Fiber Selection for Reinforced Additive Manufacturing

Abstract

The purpose of this review is to survey, categorize, and compare the mechanical and thermal characteristics of fibers in order to assist designers with the selection of fibers for inclusion as reinforcing materials in the additive manufacturing process. The vast “family of fibers” is described with a Venn diagram to highlight natural, synthetic, organic, ceramic, and mineral categories. This review explores the history and practical uses of particular fiber types and explains fiber production methods in general terms. The focus is on short-cut fibers including staple fibers, chopped strands, and whiskers added to polymeric matrix resins to influence the bulk properties of the resulting printed materials. This review discusses common measurements for specific strength and tenacity in the textile and construction industries, including denier and tex, and discusses the proposed “yuri” measurement unit. Individual fibers are selected from subcategories and compared in terms of their mechanical and thermal properties, i.e., density, tensile strength, tensile stiffness, flexural rigidity, moisture regain, decomposition temperature, thermal expansion, and thermal conductivity. This review concludes with an example of the successful 3D printing of a large boat at the University of Maine and describes considerations for the selection of specific individual fibers used in the additive manufacturing process.

Digital Twin Geometry for Fibrous Air Filtration Media

“…Recommended future efforts include the refinement of this digital twin geometry creation algorithm and CFD analysis of air filtration media with the goal of matching experimental, analytical, and computational models of air filtration. This method of nonwoven fiber mesh digital twin creation may also be extended to other computational models requiring semi-random fiber placement, to include mechanical and thermal evaluation of fiber reinforced composite materials produced by additive manufacturing [38]. Given this, the primary advantage of this geometry generation method may be stated to be the simplicity and ease of adjusting parameters to achieve realistic random, semi-random, and aligned fiber orientations.…”

Environmental Effects on Strength and Failure Strain Distributions of Sheep Wool Fibers

“…High hygroscopicity, thermal and sound insulation, flame retardant, and antistatic properties are desirable for materials used in building and automotive sectors [9,10]. Wool fibers are durable and flexible; their mechanical characteristics are comparable to or exceed the values of other natural fibers, e.g., cotton and coir/husk [1,11]. Thus, wool is used as fiber reinforcement in mortars and concrete [9,12,13], polymer composites, and laminates [2,[14][15][16][17], increasing the value of the wool fiber.…”

“…Thus, wool is used as fiber reinforcement in mortars and concrete [9,12,13], polymer composites, and laminates [2,[14][15][16][17], increasing the value of the wool fiber. Recently, wool has become an alternative material in some high-tech industrial sectors, e.g., it is used in reinforcing compounds for additive manufacturing [11,18].…”

“…Thermal and UV aging destroy wool fibers' surface composition, leading to their yellowing and up to a twofold reduction of their strength [29]. Wool is hydrophilic and absorbs water up to 30% of its weight [2,11]. Absorbed moisture plasticizes the fibers, increasing their stretching ability while reducing the elastic and strength characteristics [9,13].…”

Natural Fibers as an Alternative to Synthetic Fibers in Reinforcement of Geopolymer Matrices: A Comparative Review

“…Another study evaluated the mechanical properties of different composites of natural fibers in polymeric matrices, proving that fiber size is directly related to the mechanical properties of the produced parts [ 47 ]. A relevant mechanism for the application of natural fibers is related to the selection method adopted, aiming to categorize and compare the main mechanical and thermal properties of the fibers in general, aiming at their better incorporation, one option is the use of additive manufacturing for these applications [ 48 ].…”