Polylactic acid/Ormocarpum cochinchinense bio-composites for sustainable 3D-printed biomedical devices.

This study used carbon rods from spent zinc-carbon batteries as a source of exfoliated graphite (EG) to produce conductive filament composites for fused deposition modeling 3D printing. The EG filler was prepared through microwave irradiation, while the resulting 3D printable electroconductive EG composites were prepared using polylactic acid (PLA) and polyethylene glycol (PEG) as the polymer matrix and compatibilizer, respectively, via a sonication-assisted solution blending and melt extrusion process. A two-level full factorial design was employed to fully investigate the influence of filament production parameters such as EG loading, PEG:PLA ratio, and sonication time on the resistivity (i.e., conductivity-1) of the prepared composites. Analysis of variance showed that both EG loading and sonication time had significant effects on the resistivity of the composites. The optimum electrical resistivity of the new EG filament composites was found to be 916.418 Ω-cm (maximum conductivity = 1.091 x10-3 S/cm) at EG loading = 45 % w/w, PEG:PLA ratio = 1:10, and sonication time = 2 hours. The conductivity of the 3D printed composites was also correlated with EG amount by the power law model of percolation theory, resulting in an electrical percolation threshold at around 35 % w/w of EG. Our filament composites enable the fabrication of high-value conductive materials from waste resources for sustainable additive manufacturing in the electronics industry.

Fabrication of superhydrophobic PLA surfaces by tailoring FDM 3D printing and chemical etching process

The objective of this study was to investigate the feasibility of using a cost-effective desktop three-dimensional (3D) fused deposition modeling (FDM) printer to fabricate dental casts to overcome the problems of conventional dental plaster casts, such as fragility and low portability. First, a 3D computer-aided design (CAD) model of the dental cast was prepared in theStandard Triangle Language (STL) format. Twelve 3D models were fabricated using a desktop FDM 3D printer under different 3D printing parameters/conditions, including shape, placement direction, and infill percentage. The fabricated 3D models were reverse-scanned with a microfocus computed tomography unit. STL models were created from the scanned data and superimposed on a reference STL model to evaluate the effect of different parameters/conditions on the accuracy and quality of the 3D models. The results showed that the percentage of infill (25% vs. 75%) affected the accuracy and quality of the model. Thermal transfer simulations highlighted the role of internal structure/infill percentage in the deformation of the model during 3D printing. In conclusion, although challenges such as thermal deformation and resolution limitations remain, it was found that even with an FDM 3D printer, the accuracy of 3D models can be improved by optimizing 3D printing parameters. This study demonstrates the feasibility of dental cast fabrication using an FDM 3D printer and may be one of the most cost-effective solutions. Depending on the future development of FDM technology, it is expected that this technology will be able to streamline the dental workflow and improve its efficiency.

This paper reported the tensile strength of the difference of modeling condition on the FDM (Fused Deposition Modeling) 3D printer. The FDM 3D printer is rapidly spread with the end of patent protection in 2009. The FDM models mainly use the prototyping part and art, because that models have low strength. This time we paid attention to that actual models weight is lighter than designing models weight to conduct study on strength. And we investigated the cause of the phenomenon of decrease of polymer extrusion by replacing with the injection molding method. The tensile test proved that the strength of model can be improved by the kind of extruder head. This paper reported influence of the cooling in the supply part of extruder head and temperature of the polymer on the strength of FDM 3D models.

Fabrication of a superhydrophobic surface using a fused deposition modeling (FDM) 3D printer with poly lactic acid (PLA) filament and dip coating with silica nanoparticles

3D printing and particularly fused deposition modelling (FDM) is widely used for prototyping and fabricating low-cost customised parts. However, present fused deposition modelling 3D printers have limited nozzle condition monitoring techniques to minimize nozzle clogging errors. Nozzle clogging is one of the significant process errors in fused deposition modelling 3D printers, and it affects the quality of prototyped parts in terms of mechanical properties and geometrical accuracy. This paper proposes a dynamic model for current-based nozzle condition monitoring in fused deposition modelling, which is briefly described as follows. First, all the process forces in filament extrusion of the fused deposition modelling were identified and derived theoretically, and theoretical equations of the feed rolling forces and flow-through-nozzle forces were derived. In addition, the effect of the nozzle clogging on the current of extruding motor were identified. Second, based on the proposed dynamic model, current-based nozzle condition monitoring method was proposed. Next, sets of experiments on FDM machine using polylactic acid (PLA) material were carried out to verify the proposed theoretical model, and the results were analysed and evaluated. Findings of the present study indicate that nozzle clogging in FDM 3D printing can be monitored by sensing the current of the filament extruding motor. The proposed model can be used efficiently for monitoring nozzle clogging conditions in fused deposition modelling 3D printers as it is based on the fundamental process modelling.

Astragalus residue powder (ARP)/thermoplastic starch (TPS)/poly(lactic acid) (PLA) biocomposites were prepared by fused-deposition modeling (FDM) 3D-printing technology for the first time in this paper, and certain physico-mechanical properties and soil-burial-biodegradation behaviors of the biocomposites were investigated. The results showed that after raising the dosage of ARP, the tensile and flexural strengths, the elongation at break and the thermal stability of the sample decreased, while the tensile and flexural moduli increased; after raising the dosage of TPS, the tensile and flexural strengths, the elongation at break and the thermal stability all decreased. Among all of the samples, sample C—which was composed of 11 wt.% ARP, 10 wt.% TPS and 79 wt.% PLA—was the cheapest and also the most easily degraded in water. The soil-degradation-behavior analysis of sample C showed that, after being buried in soil, the surfaces of the samples became grey at first, then darkened, after which the smooth surfaces became rough and certain components were found to detach from the samples. After soil burial for 180 days, there was weight loss of 21.40%, and the flexural strength and modulus, as well as the storage modulus, reduced from 82.1 MPa, 11,922.16 MPa and 2395.3 MPa to 47.6 MPa, 6653.92 MPa and 1476.5 MPa, respectively. Soil burial had little effect on the glass transition, cold crystallization or melting temperatures, while it reduced the crystallinity of the samples. It is concluded that the FDM 3D-printed ARP/TPS/PLA biocomposites are easy to degrade in soil conditions. This study developed a new kind of thoroughly degradable biocomposite for FDM 3D printing.

In today’s landscape, amidst the pressing planetary ecological dilemmas, biodegradable and compostable plastics are rising as the cornerstone for nurturing sustainability in the society of tomorrow. Additive Manufacturing (AM) is a rapidly growing technology that is highly applied to several industries and has ideal material, geometric, and customization attributes not offered by other production methods. Biodegradable poly (lactic acid) (PLA), a routine feedstock for FDM (fused deposition modeling) 3D printing process, is sourced entirely from renewable resources, offering advantages such as speedy printing without the need for other chemicals or biologically harmful elements. Despite its mechanical strength, PLA faces limitations hindering widespread use in 3D printing technique. To address this, recent studies focus on enhancing PLA through modifications or blending for 3D printing process to strengthen its durability & heat resistance, and elevating its printability for a wide range of industrial uses. In light of these perspectives, the present study involves the compounding of 60 wt% of PLA with (35 & 39 wt% of) poly [(butylene adipate)-co-terephthalate] (PBAT) and graphene nanoplatelets (GnP) at 1 & 5 wt% in a twin screw extruder to obtain PLA/PBAT/GnP composite filaments. Subsequently, different specimens are fabricated from the composite filaments using a FDM 3D printing system in accordance with ASTM standards. An examination into the mechanical properties, thermal behavior, and morphology of 3D printing composites is conducted. The PLA/PBAT/GnP composites have demonstrated outstanding characteristics in terms of both printability and dimensional stability. As the GnP content rises in the bio-composite, flexural, tensile, and compressive strengths experience a decrease. Notably, the addition of fillers did not demonstrate any significant impact on Shore D hardness and thermal stability.

The metal bone screws are generally used in bone fractures. The bio-composite bone screws will be fabricated soon by using hydroxyapatite (HA) to reinforce polylactic acid (PLA) and polycaprolactone (PCL) filament for 3D printing. In this study aimed to characterize morphological and physical properties of bio-composite filaments. HA was synthesized from bovine bone. X-ray diffraction analysis indicated that the obtained HA and HA standard showed a similar chemical composition. The morphological observation of bio-composite filaments by scanning electron microscope (SEM) revealed the distribution of HA in bio-composite filaments. The elemental composition of the filament by energy dispersive spectrometer indicated the consisting of calcium, carbon and oxygen elements. The diameter measurement of all bio-composite filaments indicated the values ranged from 1.66 to 1.86 mm which were non-significantly different value in each composite filament and similar with a filament standard.

Development of customised 3D printed biodegradable projectile for administrating extended-release contraceptive to wildlife

A notable increase in prominence has been observed in the application of Fused Deposition Modeling (FDM) 3D printing, resulting in a transformative influence on manufacturing processes in various sectors. The paramount importance of careful material selection for fully harnessing the capabilities of this technology is acknowledged. Within the scope of this comprehensive study article, an examination is conducted regarding the characteristics, benefits, and limitations associated with the three primary materials used in FDM 3D printing, namely Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), and Polyethylene Terephthalate Glycol (PET-G). Each of these materials is recognized for possessing unique characteristics that render them suitable for a diverse array of applications, including educational and creative pursuits, as well as industrial prototyping and the creation of functional components. Importantly, the potential to enhance the mechanical, thermal, and electrical characteristics of these substances has been demonstrated through the integration of additives, such as carbon nanotubes, nanoclay, and graphene. Through the cooperative efforts of material scientists, engineers, and 3D printing enthusiasts, it is anticipated that FDM 3D printing will emerge as an essential and invaluable instrument across a wide range of disciplines.

Biodegradable polylactic acid (PLA) has been widely used in fused deposition modeling (FDM) 3D printing. In order to improve its comprehensive properties in 3D printing, in this study, 0-40% content of polybutylene adipate terephthalate(PBAT) was selected to be blended with PLA in a twin-screw extruder; the resulting pellets were drawn into a homogeneous filament; then, PBAT/PLA samples were prepared by FDM 3D printing, and the effects of the dosage of PBAT on the mechanical properties, thermal behavior, surface wettability and melt flowability of the samples were investigated. The results showed that all the samples could be printed smoothly, and the ductility was slightly improved by the increase in the PBAT dosage; the thermal stability of PLA was enhanced by blending with PBAT, and the crystallinity increased monotonically with the increase in PBAT. After blending with PBAT, the surfaces of the samples were more hydrophilic and flowable. The important conclusion achieved in this work was that the PBAT/PLA blends, especially those containing 30%PBAT, showed great potential to replace petroleum-based plastics and are suitable for use in FDM 3D printing technologies for different applications.

Fused Deposition Modeling (FDM) 3D printing is a widely utilized additive manufacturing method that finds widespread application in diverse industrial sectors. The incorporation and arrangement of infill structures have a substantial impact on the mechanical characteristics of objects fabricated by FDM. A multitude of scholarly investigations have thoroughly examined the effects of various infill structures and infill ratios on structural properties. Nonetheless, there exists a noticeable gap in research regarding the consequences of incorporating many infill structures inside a singular constituent produced through 3D printing. The aim of this study is to address the current research gap by investigating the impact of different combinations of infill structures on the mechanical properties of 3D-printed objects, with a particular focus on the commonly used Polylactic Acid (PLA) material. PLA is selected as a suitable material owing to its biodegradable nature, user-friendly characteristics, and extensive acceptance, rendering it a pertinent choice for a diverse array of applications. This research focuses on evaluating ASTM Type VI dogbone-shaped samples featuring 25 unique infill structures. These structures result from various combinations of five prevalent infill patterns: lines, cubic, triangles, grids, and gyroid. Each combination is structured in a “sandwich” configuration, creating complex and diverse infill designs. Tensile testing of these samples provides critical data for assessing the mechanical properties of the combined infill pattern specimens. The findings have significant implications for localized reinforcement in additive manufacturing. To illustrate this, an S-type hook was fabricated using a combined infill pattern of Cubic and Gyroid. This hook was then compared to others made with singular infill patterns to demonstrate the effectiveness of combined infill strategies in enhancing mechanical performance. The research outcomes provide significant insights into the mechanical characteristics of 3D-printed objects using infill structures. It has been demonstrated that the use of various infill structures can enhance structural performance in specific areas of the printed components. This approach offers targeted reinforcement and optimizes resource utilization, making it an attractive choice for industries reliant on FDM 3D printing. Moreover, this research lays the groundwork for future studies in this domain. In subsequent research endeavors, it’s possible to broaden the scope of this study by examining a more extensive range of infill structure combinations and exploring different ratios within the same category of infill structures. Additionally, predictive models derived from the findings of this study could assist engineers and designers in efficiently optimizing infill structures, leading to significant savings in material and time during the 3D printing process. The significance of this study goes beyond its direct applications. This research enhances the overall understanding of improving infill structures in FDM 3D printing, thereby having significant implications for industries such as aerospace, automotive, and other relevant sectors. The ability to enhance the mechanical properties of 3D-printed components while maintaining cost-effectiveness can potentially drive advancements and improvements across various industries. This further solidifies FDM 3D printing as a versatile and reliable manufacturing method.

Fused Deposition Modelling (FDM) 3D printing has received much interest as a fabrication method in the medical and pharmaceutical industry due to its accessibility and cost-effectiveness. A low-cost method to produce biocompatible and biodegradable filaments can improve the usability of FDM 3D printing for biomedical applications. The feasibility of producing low-cost filaments suitable for FDM 3D printing via single screw and twin-screw hot melt extrusion was explored. A single-screw extruder and a twin-screw extruder were used to produce biocompatible filaments composed of varying concentrations of polyethylene glycol (PEG) at 10%, 20%, 30% w/w and polylactic acid (PLA) 90%, 80% and 70% w/w, respectively. DSC, TGA and FTIR were employed to investigate the effect of PEG on the PLA filaments. The presence of PEG lowered the processing temperature of the formulation compositions via melt-extrusion, making it suitable for pharmaceutical applications. The use of PEG can lower the melting point of the PLA polymer to 170°C, hence lowering the printing temperature. PEG can also improve the plasticity of the filaments, as the rupture strain of twin-screw extruded filaments increased up to 10-fold as compared to the commercial filaments. Advanced application of FTIR analysis confirmed the compatibility and miscibility of PEG with PLA. Twin-screw extrusion is more effective in producing a polymeric mixture of filaments as the mixing is more homogenous. The PEG/PLA filament is suitable to be used in 3D printing of medical or pharmaceutical applications such as medical implants, drug delivery systems, or personalised tablets.

There have been critical needs for the development of biomedical and cost-effective filaments for fused deposition modeling 3D printer. In the present work, we prepared poly-L-lactic acid (PLLA)/10 wt % nanohydroxyapatite (nHA) composite filaments suitable for 3D printing by melt extrusion. Scanning electron microscopy and tensile tests were carried out to examine surface morphology and tensile properties of the materials. Differential scanning calorimetry and thermal gravimetric analysis had been performed in order to assess filaments’ suitability for the 3D printing process, in terms of melting point, degradation temperature and so on. Thermally-activated shape memory response of the composites had also been studied. The printing effects of filaments were tested using a desktop 3D printer. The samples printed in different directions were used to perform compression and bending experiments. PLLA/nHA macroporous bone scaffold fabricated by 3D printing showed shape memory effect retained from PLLA/nHA composite. Even though the bone scaffold we obtained was far from the ultimate application in minimally invasive surgery, possible solutions to print more satisfying scaffold are discussed in the conclusion of this article.