Various FDM Mechanisms Used in the Fabrication of Continuous-Fiber Reinforced Composites: A Review

Abstract

Fused Deposition Modeling (FDM) is an additive manufacturing technology that has emerged as a promising technique for fabricating 3D printed polymers. It has gained attention recently due to its ease of use, efficiency, low cost, and safety. However, 3D-printed FDM components lack sufficient strength compared to those made using conventional manufacturing methods. This low strength can be mainly attributed to high porosity and low sinterability of layers and then to the characteristics of the polymer used in the FDM process or the FDM process itself. Regarding polymer characteristics, there are two main types of reinforcing fibers: discontinuous (short) and continuous. Continuous-fiber reinforced composites are becoming popular in various industries due to their excellent mechanical properties. Since continuous reinforcing fibers have a more positive effect on increasing the strength of printed parts, this article focuses primarily on continuous long fibers. In addition to polymer characteristics, different mechanisms have been developed and introduced to address the issue of insufficient strength in 3D-printed FDM parts. This article comprehensively explains two main FDM mechanisms: in-situ fusion and ex-situ prepreg. It also provides relevant examples of these mechanisms using different reinforcing elements. Additionally, some other less frequently utilized mechanisms are discussed. Each mechanism has its own advantages and disadvantages, indicating that further development and modification are needed to increase the strength of 3D-printed FDM parts to be comparable to those produced using traditional methods.

4D printing and annealing of PETG composites reinforced with short carbon fibers

“…To enable widespread applications of this method, optimizing mechanical properties such as strength and toughness is necessary [14]. Various techniques such as fiber-reinforced polymers, optimizing printing parameters, printing in an oxygen-free environment, and annealing have been used to improve mechanical properties [19,20]. Mohammadizadeh et al studied the mechanical and structural properties of Continuous Fiber Reinforced Additively Manufactured components, showing that the presence of these reinforced fibers in the structure, results in superior mechanical properties compared to other specimens [21].…”

Tribological performance of functional coated fiber reinforced additively manufactured polymer composite

“…FDM 3D printing offers a more economical alternative to traditional subtractive manufacturing techniques. FDM 3D printing enables fast material deposition rates, facilitating the rapid manufacture of parts and drastically lowering turnaround time to satisfy client requests promptly [6]. 3D printed objects offer exceptional durability and quality, characterized by precise designs.…”

Evaluation of the Viability of 3D Printing in Recycling Polymers

“…The technique is lauded as a clean, sustainable processing technology, since it facilitates the transformation of consumer polymer and plastic waste into new components [ 22 ]. Karimi et al [ 23 ] further report that 3D printing techniques such as Fused Deposit Modeling (FDM) are popular due to their ease of use, low cost, high efficiency, and safety. Therefore, [ 22 , 23 ] emphasize that 3D printing supports circular economic goals given that it helps address plastic contamination and limit over-reliance on methods, such as incineration, that account for the highest amount of carbon dioxide emissions that have accelerated global warming, promoting climate change.…”