Fiber Composite Manufacturing Research Articles

Modeling of mechanical behavior of Agave sisalana fiber's yarn using the design of experiments method

The aim of this study is to propose a model for predicting the mechanical properties of natural sisal yarn based on mechanical strength of used fibers, unit twist of yarn and its density. To achieve this, a complete factorial design modelling method was used, based on a design of experiments approach, which is recommended today because of the ease it offers in taking into account the most complex phenomena. It was developed on the basis of laboratory tests. The model obtained predicts mechanical strength and elasticity modulus of sisal yarn, based on control parameters such as fiber strength, unit twist and yarn mass. This model is currently one of the most accurate tools for predicting and optimising the mechanical properties of sisal yarns. The iso-surface curves represented by this model, can be used to obtain the strength and elasticity modulus of sisal yarn during manufacture, by varying the optimum control parameters. This model is an original tool that can be recommended to the spinning and sisal fiber composite manufacturing industries and others, as it saves time and materials and ensures precision in the manufacture of yarns according to the field of application, thereby contributing to safety in use.

Development of a Prototype Drone through Carbon Fiber Composite Structures and Additive Manufacturing Techniques

Development of a Prototype Drone through Carbon Fiber Composite Structures and Additive Manufacturing Techniques

Permeability testing and mechanism analysis of aramid fiber hybrid fabrics

Aramid fiber composites have exceptional mechanical and insulating properties and are used in ultra-high-voltage power transmission. Fabric permeability is crucial for controlling composite defects. At present, the effective method to improve the permeability of aramid fibers is the hybridization of fiber fabrics. This study investigates permeability tests and impregnation mechanisms of aramid fiber fabric and its hybrid fabric. The permeability of the aramid fiber fabric and the hybrid fiber fabric was measured using a camera and a pressure sensor. The permeability of the fabric was analyzed by observing the structure, surface topography, dynamic contact angle, and surface free energy. The results show that the dynamic contact angle can be reduced and the surface free energy can be increased by hybridizing the fibers and the wettability of the fiber fabric is improved. Compared to an aramid fiber fabric, the in-plane permeability of aramid/glass fiber interlayer hybrid fabric increases by 36.19%, while the in-plane permeability of aramid/glass fiber intralayer hybrid fabric increases by 64.97%. The out-of-plane permeability of aramid/glass fiber interlayer hybrid fabric increases by 16.79%, while the in-plane permeability of aramid/glass fiber intralayer hybrid fabric increases by 30.1%. This study offers theoretical guidance for aramid fiber composite manufacturing and simulation input parameters.

Inter-bead void reduction by crossing printing routes of fused filament fabricated composites

PurposeThe use of continuous fiber-reinforced filaments improves the mechanical properties obtained with the fused filament fabrication (FFF) process. Yet, there is a lack of simulation tailored tools to assist in the design for additive manufacturing of continuous fiber composites. To build such models, a precise elastic model is required. As the porosity caused by interbead voids remains an important flaw of the process, this paper aims to build an elastic model integrating this aspect.Design/methodology/approachTo study the amount of porosity, which could be a failure initiator, this study proposes a two step periodic homogenization method. The first step concerns the microscopic scale with a unit cell made of fiber and matrix. The second step is at the mesoscopic scale and combines the elastic material of the first step with the interbead voids. The void content has been set as a parameter of the model. The material models predicted with the periodic homogenization were compared with experimental results.FindingsThe comparison between periodic homogenization results and tensile test results shows a fair agreement between the experimental results and that of the numerical simulation, whatever the fibers’ orientations are. Moreover, a void content reduction has been observed by increasing the crossing angle from one layer to another. An empiric law giving the porosity according to this crossing angle was created. The model and the law can be further used for design evaluation and optimization of continuous fiber-reinforced FFF.Originality/valueA new elastic model considering interbead voids and its variation with the crossing angle of the fibers has been built. It can be used in simulation tools to design high performance fused filament fabricated composite parts.

Experimental and statistical study on the effect of process parameters on the quality of continuous fiber composites made via additive manufacturing

Ongoing research in additive manufacturing towards structural and industrial application has led to the use of commingled roving as a manufacturing feedstock for printing high fiber volume fraction composites. The prospects of using this technology for high performance applications necessitates the need for a comprehensive experimental investigation into the effects of processing parameters on the quality of an additively manufactured composite printed from commingled roving feedstock. In this work, transverse flexure and void fraction matrix pyrolysis testing are both performed to evaluate composite quality. The transverse flexure test is a testing approach that evaluates the quality of the interfacial fiber-matrix bond while the void fraction test estimates the void content in the printed composite. A full observational study consisting of 27 different test combinations is done to investigate the effects of three different process parameters namely, temperature, pressure, and print speed across three different levels. Composite samples were made from commingled roving of E-glass and amorphous PET using an in-house built continuous fiber composite digital manufacturing system. Least squares regression analysis is performed to study the main, interaction and quadratic effects of process parameters. A statistical regression model having an R2 adjusted value of 80.1% is generated from the transverse flexure study, which is used to explain main and interaction effects and also predict performance. Response surface plots are also generated and are used to optimize process parameters which can subsequently be of help in scaling up composite manufacturing. Results show that all three process parameters are highly statistically significant at the 0.01 level of significance. Pressure * Temperature and Pressure * Printspeed are significant interaction terms. Pressure plays a weightier role when print speed is increased or temperature is decreased as it closes more voids that would ordinarily have been introduced because of drop in polymer melt viscosity. Micrographic analysis is also performed.

Evaluation and prediction of tensile properties of 3D‐printed continuous carbon/Kevlar fiber‐filled composites by coaxial hybrid process

AbstractContinuous hybrid fiber‐reinforced composites (CHFRCs) have excellent mechanical properties, and strong designability, and are widely used in aerospace and other fields. The development of 3D printing technology offers novel directions in the design and manufacture of complicated CHFRC components in aerospace. For this purpose, this study focused on the design and characterization of hybrid continuous fiber‐reinforced composites prepared by 3D printing. The rapid mold‐free integrated manufacturing of hybrid continuous Kevlar/carbon fiber‐reinforced composites was realized by coaxial hybrid 3D printing technology. The regulation and mechanism of tensile properties of 3D‐printed CHFRCs were elucidated. The tensile strengths of 3D‐printed CHFRCs were enhanced by up to 15.3% and 92.4%, respectively, compared to single continuous carbon and Kevlar fiber composites produced by the same process parameter. A new tensile modulus predicting method for 3D‐printed CHFRCs was proposed. It mitigated the influence of complex interfacial characteristics on mechanical property prediction and achieved precise estimation of the tensile modulus of 3D‐printed CHFRCs. This will provide the theoretical support for the application and development of 3D‐printed CHFRCs.Highlights Mouldless rapid manufacturing of coaxial hybrid fiber composites achieved. The tensile strength and modulus of the fiber composites are greatly improved. A new prediction method for the tensile modulus of 3D‐printed composites is proposed.

Assessing sustainability and green chemistry in synthesis of a Vanillin-based vitrimer at scale: Enabling sustainable manufacturing of recyclable carbon fiber composites

Sustainable manufacturing of carbon fibre (CFs) reinforced polymer (CFRP) composites featured technically by low-cost and rapid manufacturing techniques, use of renewable materials, and non-destructive recycling process. By developing an inherently recyclable thermoset, this research bridges between these three components of sustainable manufacturing by focusing on a fast cured vanillin-based Schiff base polyimide network in all-solid state. In this study, a multifunctional vanillin-based monomer was synthesised at scale in water which can be cured using a diamine without requiring any organic solvent. A CFRP was fabricated using this newly developed Schiff base polymer using compression moulding technique, and its mechanical and thermal/fire performance were compared to a CFRP made of a commercially available automotive grade epoxy resin. The resulting Schiff base CFRP composite demonstrated exceptional fire retardancy, complemented by remarkable tensile strength and modulus values of 427 MPa and 45 GPa, respectively. These characteristics meet the criteria for a broad spectrum of high-performance applications. In contrast to conventional CF reclaiming processes, a novel and efficient chemical recycling approach was introduced, enabling the delamination of CF layers containing the Schiff base network without requiring the separation and purification of the polymer matrix. This approach facilitates the low-cost remanufacturing of new CFRP composites with mechanical performance comparable to the original composite. Finally, green chemistry matrices as well as simplified life cycle assessment (LCA)-like approaches, including the EcoScale and GREEN MOTION rates, were employed to evaluate the efficiency and environmental impact of the CFRP manufacturing process.

Effects of alkaline treatment and manufacturing process on mechanical and absorption properties of Wild Abyssinia Banana fiber reinforced epoxy composite

To enhance the properties of natural fiber composite, proper selection of an optimum alkaline concentration for fiber surface modifications and composite manufacturing techniques are the main criteria to be considered. This study examined how NaOH and manufacturing methodsaffect the mechanical and absorbency characteristics of a Wild Abyssinia Banana (WAB) epoxy composite. 2 %, 5 %, and 7 % (w/v) NaOH concentrations; hand-layup and hydraulic press manufacturing techniques have been considered. Petroleum, diesel, distilled, and artificial lake water (wastewater) were used for the absorption test. A 5 % NaOH treatment improves composite tensile, flexural, and impact strengths by 14.78 %, 8.59 %, and 29.63 %, respectively. Moreover, the 5 % NaOH treatment reduced the absorption rate of the WAB fiber composite. Hydraulic press manufactured untreated WAB fiber composite was observed to have 26.27 % and 13.45 % higher tensile and flexural strengths than hand layup. The treated WAB fiber-reinforced composite can be utilized in gas stations, home appliances, and finishing materials for construction applications.

An Overview of the Additive Manufacturing of Bast Fiber-Reinforced Composites and Envisaging Advancements Using the Patent Landscape.

Natural fiber composites attract attention owing to their environmentally friendly attributes. Many techniques, including fiber treatment, coatings, and fiber orientations, are used to improve the strength of natural fiber-reinforced composites. Still, the strength needs to be improved as expected. At present, some automation in manufacturing is also supported. Recently, additive manufacturing (AM) of natural fiber-reinforced composites has attracted many researchers around the globe. In this work, researchers' attention to various natural fibers that are 3D printed is articulated and consolidated, and the future scope of the additive manufacturing of natural fiber-reinforced composite is envisaged using the patent landscape. In addition, some of the advancements in additive manufacturing of natural fiber composites are also discussed with reference to the patents filed lately. This may be helpful for the researchers working on AM of natural fiber composites for taking their research into new orientations.

Thermal and Mechanical Characterization of 3D Printed Continuous Fiber Reinforced Composites

Additive manufacturing of composite materials is a nascent technology that is being investigated for manufacturing optimized structural composite designs. By combining additive manufacturing of continuous fiber composites with topology optimization, fibers can be steered in the loading direction. Steered fibers allow for decreased weight, decreased manufacturing time, and reduced cost. Realizing the benefit of printed composites enables production of low cost unmanned vehicles at a higher rate with high specificity. Mechanical properties of printed composites, which are needed for design, are measured in this work. Composite properties were comparable to traditionally manufactured composites, especially when normalized by cured ply thickness. Transverse properties were limited by the brittleness of the photopolymer matrix. Matrix cure characteristics and thermal properties were also measured which revealed the high temperature capabilities of the matrix with a Tg of 198°C.

Analyzing Surface Roughness Variations in Material Extrusion Additive Manufacturing of Nylon Carbon Fiber Composites.

In recent years, fused deposition modeling (FDM) based on material extrusion additive manufacturing technology has become widely accepted as a cost-effective method for fabricating engineering components with net-shapes. However, the limited exploration of the influence of FDM process parameters on surface roughness parameters, i.e., Ra (average surface roughness), Rq (root mean square surface roughness), and Rz (maximum height of the profile) across different sides (bottom, top, and walls) poses a challenge for the fabrication of functional parts. This research aims to bridge the knowledge gap by analyzing surface roughness under various process parameters and optimizing it for nylon carbon fiber printed parts. A definitive screening design (DSD) was employed for experimental runs. The Pareto chart highlighted the significant effects of layer height, part orientation, and infill density on all surface roughness parameters and respective sides. The surface morphology was analyzed through optical microscopy. Multi-response optimization was performed using an integrated approach of composited desirability function and entropy. The findings of the present study hold significant industrial applications, enhancing the quality and performance of 3D printed parts. From intricate prototypes to durable automotive components, the optimized surfaces contribute to production of functional and visually appealing products across various sectors.

Preparation of nitro‐phenothiazine‐based oxime esters as dual photo/thermal initiators for 3D printing

AbstractNowadays, photopolymerization has spanned across all academic and industrial applications due to its appealing features such as energy saving, environmentally‐friendly polymerization conditions, high monomer conversions, rapid polymerization kinetics and so on. Photoinitiator (PI), as a crucial component of the photoinitiating system (PIS) are capable of interacting with light efficiently, enabling to generate initiating species in mono or multicomponent systems. In this work, 13 phenothiazine‐based oxime esters (OXEs) (never reported before) were synthesized and their photoinitiation abilities for the free radical photopolymerization (FRP) of acrylates were examined upon irradiation with LED@405 nm. Parallel to their photochemical reactivities, their abilities to initiate thermal polymerization processes were also investigated. Finally, these OXEs exhibited excellent photo/thermal initiation performances, demonstrating their dual initiation properties. Phenothiazine‐based oxime esters can be used as PIs in 3D printing as well as thermal initiator in the manufacturing of carbon fiber composites.

In-situ process evaluation for continuous fiber composite additive manufacturing using multisensing and correlation analysis

In-situ process evaluation for continuous fiber composite additive manufacturing using multisensing and correlation analysis

Modeling the through‐thickness frontal polymerization of unidirectional carbon fiber thermoset composites: Effect of microstructures

AbstractThe frontal polymerization is a technique that creates a self‐sustaining “cure front” that propagates through the thermoset resin material. Such a technique is potentially capable of substantially reducing the curing time of thermoset resin fiber composites from several hours to only a few minutes or even seconds, which is promising for the additive manufacturing and repair of thermoset fiber composites. In this study, the effect of the microstructures (i.e., fiber volume fraction, fiber tow size, and fiber tow shape) of unidirectional fiber composites on the frontal polymerization initiated in the through‐thickness direction of the composites is investigated through computational modeling. The computational model is verified through comparisons with experimental data. The simulation results show that the frontal polymerization process is largely affected by the fiber volume fraction and the fiber tow shape and is insensitive to the fiber tow size. The average front velocity decreases significantly as the fiber volume fraction increases from 0% to 30% and then decreases mildly from 30% to 46%. Above 46%, the average front velocity plateaus. Moreover, the average front velocity decreases in an approximately linear fashion as the ratio between the major radius and minor radius of the elliptical cross section of fiber tow increases.

Experimental Investigation of Additive Manufacturing of Continuous Carbon Fiber Composites with Multifunctional Electro-Tensile Properties

Manufacturing processes for monofunctional and multifunctional materials vary depending on the design optimization. Multifunctional continuous carbon fiber composites provide great potential in achieving coupled structural and electrical properties for their applications in aircraft, unmanned aircraft systems, and spacecraft. Proper optimization of tensile and electrical properties offers benefits early in the design and continuous operational safety phases to obtain coupled multifunctional properties. In this paper, fused filament fabrication additive manufacturing (AM) technique was used to fabricate continuous carbon fiber solid laminated composites test coupons. The proposed new method characterizes the electrical conductivity’s coupled effects on the tensile properties, including the failure loads and modes. This paper addresses a novel way of integrating electrical function into the composites that significantly reduce weight, potentially replacing the bulky electrical wires. Tensile and electrical conductivity tests were concurrently conducted on coupons, and the results were plotted and tabulated. The results showed the multifunctional properties of the maximum ultimate tensile strength of 392 MPa with the maximum tensile load of 8907 N, and resistance of 37.5 G·Ω. The average values for ultimate tensile strength and maximum load were 371 MPa and 8459 N, respectively.

Synthesis of Carbon Fiber Composites and Different Methods to Improve its Mechanical Properties: A Comprehensive Review

Efficient and innovative products can be made using high strength and lighter weight (almost half the steel weight) in modern-day automobile industries. One such material is Carbon Fiber, and it is used as its composites made with the help of epoxy resins. Carbon Fibers applications are increasing in use, in both the aerospace and automobile industries. The corrosion resistance and damping properties of the material can be put to better use in constructions that are heavily strained. The paper aims to review the manufacturing of Carbon fiber composites and their mechanical properties (tensile & flexural strength), which ultimately deals with their applications in the automobile industry. Also, it deals with a review of a few methods or substances used to improve the mechanical properties of carbon fiber composites.

Interfacial Bonding Mechanism and Mechanical Performance of Continuous Fiber Reinforced Composites in Additive Manufacturing

The additive manufacturing of continuous fiber composites has the advantage of a high-precision and efficient forming process, which can realize the lightweight and integrated manufacturing of complex structures. However, many void defects exist between layers in the printing process of additive manufacturing; consequently, the bonding performance between layers is poor. The bonding neck is considered a key parameter for representing the quality of interfacial bonding. In this study, the formation mechanism of the bonding neck was comprehensively analyzed. First, the influence of the nozzle and basement temperatures on the printing performance and bonding neck size was measured. Second, CT scanning was used to realize the quantitative characterization of bonding neck parameters, and the reason behind the deviation of actual measurements from theoretical calculations was analyzed. When the nozzle temperature increased from 180 to 220 °C, CT measurement showed that the bonding neck diameter increased from 0.29 to 0.34 mm, and the cross-sectional porosity reduced from 5.48% to 3.22%. Finally, the fracture mechanism was studied, and the influence of the interfacial bonding quality on the destruction process of the materials was determined. In conclusion, this study can assist in optimizing the process parameters, which improves the precision of the printing parts and performance between the layers.

Sustainable and Multifunctional Composites of Graphene‐Based Natural Jute Fibers

AbstractSmart and sustainable natural fiber‐based composites are of great interest due to their biodegradability, recyclability, and environmental benefits over synthetic fiber composites. In addition, the environmental impact of plastics and synthetic fibers are widespread and substantial, as they can stay in the environment for hundreds of years and contribute significantly to global carbon emissions. Natural fibers such as jute can potentially replace synthetic fibers to manufacture environmentally sustainable, biodegradable, and lightweight composites with improved properties, good thermal and acoustic insulation, and a smaller carbon footprint. However, natural jute fiber‐based composites suffer not only from poor mechanical properties but also being inherently electrically insulating, which limits their applications as multifunctional composites. Here multi‐functional and environmentally sustainable smart composites of graphene‐based natural jute fibers with excellent tensile and interfacial properties are reported. The reduced graphene oxide‐based natural jute fiber enhance the Young's modulus of the composites by ≈450%, and tensile strength by ≈183% after physical and chemical treatment. Such high‐performance composites can also be used as multifunctional smart composites, as demonstrated by effective electro‐magnetic interference shielding performance. This may lead to manufacturing of next generation smart, strong, and sustainable natural fiber composites for high performance engineering applications without conferring environmental problems.

Poly(ε-Caprolactone)/Brewers’ Spent Grain Composites—The Impact of Filler Treatment on the Mechanical Performance

Waste lignocellulose materials, such as brewers’ spent grain, can be considered very promising sources of fillers for the manufacturing of natural fiber composites. Nevertheless, due to the chemical structure differences between polymer matrices and brewers’ spent grain, filler treatment should be included. The presented work aimed to investigate the impact of fillers’ reactive extrusion on the chemical structure and the poly(ε-caprolactone)/brewers’ spent grain composites’ mechanical performance. The chemical structure was analyzed by Fourier-transform infrared spectroscopy, while the mechanical performance of composites was assessed by static tensile tests and dynamic mechanical analysis. Depending on the filler pretreatment, composites with different mechanical properties were obtained. Nevertheless, the increase in pretreatment temperature resulted in the increased interface surface area of filler, which enhanced composites’ toughness. As a result, composites were able to withstand a higher amount of stress before failure. The mechanical tests also indicated a drop in the adhesion factor, pointing to enhanced interfacial interactions for higher pretreatment temperatures. The presented work showed that reactive extrusion could be considered an auspicious method for lignocellulose filler modification, which could be tailored to obtain composites with desired properties.

Recycled PVC as Material for Natural Fiber Composite Manufacturing—study of Mechanical Performance and Durability

Manufacturing wood plastic composites from polyvinyl chloride (PVC) construction waste is one of the options for its continuously increasing scrap utilization. The aim of this study is to estimate the mechanical properties and durability of composites manufactured from recycled and commercially available PVC grades. The mechanical properties of PVC were reduced significantly after wood flour loading, showing weak compatibility between the matrix and the wood fibers. The composites from both PVC sources had weak durability, declining by up to 64% in tensile strength. The composite samples from recycled PVC displayed, however, better resistance to weathering compared to the composites from neat PVC. Chemical analysis of the composite surfaces by infrared spectroscopy and morphology study with a scan electron microscope before and after weathering confirmed the mechanical test results.