Studies of energy absorption of lattice structures manufactured from PETG filament with FFF 3D printing

PurposeThis study aims to reveal the influences of three-dimensional (3D) printing parameters such as layer heights (0.1 mm, 0.2 mm and 0.4 mm), infill rates (40, 70 and 100%) and geometrical property as tapered angle (0, 0.25 and 0.50) on vibrational behavior of 3D-printed polyethylene terephthalate glycol (PET-G) tapered beams with fused filament fabrication (FFF) method.Design/methodology/approachIn this performance, all test specimens were modeled in AutoCAD 2020 software and then 3D-printed by FFF. The effects of printing parameters on the natural frequencies of 3D-printed PET-G beams with different tapered angles were also analyzed experimentally, and numerically (finite element analysis) via Ansys APDL 16 program. In addition to vibrational properties, tensile strength, elasticity modulus, hardness, and surface roughness of the 3D-printed PET-G parts were examined.FindingsIt can be stated that average surface roughness values ranged between 1.63 and 6.91 µm. In addition, the highest and lowest hardness values were found as 68.6 and 58.4 Shore D. Tensile strength and elasticity modulus increased with the increase of infill rate and decrease of the layer height. In conclusion, natural frequency of the 3D-printed PET-G beams went up with higher infill rate values though no critical change was observed for layer height and a change in tapered angle fluctuated the natural frequency values significantly.Research limitations/implicationsThe influence of printing parameters on the vibrational properties of 3D-printed PET-G beams with different tapered angles was carried out and the determination of these effects is quite important. On the other hand, with the addition of glass or carbon fiber reinforcements to the PET-G filaments, the material and vibrational properties of the parts can be examined in future works.Practical implicationsAs a result of this study, it was shown that natural frequencies of the 3D-printed tapered beams from PET-G material can be predicted via finite element analysis after obtaining material data with the help of mechanical/physical tests. In addition, the outcome of this study can be used as a reference during the design of parts that are subjected to vibration such as turbine blades, drone arms, propellers, orthopedic implants, scaffolds and gears.Social implicationsIt is believed that determination of the effect of the most used 3D printing parameters (layer height and infill rate) and geometrical property of tapered angle on natural frequencies of the 3D-printed parts will be very useful for researchers and engineers; especially when the importance of resonance is known well.Originality/valueWhen the literature efforts are scanned in depth, it can be seen that there are many studies about mechanical or wear properties of the 3D-printed parts. However, this is the first study which focuses on the influences of the both 3D printing parameters and tapered angles on the vibrational behaviors of the tapered PET-G beams produced with material extrusion based FFF method. In addition, obtained experimental results were also supported with the performed finite element analysis.

One of the most researched technologies among technologies used for producing complex and diverse parts today is additive manufacturing. In additive manufacturing, production can be carried out using thermoplastic and metal materials without requiring an additional process. Among the additive manufacturing technologies, the Fused Filament Fabrication (FFF) method is the most widely used method worldwide due to its affordability and broad application area. FFF is a method in which part formation is achieved by depositing melted materials on each other. In recent years, polymer materials such as polylactic acid (PLA), polyethylene terephthalate glycol (PETG), and acrylonitrile butadiene styrene (ABS) have been frequently used in many industrial areas in the FFF method because they are lightweight, inexpensive, sustainable, and provide sufficient strength for engineering applications. This study conducted tensile, three-point bending, Charpy, and compression tests on PLA, PETG, and ABS materials at angles of 15°–75° and 30°–60°, and the results were compared.

Fused Filament Fabrication (FFF) has been established as a widely practiced Additive Manufacturing technique, using various thermoplastic filaments. Carbon fibre (CF) additives enhance mechanical properties of the materials. The main operational hazard of the FFF technique explored in the literature is the emission of Ultrafine Particles and Volatile Organic Compounds. Exposure data regarding novel materials and larger scale operations is, however, still lacking. In this work, a thorough exposure assessment measurement campaign is presented for a workplace applying FFF 3D printing in various setups (four different commercial devices, including a modified commercial printer) and applying various materials (polylactic acid, thermoplastic polyurethane, copolyamide, polyethylene terephthalate glycol) and CF-reinforced thermoplastics (thermoplastic polyurethane, polylactic acid, polyamide). Portable exposure assessment instruments are employed, based on an established methodology, to study the airborne particle exposure potential of each process setup. The results revealed a distinct exposure profile for each process, necessitating a different safety approach per setup. Crucially, high potential for exposure is detected in processes with two printers working simultaneously. An updated engineering control scheme is applied to control exposures for the modified commercial printer. The establishment of a flexible safety system is vital for workplaces that apply FFF 3D printing.

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

ABSTRACTReduced environmental impact is commonly cited as a driver for additive manufacturing, but non‐circular end‐of‐life disposition of the printed materials reduces these advantages. In particular, thermoplastics commonly used in material extrusion additive manufacturing (MEX) are not compatible with most recycling infrastructures; polyethylene terephthalate glycol (PETG) is particularly problematic as it compromises the integrity of polyethylene terephthalate (PET) recycling streams. Thus, circular recycling of PETG within the MEX ecosystem is necessary, but the comonomer, cyclohexane dimethanol (CHDM), content differs across commercial sources. Here, we demonstrate that the reduction in the viscosity of the PETG through multiple cycles of print‐test‐reprocess to filament (recycling) is dependent on the sourcing but not directly correlated with the CHDM content or molar mass. The elastic modulus and tensile strength of the printed PETG are not significantly impacted by recycling over 5 prints. However, the ductility of the printed PETG decreases after recycling one time for the lowest CHDM content PETG while the ductility first increases and then decreases through multiple reprocess cycles with higher CHDM content in the PETG. These results illustrate circular recycling through MEX may increase the number of cycles possible without significant degradation in part stiffness and strength when compared with mechanical recycling using traditional manufacturing methods.

3D printing technology through fused filament fabrication has found various industrial applications in the field of rapid manufacturing to fabricate prototypes and concept models. However, being the most popular technology, fused filament fabrication requires through understanding about the influence of the process parameters on resulting products. This investigation attempts to provide the terse behavior of the viscoelastic properties of fused filament fabrication processed with Poly Ethylene Terephthalate Glycol (PETG) samples considering the impact of fused filament fabrication process parameters. Dynamic mechanical analyzer is used to perform the dynamic mechanical analysis (DMA) and the dynamic response of fused filament fabrication PETG specimens is studied while they are subjected to dual cantilever loading under periodic stress. The fused filament fabrication process parameters such as, feed rate, layer thickness and infill density are considered. PETG parts are fabricated using 100% infill density at a feed rate of 50 mm/sec with three different layer thicknesses of 0.17 mm, 0.23 mm and 0.3 mm. DMA is performed with temperature ranging from room temperature to 130°C at five different frequency values of 1 Hz, 2 Hz, 5 Hz, 7 Hz & 10 Hz. The effect of process parameters of fused filament fabrication and frequencies on the viscoelastic properties of 3D printed PETG specimens is explored. The results reveled that, the storage module and loss module values are better for the specimens prepared with a layer thickness of 0.17 mm irrespective of the variation in the frequency values.

Additive technology (3D printing) is a method of manufacturing plastics that allows you to create sophisticated shaped parts at relatively low costs and in a short time. This method is particularly useful for rapid manufacturing, including engineering applications such as rapid prototyping. The most common commercially used Fused Filament Fabrication (FFF) method consists in dispensing the filament from a heated nozzle located in three moving axes, which solidifies after exiting the nozzle. This technology has gained significant popularity due to its versatility in producing custom parts and prototypes efficiently. Moreover, it enables designers to experiment with complex geometries that would be difficult or costly to achieve with traditional manufacturing techniques. This article presents research focused on the mechanical properties (tensile strength and elongation) of FFF printed parts made of polyethylene terephthalate glycol (PETG) in three infill density patterns: 100% rectilinear, 50% gyroid, and 50% Hilbert curve. The article describes the strengths and weaknesses of the material used and compares the mechanical properties of individual infill printing patterns.

In this work a fused filament fabrication (FFF) die design, capable of extruding two thermoplastics simultaneously in a core–shell configuration, is demonstrated as a means to produce composite structures in a single step. Despite the enormous advancements in 3D printing, fabrication of FFF objects with a composite structure remains a challenge due to the difficulty in finding dies to extrude such structures. We used polyethylene terephthalate glycol (PETG) and high-density polyethylene (HDPE) filaments to perform core–shell 3D printing. HDPE is one of the most commonly produced plastics but rarely used in FFF due to the severe warpage caused by volume changes upon its crystallization. Rheological and thermal analyses suggest the use of HDPE as a shell material due to its extremely short reptation time and sharp melting peak that facilitate superior surface contact and interlayer weld strength at the interface between neighboring FFF tracks. PETG is a commonly used 3D printing filament with excellent printability and sufficient zero shear viscosity to help maintain the extruded filament shape against shrinkage induced by the HDPE shell. Impact and tensile properties of core–shell objects revealed tremendous improvements in the impact resistance and toughness especially at 30 vol % HDPE shell with 1280% and 150% enhancement in impact resistance when compared to individual components: PETG and HDPE, respectively. Scanning electron microscopy was used to analyze the fracture morphology of the tested specimens to obtain an understanding of the fracture mechanism leading to the increased impact resistance. Using this die design can help open avenues of fabricating high impact resistance materials suitable for high performance applications and using HDPE in 3D printed objects with its superior solvent resistance.

ABSTRACTPolyethylene (PE) is one of the most widely used commodity plastics, yet its integration into the pioneering field of polymer‐based 3D and 4D printing remains challenging. Conversely, polyethylene terephthalate glycol (PETG) is a widely utilized material in 3D and 4D printing, capable of mitigating the limitations of PE in these applications through blending. Herein, three weight percentages of 15, 30, and 45 wt% PETG were added to low‐density polyethylene (LDPE), and the 3D printed samples were subjected to a comprehensive evaluation of mechanical properties, morphology, thermal analysis, and shape memory properties. The results of dynamic mechanical thermal analysis (DMTA) revealed a noticeable peak in tan δ around 80°C, which becomes more pronounced in blends with higher PETG content. Scanning electron microscopy (SEM) analysis showed that increasing PETG concentration in 3D‐printed LDPE/PETG blends transforms their morphology from distinct, void‐rich phases at 15 wt% PETG to improved dispersion at 30 wt% PETG, and finally to a co‐continuous, strongly adhered structure at 45 wt% PETG, indicating enhanced compatibility. Tensile testing demonstrated a shift from ductile to brittle behavior as the PETG content increased. Shape memory evaluation of blends indicated that higher PETG concentrations improve shape recovery performance, with the 30 wt% PETG blends achieving the highest recovery ratio (88.7%) and the 15 wt% PETG blends showing the lowest recovery ratio (68.7%). These results represent a significant step toward incorporating LDPE into commercial 3D printing materials.

Nozzle condition monitoring in 3D printing

A fused-deposition modeling (FDM) 3D-printed polyethylene terephthalate glycol (PETG)-sepiolite composite showed effective synergetic mechanical reinforcement in tensile testing compared to an injection-molded composite. The results showed that the addition of 3 phr sepiolite improved the tensile strength of 3D-printed PETG samples by 35.4%, while the tensile strength of injection-molded PETG samples was improved by 7.2%. To confirm these phenomena, FDM PETG-sepiolite composites were investigated by small-angle X-ray scattering to correlate the nanostructures of the composites with their mechanical strengths. The small-angle X-ray scattering data and transmission electron microscopy observations demonstrated that needle-shaped sepiolite particles were aligned in the printing direction. This fine oriented nanostructure formed during 3D printing created a synergistic effect that improved the material properties of the composite. These novel PETG-sepiolite composites with enhanced mechanical properties can be promising materials fabricated via FDM 3D printing.

Nowadays, the intermediate of digital fabrication technology is also referred to as 3D printing or assembling production, the continuous addition of all these elements to create physical objects from geometric representations. Fused deposition modeling (FDM) 3D printers work by adding one layer after another through FDM filaments. Some commonly used FDM filaments are polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), thermoplastic polyurethane (TPU), polycarbonate (PC), nylon, acrylonitrile styrene acrylate (ASA), and polyetherimide (PEI). Also, FDM filament allows the adjustment of several process parameters which are strength, temperature resistance, visual quality, impact strength, wear and chemical resistance, flexible, etc. Thus, confusion arises for the selection of the best filament to create any desired object. So, to get rid of this confusion need to know some immediate decision-making techniques. Analytical network process (ANP) and multi-objective optimization by ratio analysis (MOORA) are one of the most important immediate decision-making techniques. These two methods provide a basis for decision-making processes, where there are many criteria, along with a number of options. In this study, the selected five criteria are density (g/cm3), printing temperature (0C), tensile strength (MPa), elongation at break (%), and flexural strength (MPa). Also, the selected six alternatives are polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PETG), nylon, acrylonitrile styrene acrylate (ASA), and polycarbonate (PC) for the best filament. Design/Procedure/Method: Multi-objective optimization by ratio analysis (MOORA) and analytical network process (ANP) have been used to fulfill the purpose of this work. In this method, ANP is used because a variety of criteria and alternatives are used to select a good FDM 3D printer filament that follows the MOORA method. Originality/Value: This work is done to select a good FDM 3D printer filament. The systematic way of choosing a good FDM 3D printer filament helps the manufacturer to implement printing quality.

Fused Deposition Modeling (FDM) can be used to manufacture any complex geometry and internal structures, and it has been widely applied in many industries, such as the biomedical, manufacturing, aerospace, automobile, industrial, and building industries. The purpose of this research is to characterize the polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) materials of FDM under four loading conditions (tension, compression, bending, and thermal deformation), in order to obtain data regarding different printing temperatures and speeds. The results indicated that PLA and PETG materials exhibit an obvious tensile and compression asymmetry. It was observed that the mechanical properties (tension, compression, and bending) of PLA and PETG are increased at higher printing temperatures, and that the effect of speed on PLA and PETG shows different results. In addition, the mechanical properties of PLA are greater than those of PETG, but the thermal deformation is the opposite. The above results will be a great help for researchers who are working with polymers and FDM technology to achieve sustainability.

Three-dimensional (3D) printing, especially using fused deposition modeling, is becoming more and more popular in the medical sector because of its exceptional advantages. While it has been used for prototyping, 3D printing has not yet been completely explored to produce a functional product. The key causes are the abundance of 3D printing materials and the lack of a comprehensive study outlining the design process. Consequently, this paper describes a reverse engineering (RE) design approach based on data acquisition utilizing laser scanning and splint design from the acquired point cloud data. This study also focuses on the evaluation of various wrist orthosis/splint designs and materials using finite element (FE) analysis in order to improve upon the conventional approach. Sixty FE analysis simulations are undertaken in flexion–extension and radial–ulnar wrist movements to investigate the displacements and the stresses. The splint is then fabricated utilizing the material and thickness that have been specified by FE analysis. The major goals of this study are to examine the RE design methodology, explore various materials, and assess the viability of 3D printing. The polylactic acid (PLA) hand splint has proven to be the sturdiest in terms of average displacements when compared to the other materials, followed by polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS), polypropylene, and thermoplastic polyurethanes. According to simulation data, the PLA splint has 38.6%, 38.8%, 38.5%, and 38.7% less displacement in the major loading direction in flexion, extension, radial, and ulnar, respectively, than the ABS splint. Moreover, the PLA-based hand splint has a peak stress value below the yield strength of PLA, rendering it reliable for patients to wear. Also, it turns out that PETG and ABS behave rather similarly. Furthermore, it has been shown that a balanced approach can reduce material use and building time. For instance, employing PLA and a thickness of 2 mm results in reduced material costs without compromising the effectiveness of the splint. As a result, choosing the right material and splint thickness can help the 3D-printed hand splint perform better.

This research worked on the mechanical properties of Carbon Fiber Reinforced Polyethylene Terephthalate Glycol (PETG) for applications in 3D printing. Carbon fiber reinforcement was incorporated into PETG and pellets as the base material. Tensile and compression tests were conducted on Carbon fiber-reinforced PETG and PETG to appraise the respective mechanical strength and stiffness. The results of these test coupled with comparisons between the two materials, provided valuable insights into the performances and potential application of Carbon fiber-reinforced PETG in additive manufacturing. The research contributed to understanding Carbon Fiber Reinforced PETG’s mechanical behavior, decisive for engineering applications. The highest tensile strength recorded for Carbon Fiber PETG was 38.51 MPa, achieved in sample 7 by infill density of 100%, a layer height of 0.30mm, and a printing speed of 40mm/s. The highest compression strength recorded for normal PETG was 52.29 MPa, observed in sample 8. under different parameters infill density of 100%, a layer height of 0.18mm, and a printing speed of 60mm/s.