3D printed bioactive and antibacterial silicate glass-ceramic scaffold by fused filament fabrication

The circular economy model offers great opportunities to companies, as it not only allows them to capture additional value from their products and materials, but also reduce the fluctuations of price-related risks and material supply. These risks are present in all kind of businesses not based on the circular economy. The circular economy also enables economic growth without the need for more resources. This is because each unit has a higher value as a result of recycling and reuse of products and materials after use. Following this circular economics framework, the Polytechnic University of Madrid (Universidad Politécnica de Madrid, UPM) has adopted strategies aimed at improving the circularity of products. In particular, this article provides the result of obtaining recycled PLA filament from waste originating from university 3D FFF (fused filament fabrication) printers and waste generated by “Coronamakers” in the production of visors and parts for PPEs (Personal Protective Equipment) during the lockdown period of COVID-19 in Spain. This filament is used in the production of 3D printed parts that university students use in their classes, so the circular loop is closed. The obtained score of Material Circularity Indicator (MCI) of this material has been calculated, indicating its high level of circularity.

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Drivers of mechanical performance variance in 3D ‐printed fused filament fabrication parts: An Onyx FR case study

Polymer Composites ◽

10.1002/pc.26187 ◽

2021 ◽

Author(s):

Christine Ma ◽

Jessica Faust ◽

Joseph D. Roy‐Mayhew

Keyword(s):

Mechanical Performance ◽

Fused Filament Fabrication ◽

3D Printed

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The Direct 3D Printing of Functional PEEK/Hydroxyapatite Composites via a Fused Filament Fabrication Approach

Polymers ◽

10.3390/polym13040545 ◽

2021 ◽

Vol 13 (4) ◽

pp. 545

Author(s):

Krzysztof Rodzeń ◽

Preetam K. Sharma ◽

Alistair McIlhagger ◽

Mozaffar Mokhtari ◽

Foram Dave ◽

...

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Selective Laser Sintering ◽

Fused Filament Fabrication ◽

Bone Apposition ◽

Innovative Solutions ◽

3D Printed ◽

Work Samples ◽

Viable Approach ◽

Crystalline Domains

The manufacture of polyetheretherketone/hydroxyapatite (PEEK/HA) composites is seen as a viable approach to help enhance direct bone apposition in orthopaedic implants. A range of methods have been used to produce composites, including Selective Laser Sintering and injection moulding. Such techniques have drawbacks and lack flexibility to manufacture complex, custom-designed implants. 3D printing gets around many of the restraints and provides new opportunities for innovative solutions that are structurally suited to meet the needs of the patient. This work reports the direct 3D printing of extruded PEEK/HA composite filaments via a Fused Filament Fabrication (FFF) approach. In this work samples are 3D printed by a custom modified commercial printer Ultimaker 2+ (UM2+). SEM-EDX and µCT analyses show that HA particles are evenly distributed throughout the bulk and across the surface of the native 3D printed samples, with XRD highlighting up to 50% crystallinity and crystalline domains clearly observed in SEM and HR-TEM analyses. This highlights the favourable temperature conditions during 3D printing. The yield stress and ultimate tensile strength obtained for all the samples are comparable to human femoral cortical bone. The results show how FFF 3D printing of PEEK/HA composites up to 30 wt% HA can be achieved.

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Fused Filament Fabrication 3D Printed Polylactic Acid Electroosmotic Pumps

Lab on a Chip ◽

10.1039/d1lc00452b ◽

2021 ◽

Author(s):

Liang Wu ◽

Stephen Beirne ◽

Joan-Marc Cabot Canyelles ◽

Brett Paull ◽

Gordon G. Wallace ◽

...

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Polylactic Acid ◽

Fused Filament Fabrication ◽

Flexible Approach ◽

Electroosmotic Pump ◽

3D Printed ◽

Electroosmotic Pumps

Additive manufacturing (3D printing) offers a flexible approach for the production of bespoke microfluidic structures such as the electroosmotic pump. Here a readily accessible fused filament fabrication (FFF) 3D printing...

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Essential work of fracture assessment of acrylonitrile butadiene styrene (ABS) processed via fused filament fabrication additive manufacturing

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-020-06580-4 ◽

2021 ◽

Author(s):

Pawan Verma ◽

Jabir Ubaid ◽

Andreas Schiffer ◽

Atul Jain ◽

Emilio Martínez-Pañeda ◽

...

Keyword(s):

Acrylonitrile Butadiene Styrene ◽

Essential Work ◽

Fused Filament Fabrication ◽

Essential Work Of Fracture ◽

Fracture Properties ◽

Raster Angle ◽

3D Printed ◽

Printing Direction ◽

Work Of Fracture ◽

Butadiene Styrene

AbstractExperiments and finite element (FE) calculations were performed to study the raster angle–dependent fracture behaviour of acrylonitrile butadiene styrene (ABS) thermoplastic processed via fused filament fabrication (FFF) additive manufacturing (AM). The fracture properties of 3D-printed ABS were characterized based on the concept of essential work of fracture (EWF), utilizing double-edge-notched tension (DENT) specimens considering rectilinear infill patterns with different raster angles (0°, 90° and + 45/− 45°). The measurements showed that the resistance to fracture initiation of 3D-printed ABS specimens is substantially higher for the printing direction perpendicular to the crack plane (0° raster angle) as compared to that of the samples wherein the printing direction is parallel to the crack (90° raster angle), reporting EWF values of 7.24 kJ m−2 and 3.61 kJ m−2, respectively. A relatively high EWF value was also reported for the specimens with + 45/− 45° raster angle (7.40 kJ m−2). Strain field analysis performed via digital image correlation showed that connected plastic zones existed in the ligaments of the DENT specimens prior to the onset of fracture, and this was corroborated by SEM fractography which showed that fracture proceeded by a ductile mechanism involving void growth and coalescence followed by drawing and ductile tearing of fibrils. It was further shown that the raster angle–dependent strength and fracture properties of 3D-printed ABS can be predicted with an acceptable accuracy by a relatively simple FE model considering the anisotropic elasticity and failure properties of FFF specimens. The findings of this study offer guidelines for fracture-resistant design of AM-enabled thermoplastics. Graphical abstract

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Metallization of Thermoplastic Polymers and Composites 3D Printed by Fused Filament Fabrication

Technologies ◽

10.3390/technologies9030049 ◽

2021 ◽

Vol 9 (3) ◽

pp. 49

Author(s):

Alessia Romani ◽

Andrea Mantelli ◽

Paolo Tralli ◽

Stefano Turri ◽

Marinella Levi ◽

...

Keyword(s):

Physical Vapor Deposition ◽

Test Sample ◽

Tensile Tests ◽

Layer By Layer ◽

Post Processing ◽

Thermoplastic Polymers ◽

Fused Filament Fabrication ◽

Scanning Calorimetry ◽

3D Printed ◽

Manufacturing Technologies

Fused filament fabrication allows the direct manufacturing of customized and complex products although the layer-by-layer appearance of this process strongly affects the surface quality of the final parts. In recent years, an increasing number of post-processing treatments has been developed for the most used materials. Contrarily to other additive manufacturing technologies, metallization is not a common surface treatment for this process despite the increasing range of high-performing 3D printable materials. The objective of this work is to explore the use of physical vapor deposition sputtering for the chromium metallization of thermoplastic polymers and composites obtained by fused filament fabrication. The thermal and mechanical properties of five materials were firstly evaluated by means of differential scanning calorimetry and tensile tests. Meanwhile, a specific finishing torture test sample was designed and 3D printed to perform the metallization process and evaluate the finishing on different geometrical features. Furthermore, the roughness of the samples was measured before and after the metallization, and a cost analysis was performed to assess the cost-efficiency. To sum up, the metallization of five samples made with different materials was successfully achieved. Although some 3D printing defects worsened after the post-processing treatment, good homogeneity on the finest details was reached. These promising results may encourage further experimentations as well as the development of new applications, i.e., for the automotive and furniture fields.

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ChemInform Abstract: Microstructural Studies of the Interfacial Zone of a SiC-Fiber-Reinforced Lithium Aluminum Silicate Glass-Ceramic.

ChemInform ◽

10.1002/chin.198935363 ◽

1989 ◽

Vol 20 (35) ◽

Author(s):

E. BISCHOFF ◽

M. RUEHLE ◽

O. SBAIZERO ◽

A. G. EVANS

Keyword(s):

Silicate Glass ◽

Glass Ceramic ◽

Aluminum Silicate ◽

Lithium Aluminum ◽

Interfacial Zone ◽

Fiber Reinforced ◽

Sic Fiber ◽

Microstructural Studies

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Manufacturing Of Aluminum Coating On 3D-Printed Onyx With Cold Spray Technology

10.25518/esaform21.858 ◽

2021 ◽

Author(s):

Roberta Della Gatta ◽

Antonello Astarita ◽

Domenico Borrelli ◽

Antonio Caraviello ◽

Francesco Delloro ◽

...

Keyword(s):

Composite Materials ◽

Cold Spray ◽

Industrial Applications ◽

Thin Metal Film ◽

Temperature Sensitive ◽

Fused Filament Fabrication ◽

Aluminum Powders ◽

Thermoplastic Matrix ◽

Military Applications ◽

3D Printed

Composite materials are widely used as main parts and structural components in different fields, especially for automotive and military applications. Although these materials supply different advantages comparing to the metals, their implementation in engineering applications is limited due to low electrical and thermal properties and low resistance to erosion. To enhance these above-mentioned properties, the metallization of composite materials by creating a thin metal film on their surface can be achieved. Among different coating deposition techniques, Cold Spray appears to be the most suitable one for the metallization of temperature-sensitive materials such as polymers and composites with a thermoplastic matrix. This process relies on kinetic energy for the formation of the coating rather than on thermal energy and consequent erosion and degradation of the polymer-based composite can be avoided. In the last years, a new method to produce composite materials, as known as Fused Filament Fabrication (FFF), has been developed for industrial applications. This technique consists of a 3D printing process that involves the thermal extrusion of thermoplastic polymer and fibers in the form of filaments from a heated mobile nozzle. The implementation of this new technique is leading to the manufacturing of customized composite materials for the cold spray application. In the presented experimental campaign, Onyx material is used as a substrate. This material is made of Nylon, a thermoplastic matrix, and chopped carbon fibers randomly dispersed in it. Aluminum powders were cold sprayed on the Onyx substrate with a low-pressure cold spray (LPCS) system. This study aims to investigate the possibility of the metalizing 3D-printed composite material by cold spray technology. For this purpose, optical and microscopical analyses are carried out. Based on the results, the feasibility of the process and the influence of the morphology of the substrate are discussed, and optimal spraying conditions are proposed.

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Experimental and numerical investigations on heat transfer in fused filament fabrication 3D-printed specimens

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-07760-6 ◽

2021 ◽

Author(s):

Nathalie Ramos ◽

Christoph Mittermeier ◽

Josef Kiendl

Keyword(s):

Heat Transfer ◽

Convective Heat Transfer Coefficient ◽

Numerical Data ◽

Fused Filament Fabrication ◽

Thermal Boundary Conditions ◽

Thermal Measurements ◽

Stress Prediction ◽

3D Printed ◽

Air Void

AbstractA good understanding of the heat transfer in fused filament fabrication is crucial for an accurate stress prediction and subsequently for repetitive, high-quality printing. This work focuses on two challenges that have been presented when it comes to the accuracy and efficiency in simulating the heat transfer in the fused filament fabrication process. With the prospect of choosing correct thermal boundary conditions expressing the natural convection between printed material and its environment, values for the convective heat transfer coefficient and ambient temperature were calibrated through numerical data fitting of experimental thermal measurements. Furthermore, modeling simplifications were proposed for an efficient numerical discretization of infill structures. Samples were printed with varying infill characteristics, such as varying air void size, infill densities and infill patterns. Thermal measurements were performed to investigate the role of these parameters on the heat transfer and based on these observations, possible modeling simplifications were studied in the numerical simulations.

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