Polyethylene Terephthalate Glycol Research Articles

Experimental testing and numerical simulations of 3D-printed PETG pins used for vehicle pedals

Abstract In this study, experimental analyses and numerical simulations of polyethylene terephthalate glycol (PETG) pedal pins with optimum production parameters are performed concerning mechanical properties. The aim of this study is twofold: first, the effect of the three-dimensional (3D) manufacturing process, which has a significant impact on the mechanical properties of the 3D-printed part, is realized experimentally. Second, the mechanical behavior of the 3D-printed clutch pedal pin is evaluated using both numerical simulation and experimental tests, which is an important application for lightweight vehicles. It is observed that the determined production parameters can significantly improve the mechanical behavior of the materials and the pin of the vehicle pedal mechanism can be replaced with a lighter structure. Thus, the results obtained in this paper are of the utmost importance for the manufacturer to choose the optimum manufacturing parameters of three-dimensional printed materials and their application to vehicle pedals and other possible parts.

Development of smart materials with versatile bending capabilities using microcellular foaming process: influence of foaming and desorption time

Abstract Herein, a smart material with versatile bending capability is developed using a microcellular foaming process (MCPs). In contrast to previous hydrogel-based approaches, the bi-layered smart material is fabricated using typical thermoplastics, polyethylene terephthalate glycol (PETG) and polymethyl methacrylate (PMMA), to achieve shape deformation in response to thermal stimuli. Further, the theoretical model for bi-layered smart materials based on the modified Timoshenko’s model is employed to predict and comprehend this thermal response phenomenon. Due to the distinct foaming characteristics of the two polymers, a reversal in the bending direction is achieved by manipulating the foaming and desorption time. The length variation after foaming differs depending on the desorption time for each polymer. PMMA decreases in length after foaming, measuring 56.25 mm at a desorption time of 40 min and 53.16 mm at 80 min. On the other hand, PETG shows an increase in length after foaming, measuring 53.33 mm at 40 min and 58.25 mm at 80 min. Consequently, when the two polymers are bonded and foamed, bending occurs depending on the desorption time, and a reversal in the bending direction is observed at the critical desorption time of around 60 min. Based on this result, the folding direction of a five-leafed flower-shaped object is successfully altered under thermal stimuli. This innovative approach extends the category of smart materials beyond the hydrogels and showcases the potential of the MCPs for the creation of smart materials for various applications that require versatile shape changes in response to temperature.

How safe are 3D-printed skull models for neurosurgical simulation? Measurement of airborne particles and VOCs while burr hole drilling

PurposeThree-dimensional (3D)printed skulls for neurosurgical training are increasingly being used due to the widespread access to 3D printing technology, their low cost and accuracy, as well as limitations and ethical concerns associated with using human cadavers. However, little is known about the risks of airborne particles or volatile organic compounds (VOCs) released while drilling into 3D-printed plastic models. The aim of this study is to assess the level of exposure to airborne contaminants while burr hole drilling.Design/methodology/approach3D-printed skull samples were produced using three different materials (polyethylene terephthalate glycol [PETG], white resin and BoneSTN) across three different 3D print processes (fused filament fabrication, stereolithography [SLA] and material jetting). A neurosurgeon performed extended burr hole drilling for 10 min on each sample. Spot measurements of particulate matter (PM2.5 and PM10) were recorded, and air samples were analysed for approximately 90 VOCs.FindingsThe particulate matter for PETG was found to be below the threshold value for respirable particles. However, the particulate matter for white resin and BoneSTN was found to be above the threshold value at PM10, which could be harmful for long periods of exposure without personal protective equipment (PPE). The VOC measurements for all materials were found to be below safety thresholds, and therefore not harmful.Originality/valueTo the best of the authors’ knowledge, this is the first study to evaluate the safety of 3D-printed materials for burr hole surgical drilling. It recommends PETG as a safe material requiring minimal respiratory control measures, whereas resin-based materials will require safety controls to deal with airborne particles.

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

Additive manufacturing (AM), shows promising advancements in layer-based modeling displaying its potential for substantial waste reduction. Out of all the AM methods, the most cost-effective and popular choice for prototyping and making customized parts is fused deposition modeling (FDM). This research investigates how various FDM process parameters specifically layer thickness, raster angle, and printing speed affect the mechanical properties of 3D-printed PETG (polyethylene terephthalate glycol) specimens reinforced with carbon fiber (CF). Optimal settings, including a 0° raster angle, 0.2 mm layer thickness, and 40 mm/s printing speed, enhance both tensile and flexural strength due to improvement in material bonding and alignment. Interestingly, lower values for raster angle, layer thickness, and printing speed also lead to notable improvements in mechanical properties. Contour and interaction plots provide valuable insights into the significant impact of these parameters. The study also explores how different printing speeds influence the mechanical characteristics of CF-reinforced PETG specimens. Furthermore, the comparative analysis demonstrated that incorporating carbon fiber into recycled PET waste materials resulted in an approximately 30% increase in tensile strength. These findings imply that using CF with plastic waste in large-scale industries can pave the way for innovative solutions, enhancing performance and sustainability, especially in the automotive, and defence sectors.

Analysing the mechanical behaviour of thermoformed dental clear aligners using acoustic emission technique

Clear aligners have been widely preferred in recent years for aesthetically pleasant orthodontic treatments. However, their efficacy in treating dental malposition and malocclusion is yet to be studied extensively. Clear aligners are mostly made from thermoplastic materials that guarantee sufficient elasticity while lowering the plastic deformations during their use. This is to guarantee a stable level of forces acting on teeth to be repositioned. This work aims to get insight into the mechanical behaviour of these devices during their period of use, by comparing aligners produced from two different thermoplastic materials: polyethylene terephthalate-glycol modified (PET-G) and polyurethane (PU) supplied by Dooris and Ghost Aligners, respectively. The aligners were subjected to cyclic compression loading, to simulate the swallowing act throughout 15 days of use. Tests were conducted by surrounding the aligners with artificial saliva to simulate the intraoral environment. The Acoustic Emission (AE) technique was used to analyse the damage progression in the aligners during the loading. Furthermore, the AE results were compared with the energy absorbed and the stiffness changes in the aligners. Finally, the damage evolution in the aligners post-loading was validated using optical microscopy. The AE results revealed a good correlation with mechanical and optical microscopy data, thus contributing to the understanding of the mechanical behaviour of the clear aligners.

A Novel PETG Microchannel Reactor for Microwave-Powered Biodiesel Production

Biodiesel stands at the forefront as a replacement for fossil diesel in compression ignition engines, particularly in the transportation sector where diesel engines are the primary movers. However, biodiesel production is hampered by poor heat and mass transfer during the transesterification reaction, leading to long production times and high costs due to inefficient energy utilisation. This study targets heat and mass transfer issues during the production of biodiesel via a synergic approach that combines microwave-assisted heating and microfluidics via a polyethylene terephthalate glycol (PETG) microchannel reactor. The transesterification reaction of palm oil and methanol was investigated using a full factorial design of experiments (DOE) method. Biodiesel yield was quantified via gas chromatographic analysis, and the results were optimised using statistical analysis. Optical analysis of slug quantification within the microchannel revealed that small slugs, smaller than 1 mm, accelerated the transesterification reaction. The composite-optimised experimental results, aimed at minimising energy costs and environmental impacts while maximising fatty acid methyl ester (FAME) yield, indicate a reaction temperature of 50 °C, a catalyst loading of 1.0 wt.%, and a 3:1 methanol to oil molar ratio. Regression analysis revealed that the reaction temperature was statistically insignificant when utilising the PETG microchannel reactor. This key finding positively impacts biodiesel production as it relates to significantly reduced energy intensity, costs, and emissions. Overall, this research work paves a pathway toward an energy-efficient and sub-minute rapid transesterification reaction, highlighting the effectiveness of microwave heat delivery and effects of microfluidics via the PETG microchannel reactor in overcoming heat and mass transfer barriers in biodiesel production.

4D-printed reusable metamaterial via shape memory effect for energy dissipation

The present study aims at developing reusable metamaterials fabricated by 4D printing technology. Honeycomb metamaterials were manufactured via fused deposition modeling (FDM) with shape memory polymers (SMPs). The reusability of these metamaterials was determined through cyclic cold programming experiments, where each cycle involved a loading-unloading-heating (shape recovery)-cooling process. The novelty of this paper lies not only in experimentally demonstrating the recoverability of metamaterials by reversing plastic deformation based on the shape memory effect of SMPs, but also in studying their reusability of SMP metamaterials under cyclic programming and the effect of printing materials and unit-cell types on the mechanical degradation. The results reveal that, under one single compression cycle, the polylactic acid (PLA) hexagonal honeycomb dissipated 22% more energy than the polyethylene terephthalate glycol (PETG) counterpart because the higher elastic modulus of PLA leads to a larger critical buckling load for segments in honeycomb structures. Furthermore, the PETG re-entrant honeycomb dissipated 25% more energy than the hexagonal counterpart due to its negative Poisson's ratio and the overall uniform deformation pattern. More importantly, it is found that under multiple compression cycles, the PETG hexagonal honeycomb maintained an energy dissipation capacity of 78.3% at Cycle 6, nearly 3.5 times that of the PLA counterpart as a result of the better ductility of PETG. Moreover, the PETG re-entrant honeycomb could be reused for 17 cycles, while the hexagonal counterpart could only be reused for 12 cycles. This is because the re-entrant unit cells are failure-resistant and of less concentration in plastic deformation. The results demonstrate that the constituent materials with better ductility and the unit-cells with more failure resistance can reduce mechanical degradation, thereby exhibiting better reusability of metamaterials.

Unlocking the nanoparticle emission potential: a study of varied filaments in 3D printing.

This study investigates nanoparticle emission during 3D printing processes, assessing various filament materials' impact on air quality. Commonly used 3D printers, including both filament and resin-based types, were examined. The study's scope encompasses diverse filament materials like ABS (acrylonitrile butadiene styrene), PLA (polylactic acid), PETG (polyethylene terephthalate glycol), ASA (acrylonitrile styrene acrylate), TPU (thermoplastic polyurethane), PP (polypropylene), nylon, and wood-based variants, alongside three types of resins. The research delves into the relationship between the type of material and nanoparticle emissions, emphasizing temperature's pivotal role. Measurement instruments were employed for nanoparticle quantification, including an engine exhaust particle sizer spectrometer, condensation particle counter, and nanozen dust counters. Notably, results reveal substantial variations in nanoparticle emissions among different filament materials, with ASA, TPU, PP, and ABS showing considerably elevated emission levels and characteristic particle size distribution patterns. The findings prompt practical recommendations for reducing nanoparticle exposure, emphasizing printer confinement, material selection, and adequate ventilation. This study offers insights into potential health risks associated with 3D printing emissions and provides a basis for adopting preventive measures.

Design and implementation of an Unmanned Aerial Vehicle (UAV) for image capture in enterprise farming

Unmanned aerial vehicle (UAV), also known as drone is one of the most interesting emerging technologies with a wide range of applications including agriculture, surveillance, security, search and rescue, mapping, farmland surveying, and wildlife conservation, among others. In Nigeria, UAV is gaining popularity in applications such as in social functions for taking both moving and static pictures, military and security, mapping and agriculture. In this work, an UAV was designed, some components produced by 3D printing, coupled and tested with certain level of local content in view. The UAV is a quadcopter equipped with a camera for real-time image capture of farmlands and it can perform autonomous missions by using global positioning system (GPS) waypoints. The weight of the quadcopter was approximately calculated and hence the electrical and mechanical components selected using a standard empirical design table. The thrust to weight ratio was set at 2:1. Autodesk Maya and Inventor software were used to design the frame in two parts: the frame arms on which the propellers are mounted and the central connecting part that links the four arms. The arms are made up of aluminum square pipes while the central connecting part for the arms was printed with a 3D printer (200 x 200 x 200 Wanhao duplicator i3) using PolyEthylene Terephthalate Glycol (PETG) Filament material of 1.75mm standard gauge. Material selection was based on material strength, cost and availability. NCH Debut video and image capture software was used to record live feeds from the UAV onboard camera. Functionality tests for lift, stability, yaw, roll, pitch, loiter, auto landing, return to launch, flight time, altitude/signal, auto mission using GPS waypoints were carried out with the completed UAV on a less windy day to avoid the influence of wind. It was generally observed that the UAV successfully took off the ground, gained stability, flew to over 100m height, captured aerial photographs of the land below it while on flight at the required height and landed safely. Cost saving advantage of 45.28% was achieved when compared to imported equivalent types.

Investigation of the Effectiveness of Silicon Nitride as a Reinforcement Agent for Polyethylene Terephthalate Glycol in Material Extrusion 3D Printing.

Polyethylene terephthalate glycol (PETG) and silicon nitride (Si3N4) were combined to create five composite materials with Si3N4 loadings ranging from 2.0 wt.% to 10.0 wt.%. The goal was to improve the mechanical properties of PETG in material extrusion (MEX) additive manufacturing (AM) and assess the effectiveness of Si3N4 as a reinforcing agent for this particular polymer. The process began with the production of filaments, which were subsequently fed into a 3D printer to create various specimens. The specimens were manufactured according to international standards to ensure their suitability for various tests. The thermal, rheological, mechanical, electrical, and morphological properties of the prepared samples were evaluated. The mechanical performance investigations performed included tensile, flexural, Charpy impact, and microhardness tests. Scanning electron microscopy and energy-dispersive X-ray spectroscopy mapping were performed to investigate the structures and morphologies of the samples, respectively. Among all the composites tested, the PETG/6.0 wt.% Si3N4 showed the greatest improvement in mechanical properties (with a 24.5% increase in tensile strength compared to unfilled PETG polymer), indicating its potential for use in MEX 3D printing when enhanced mechanical performance is required from the PETG polymer.

Enhancing Mechanical Characteristics of PETG Carbon Fiber Composite through Various Shell Thickness in FDM Processing

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.

Tensile performance of 3D printed geogrids: effect of geometrical configuration

The aim of this study was to evaluate the tensile performance of additively manufactured polyethylene terephthalate glycol (PETG) geogrids, printed three-dimensionally using the material extrusion technique. The Creality Ender-3 V2 printer was employed for this purpose. The printed specimens were subjected to loading at a rate of 1 mm/min until failure occurred. The geometrical parameters investigated were the shape of the aperture (square, triangular and hexagonal), the aperture size, the rib thickness and the type of junction. The results revealed that the failure of specimens was primarily brittle and independent of any specific geometrical configuration or modifications. The initiation of failure consistently originated from the junctions. Among the specimens with typical junctions, the triaxial geogrids exhibited the highest tensile capacity; among geogrids with modified junctions, the square geogrids performed the best. The load capacity of the geogrids was found to be primarily governed by linear behaviour in terms of rib width, regardless of the aperture size or shape, whereas a non-linear regression model characterised the load–displacement curves. The results indicate that it is important to account for geometrical non-linearity in specimens with hexagonal apertures.

Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number

A novel concept of morphing airfoils, capable of changing camber and thickness, is proposed. A variable airfoil shape, defined by six input parameters, is achieved by allowing the three spinal points (at fixed axial positions) to slide vertically, while the upper and lower surfaces are determined by the lengths of the three corresponding ribs that are perpendicular to the spine. Thus, it is possible to find the most appropriate geometric configuration for a wide range of possible operating conditions often present with contemporary unmanned aerial vehicles. Shape optimizations for different Reynolds numbers and different cost functions are performed by coupling a genetic algorithm with simple panel method flow calculations. The obtained airfoils are presented and compared, whereas the proposed concept is validated by more advanced flow simulations. It appears that improvements in aerodynamic performance of nearly 20% can be expected at Re ranging from 0.05 × 106 to 0.1 × 106. The proposed methodology shows promise and can be applied to different types of lifting surfaces, including wing, tail or propeller blade segments. To check the viability of this method for producing airfoils that can be used in a practical sense, structural analysis of one of the obtained geometries using a simplified 1D finite element method as well as a more detailed 3D analysis are performed. The model is then 3D-printed on a fused deposition modeling (FDM) printer with a polyethylene terephthalate glycol (PETG) filament, and the capability of the airfoil to adequately morph between the two desired geometries is experimentally shown.

A preliminary study on multi-material fused filament fabrication of an embedded strain gauge for low-cost real-time monitoring of part strain

Unlike other manufacturing techniques, additive manufacturing enables part consolidation through the production of multi-material parts with enhanced functionality. With reference to the functionality of monitoring the structural integrity of a product during its use, conductive filaments can be used in additive manufacturing. This work aims to investigate the applications of multi-material fused filament fabrication to produce embedded strain gauges for real-time monitoring of part deformations. In layer-by-layer fabrication, conductive filaments can be used to produce strain-sensitive elements inside products at a low cost. This preliminary study demonstrated the feasibility of the proposed approach using tensile samples fabricated through additive manufacturing. The samples were produced using a polyethylene terephthalate glycol filament and an acrylonitrile styrene acrylate filament, while electrically conductive polylactic acid was used for the strain gauge. The characterization and testing activities were conducted by comparing the results of the tensile testing with data acquired through an experimental system set up with an Arduino board, aligning with the resistance-based strain gauge theory. The findings show that the co-fabricated strain gauge successfully traces part deformation, enabling real-time monitoring of strain in the elastic field. Nevertheless, further optimization of the proposed approach is imperative to enhance the reliability and accuracy of the methodology.

Assessment of mechanical properties and shape memory behavior of 4D printed continuous fiber-reinforced PETG composites

Additive manufacturing (AM) has transformed composite structure production with continuous fiber-reinforced composites (CFRCs). Integrating shape memory polymers (SMPs) into AM enables 4D printing, holding promise across industries. Despite SMP brittleness at low temperatures, most studies focus on high-temperature shape memory behavior. Polyethylene Terephthalate Glycol (PETG), known for good printability, shape memory, and room temperature flexibility, is reinforced with carbon fiber in this study and its chemical and thermo-mechanical properties are systematically evaluated. The investigation extends to assessing the influence of printing parameters on CFRC printability and mechanical properties to identify optimal settings. Mechanical property enhancement is significant, especially with 7% carbon fiber, resulting in 474% and 386% improvement in tensile and flexural modulus, respectively. Shape-recovery tests at room temperature show 98% recovery for pure PETG and 94% for composites. PETG CFRC's high mechanical properties, room temperature flexibility, and promising shape recovery position them for potential load-bearing applications in various industries.

Mass-based fates of microplastics throughout wastewater treatment processes

Sewage treatment plants (STPs) are crucial in removing microplastics from wastewater but also serve as essential point sources for microplastic pollution in environments. To address this issue by improving the microplastic removal efficiency, unveiling the mass-based fates of microplastics during treatments in STPs is essential, as these treatment systems are not specially designed to target microplastics. Herein, a thermodesorption–gas chromatography–mass spectrometry (TD–GC/MS) was developed to quantify the mass of five microplastics: polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethyleneglycol terephthalate (PET) in the range of 0.22 μm–5.00 mm in size. Then, the approach was further applied to evaluate the mass-based fates of these microplastics throughout the whole STP treatment process. Results showed that PE was the most common polymer detected in influent (1313.11 ± 336.96 μg/L) and effluent (25.84 ± 3.75 μg/L), while PP was the least prevalent in influent (52.47 ± 11.49 μg/L) and PS in the effluent (2.74 ± 0.26 μg/L). Moreover, the proportion of the smallest particles (0.22–20 μm) was dominant in all samples. Based on mass estimations, an average of 95.82 % ± 2.02 % of microplastics were efficiently removed from the influent, with removal rates ranging from 92.55 % for PP to 98.03 % for PE. Moreover, the removal of microplastic mainly occurred in the primary treatment unit, and their removal efficiencies decreased as the microplastic concentrations decreased, regardless of their sizes and polymer types. To the best of our knowledge, this is the first report on the mass-based fates of microplastics in STP throughout wastewater treatment processes, enabling the comparison of microplastic removal efficiencies among studies to direct future improvements in the treatment process.

The role of printing parameters on the short beam strength of 3D-printed continuous carbon fibre reinforced epoxy-PETG composites

It is well known that printing parameters strongly affect the mechanical performance of 3D printed parts. This work explores the role of i) extruder temperature, ii) print speed, and iii) layer height on the interlaminar strength of 3D-printed continuous fibre-reinforced composites. The carbon fibre-reinforced thermoset filament is printed concomitantly with polyethylene terephthalate glycol (PETG) thermoplastic filament in a single nozzle, characterising a continuous fibre co-extrusion (CFC) process. There is a significant variation in the short beam strength for composites printed with different parameters. The load–displacement curves have a similar pattern, with clear load peaks followed by a plastic zone. Optical micrographs and computed tomography (CT) scans reveal that the microstructure is dependent on the printing parameters. Image analysis elucidates the various mechanisms of void formation. Following the application of a three-way ANOVA and statistical tests to quantify the effects and interactions among variables, the analysis concludes that the extruder temperature has the highest influence, followed by print speed and layer height. When considering all possible interactions between the factors, the interaction between print speed and layer height is the most impactful.

Investigating the Effect of ABS on the Mechanical Properties, Morphology, Printability, and 4D Printing of PETG‐ABS Blends

AbstractIn this study, Acrylonitrile butadiene styrene (ABS) with three different ratios of 30%, 50%, and 70% is used to enhance the shape memory and mechanical properties of Polyethylene terephthalate glycol (PETG). Additionally, morphology, printability, and dynamic thermomechanical analysis are also examined. The thermal test results show that PETG‐ABS compounds have two transition temperatures in the range of 80 and 110 °C, which are related to the components. By changing the weight percentage of PETG from 30 to 70%, three morphologies of matrix‐droplet, sea‐island, and combination of co‐continuous and matrix‐droplet are observed. The results of the mechanical properties show an increase in strength with the increase of ABS, which can be justified due to the higher strength of ABS compared to PETG. The highest tensile strength of 32.48 MPa and 15.16% elongation is obtained for PETG‐ABS(30‐70) and PETG‐ABS(70‐30), respectively. Due to the better shape memory performance of PETG, PETG‐ABS(50‐50) and PETG‐ABS(70‐30) have complete shape recovery, and with the increase of PETG, the shape recovery rate also increased. This diversity in morphology, mechanical properties, and shape memory effect is one of the goals of this research which is well fulfilled.

A novel geometric predictive algorithm for assessing compressive elastic modulus in MEX additive processes, based on part nonlinearities and layers stiffness, validated with PETG and PLA materials

MEX (Material Extrusion) is an intrusive technological process that inherently induces alterations in the elastic and mechanical parameters of plastic materials. Manufacturers provide initial mechanical parameters for plastic filaments, which undergo modifications during MEX manufacturing, influenced by intrinsic manufacturing factors such as temperature and pressure changes, as well as geometric and technological parameters of the 3D additive process. These factors, compounded by the inherent geometric nonlinearities in plastic components, directly impact the post-manufacture mechanical and elastic properties of the material. Presently, material characterization in MEX manufacturing relies on manual experimental testing, necessitating new tests for any variation in manufacturing parameters. In this scenario of mechanical uncertainty, rigorously validating component behavior involves costly experimental trials. Intending to solve the problems of MEX components manufacturing, the paper presents an innovative methodology based on the use of a new predictive algorithm created by the researchers capable of obtaining the elastic modulus of a plastic material manufactured with MEX and its mechanical behavior in the elastic zone under compressive loads. The predictive algorithm only needs as input the compressive elastic modulus of the isotropic plastic material filament and the manufacturing parameters of the MEX process. The smart developed algorithm calculates the stiffness of each layer considering the number of holes in the projected area. The innovative predictive algorithm has been experimentally and numerically validated using PETG (Polyethylene Terephthalate Glycol) material and PLA (Polylactic Acid) on test specimens and on a case study of variable topology. The results show deviations from [0.2%–4.3%] for PETG and [0.4%] for PLA concerning the experimental tests and [1.1%–13.5%], to the numerical analyses. In this line, the presented algorithm greatly improves the results obtained by the simulation software since this software currently can not consider the geometric and technological parameters associated with the 3D manufacturing process of the component. The predictive algorithm is valid for each print pattern and manufacturing direction. The new algorithm improves the existing state of the art significantly since this algorithm extends its utility to most plastic polymer materials suitable for MEX 3D printing, provided that the mechanical and elastic properties of the filament are known. Its versatility extends to complex component geometries subjected to uniaxial compression loads, eliminating the need for mechanical analysis software or expensive experimental validations.

Investigating the influence of annealing and nozzle diameter on tensile strength of polyethylene terephthalate glycol composites

Additive Manufacturing (AM) techniques, particularly Fused Filament Fabrication (FFF), have revolutionized prototyping and low-volume production. Improving the tensile properties of FFF-printed parts is a primary objective to elevate their functional utility. This study aimed to investigate the effects of annealing time (ATM), annealing temperature (ATP), and nozzle diameter (ND) on the tensile strength (TS) of two commonly used printing materials: Polyethylene Terephthalate Glycol (PETG) and PETG reinforced with carbon fibre (PETG-CF). Samples with varying ND (0.4 mm, 0.6 mm, and 0.8 mm) underwent annealing at ATP of 80°C and 100°C for ATM of 60 min and 120 min, respectively. Subsequent tensile tests were meticulously conducted, and regression models were employed to comprehensively analyse the influence of these control factors on TS. The findings from the tensile tests on annealed specimens revealed substantial improvements in TS for both PETG and PETG-CF materials. Statistical analysis, Taguchi method (TM), and response surface methodology (RSM) indicated that ND exerted a more pronounced impact on TS compared to ATM and ATP. By identifying the optimal control factor combinations for each material, the study pinpointed that the best TS was achieved at 0.8 mm ND, 120 minutes ATM, and 100°C ATP for PETG-CF. The remarkable enhancement in tensile properties for annealed FFF-printed parts underscores the potential of PETG-CF to replace structural metallic components in critical applications within the automotive and aeronautical industries.