3D printing for continuous fiber reinforced thermoplastic composites: mechanism and performance

Experimental and theoretical studies on 3D printed short and continuous carbon fiber hybrid reinforced composites

Tailorable rigidity and energy-absorption capability of 3D printed continuous carbon fiber reinforced polyamide composites

Synergistic reinforcement of polyamide-based composites by combination of short and continuous carbon fibers via fused filament fabrication

Recycling and remanufacturing of 3D printed continuous carbon fiber reinforced PLA composites

Separated 3D printing of continuous carbon fiber reinforced thermoplastic polyimide

Three-dimensional printing of composites reinforced by continuous fiber and based on heat-resistant materials requires a prepreg compatible with these plastics. This kind of a prepreg, in its turn, would necessarily have to be similar to these plastics in terms of its chemistry and operational thermal range. This work was an investigation of factors relevant for the strength of adhesion between carbon fiber and polymeric binder. The authors managed to develop the compounds (coupling agents) facilitating fiber impregnation with polymer and improving fiberbinder adhesion. To obtain a thermoplastic binder various polyimide matrices have been synthesized. The properties of polymers thus created were studied as per the methods of thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as measurement of limiting wetting angle. Then these materials were subject to solution impregnation so as to obtain prepreg samples suitable for 3D printing. Impregnation quality of these samples was studied by means of scanning electronic microscopy. The most promising prepreg samples were used for 3D printing of try-out product specimens. Composites based on the plastics reinforced by continuous fibers (glass, carbon, polymeric, etc.) are widely used in special fields of today’s technology [1–4]. They have already become indispensable for rocketry or aircraft industries, and they are steadily gaining ground in other industries, too, like machine engineering, shipbuilding, civil engineering, etc. Polymeric composite have become so popular because they are quite strong [5, 6] and light [7] at the same time. Today, manufacturing of fiber-reinforced composites is quite tedious and only allows a limited scope of geometries for final products [8] because fiber impregnation with viscous solutions/melts of polymers is a difficult process. Besides, final product takes time to harden, so until it happens it needs a moulding cast or skeleton to maintain its shape. This tedious process of product manufacturing from the parts reinforced with continuous fiber might proceed much easier and with greater automation thanks to 3D printing as per fused deposition modeling (FDM) technique that uses a filament of preimpregnated fiber [9]. In particular, one of the techniques steadily improving today is 3D printing with continuous carbon fiber and prepregs based on epoxy binders. Final products manufactured as per this technology and reinforced by continuous carbon fiber feature stable size and complex shape. However, prepregs based on epoxy resins will work only with the materials that have good adhesion with them, otherwise final composites will be too weak. Current materials can only be used for the products with low operational temperatures whereas hi-tech applications require strong and heat-resistant materials. To meet this requirement, it is necessary to develop prepregs based on heat-resistant compounds, as well as filaments based on heat-resistant plastics compatible with these prepregs. Polyimides as a class of compounds have long been known to remain stable at high temperatures. Therefore, prepregs based on them, as well as polyimide matrices fit for FDM 3D printing technique will pave way to the products simultaneously featuring high thermal resistance and good strength. The purpose of this work was to develop prepregs based on carbon fiber and polyimides featuring good resistance to high temperatures and aggressive media, as well as to develop thermoplastic polyimide matrices fit for 3D printing.

Three‐dimensional (3D) printing is a new paradigm in customized manufacturing and allows the fabrication of complex optical components and metaphotonic structures that are difficult to realize via traditional methods. Conventional lithography techniques are usually limited to planar patterning, but 3D printing can allow the fabrication and integration of complex shapes or multiple parts along the out‐of‐plane direction. Additionally, 3D printing can allow printing on curved surfaces. Four‐dimensional (4D) printing adds active, responsive functions to 3D‐printed structures and provides new avenues for active, reconfigurable optical and microwave structures. This review introduces recent developments in 3D and 4D printing, with emphasis on topics that are interesting for the nanophotonics and metaphotonics communities. In this article, we have first discussed functional materials for 3D and 4D printing. Then, we have presented the various designs and applications of 3D and 4D printing in the optical, terahertz, and microwave domains. 3D printing can be ideal for customized, nonconventional optical components and complex metaphotonic structures. Furthermore, with various printable smart materials, 4D printing might provide a unique platform for active and reconfigurable structures. Therefore, 3D and 4D printing can introduce unprecedented opportunities in optics and metaphotonics and may have applications in freeform optics, integrated optical and optoelectronic devices, displays, optical sensors, antennas, active and tunable photonic devices, and biomedicine. Abundant new opportunities exist for exploration.

3D printing and modelling of continuous carbon fibre reinforced composite grids with enhanced shear modulus

Graphene is an important nanocarbon nanofiller for polymeric matrices. The polymer–graphene nanocomposites, obtained through facile fabrication methods, possess significant electrical–thermal–mechanical and physical properties for technical purposes. To overcome challenges of polymer–graphene nanocomposite processing and high performance, advanced fabrication strategies have been applied to design the next-generation materials–devices. This revolutionary review basically offers a fundamental sketch of graphene, polymer–graphene nanocomposite and three-dimensional (3D) and four-dimensional (4D) printing techniques. The main focus of the article is to portray the impact of 3D and 4D printing techniques in the field of polymer–graphene nanocomposites. Polymeric matrices, such as polyamide, polycaprolactone, polyethylene, poly(lactic acid), etc. with graphene, have been processed using 3D or 4D printing technologies. The 3D and 4D printing employ various cutting-edge processes and offer engineering opportunities to meet the manufacturing demands of the nanomaterials. The 3D printing methods used for graphene nanocomposites include direct ink writing, selective laser sintering, stereolithography, fused deposition modeling and other approaches. Thermally stable poly(lactic acid)–graphene oxide nanocomposites have been processed using a direct ink printing technique. The 3D-printed poly(methyl methacrylate)–graphene have been printed using stereolithography and additive manufacturing techniques. The printed poly(methyl methacrylate)–graphene nanocomposites revealed enhanced morphological, mechanical and biological properties. The polyethylene–graphene nanocomposites processed by fused diffusion modeling have superior thermal conductivity, strength, modulus and radiation- shielding features. The poly(lactic acid)–graphene nanocomposites have been processed using a number of 3D printing approaches, including fused deposition modeling, stereolithography, etc., resulting in unique honeycomb morphology, high surface temperature, surface resistivity, glass transition temperature and linear thermal coefficient. The 4D printing has been applied on acrylonitrile-butadiene-styrene, poly(lactic acid) and thermosetting matrices with graphene nanofiller. Stereolithography-based 4D-printed polymer–graphene nanomaterials have revealed complex shape-changing nanostructures having high resolution. These materials have high temperature stability and high performance for technical applications. Consequently, the 3D- or 4D-printed polymer–graphene nanocomposites revealed technical applications in high temperature relevance, photovoltaics, sensing, energy storage and other technical fields. In short, this paper has reviewed the background of 3D and 4D printing, graphene-based nanocomposite fabrication using 3D–4D printing, development in printing technologies and applications of 3D–4D printing.

Inspired by microstructure characteristics of mantis shrimp propodus with high mechanical strength, the bionic continuous carbon fiber (CF) reinforced acrylonitrile butadiene styrene (ABS) resin composite with layered spiral structure was prepared successfully via self-built integration 3D printing. Combined with integration 3D printing demands of continuous carbon fiber reinforced ABS resin, bionic structure model was divided into 10 layers with cylindrical entities which spiralled from 0° to 45°. The 3D printed continuous carbon fibers realized designed specific arrangement direction in ABS matrix, which reappeared the layered spiral structure of mantis shrimp propodus. The existence of bionic layered spiral structure led to the higher tensile strength and impact toughness of bionic composite than that of ABS matrix and ABS/CF composite with unidirectional continuous carbon fiber arrangement via the mechanisms of fracture and pull-out of continuous carbon fibers. The high mechanical properties of integration 3D printed bionic composite proved the effectiveness and feasibility of 3D printing method and bionic layered spiral structure design, which extended the preparation method and application fields of carbon fiber reinforced thermoplastic resin composite in engineering materials.

The three-dimensional (3D) printing of recycled carbon fiber was demonstrated by the fused filament fabrication technique. A recycled carbon fiber spun yarn was processed into a filament for 3D printing using polyamide 6 and polyamide 12 as the matrix. The fibers were aligned in the axial direction of the filament, and the filament followed the print path during 3D printing. Four specimens were prepared from the filament by 3D printing. The effect of the 3D printing process on the tensile properties of the recycled carbon fiber filament was evaluated. The comparison of the four specimens showed that the 3D-printing process adversely affected the tensile properties of the composite by damaging the fibers and dispersing the fiber direction. Multiplying the filament compensated for the variability in the tensile properties and improved the tensile properties of the 3D-printed coupon. The 3D-printed recycled carbon fiber-reinforced polyamide showed intermediate properties between those of 3D-printed continuous and milled carbon fiber composites. 3D printing is an effective molding technique for the use of recycled carbon fibers.

Key role of interphase in continuous fiber 3D printed ceramic matrix composites

The development of patient-specific prosthetics, medication administration, the manufacture of tissues and organs, and surgical planning have all benefited significantly from the use of three-dimensional (3D) printing during the past few decades. The enthusiasm for customized healthcare has increased because the United States of America launched its Precision Medicine Initiative in 2015. In a nutshell, the phrase “personalized medicine” refers to medical care that is tailored to the patient. Nevertheless, the biomedical materials utilized in 3D printing are often stable and can’t react or be adaptive and intelligent in the body’s interior environment. Ex-situ fabrication of these substances, which includes printing on a flat substrate before releasing it onto the target surface, may cause a discrepancy between the printed portion and the target areas. The 3D printing is one method that might be used to provide customized treatment. The four-dimensional (4D) printing is developed while employing components that can be tweaked with stimulation. Several researchers have been looking at a new area recently that blends medicines with 3D and 4D printing. The development of 4D printing overcomes a number of these issues and creates a promising future for the biomedical industry. Smart materials that have been pre-programmed can be used in 4D printing to create structures that react interactively to outside stimuli. Despite these benefits, dynamic materials created using 4D technology remain in their development. As a result, several ideas for pharmaceutical products and formulas that may be customized and printed have emerged. Furthermore, Spritam®, the first medicine produced by 3D printing, has indeed reached a medical facility. This paper offers a summary of several 3D and 4D printing technologies and how they are used in the pharmaceutical industry for customized medicine and drug delivery systems.

Aiming at the limited mechanical properties of general thermoplastic 3D printed models, a 3D printing process method for selective enhancement of continuous carbon fiber composite material is proposed. Firstly, the selective enhanced double nozzle working mechanism and crafts planning process are put forward. Then, based on the double nozzle carbon fiber 3D printing device, test samples are printed by polylactic acid (PLA) and carbon fiber material, and the test samples are enhanced by inserting layers of continuous carbon fiber material. The performance test of the samples is carried out. Experiment results show that when the volume fraction of continuous carbon fiber material increases gradually from 5% to 40%, the tensile strength increases from 51.22 MPa to 143.11 MPa. The performance improvement curve is fitted through experimental data. Finally, field scanning electron microscopy is used to observe the microscopic distribution of continuous fibers in the samples. The results of the research lay the foundation for the performance planning of 3D printed models.

This study presents Additive Preforming, a novel technique for manufacturing continuous fiber‐reinforced polymer composites. The new technique consists of 3D printing continuous fiber filaments coated with a suitable thermoplastic for the fabrication of continuous fiber preforms. These preforms can eventually be used to produce thermoset composite parts. The manufacturing technology used here to produce epoxy‐carbon composites involved coating a continuous carbon fiber roving with a thermoplastic polymer (binder) to produce a 3D‐printable filament. This filament was then 3D‐printed to create a preform, and the final composite was obtained by impregnating the preform with the epoxy matrix. To optimize the final properties of the epoxy‐carbon composite, a screening protocol for potential thermoplastic binders was developed and implemented. This protocol aimed to identify the most compatible/miscible binders for the epoxy resin. The evaluation was conducted using Hansen's solubility parameters, interfacial tension determinations, and optical microscopy observations. The results identified polycarbonate (PC) and phenoxy resin (PH) as the most suitable candidates. The mechanical properties of the composites were strongly influenced by the binder used, and the best properties (elastic modulus of 32 GPa and flexural strength of 609 MPa) were achieved when PH was used. The carbon fiber content of the composites was also optimized by comparing the mechanical properties of the composites obtained with 12 and 24 k carbon fibers. The resulting epoxy composites – made of phenoxy‐coated continuous carbon fibers and containing approximately 40 wt% of carbon fibers – featured an elasticity modulus of 62 GPa and flexural strength of 852 MPa. Highlights Additive Preforming is proposed for manufacturing CFPCs. Continuous carbon fiber is coated and 3D‐printed prior to impregnation in epoxy. The established screening protocol ranks binders based on their compatibility. PH was identified as the optimum binder and was validated by mechanical tests. The optimization of the fiber content led to superior mechanical properties.