Advances in powder bed fusion 3D printing in drug delivery and healthcare

Powder bed fusion (PBF) is a 3D printing method that selectively consolidates powders into 3D objects using a power source. PBF has various derivatives; selective laser sintering/melting, direct metal laser sintering, electron beam melting and multi-jet fusion. These technologies provide a multitude of benefits that make them well suited for the fabrication of bespoke drug-laden formulations, devices and implants. This includes their superior printing resolution and speed, and ability to produce objects without the need for secondary supports, enabling them to precisely create complex products. Herein, this review article outlines the unique applications of PBF 3D printing, including the main principles underpinning its technologies and highlighting their novel pharmaceutical and biomedical applications. The challenges and shortcomings are also considered, emphasising on their effects on the 3D printed products, whilst providing a forward-thinking view

Applications and multidisciplinary perspective on 3D printing techniques: Recent developments and future trends

In industries as diverse as automotive, aerospace, medical, energy, construction, electronics, and food, the engineering technology known as 3D printing or additive manufacturing facilitates the fabrication of rapid prototypes and the delivery of customized parts. This article explores recent advancements and emerging trends in 3D printing from a novel multidisciplinary perspective. It also provides a clear overview of the various 3D printing techniques used for producing parts and components in three dimensions. The application of these techniques in bioprinting and an up-to-date comprehensive review of their positive and negative aspects are covered, as well as the variety of materials used, with an emphasis on composites, hybrids, and smart materials. This article also provides an updated overview of 4D bioprinting technology, including biomaterial functions, bioprinting materials, and a targeted approach to various tissue engineering and regenerative medicine (TERM) applications. As a foundation for anticipated developments for TERM applications that could be useful for their successful usage in clinical settings, this article also examines present challenges and obstacles in 4D bioprinting technology. Finally, the article also outlines future regulations that will assist researchers in the manufacture of complex products and in the exploration of potential solutions to technological issues

Advanced Materials in 3D/4D Printing Technology

This reprint contains a collection of state-of-the-art reviews and original research articles from leaders in the field of 3D/4D printing. It focuses on 3D/4D printing materials with novel and/or advanced functionalities, novel applications of 3DP material, and material synthesis and characterization techniques

Additive manufacturing of carbon fiber reinforced thermoplastic polymer composites

L'abstract è presente nell'allegato / the abstract is in the attachmen

Technical and economic feasibility study of Metal 3D Printing in the Chemical Industry: Application to pump impellers

Les tècniques de fabricació d'Impressió 3D en Metall, també anomenada Fabricació Additiva (AM), es troben a la seva gènesi des d'un punt de vista d'aplicació industrial i divulgació massiva. Estan renovant el panorama de les tecnologies de producció disponibles fins a l'actualitat i així són/seran, a nivell industrial, una alternativa al procés de compra de materials (negociació de preus), fabricació de peces obsoletes (ja no comercialitzades) o noves i emmagatzematge/custòdia de recanvis tècnics per a la Indústria. L'objectiu d'aquest estudi se centra en l'aplicació de la fabricació additiva en metall per a impulsors de bombes a la indústria química, però també vàlid per a molts altres tipus d'indústria. L'abast del Projecte inclou la construcció de 2 impulsors metàl·lics de bomba, segons les estratègies 1 i 2 indicades a continuació: Estratègia 1: Fabricació AM tipus BJ (Binder Jetting) i posada en funcionament en una bomba centrífuga en una planta de Poliol/Poliglicol de Dow Chemical Ibérica SL, 30-octubre-2020, 6 mesos. Estratègia 2: Fabricació AM tipus SLM (Selective Laser Melting) i posada en funcionament en una bomba de buit a una planta d'hidrocarburs de Dow Chemical Ibérica SL, 16-juny-2022, 4 mesos. El desenvolupament del present treball es va basar en els passos següents: disseny/escaneig, fabricació, muntatge en bomba i posada en servei. Tot seguit es va procedir a l'anàlisi dels resultats una vegada posada en funcionament la bomba a planta. I, finalment, fer una comparació -en condicions normals de funcionament- amb el mateix servei anterior i amb el mateix tipus d'impulsor metàl·lic però fabricat de manera convencional. Aquest treball va demostrar que la implementació de tecnologies AM en metall per a processos químics és una solució útil per a fabricar recanvis que podrien ser difícils de replicar amb altres tecnologies convencionals i, a més, brinda/demostra potencials beneficis econòmics.Las técnicas de fabricación de Impresión 3D en Metal, también denominada Fabricación Aditiva (AM), se encuentran en su génesis desde un punto de vista de aplicación industrial y divulgación masiva. Están renovando el panorama de las tecnologías de producción disponibles hasta la actualidad y así son/serán, en el ámbito Industrial, una alternativa al proceso de compra de materiales (negociación de precios), fabricación de piezas obsoletas (ya no comercializadas) o nuevas y almacenamiento/custodia de repuestos técnicos para la Industria. El objetivo de este estudio se centra en la aplicación de la Fabricación Aditiva en metal para impulsores de bombas en la Industria Química, pero también válido para muchos otros tipos de Industria. El alcance del Proyecto incluye la construcción de 2 impulsores metálicos de bomba, según las estrategias 1 y 2 indicadas a continuación: Estrategia 1: Fabricación AM tipo BJ (Binder Jetting) y puesta en funcionamiento en una bomba centrífuga en una planta de Poliol/Poliglicol de Dow Chemical Ibérica SL, 30- octubre- 2020, 6 meses. Estrategia 2: Fabricación AM tipo SLM (Selective Laser Melting) y puesta en funcionamiento en una bomba de vacío en una planta de hidrocarburos de Dow Chemical Ibérica SL, 16-junio-2022, 4 meses. El desarrollo del presente trabajo se basó en los siguientes pasos: diseño/escaneo, fabricación, montaje en bomba y puesta en servicio. A continuación se procedió al análisis de los resultados una vez puesta en funcionamiento la bomba en planta. Y, por último, hacer una comparación -en condiciones normales de funcionamiento- con el mismo servicio anterior y con el mismo tipo de impulsor metálico pero fabricado de forma convencional. Este trabajo demostró que la implementación de tecnologías AM en metal para procesos químicos es una solución útil para fabricar recambios que podrían ser difíciles de replicar con otras tecnologías y, además, brinda/demuestra potenciales beneficios económicos.The Metal 3D Printing fabrication techniques, also named Additive Manufacturing (AM), are in its birth starting point from the perspective of industrial applications and worldwide massive divulgation. The emergence of AM is renovating the landscape of available production technologies with multiple different and potential uses. Among them, in the Industrial field, as an alternative to the process of materials purchasing (price negotiations), manufacturing obsolete (not yet in the market) or new pieces and storage/custody of technical spare parts for the Chemical Industry. The purpose of this study focus on the application of Additive Manufacturing in metal for pump impellers in the Chemical Industry, but also in many other types of Industry. The scope of the project includes the construction of 2 metallic pump impellers, according to strategies 1 and 2 indicated below: Strategy 1: Manufacture additive technology type BJ (Binder Jetting) put into operation in a centrifugal pump at a Polyol/Polyglycol plant of Dow Chemical Ibérica SL from October 30, 2020, 6 months. Strategy 2: Manufacture additive technology type SLM (Selective Laser Melting) put into operation in a vacuum pump at a hydrocarbon plant of Dow Chemical Ibérica SL from October 16, 2022, 4 months. The development of the present work was based on next steps: design/scanning, manufacturing, pump assembly and commissioning. Next was analysis of the results once the pump is assembled and put into operation in the plant. And finally, make a comparison - under normal operating conditions - with the same previous service and with the same type of metal impeller but manufactured in a conventional way. This work further demonstrated that the implementation of metal additive manufacturing technologies in chemical process is a useful solution to fabricate spare parts that could be difficult to replicate with other technologies, providing potential economic benefits

Materials-processing relationships for metal fused filament fabrication of Ti-6Al-4V alloy.

Additive manufacturing (AM) is at the mainstream to cater the needs for rapid tooling and small-scale part production. The metal AM of complex geometries is widely accepted and promoted in the industry. While several metal AM technologies exist and are matured to a level where expectation in terms of design and properties are possible to realize. But the metal AM suffers from the heavy expense to acquire equipment, isotropic property challenges, and potential hazards to work with loose reactive metal powder. With this motivation, the dissertation aims to develop the fundamental aspects to print metal parts with bound Ti-6Al-4V powder filaments with the approach of metal fused filament fabrication (MF3). Since fused filament fabrication (FFF) is the most accessible form of AM technology and combining with the conventional sintering process yields the advantage of producing net shape parts to the well-established standards. Ti-6Al-4V is the material of most interest in the aerospace, medical and automotive industry due to its high strength to weight ratio, great corrosion resistance, and bio-inert nature. In order to fabricate three-dimensional components from Ti-6Al-4V using the MF3 process, it is critical to understand and address material, process, and design-related constraints to meet end properties. The goal of this dissertation is to establish a fundamental understanding of the MF3 process with Ti-6Al-4V alloy, to produce parts with comparable properties to the traditional process of metal injection molding (MIM). The effect of Ti-6Al-4V particle size distribution on material printability and the process productivity with MF3 is studied with modeling and experimental observations. It was inferred that bound filament viscosity and strength properties are crucial to its printability and processing rate limits. The Ti-6Al-4V particle size variations were also investigated after printing for the effect of sintering conditions to evaluate the resulting physical, mechanical and microstructural properties. It was found that maintaining a low oxygen concentration in the starting powder and throughout the processing, cycle is crucial to obtain useful mechanical properties with MF3 of Ti-6Al-4V. When designing parts for MF3 (DfMF3), it is important to understand how the filament properties affect processability, part quality, and ensuing properties. But there doesn’t exist any database containing powder-polymer material properties and generating data via experiments can be expensive and time taking. A part of the dissertation investigated models that can predict powder-polymer material properties which are required as input parameters for simulating the MF3 using the Digimat-AM® process design platform for fused filament fabrication. Here, Ti-6Al-4V powder-binder feedstock at powder loading from 56-60 vol.% was used to predict properties such as density, specific heat, thermal conductivity, Young\u27s modulus, viscosity, and specific volume. Thus, estimated material properties served as an input parameter to conduct DfMF3 simulations to understand material-processing-geometry interactions

Macro-, meso- and microstructural characterization of metallic lattice structures manufactured by additive manufacturing assisted investment casting

Cellular materials are recognized for their high specific mechanical properties, making them desirable in ultra-lightweight applications. Periodic lattices have tunable properties and may be manufactured by metallic additive manufacturing (AM) techniques. However, AM can lead to issues with un-melted powder, macro/micro porosity, dimensional control and heterogeneous microstructures. This study overcomes these problems through a novel technique, combining additive manufacturing and investment casting to produce detailed investment cast lattice structures. Fused filament fabrication is used to fabricate a pattern used as the mold for the investment casting of aluminium A356 alloy into high-conformity thin-ribbed (~ 0.6 mm thickness) scaffolds. X-ray micro-computed tomography (CT) is used to characterize macro- and meso-scale defects. Optical and scanning electron (SEM) microscopies are used to characterize the microstructure of the cast structures. Slight dimensional (macroscale) variations originate from the 3D printing of the pattern. At the mesoscale, the casting process introduces very fine (~ 3 µm) porosity, along with small numbers of (~ 25 µm) gas entrapment defects in the horizontal struts. At a microstructural level, both the (~ 70 μm) globular/dendritic grains and secondary phases show no significant variations across the lattices. This method is a promising alternative means for producing highly detailed non-stochastic metallic cellular lattices and offers scope for further improvement through refinement of filament fabrication.This work was supported by Portuguese FCT, under the reference project UIDB/04436/2020. We are grateful to the funding from the European Research Council through the ERC grant CORREL-CT, number 695638 to enable VHC to visit the Henry Royce Institute to undertake the X-ray CT studies. Tis work was supported by the Henry Royce Institute for Advanced Materials, funded through EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1 and the Henry Moseley X-ray Imaging Facility funded by EP/T02593X/1