Innovation in Additive Manufacturing Using Polymers: A Survey on the Technological and Material Developments

Abstract

This review summarizes the most recent advances from technological and physico-chemical perspectives to improve several remaining issues in polymeric materials’ additive manufacturing (AM). Without a doubt, AM is experimenting with significant progress due to technological innovations that are currently advancing. In this context, the state-of-the-art considers both research areas as working separately and contributing to developing the different AM technologies. First, AM techniques’ advantages and current limitations are analyzed and discussed. A detailed overview of the efforts made to improve the two most extensively employed techniques, i.e., material extrusion and VAT-photopolymerization, is presented. Aspects such as the part size, the possibility of producing parts in a continuous process, the improvement of the fabrication time, the reduction of the use of supports, and the fabrication of components using more than one material are analyzed. The last part of this review complements these technological advances with a general overview of the innovations made from a material perspective. The use of reinforced polymers, the preparation of adapted high-temperature materials, or even the fabrication of metallic and ceramic parts using polymers as supports are considered. Finally, the use of smart materials that enable the fabrication of shape-changing 3D objects and sustainable materials will also be explored.

3D printed triply periodic minimal surfaces as advanced structured packings for solvent-based CO2 capture

“…Industrially relevant 3D printing methods like stereolithography or fused deposition modeling are costly and have fairly slow vertical build rates (current best on the order of 0.5 m h −1 ). 64,65 However, additive manufacturing is being rapidly adopted across industries, and costs are expected to fall as adoption increases. For certain TPMS structures, it may be feasible to manufacture or assemble geometrically identical structures through conventional manufacturing.…”

New Partially Water-Soluble Feedstocks for Additive Manufacturing of Ti6Al4V Parts by Material Extrusion

“…Additive manufacturing, quite often also denoted as 3D printing, is nowadays an established fabrication method of polymer, metal and ceramic parts. In most cases, 3D printing is used for rapid prototyping, but these methods have gained more and more importance for rapid tooling and even rapid manufacturing of small-scale series [1][2][3][4][5][6][7][8]. Due to their history of invention and the operation principle, the most important techniques are VAT photopolymerization such as stereolithography (SLA), material extrusion (MEX) such as fused filament fabrication (FFF), and powder bed fusion such as selective laser melting (SLM) or electron beam melting (EBM).…”

“…With the knowledge of the applied angular frequency, the complex viscosity can be estimated (2). The direct relationship between the complex shear modulus and the complex viscosity is shown in (3) [38]. An accurate determination of the viscoelastic flow and the feedstocks yield point is of particular importance for feedstock and printing parameter development with respect to proper and defect-free deposition of a freshly printed layer on the previous one.…”

Photocurable Glycerol- and Vanillin-Based Resins for the Synthesis of Vitrimers

“…7,8 Frequently used optical 3D printing technologies, such as stereolithography (SLA) and digital light processing (DLP), have advantages such as high resolution and accuracy, good surface finish, and high fabrication speed. 9 However, the resin must consist of a monomer, a photoinitiator, and a diluent that adjusts the viscosity 10 as the resin must have a relatively low or medium viscosity that meets the requirements of a 3D printer. 11 Acrylate-and methacrylate-based resins are the most commonly used for 3D printing due to the high polymerization rate and commercially available monomers.…”