Manufacturing Of Polymer Composites Research Articles

Interfacing the IoT in composite manufacturing: An overview

Abstract It is a well-known fact that many sophisticated works consume a lot of human resources, leading to the need to find effective alternative. The manufacturing industry demands a lot of human resources, with around half of the global working population participating in this sector. Challenges such as sudden conflicts in the data, disasters, and loss of productivity are encountered by the manufacturing industries and can be overcome by monitoring machine performance data and automatically configuring the machines according to changing needs. This emphasizes the importance of the Internet of Things (IoT) in addressing niche areas of manufacturing. IoT is a buzzword heard everywhere around the globe. Implementing this technology makes most of the work more accessible than other conventional methods. This has created a lot of research interest on this topic. Among many manufacturing sectors, polymer composite material manufacturing is one of the most demanding. This review article purely focuses on polymer composite manufacturing and its allied processes. The consolidation of data is based on the influence of IoT on the extraction of fibers and manufacturing of polymer composite material using novel techniques, quality assessment of manufactured polymer composite material, challenges faced in exploring the use of IoT, and future scope. It can be stated from the survey that various researchers have minimally explored the incorporation of IoT, but its future looks very promising in terms of producing high-quality products at less time and lower cost by integrating this technique with conventional methods.

Multiscale porosity characterization in additively manufactured polymer nanocomposites using micro-computed tomography

Extrusion-based additive manufacturing (AM) of polymer composites exhibits complex thermally driven phenomena that introduce severe discontinuities in the internal structure across length scales, especially voids or porosity. This study utilizes a high-throughput porosity characterization technique to analyze large datasets from numerous micro-computed tomography (μCT) scans to capture the influence of AM print parameters on the size, shape, and location of porosity across multiple print layers (up to a few cm) on fused granular fabrication (FGF) printers. The materials investigated include nanocomposite formulations based on commercially relevant nylon-12 and polyether ketone ketone (PEKK) materials comprising nano- or micro-sized fillers. The estimated global porosity follows an inverse linear correlation against the bulk density of the printed samples. Increasing the extrusion multiplier (EM) and the nozzle temperature while decreasing the print speeds reduces the global porosity. Outlier analyses (local porosity morphology) show that faster print speeds and higher extrusion rates result in long, slender inter-layer voids, while lower nozzle temperatures lead to large, symmetrical, inter-bead voids (at the bead junction). Lack of active chamber temperature increases inter-layer and intra-bead voids with a two-fold increase in global porosity. Overall, the micro filler-reinforced composites exhibit higher global porosity than nanofiller-reinforced composites, which is attributed to the increased mismatch in the thermal expansion coefficient between the filler and the polymers used in the study.

A powder-scale multiphysics framework for powder bed fusion of fiber-reinforced polymer composites

Additive manufacturing of fiber-reinforced polymer composites has garnered great interest due to its potential in fabricating functional products with lightweight characteristics and unique material properties. However, the major concern in polymer composites remains the presence of pore defects, as a thorough understanding of pore formation is insufficient. In this study, a powder-scale multiphysics framework has been developed to simulate the printing process of fiber-reinforced polymer composites in powder bed fusion additive manufacturing. This numerical framework involves various multiphysics phenomena such as particle flow dynamics of fiber-reinforced polymer composite powder, infrared laser–particle interaction, heat transfer, and multiphase fluid flow dynamics. The melt depths of one-layer glass fiber–reinforced polyamide 12 composite parts fabricated by selective laser sintering are measured to validate modelling predictions. The numerical framework is employed to conduct an in-depth investigation of pore formation mechanisms within printed composites. Our simulation results suggest that an increasing fiber weight fraction would lead to a lower densification rate, larger porosity, and lower pore sphericity in the composites.

Polymer Composites in 3D/4D Printing: Materials, Advances, and Prospects.

Additive manufacturing (AM), commonly referred to as 3D printing, has revolutionized the manufacturing landscape by enabling the intricate layer-by-layer construction of three-dimensional objects. In contrast to traditional methods relying on molds and tools, AM provides the flexibility to fabricate diverse components directly from digital models without the need for physical alterations to machinery. Four-dimensional printing is a revolutionary extension of 3D printing that introduces the dimension of time, enabling dynamic transformations in printed structures over predetermined periods. This comprehensive review focuses on polymeric materials in 3D printing, exploring their versatile processing capabilities, environmental adaptability, and applications across thermoplastics, thermosetting materials, elastomers, polymer composites, shape memory polymers (SMPs), including liquid crystal elastomer (LCE), and self-healing polymers for 4D printing. This review also examines recent advancements in microvascular and encapsulation self-healing mechanisms, explores the potential of supramolecular polymers, and highlights the latest progress in hybrid printing using polymer-metal and polymer-ceramic composites. Finally, this paper offers insights into potential challenges faced in the additive manufacturing of polymer composites and suggests avenues for future research in this dynamic and rapidly evolving field.

Core-shell structured tow-pregs enabled additive manufacturing of continuously reinforced thermoset composites

One of the major challenges in thermally curable polymer composite additive manufacturing is the slow curing time of thermally curable resins, coupled with a significant drop in thermoset viscosity upon heating, making the formation of complex shapes difficult. To tackle these issues, we have introduced a novel rapid composite preformation strategy called Tow-Preg Cladding (TPC). This technique involves the use of a thin and rapidly curable dual-cure resin, which combines a thermally curable resin (such as epoxy) with a fast photo-curable resin. The dual-cure resin is applied as a coating over a thermally curable resin tow-preg, enabling the formation of a rigid cladding that supports and shapes the tow-pregs into the desired geometries and patterns. The key advantage of this approach lies in the sequential formation of an interpenetrating polymer network (IPN) at the interlayer between laminates, resulting from the curing of the photocurable resin and the thermally curable resin sequentially. This IPN formation enhances interlaminar bonding in the composite, contributing to its overall strength and performance. The composites produced using this technique exhibited impressive mechanical properties, including longitudinal tensile strength of 1058.2 MPa, longitudinal tensile modulus of 74.2 GPa, flexural strength of 1080.4 MPa, and flexural modulus of 41.7 GPa. Overall, our Tow-Preg Cladding approach shows great promise in overcoming the challenges associated with thermally curable polymer composite additive manufacturing. It offers a viable solution to creating strong, shape-specific thermoset composites efficiently with enhanced mechanical properties.

Novel cellular coil design for improved temperature uniformity in inductive heating of carbon fibre composites

Electromagnetic induction has great potential for energy efficient manufacturing of polymer composites. Carbon fibre can be directly heated inductively, achieving rapid, localised, and volumetric heating. The main obstacle to wider adaption of induction in composites processing is the non-uniformity of temperature distribution in-plane and through thickness of composite laminates. This study puts forward a new cellular architecture of the coil and examines the feasibility of addressing the problem of field uniformity. The geometrical parameters of the coil were examined in concurrent modelling and experimental work, aiming at reducing the effect of field cancellation in neighbouring cells and maximising both the coil efficiency and the field uniformity. The paper demonstrates good potential of the new coil designed with significantly improved uniformity of temperature field compared to traditional commercially available coils. This result has been further optimised with parametric finite element analysis to reduce the standard deviation in surface temperature by a further 37%.

Wood fiber production from downed timber for manufacturing wood polymer composite: fiber property characterization

ABSTRACT Massive amount of downed timber is generated by hurricanes and tornados. This research studied the properties of wood fibers (WFs) generated from downed loblolly pine (Pinus taeda L.) trees at different maturity (ages 15, 30, and 39 years) with various natural environmental exposure periods (0, 6, and 12 months) for wood polymer composite (WPC) manufacturing. The wood fiber critical properties for WPC manufacturing, including particle size and morphologies, physical and chemical properties, and thermal stability, were characterized. Prolonged environmental exposure increased WF surface roughness. The density and 1% sodium hydroxide solubility of WFs for the 15 – and 30-year-old tree decreased after 12 months of environmental exposure. The WFs generated from the 39-year-old tree contain extractives due to heartwood development, resulting in significantly less moisture absorption. Thermogravimetric analysis results showed no significant change in the thermal stability of WFs generated from the 15 – and 30-year-old trees after natural environmental exposure because of the loss of degraded wood components. The cellulose and lignin thermal degradation peak temperatures decreased by up to 9 and 6 °C for WFs extracted from the 39-year-old tree. The degraded wood components were fixed within WFs due to extractives, causing thermal degradation peak temperatures to decrease.

Polymer composites–Special issue review for additive manufacturing of composites

AbstractThis special issue of Polymer Composites on “Additive Manufacturing of Composites” seeks to provide insight into recent advances in the field of additive manufacturing (AM), often termed 3D printing, using composite materials. We hope this issue provides help to the practicing engineer, material suppliers, original equipment manufacturers (OEMs), Tier‐1 suppliers, academics and scientists, and others with an interest in using or applying AM to their products and systems. This issue presents new materials, new material systems, enhancements of the final part performance, novel manufacturing methods, and applications, and improvements of existing manufacturing methods for AM. Solutions are presented by the research community to solve specific scientific and engineering challenges within the field in this issue. This issue is highlighted by several review articles on recent advances within the field of polymer composite additive manufacturing.

Recycling as a Key Enabler for Sustainable Additive Manufacturing of Polymer Composites: A Critical Perspective on Fused Filament Fabrication.

Additive manufacturing (AM, aka 3D printing) is generally acknowledged as a "green" technology. However, its wider uptake in industry largely relies on the development of composite feedstock for imparting superior mechanical properties and bespoke functionality. Composite materials are especially needed in polymer AM, given the otherwise poor performance of most polymer parts in load-bearing applications. As a drawback, the shift from mono-material to composite feedstock may worsen the environmental footprint of polymer AM. This perspective aims to discuss this chasm between the advantage of embedding advanced functionality, and the disadvantage of causing harm to the environment. Fused filament fabrication (FFF, aka fused deposition modelling, FDM) is analysed here as a case study on account of its unparalleled popularity. FFF, which belongs to the material extrusion (MEX) family, is presently the most widespread polymer AM technique for industrial, educational, and recreational applications. On the one hand, the FFF of composite materials has already transitioned "from lab to fab" and finally to community, with far-reaching implications for its sustainability. On the other hand, feedstock materials for FFF are thermoplastic-based, and hence highly amenable to recycling. The literature shows that recycled thermoplastic materials such as poly(lactic acid) (PLA), acrylonitrile-butadiene-styrene (ABS), and polyethylene terephthalate (PET, or its glycol-modified form PETG) can be used for printing by FFF, and FFF printed objects can be recycled when they are at the end of life. Reinforcements/fillers can also be obtained from recycled materials, which may help valorise waste materials and by-products from a wide range of industries (for example, paper, food, furniture) and from agriculture. Increasing attention is being paid to the recovery of carbon fibres (for example, from aviation), and to the reuse of glass fibre-reinforced polymers (for example, from end-of-life wind turbines). Although technical challenges and economical constraints remain, the adoption of recycling strategies appears to be essential for limiting the environmental impact of composite feedstock in FFF by reducing the depletion of natural resources, cutting down the volume of waste materials, and mitigating the dependency on petrochemicals.

Effect of an amine-aldehyde condensate modifier on the thermal and mechanical properties of fiber-reinforced epoxy composites

Purpose The manufacture of polymer composites with a lower environmental footprint requires incorporation of sustainably sourced components. In addition, the incorporation of novel components should not compromise the material properties. The purpose of this paper is to demonstrate the use of a synthetic amine functional toluidine acetaldehyde condensate (AFTAC) as a modifier for fiber-reinforced epoxy composites. One of the fiber components was sourced from agricultural byproducts, and glass fiber was used as the fiber component for comparison. Design/methodology/approach The AFTAC condensate was synthesized via an acid-catalyzed reaction between o-toluidine and acetaldehyde. To demonstrate its efficacy as a toughening agent for diglycidyl ether bisphenol A resin composites and for the comparison of reinforcing materials of interest, composites were fabricated using a natural fiber (mat stick) and a synthetic glass fiber as the reinforcing material. A matched metal die technique was used to fabricate the composites. Composites were prepared and their mechanical and thermal properties were evaluated. Findings The inclusion of AFTAC led to an improvement in the mechanical strengths of these composites without any significant deterioration of the thermal stability. It was also observed that the fracture strengths for mat stick fiber-reinforced composites were lower than that of glass fiber-reinforced composites. Originality/value To the best of the authors’ knowledge, the use of the AFTAC modifier as well as incorporation of mat stick fibers in epoxy composites has not been demonstrated previously.

Thermo-mechanical analysis of additive manufacturing for material properties estimation of layered polymer composite

This paper proposes a numerical approach for predicting residual stresses induced during the additive manufacturing (AM) of polymer composites and their effect on the deformation behavior of the composites. A finite element (FE) model was developed on Abaqus/Standard for 3D printing of layered polymer composite using three polymers: HDPE, PVC, and ABS. The material properties of pure polymers and their blends were measured through tensile testing of injection-molded specimens. These properties were then used as input data in the FE model for the regions of pure polymers and their interfaces. An uncoupled thermo-mechanical analysis was performed, where a heat transfer analysis was realized first using elements birth (activation/deactivation) technique and a moving cylindrical volumetric heat source as a Fortran subroutine (DFLUX). With temperature input from thermal simulation, a mechanical analysis was carried out to deform the polymer composites along and across the print direction, i.e. under isostrain and isostress conditions, respectively. It was observed that the theoretical models existing in the literature underestimate the material properties as they do not consider the residual stresses developed during fabrication. The FE simulations predicted that the estimated material properties were 10 to 50% different from those calculated by the theoretical models, depending upon the residual stress level and the print direction.

EMI shielding, thermal and antibacterial performances of ecofriendly castor oil–based waterborne polyurethane favored by combining carbon nanotube and cetyltrimethylammonium bromide

Many ecofriendly and antibacterial polymer-based shielding nanocomposites have been designed to address the increasingly serious issues of electromagnetic interference (EMI) pollution and antibiotic resistance. These composites contain high amounts of conductive and antibacterial material and exhibit an unsurpassed EMI shielding performance and strong antibacterial properties. However, it is extremely challenging to prepare these materials because of the formation of large aggregates coupled with the high viscosity. Herein, carbon nanotubes (CNTs) and an antibacterial surfactant (cetyltrimethylammonium bromide (CTAB)) are mixed with castor oil–based waterborne polyurethane (WPU) via ultrasonic-assisted solution mixing followed by a freeze-drying approach. Owing to the presence of CTAB, CNTs (at a concentration of 24.3 wt%) are evenly dispersed and connected to each other in the WPU matrix. This morphology and intrinsic characteristics of CNTs enable the resultant CNT/WPU composites to exhibit an excellent electrical conductivity (635.8 S/m) and thermal conductivity (0.308 W/(m·K)) as well as an incomparable shielding effectiveness (SE, 88.81 dB). Notably, the specific SE reaches 997.4 dB/cm, which exceeds those of the reported composites. Moreover, the combination of CNTs and CTAB improves the antibacterial activities of the WPU composites. Due to these merits, the resultant composites have great potential for applications in portable and wearable smart electronics. Overall, this study opens a new way toward the manufacture of ecofriendly and multifunctional polymer composites.

Evaluating Residual Stress in Carbon Fiber-Reinforced Polymer (CFRP) at Microscale Using Fiber Push-Out Experiment and Finite Element Modeling.

Microscale residual stress may develop during the manufacturing of Carbon Fiber-Reinforced Polymer (CFRP) composites and negatively affect apparent macroscale mechanical properties. Accordingly, accurately capturing residual stress may be essential in computational methods used for composite material design. This work presents a new data-driven methodology for the evaluation of microscale residual stress in CFRPs using fiber push-out experiments with in situ scanning electron microscopy (SEM) imaging. SEM images reveal significant through-thickness matrix sink-in deformation in resin-rich areas after nearby fibers are pushed out, which is attributed to the release of microscale process-induced residual stress. The sink-in deformation is measured experimentally, and a Finite Element Model Updating (FEMU) method is used to retrieve the associated residual stress. The finite element (FE) analysis includes simulation of the curing process, test sample machining, and fiber push-out experiment. Significant out-of-plane matrix deformation larger than 1% of the specimen thickness is reported and associated with a high level of residual stress in resin-rich areas. This work emphasizes the importance of in situ data-driven characterization for integrated computational materials engineering (ICME) and material design.

Use of Chicken Litter for In Situ Polymerization of Poly(Butylene Succinate) (PBS) Based Polymer Composites

AbstractIn the recent years, the growing amounts and incorrect disposal of solid wastes have created serious negative environmental impacts, including land and water pollution. Chicken litter (CL) is a type of solid waste which is generated during chicken production, the appropriate final destination of which is still subject to technical discussion. Because CL is composed mostly of fibers, proteins, carbohydrates, and different minerals, the use of this material as a filler for the manufacture of polymer materials has been suggested. The main objective of the present work is the manufacture of polymer composites in situ polymerization using CL as a filler and succinic acid and 1,4‐butanediol as monomers, considering that the fiber content in CL is ≈20 wt%. The obtained poly(butylene succinate) (PBS) composites are characterized by Fourier transformed infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), degradability in distilled water, and compression analyses. The results show that the addition of CL to the mixture do not affect the course of the polycondensation reaction significantly. Furthermore, compression tests show that the compressive strength of test pieces increases with the CL content.

Recent Developments in Additive Manufacturing of Conductive Polymer Composites

AbstractAdditive manufacturing, also named 3D printing, can be used to create objects from diverse polymers, metals, and other materials in diverse shapes and dimensions. If special physical or chemical properties are necessitated, using corresponding feedstock enables varying such properties in a broad range. Besides choosing a suitable base material, often composite materials are used for specific applications. Here, an overview of recent developments in 3D printing of polymer composites with conductive properties is given. After a definition of conductivity ranges and the respective potential applications, additive manufacturing methods applicable for these polymer composites as well as potential resistivity or resistance measurement methods are reported. An overview of the most recent reports of 3D printing polymer composites with different conductive fillers is followed by a summary of the applications found in the recent literature.

A Systematic Literature Network Analysis: Development of Manufacturing, Enhancement and Sustainability of Fiber-Reinforced Polymer Composites (1998–2020) and Future Research Agenda

A Systematic Literature Network Analysis: Development of Manufacturing, Enhancement and Sustainability of Fiber-Reinforced Polymer Composites (1998–2020) and Future Research Agenda

Additive manufacturing of fiber-reinforced polymer composites: A technical review and status of design methodologies

Additive manufacturing (AM) of fiber-reinforced composites is gaining traction as an important manufacturing technology to produce complex, highly customized structures. AM processes enable the fabrication of complex 3D structures with control over fiber position and orientation, offering tremendous design freedom. Although the use of AM to fabricate fiber-reinforced composites is promising, various design difficulties remain. These include consideration of structural performance subject to manufacturing constraints on fiber placement, orientation, bend radius, and other relevant limitations. Design engineers will have to consider these limitations to be able to reap the full benefits of AM to fabricate fiber-reinforced polymer composites. This paper aims to provide a survey on the advances in multi-scale topology optimization, fiber orientation parameterization, micromechanics of fiber-matrix interactions and process planning specific for the AM of complex fiber reinforced composites. The status of recent research is summarized, and future directions outlined.

Sustainable fabrication of polypropylene-postconsumer cotton composite materials: circularity, characterization, mechanical testing, and tribology

The processing, microstructure, mechanical properties, characterization, and performance as paradigms play vital in determining a material's ultimate role in commercial applications. Circularity of natural polymer waste is required innovation in industrial processing. In this creative research, an industrial model is introduced for pilot fabrication of polypropylene–postconsumer cotton fiber reinforced composites. International organization for standardization (ISO 9001–2) standards are instigated for selection and categorization of manufacturing techniques and waste. In this research, we applied compression and injection molding techniques to fabricate polypropylene (PP)–cotton composites. Postconsumer cotton waste was used as a reinforcement material. Postconsumer cotton fiber (PCCF) content in the composites was 10, 30, and 40% wt. Injection molding was found to produce composites with better structure than compression molding. As compared to the PP samples, the best results were achieved with 10% wt. Similarly, American standards are established to validate the performance and quality of developed PP-PCCF composites. The PP-PCCF composite (10% wt.) exhibited good mechanical properties with a tensile strength of 26.31 MPa, modulus of elasticity of 1476 MPa, and strain of 8%. The composite of 10% wt. PP-PCCF demonstrated reasonable thermal, wear, and surface properties, including crystallinity of 44%, degradation temperature of 360 °C, wear rate of 3 × 10−6 mm3/Nm in sliding tests against silicon carbide (SiC) sandpaper, the average weight loss of 12 mg/kg in erosion tests, and the surface roughness Ra of 0.20 μm. Theoretical models and experimental investigations (tensile, bending, impact, surface, erosion, abrasion and thermal) are established through quantitative discussion. This pilot framework provides a foundation for the implementation of close loop manufacturing of polymer composites. Moreover, this work also controlled the commercial green production of polymer composites products with negligible waste. The investigated PP-PCCF composite materials have potential applications in the automotive and construction industries.

Deep learning-assisted real-time defect detection and closed-loop adjustment for additive manufacturing of continuous fiber-reinforced polymer composites

• A closed-loop control approach is successfully developed for online detection of defects and adjustment of process parameters by deep learning, which is never achievable in any conventional methods of composite fabrication. • Deep learning is implemented to detect the CFRP defects for AM in real-time with high accuracy and low latency. The proposed method is able to identify different types of CFRP defects (i.e., misalignment and abrasion). • The combined deep learning with geometric analysis of the level of misalignment is applied to quantify the severity of individual defects. Real-time defect detection and closed-loop adjustment of additive manufacturing (AM) are essential to ensure the quality of as-fabricated products, especially for carbon fiber reinforced polymer (CFRP) composites via AM. Machine learning is typically limited to the application of online monitoring of AM systems due to a lack of accurate and accessible databases. In this work, a system is developed for real-time identification of defective regions, and closed-loop adjustment of process parameters for robot-based CFRP AM is validated. The main novelty is the development of a deep learning model for defect detection, classification, and evaluation in real-time with high accuracy. The proposed method is able to identify two types of CFRP defects (i.e., misalignment and abrasion). The combined deep learning with geometric analysis of the level of misalignment is applied to quantify the severity of individual defects. A deep learning approach is successfully developed for the online detection of defects, and the defects are effectively controlled by closed-loop adjustment of process parameters, which is never achievable in any conventional methods of composite fabrication.

Manufacturing Technologies of Polymer Composites-A Review.

Polymer composites have been widely used in the aviation, aerospace, automotive, military, medical, agricultural and industrial fields due to their excellent mechanical properties, heat resistance, flame retardant, impact resistance and corrosion resistance. In general, their manufacturing process is one of the key factors affecting the life cycle of polymer composites. This article provides an overview of typical manufacturing technologies, including surface coating, additive manufacturing and magnetic pulse powder compaction, which are normally used to reduce the failure behaviour of polymer composites in service so that the quality of composite products can be improved. Advanced polymer composite powder manufacturing processes, the processing mechanism and experimental methods are described, and the influence of different manufacturing processes on the moulding quality is revealed. This investigation can provide suitable methods for the selection of manufacturing technology to improve the quality of polymer composite products.