Current status and future directions of fused filament fabrication

Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling.

Additive manufacturing (AM) is rapidly evolving as the most comprehensive tool to manufacture products ranging from prototypes to various end-user applications. Fused filament fabrication (FFF) is the most widely used AM technique due to its ability to manufacture complex and relatively high strength parts from many low-cost materials. Generally, the high strength of the printed parts in FFF is attributed to the research in materials and respective process factors (process variables, physical setup, and ambient temperature). However, these factors have not been rigorously reviewed for analyzing their effects on the strength and ductility of different classes of materials. This review systematically elaborates the relationship between materials and the corresponding process factors. The main focus is on the strength and ductility. A hierarchical approach is used to analyze the materials, process parameters, and void control before identifying existing research gaps and future research directions.

https://www.mdpi.com/1996-1944/12/10/1664/pdf

Effect of Material and Process Specific Factors on the Strength of Printed Parts in Fused Filament Fabrication: A Review of Recent Developments.

3D printing (3DP) has transformed engineering, manufacturing, and the use of advanced materials due to its ability to produce objects from a variety of materials, ranging from soft polymers to rigid ceramics. 3DP offers the advantage of being able to print at a variety of lengths scales; from a few micrometers to many meters. 3DP has the unique ability to produce customized small lots, efficiently. Yet, one crucial industry that has not been able to adequately explore its potential is textile manufacturing. The research in 3DP of textiles has lagged behind other areas primarily due to the difficulty in obtaining some of the unique characteristics of strength, flexibility, etc., of textiles, utilizing a fundamentally different manufacturing technology. Textiles are their own class of materials due to the specific structural developments that occur during the various stages of textile manufacturing: from fiber extrusion to assembly of the fibers to fabrics. Here, the current 3DP technologies are reviewed with emphasis on soft and anisotropic structures, as well as the efforts toward 3DP of textiles. Finally, a potential pathway to 3DP of textiles, dubbed as printing with fibers to create textile structures is proposed for further exploration.

3D Printing of Textiles: Potential Roadmap to Printing with Fibers.

3D printing is a rapidly emerging additive manufacturing technology which can offer cost efficiency and flexibility in product development and production. In textile production 3D printing can also serve as an add-on process to apply 3D structures on textiles. In this study the low-cost fused deposition modeling (FDM) technique was applied using different thermoplastic printing materials available on the market with focus on flexible filaments such as thermoplastic elastomers (TPE) or Soft PLA. Since a good adhesion and stability of the 3D printed structures on textiles are essential, separation force and abrasion resistance tests were conducted with different kinds of printed woven fabrics demonstrating that a sufficient adhesion can be achieved. The main influencing factor can be attributed to the topography of the textile surface affected by the weave, roughness and hairiness offering formlocking connections followed by the wettability of the textile surface by the molten polymer, which depends on the textile surface energy and can be specifically controlled by washing (desizing), finishing or plasma treatment of the textile before the print. These basic adhesion mechanisms can also be considered crucial for 3D printing on knitwear.

https://iopscience.iop.org/article/10.1088/1757-899X/141/1/012011/pdf

Possible Applications of 3D Printing Technology on Textile Substrates

Composites combining two or more different materials with different physical and chemical properties allow for tailoring mechanical and other characteristics of the resulting multi-material system. In relation to fiber-reinforced plastic composites, combinations of textile materials with 3D printed polymers result in different mechanical properties. While the tensile strength of the multi-material system is increased compared to the pure 3D printed material, the elasticity of the polymer layer can be retained to a certain degree, as the textile material is not completely immersed in the polymer. Instead, an interface layer is built in which both materials interpenetrate to a certain degree. The purpose of this study is to investigate the adhesion between both materials at this interface.,This paper gives an overview of the parameters affecting the interface layer. It shows that both the printing material and the textile substrate influence the adhesion between both materials due to viscosity during printing, thickness and pore sizes, respectively. While some material combinations build strong form-locking connections, others can easily be delaminated.,Depending on both materials, significantly different adhesion values can be found in such 3D printed composites.,This makes some combinations very well suitable for building composites with novel mechanical properties, while other suffer of insufficient connections.,For the first time, the dependence of the polymer-textile adhesion force was evaluated according to the distance between both compound partners. It was shown that this value is of crucial interest and must thus be taken into account when producing printed polymer-textile composites.

Adhesion of 3D printed material on textile substrates

Three-dimensional (3D) printing is an additive manufacturing process that creates novel shapes or adds functionalities to other objects, such as textile fabrics Especially with fused deposition modeling technology, multimaterial items can be created by printing onto existing objects or including other materials during the printing process In this way, composites with new mechanical properties can be formed This chapter shows the possibilities of including textile materials into 3D printed objects created from diverse polymers and discusses the influence of physical and chemical modifications of both materials' surfaces It shows how the interface adhesion changes the mechanical properties of composites from textile materials and one or more 3D printed polymers

Michael Korger

Papers

Adhesion of 3D printed material on textile substrates

Mechanical properties of composites from textiles and three-dimensional printed materials