of the components of the hip prostheses, carried out using an X-ray spectrometer to identify the elements contained in the PETG (polyethylene terephthalate glycol) material that was used to obtain the samples. The second method of analysis was the microscopic one and finally the samples were subjected to external forces, through bending and compression testing. This comparison aimed to demonstrate the dependence between the shape of the prosthesis and the mechanical properties of the analysed samples.

Simple Determination of the Melt Flow Index of Composite Polymer Filaments Used in Material Extrusion Additive Manufacturing

The mechanical properties improving filler introduction into polymer filaments often lead to the formation of defects in 3D-printed products. Studying the bulk modification of polyethylene terephthalate glycol (PETG) filaments with 0.5–1.5 wt% of natural shungite and molybdenum disulfide, we found the melt flow index (MFI) value reduced by 18%–30%. We investigate the effect of bulk modification on the filaments’ rheological properties, develop a technique that eliminates typical additive prototyping defects by regulation of the extrusion parameters in Cura slicing software, and propose an effective method for the MFI-measurement of the 3D-printed filaments that does not require special laboratory equipment (plastometers).

Permeability and diffusion of tritium in bentonite

Abstract. As a part of the Croatian RD&D (research, development, and demonstration) program within the Program for LILW (low- and intermediate-level waste) and SNF (spent nuclear fuel) disposal, research of permeability and the diffusion of tritium in bentonite was organized, as part of the research of the future engineering barriers for repositories of LILW and SNF. Two types of materials were prepared, namely pure sodium bentonite and a mixture of sodium bentonite (12 %) with quartz sand (88 %). Compaction of materials was conducted with a modified Proctor test, and the apparatus was designed and made at the Faculty of Mining, Geology and Petroleum Engineering at the University of Zagreb, utilizing fused deposition modeling 3D printer and PETG (polyethylene terephthalate glycol) material. Water enriched with 3H has been prepared by dilution of the National Institute of Standards and Technology (NIST) 3H standard (4926e) to 6 L. The activity of the prepared enriched water was 49 700±180 TU. One part of the device was filled with 3H-free water and the other with 3H-spiked water (0.6 L volume for each part). In total, five devices with bentonite and five devices with a sand–bentonite mixture were prepared this way. The devices were thoroughly sealed to avoid loss of sample and isotopic exchange with the atmosphere and put horizontally in holders. The water for 3H activity measurements was sampled monthly or bimonthly. A total of 8 mL of the sample was taken by syringe and transferred to a measurement vial. Each vial was additionally filled with 12 mL of a scintillator (Ultima Gold LLT, PerkinElmer) and thoroughly mixed. 3H activity was determined by a liquid scintillation counter (LSC; Quantulus 1220) at the Laboratory for Low-level Radioactivities, Ruđer Bošković Institute, Zagreb. Due to the penetration of bentonite from the barrier into the water samples, tritium-free water has relatively high activity after 2 months of the experiment (average value was 5560±240 TU). In the final sampling, after a 2-month time span, the activity reached 9670±2490 TU. Later, sampling and measurement were not possible due to the high bentonite amount within the samples. Tritium-free samples from the sand–bentonite mixture device were stable, and the first analyses (1 month after the experiment setup) showed an average activity of 533±31 TU, while the final (5-month time span from the first sampling) average activity was 12 800±3430 TU. The increase in the concentration from the beginning to the end of the experiment was almost exponential. Spiked samples from the bentonite device had an average activity of 36 950±2550 TU at the first sampling and 17 580±13 320 TU after a 1-month time leg. Later, sampling was not possible. Spiked samples from sand–bentonite mixture showed a decrease in tritium activity from the first sampling (43 390±1310 TU) to 27 210±285 TU (5 months after the first sampling). Considering the penetration of bentonite material into the water samples, only the sand–bentonite mixture can be considered for further analyses through the calculation of the diffusion.

Improved Terahertz Time-Domain Spectroscopy via the Extended Kalman Filter

To implement terahertz time-domain spectroscopy (THz-TDS) systems that have short integration time and maintain performance, the extended Kalman filter (EKF) has been used. Performance of EKF with THz-TDS on vapor samples and solid samples is untested. Previous EKF methods were not adaptive for use on multiple THz-TDS systems. We provide an adaptive EKF method that can work on any THz setup, to improve maximum measurable absorption coefficient. Our adaptive EKF method responds to THz pulse properties. The adaptive EKF is exhaustively demonstrated for six different time-constant data sets spanning 1 ms to 300 ms for THz-TDS on vapor with electro-optic THz detection. The acquisition time saved is quantified and shown to significantly reduce acquisition time from 2.58 ms to 1 ms. This improvement of 2.58 times will have a significant effect to move spectral imaging from taking hours to taking minutes. Vapor absorption lines are maintained. We show the adaptive EKF maintain correct spectral information when compared to the high-resolution transmission molecular absorption (HITRAN) database. The adaptive EKF is also demonstrated for THz-TDS on vapor with photoconductive THz detection, thus demonstrating adaptability, and is applied for THz-TDS of a solid sample of polyethylene terephthalate glycol.

Performance evaluation of the novel 3D-printed aquatic plant-microbial fuel cell assembly with Eichhornia crassipes

Plant-Microbial Fuel Cells (PMFCs) are a sustainable derivative of fuel cells that capitalizes on plant rhizodeposition to generate bioelectricity. In this study, the performance of the novel 3D-printed aquatic PMFC assembly with Eichhornia crassipes as the model plant was investigated. The design made use of 1.75 mm Protopasta Conductive Polylactic Acid (PLA) for the electrodes and 1.75 mm CCTREE Polyethylene Terephthalate Glycol (PETG) filaments for the separator. Three systems were prepared with three replicates each: PMFCs with the original design dimensions (System A), PMFCs with cathode-limited surface area variations (System B), and PMFCs with anode-limited surface area variations (System C). The maximum power density obtained by design was 82.54 µW/m2, while the average for each system is 26.99 µW/m2, 36.24 µW/m2, and 6.81 µW/m2, respectively. The effect of variations on electrode surface area ratio was also examined, and the results suggest that the design benefits from increasing the cathode surface area up to a cathode-anode surface area ratio of 2:1. This suggests that the cathode is the crucial component for this design due to it facilitating the rate-limiting step. Plant health was also found to be a contributing factor to PMFC performance, thereby suggesting that PMFCs are an interplay of several factors not limited to electrode surface area alone. The performance of the novel PMFC did not achieve those obtained from existing studies. Nevertheless, the result of this study indicates that 3D-printing technology is a possible retrofit for PMFC technology and can be utilized for scale-up and power amplification.

Study on Low Thermal-Conductivity of PVDF@SiAG/PET Membranes for Direct Contact Membrane Distillation Application.

In order to enhance the separation performance and reduce the heat loss of transmembrane for membrane distillation, the thermal efficiency and hydrophobicity of the membrane distillation need to be simultaneously enhanced. In this work, a polyvinylidene difluoride/polyethylene glycol terephthalate (PVDF/PET) hydrophobic/hydrophilic membrane has been prepared by non-solvent phase induction method. Nanosized silica aerogel (SiAG) with high porosity has been added to the composite membranes. The modifying effects and operating conditions on permeate flux and thermal efficiency in direct contact membrane distillation (DCMD) are investigated. Furthermore, the latent heat of vaporization and the heat transfer across the membranes have been compared for SiAG addition, which indicates that the composite PVDF@SiAG/PET membranes demonstrate a great potential for distillation-separation application due to their high heat efficiency.

3D Printing of sustainable coal polymer composites: Thermophysical characteristics

Recently, there has been a growing interest in enlisting polymer-based additive manufacturing in high-volume structural applications such as wind turbine blade tooling and additive housing construction. However, the availability of sustainable and environmentally friendly 3D printable materials could present a serious challenge, precluding the technology expansion to such applications. This research was focused on developing sustainable and environmentally friendly coal-plastic composites for use in high-volume applications. Polylactic acid, polyethylene terephthalate glycol, high-density polyethylene, and polyamide-12 resins were melt-mixed with bituminous Pittsburgh No. 8 coal at loadings varying from 20 wt % to 70 wt % coal. Thermoplastic composite filaments were extruded and processed with commercial 3D printers. Important thermophysical properties including coefficients of thermal expansion, heat deflection temperatures, glass transition and melt temperatures, specific heat capacities, thermal conductivities, and thermal stabilities of the coal-plastic composites were investigated. Coefficient of thermal expansion values for the composites had an inverse relationship with coal content lending to decreased print warping and consistent 3D printing of high-density polyethylene materials. Coal increased the heat deflection temperature of high-density polyethylene composites while little to no effect was observed for the other plastics. All composites maintained comparable melt temperatures, allowing for processing with commercial equipment. Specific heat capacity and thermal conductivity decreased with coal loading for all composite materials. Thermogravimetric analysis under air showed that the introduction of coal improved the thermal stability of all plastics by increasing the decomposition temperatures at 5 % and 50 % weight loss and by reducing the maximum decomposition rates.

Pengaruh Parameter Proses Terhadap Kekasaran Permukaan Menggunakan Filamen PETG (Polyethylene Terephthalate Glycol)

3D printing is a manufacturing process technology that has been developed to create a fast prototype according to the desired design, one of which is FDM (Fused Deposition Modeling) technology. Fused Deposition Modeling (FDM) technology is a printing technique used to print products using fibrous materials, the printed products have ideal geometric characteristics. The working principle of FDM is by extruding thermoplastic through a nozzle at a melting temperature, then the product is printed layer by layer. In this study the filament used is PETG (Polyethylene Terephthalate Glycol) filament. In this study using the Taghuci L9(4^3) OA method. This study aims to determine the most optimal process parameters with the parameters used in surface roughness testing according to the process parameters used, namely Nozzle Temperature, Flowrate, Printing Speed, Layer Thickness. the results of the research that has been carried out show the optimum parameter values for surface roughness, namely Nozzle Temperature (230℃), Flowrate (110%), Printing Speed (40mm/s), Layer Thickness (0.15mm).

Evaluation of polyethylene terephthalate glycol (PETG), Simubone™, and photopolymer resin as 3D printed temporal bone models for surgical simulation

ObjectivesAmong types of 3D printing, fused deposition modeling (FDM) and digital light processing (DLP) are the most accessible, making them attractive, low-cost options for simulating surgical procedures. This study characterized and compared inexpensive, synthetic temporal bone models printed using Resin, PETG, and Simubone™. Materials and methodsThis study compared models made of polyethylene terephthalate glycol (PETG), Simubone™ produced from a FDM printer, and photopolymer resin from a DLP printer. These temporal bone models were processed by: (1) DICOM files from a patient's CT scan were segmented to define critical parts expected in a temporal bone surgery. (2) The model was appended with a base that articulates with a 3D-printed temporal bone holder. (3) The refined, patient-specific model was manufactured using FDM and DLP printing technologies. (4) The models were sent to evaluators, who assessed the models based on anatomic accuracy, dissection experience, and its applicability as a surgical simulation tool for temporal bone dissection. ResultsThe photopolymer resin outperformed PETG and Simubone™ in terms of anatomical accuracy and dissection experience. Additionally, resin and PETG were evaluated to be appropriate for simple mastoidectomy and canal wall down mastoidectomy while Simubone™ was only suitable for simple mastoidectomy. All models were unsuitable for posterior tympanotomy and labyrinthectomy. ConclusionsPhotopolymer resin and PETG have shown to be suitable materials for dissection models with 3D-printed resin models showing more accuracy in replicating anatomical structures and dissection experience. Hence, the use of 3D-printed temporal bones may be a suitable low-cost alternative to cadaveric dissection.

Identification of temperature-dependent parameters for an elastic–plastic-damage material model of 3D-printed PETG

The presented paper focuses on identifying temperature-dependent parameters for a newly designed material model of 3D-printed PETG (polyethylene terephthalate glycol). An uniaxial elastic–plastic material model with damage and different properties in tension and compression was developed to describe this material’s non-linear behaviour. The monotonic and cyclic tests were carried out in tension and compression at several temperatures. The specimens were printed using FDM (fused deposition modelling) technology on the printer from Prusa Research. The principal material parameters such as Young’s modulus, yield stress and ultimate tensile stress were derived directly from the force–displacement diagrams obtained experimentally. Other necessary material characteristics were identified using numerical simulations combining the finite element method and parametric optimization. The model was implemented for the software Abaqus using subroutine UMAT and the optimization was performed using software Isight.

Parametric investigation and optimisation of mechanical properties of thick tri-material based composite of PLA-PETG-ABS 3D-printed using fused filament fabrication

Tri-material and tri-layered composites find numerous applications in the biomedical, aerospace, and automotive industries. However, such composites face challenges when fabricated through conventional methods (Electrospinning, hand lay-up, Film Casting, In-situ polymerization), such as interface bond strength, strength-to-mass ratio, etc. Additive manufacturing can be used to fabricate such composites to overcome these challenges. In this study, tensile samples of tri-material based 3D-printed (TM3DP) polymer composite of polylactic acid (PLA), polyethylene terephthalate glycol (PETG), and acrylonitrile butadiene styrene (ABS) were successfully processed using fused filament fabrication (FFF) for the first time. The composite is fabricated such that 33.333% PLA was printed first, followed by 33.333% PETG, and, in the end, 33.333% ABS so that PETG is sandwiched between PLA and ABS. The effect of FFF processing parameters on the tensile properties of the printed composites was investigated. After preliminary experiments and a literature review, infill density (ID), printing speed (PS), and layer thickness (LT) were selected as the main processing parameters. The tensile strength (TS) and tensile strain (ℇ) were selected as the outputs (responses) of this study. Tensile testing was performed after printing composite tensile samples on Instron Universal Testing Machine (5 KN). An analysis of variance (ANOVA) was also performed to check the significance of FFF process parameters. The results concluded that the selected FFF process parameters were significant in the interaction state of both tensile properties. Scanning electron microscopy (SEM) and optical microscopy were also performed, which indicated that various defects, including micropores, voids, and micro / major delamination occurred in conditions of high LT, high PS, and low ID. This resulted in a low TS of 27.1 MPa and ℇ of 0.5 mm/mm. No major defects were observed under high LT, high PS, and high ID, which resulted in the highest TS of 39.5 MPa and ℇ of 0.95. Finally, optimum conditions were suggested for fabricating the thick TM3DP composite samples, believed to enhance the TS-to-mass ratio by 16.4% compared to the single solid 3D-printed base materials.

Quantifying hydrolytic degradation of poly(ethylene terephthalate glycol) under storage conditions and for fused filament fabrication mechanical properties

Poly(ethylene terephthalate glycol) (PETG) is a promising polyester for additive manufacturing (AM) applications. However, an important question is its thermal and hydrolytic stability under storage conditions. The current work investigates which measuring technique is most suited to qualitatively answer this question, completing the field for polyester stability analysis by focusing on more amorphous structures. In combination with regression analysis under lab accelerated conditions to practically estimate characteristic degradation time scales and currently lacking (overall) Arrhenius parameters, a distinction is made between techniques dealing with molecular and larger scale properties, distinguishing between Fourier Transfer Infrared (FTIR) spectroscopy, size exclusion chromatography (SEC), rheological measurements, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It is shown that hydrolytic scission is dominant over thermal scission, and mainly affects the lower mass region of the molar mass distribution. However, the degradation sensitivity can only be assessed using the SEC number average molar mass, and a more pronounced qualitative sensitivity is only obtained applying rheological analysis, with an extrapolated very low half-life time under water-saturated conditions of ca. 3 days in the Newtonian region and of 2 days in the shear thinning region. It is further highlighted that hydrolytic degradation influences the tensile properties of parts fabricated with fused filament fabrication, which is an important AM technique.

Dry sliding wear behavior of additively manufactured cenosphere-filled PETG syntactic foam composites

PurposeThis study aims to deal with developing composite filaments and investigating the tribological behavior of additively manufactured syntactic foam composites. The primary objective is to examine the suitability of the cenosphere (CS; 0–30 Wt.%) to develop a high-quality lightweight composite structure with improved abrasion strength.Design/methodology/approachCS/polyethylene terephthalate glycol (PETG) composite feedstock filaments under optimized extrusion conditions were developed, and a fused filament fabrication process was used to prepare CS-filled PETG composite structures under optimal printing conditions. Significant parameters such as CS (0–30 Wt.%), sliding speed (200–800 rpm) and typical load (10–40 N) were used to minimize the dry sliding wear rate and coefficient of friction for developed composites.FindingsThe friction coefficient and specific wear rate (SWR) are most affected by the CS weight percentage and applied load, respectively. However, nozzle temperature has the least effect on the friction coefficient and SWR. A mathematical model predicts the composite material’s SWR and coefficient of friction with 87.5% and 95.2% accuracy, respectively.Practical implicationsBecause of their tailorable physical and mechanical properties, CS/PETG lightweight composite structures can be used in low-density and damage-tolerance applications.Social implicationsCS, an industrial waste material, is used to develop lightweight syntactic foam composites for advanced engineering applications.Originality/valueCS-reinforced PETG composite filaments were developed to fabricate ultra-light composite structures through a 3D printing routine.

Broadband inhomogeneous lens with conical radiation pattern

This manuscript presents a lens antenna with simultaneous broadside and conical beams. The lens is designed for the Ku band using the ray inserting method. The proposed conical radiation pattern is broadband due to good matching with the source and surroundings. The simulation is conducted using the CST microwave studio solver. Instead of complex antenna shapes used in other works, a simple circular patch ring and RF connector are used as the lens feed to generate broadside and omnidirectional conical patterns, respectively. To validate the performance of the designed lens and its two-port feed antenna, the lens structure is realized and fabricated using the 3D printing method. Polyethylene terephthalate glycol (PETG) plastic material is utilized for constructing the lens in this work. The electromagnetic characteristics of PETG in the Ku band are accurately measured. The results of simulations and experiments demonstrate the good performance of the designed lens over a wide frequency bandwidth. The advantage of this designed structure over other works is its high gain and broad bandwidth.