Structural behaviour of polyethylene terephthalate glycol reinforced with carbon fibre through fused filament fabrication for automotive components

Automotive manufacturers are presently encountering numerous challenges, including disruptions in the supply chain and concerns regarding sustainability. They are adapting to evolving consumer preferences for vehicle features and performance. Fused filament fabrication is one of the additive manufacturing techniques that will novelly address these issues with rapid prototyping, custom part production, intricate designs, lightweight yet strong components, and reducing assembly time for complex functional parts. This study aims to examine the influence of process parameters, specifically nozzle diameter (0.2, 0.4, and 0.6 mm) and internal filling pattern (triangular, honeycomb, rectilinear), on the structural behaviour, namely impact, compression, and flexural behaviour, of different polymer composites through fused filament fabrication. The composites being investigated are carbon fibre-reinforced poly-lactic acid (CF-PLA), carbon fibre-reinforced poly-ethylene terephthalate glycol (CF-PETG), and multi-walled carbon nanotube-reinforced poly-lactic acid (MWCNT-PLA). The maximum flexural strength achieved is 72.463 MPa for MWCNT-PLA, the maximum impact strength 39.648 kJ/m2 for CF-PLA, and the maximum compression strength 51.051 MPa for CF-PETG. Tailoring nozzle diameter and internal filling patterns is essential for optimizing the performance and structural characteristics of automotive components. This work introduces a novel approach utilizing the XGB algorithm for machine learning optimization in additive manufacturing, offering significant potential to enhance precision, efficiency, and innovation in automotive component design and production.

Augmenting effect of infill density and annealing on mechanical properties of PETG and CFPETG composites fabricated by FDM

Electrical properties of different types of carbon fiber reinforced plastics (CFRPs) and hybrid CFRPs

Measurements have been made using a polarized optical microscope equipped with hot stages to investigate the surface-induced crystallization of syndiotactic polystyrene(s-PS) on high modulus(HM) carbon fibers. Both the induction times and crystal growth rates at various crystallization temperatures were measured. Based on the theory of heterogeneous nucleation, the interfacial free energy difference function Δσ of s-PS on HM carbon fibers was determined to be 0.61±0.02 erg/cm2. No difference in the crystal growth rate of s-PS has been found in either spherulites in the bulk or transcrystalline layers at the interface. From the morphology studies, it has been found that the thickness of the transcrystalline layer increases with crystallization temperatures, from 5 to 13 μm in the temperature range of 247–269°C. The efficiency of HM carbon fibers to induce the transcrystalline layer is found better in s-PS matrix than that in i-PP matrix based on the surface energies of the constituents. (Keywords: transcrystalline layer · syndiotactic polystyrene · high modulus carbon fibers)

The utilization of PETG (Polyethylene Terephthalate Glycol) carbon fiber composites in Fused Deposition Modelling (FDM) processes has gained significant attention due to their enhanced mechanical properties compared to traditional PETG filaments. This study focuses on investigating the impact of varying shell thickness on the mechanical characteristics of PETG carbon fiber composites fabricated through FDM. The objective is to optimize the shell thickness to achieve superior mechanical performance while maintaining printing efficiency. A series of PETG carbon fiber composites with different shell thicknesses were manufactured using an FDM 3D printer. Mechanical tests, including tensile strength, flexural strength, and impact resistance, were conducted to evaluate the performance of the fabricated specimens. Additionally, micro-structural analysis was performed to understand the influence of shell thickness on the interfacial bonding between PETG matrix and carbon fibers. Preliminary results indicate that increasing shell thickness positively affects the mechanical properties of PETG carbon fiber composites. Tensile and flexural strength show a noticeable improvement with an increase in shell thickness, attributed to enhanced interlayer adhesion and improved load-bearing.

Enhancing Mechanical Behavior of As-Built and Annealed Polyethylene Terephthalate Glycol (PETG) Fabricated With Fused Filament Fabrication by Varying Infill Densities

Effect of process parameters on the mechanical performance of FDM printed carbon fiber reinforced PETG

The emergence of additive manufacturing has enabled scientists to efficiently construct complex geometries, facilitating the development of novel, high-impact energy-absorbing structures suitable for a wide range of industrial applications. The present study conducted flexural and impact test to quantitatively assess the energy absorption capabilities of polymer composites fabricated through fused filament fabrication. Specifically, the polymer composites investigated were multi-walled carbon nanotubes reinforced poly-lactic acid, carbon fibre reinforced poly-ethylene terephthalate glycol, and carbon fibre reinforced poly-lactic acid. The investigation also examined the influence of different infill patterns and nozzle hole diameters on the polymer composites. The investigation depicts that by altering the process parameters, the flexural strength is improved from 21.079 MPa to 70.653 MPa by 235.18%. The experimental study of impact specimens utilising the Izod impact test demonstrates that the rectilinear infill pattern and a nozzle hole diameter of 0.6 mm result in the highest energy absorption of 37.76 kJ/m2 for carbon fibre reinforced poly-lactic acid. The study revealed that the energy absorption of the specimens was significantly influenced by both the independent and interaction effects of process variables. The application of the fused filament fabrication demonstrates an improved energy absorption, making it suitable for manufacturing of vehicle and aircraft components.

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.

Carbon fibers (CFs) were used as reinforcement in developing a polyethylene terephthalate glycol (PETG)-based polymer composite using the fused deposition modeling (FDM) 3D printing technique. The influence of CF and process factors (infill percentage, layer thickness, infill pattern) were studied by measuring the prepared polymer composite's tensile, flexural, and compressive properties. The innovative work that was carried out for this study and the tests that were performed revealed that it is difficult to predict the position of the specimen break area before a test. The PETG-reinforced polymer only showed enhanced flexural and tensile strength at a layer thickness of 0.25 mm and a maximum infill percentage of 20% for a solid structural design. Compressive strength improved in reinforced PETG hexagonal and circle structures. The confirmation of the numerical modeling applied to determine the mechanical properties of PETG for FDM additive manufacturing is one of the goals suggested in this research, along with a comparison of experimental and computational data. Scanning electron microscopy examination of the fractured sample surfaces revealed various fracture mechanisms and morphologies for the materials tested. The research found that the 3D-printed composite could further expand the application of PETG as an engineering material.

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.

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.

Thin‐walled structures with good energy absorption capability can significantly use as energy absorbers in passive vehicle safety systems. The present study deals with designing and developing thin‐walled carbon fiber (CF) reinforced PETG (polyethylene terephthalate glycol) composite tubes with octagonal corrugated lattice structures on the lateral surfaces. The FFF (fused filament fabrication) factors such as layer height, nozzle temperature, printing speed, line width, and infill density were optimized. The experiment outcomes such as compressive strength and dimensional length error, are measured for the respective octagonal corrugated lattice structure incorporated in 3D printed CF/PETG composite tubes. The results proclaimed that, the optimum factors for improved compressive strength in the octagonal corrugated lattice‐structured CF/PETG composite will be 0.1 mm layer height, 220°C nozzle temperature, 20 mm/sec printing speed, 0.1 mm line width and 100% infill density. Furthermore, the R‐square value for the compressive strength and dimensional length error is within an acceptable limit of 91.25% and 93.31%. So, the developed mathematical models are in good form for practical acceptance. The optimized condition3D printed samples exhibit better compressive strength and lower dimensional length deviation, which is essential for considering it in the safety protection application in automotive components.Highlights• 3D printed octagonal shaped lattice structured PETG/CF composite tube.• Process parameters were optimized in terms of compressive strength.• Layer height has contributed a major impact on the compressive strength response.

The objective of this study was to develop a novel approach to enhance the flexural strength of polymer composites used in the fabrication of prosthetic sockets. The effects of control factors such as nozzle hole diameter and internal filling pattern on the flexural behavior of three distinct composite materials were examined: poly lactic acid reinforced with carbon fiber (PLA‐CF), polyethylene terephthalate glycol reinforced with carbon fiber (PETG‐CF), and PLA reinforced with multi‐walled carbon nanotubes (PLA‐MWCNTs), fabricated through fused filament fabrication. During study, samples of each composite material were created using 3D printing technology and underwent flexural testing. Fractography was then performed on the samples, and statistical analysis techniques, including Taguchi's method and response surface methodology (RSM) were used to analyze the results. The study found that the flexural behavior of the prosthetic socket materials varied significantly based on the control factors used. Specifically, a nozzle hole diameter of 0.6 mm and a rectilinear internal filling pattern with PLA‐MWCNTs composite material had the highest flexural strength among the three materials tested. Through this study, the authors demonstrated the potential to improve the design and manufacture of prosthetic sockets, which can lead to better functionality and comfort for the user. The low‐cost transtibial prosthetic socket developed in this study using the optimized composite material and 3D printing technology shows promise as an application in the field of prosthetics. This research can pave the way for the development of even stronger and more durable prosthetic sockets in the future.

<div class="section abstract"><div class="htmlview paragraph">Additive Manufacturing (AM), particularly Fused Deposition Modeling (FDM), has emerged as a revolutionary method for fabricating complex geometries using a variety of materials. Polyethylene terephthalate glycol (PETG) is a thermoplastic material that is biodegradable and environmentally friendly, making it a preferred choice in additive manufacturing (AM) due to its affordability and ease of use. This study aims to optimize the FDM settings for PETG material and investigate the impact of key process parameters on printing performance. An experimental study was conducted to evaluate the influence of crucial factors in FDM, including layer thickness, infill density, printing speed, and nozzle temperature, on significant outcomes such as dimensional accuracy, surface quality, and mechanical properties. The use of the Grey Relational Analysis (GRA) approach enabled a systematic assessment of multi-performance characteristics, facilitating the optimization of the FDM process. The findings demonstrated that the GRA approach is an effective tool for determining optimal parameter settings to enhance printing productivity and ensure the production of high-quality components. This study provides deeper insights into the Fused Deposition Modeling (FDM) process for Polyethylene terephthalate glycol (PETG) material, offering valuable strategies for improving manufacturing processes. By leveraging the GRA approach, this work highlights a reliable method for enhancing printing efficiency and quality, thereby promoting the wider adoption of FDM technology across various industries such as prototyping, manufacturing, and healthcare.</div></div>