Manufacturing Of Polymer Composites Research Articles

Evaluation of Different ZX Tensile Coupon Designs in Additive Manufacturing of Amorphous and Semi-Crystalline Polymer Composites

The layer-by-layer deposition of molten polymer filament in fused deposition modeling (FDM) has evolved as a disruptive technology for building complex parts. This technology has drawbacks such as the anisotropic property of the printed parts resulting in lower strength for parts printed in the vertical Z direction compared with the other two planes. In this manuscript, we attempt to address these challenges as well as the lack of standardization in sample preparation and mechanical testing of the printed parts. The paper focuses on process parameters and design optimization of the ZX build orientation. Type I tensile bars in ZX orientation were printed as per the ASTM D638 standard using two (2B) and four (4B) tensile bar designs. The proposed design reduces material loss and post-processing to extract the test coupons. Printing a type I tensile bar in the ZX orientation is more challenging than type IV and type V due to the increased length of the specimen and changes in additional heat buildup during layer-by-layer deposition. Three different polymer composite systems were studied: fast-crystallizing nanofiller-based high-temperature nylon (HTN), slow-crystallizing nanofiller-based polycyclohexylene diethylene terephthalate glycol-modified (PCTG), and amorphous carbon fiber-filled polyetherimide (PEI-CF). For all the polymer composite systems, the 2B showed the highest strength properties due to the shorter layer time aiding the diffusion in the interlayers. Further, rheological studies and SEM imaging were carried out to understand the influence of the two designs on fracture mechanics and interlayer bonding, providing valuable insights for the field of additive manufacturing and material science.

Additive manufacturing of continuous fiber-reinforced polymer composites: current trend and future directions

Additive manufacturing of continuous fiber-reinforced polymer composites: current trend and future directions

Non‐isometric deformation in double curvature and symmetric composite laminates due to shrinkage

AbstractApplication of the global Gauss–Bonnet theorem for the prediction of changes in Gaussian curvature for double curvature laminate geometries due to shrinkage is developed for non‐isometric deformation states where in surface area change accompanies changes in curvature. The transition between isometric and non‐isometric deformation is strongly influenced by the ratio of the principal radii of curvature of the double curved surface and a relationship is proposed by the authors to accommodate the transition. Examples for the radii of curvature ratios of 2, 3, and 4 are compared to results from finite‐element simulations and the developed relationship is shown to be accurate within 0.55%. Furthermore, these results demonstrate that isometric deformation state can be taken as an adequate representation for double curvature toroidal laminate geometries of >10 and the class of materials studied in this work.Highlights Shrinkage induced deformation in multi‐curvature composite laminates is a recurring issue in polymer composite manufacturing. Thermal, crystallization and cure shrinkage are the dominant sources of shrinkage deformation in polymer composite systems. Isometric deformation of multi‐curvature, symmetric laminates composite is defined by the absence of membrane strain. The Gauss–Bonnet theorem provides a platform for determining radii of curvature changes in multi‐curvature symmetric laminates, Non‐isometric deformation of symmetric laminates can be treated by the Gauss–Bonnet theorem for radii of curvature ratios that correspond to geometric self‐constraint. The above highlights yield insight into the anticipated geometric distortions due to shrinkage in polymer composites.

Effect of process parameters on mechanical and tribological characteristics of FDM printed glass fiber reinforced PLA composites

PurposeAdditive manufacturing of polymer composites is a transformative technology that leverages the benefits of both composite material and 3D printing to produce highly customizable, lightweight and efficient composites for a wide range of applications.Design/methodology/approachIn this research work, glass fiber-reinforced polylactic acid (PLA) filament is used to print the specimen via fusion deposition modeling process. The process parameters such as infill densities (40%, 50% and 60%) and raster angle/orientations (0°, 45° and 90°) are varied, and the specimens for tensile, flexural, impact, hardness and wear testing are prepared as per their respective ASTM standards.FindingsThe results revealed that with an increase in infill density, the mechanical properties of glass fiber-PLA specimens increase progressively. Optimal tensile properties and flexural properties are obtained at 0° and 90° raster angle orientations and 60% infill density. Minimum wear rate is achieved at 0° raster angle orientation and it increases at 45° and 90° raster angle orientations.Originality/valueUsing SEM, the microscopic analysis of the fractured specimen was analyzed to study the interface between the fibers and matrix and it indicates the presence of good adhesion between the layers at 60% infill density and 0° print orientation.

Investigation of the rheological behaviour for improved extrusion-based additive manufacturing of polymer composites based on dissociative dynamic covalent bonds

More complex 3D structures were manufactured out of reversible covalent polymer networks using multi-material extrusion-based additive manufacturing. The rheological behaviour of reversible polymer networks based on the thermoreversible Diels-Alder reaction was optimized through the addition of different types of nanoclays and carbon black. The extrudability and deposition of the composites improved up to 5 wt% nanoclay, as the viscosity behaviour increased by an order of magnitude in the nozzle and by two orders of magnitude at the print bed temperature, without affecting the reversible gel transition temperature and the healing performance. An electrically conductive composite with 20 wt% carbon black and 1 wt% nanoclay could be printed using nozzle sizes down to 0.3 mm, resulting in higher resolution and accuracy than the pristine polymer networks. The percolating filler network enabled the printing of overhangs and hollow structures without the need for support material with perfect mechanical and electrical isotropy. Multi-material printing combining the electrically conductive and non-conductive composites enabled manufacturing self-healing deformation and force sensors that could recover their sensing performance upon damage healing at 90 °C for one hour.

Additive Manufacturing of Continuous Fiber-Reinforced Polymer Composites via Fused Deposition Modelling: A Comprehensive Review.

Additive manufacturing (AM) has arisen as a transformative technology for manufacturing complex geometries with enhanced mechanical properties, particularly in the realm of continuous fiber-reinforced polymer composites (CFRPCs). Among various AM techniques, fused deposition modeling (FDM) stands out as a promising method for the fabrication of CFRPCs due to its versatility, ease of use, flexibility, and cost-effectiveness. Several research papers on the AM of CFRPs via FDM were summarized and therefore this review paper provides a critical examination of the process-printing parameters influencing the AM process, with a focus on their impact on mechanical properties. This review covers details of factors such as fiber orientation, layer thickness, nozzle diameter, fiber volume fraction, printing temperature, and infill design, extracted from the existing literature. Through a visual representation of the process parameters (printing and material) and properties (mechanical, physical, and thermal), this paper aims to separate out the optimal processing parameters that have been inferred from various research studies. Furthermore, this analysis critically evaluates the current state-of-the-art research, highlighting advancements, applications, filament production methods, challenges, and opportunities for further development in this field. In comparison to short fibers, continuous fiber filaments can render better strength; however, delamination issues persist. Various parameters affect the printing process differently, resulting in several limitations that need to be addressed. Signifying the relationship between printing parameters and mechanical properties is vital for optimizing CFRPC fabrication via FDM, enabling the realization of lightweight, high-strength components for various industrial applications.

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.

Polymer composite additive manufacturing: Applications, challenges and opportunities

Polymer composite prototypes and final products have been produced using additive manufacturing (AM) or three-dimensional printing (3DP). Due to their exceptional physical, chemical, mechanical, and structural properties, composite or reinforced materials, particularly polymers, are gaining popularity in the fields of engineering and science. High-performance printable polymer composites are urgently required due to the mechanical and functional limitations of printed pure polymer components. Customizable geometry, reduced waste, and accessible material shifting are among the benefits of 3D printing. The market expansion of young industrialists may be restricted by the necessity to recognize the potential of 3DP technology. Furthermore, the literature on this subject must be more specialized or cohesive in order to expand beyond the fundamentals for professionals. This article explores the application of 3D printing matrix composite materials with enhanced properties in the fields of electronics, medical, cars, and aircraft. FDM, PLP, DLP, SLA, SLS, and robocasting are among the AM processes that are addressed in this document. Additional applications for these materials are recommended. Finally, the advantages and disadvantages of 3D printing are highlighted in order to facilitate enhancements.

Progress in selective laser sintering ofmultifunctional polymer composites for strain- and self-sensing applications

Recent decades have witnessed significant advancements in additive manufacturing (AM) of polymer composites, leading to the development of material systems with intricate architecture and composition. Selective laser sintering (SLS), among various AM methods, offers numerous advantages such as high mechanical strength in printed parts, recyclability of unused powders, and the ability to print large batches without support structures. Moreover, SLS has remarkably succeeded in fabricating electrically conductive polymer composites (ECPCs) with exceptional functional performance which is attributed primarily to the formation of a segregated filler network along the powder particle boundaries. This review aims to delve into SLS for processing polymer-based materials, examining consolidation mechanisms and process parameters, specifically highlighting advancements in electrically conductive polymer composites with a focus on piezoresistive strain-sensing materials and self-sensing structures. Furthermore, the review seeks to elucidate the complex process-structure-property relationships in SLS 3D printed polymer composites, providing an exhaustive overview of the current state-of-the-art in piezoresistive polymer composites.

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.

Emergence of long-range attractive interactions between colloidal particles during curing of dispersion media.

Compared to traditional drying methods, curing processes result in lower emissions of volatile organic compounds and reduced energy consumption. Consequently, curing processes are widely used in the manufacturing of various polymer products, including inks, coatings, composites, and adhesives. In recent years, the functionality of these polymer products has been enhanced by incorporating colloids with antiviral and conductive properties. Despite the significant influence of colloidal arrangement on physical properties, the kinetics of colloidal particles during curing remains poorly understood. To explore the effective interactions between colloidal particles during curing, we investigated the dynamics of soft particles within dispersing media using molecular dynamics simulations. The likelihood of particle aggregation during curing significantly surpasses that of random contact. Our calculations reveal an effective potential, indicating a long-range attractive interaction between the large particles. This attraction results from the heterogeneity in the crosslink network of the dispersing media, distinguishing it from the classical depletion force. Since the structure of particle aggregation could be controlled by the interplay between curing rate and particle diffusion, our findings offer promising prospects for advancing the manufacturing processes of increasingly functional polymeric products.

Concurrent Design of Composite Structure and Continuous Toolpath for Additive Manufacturing of Fiber-Reinforced Polymer Composites

Concurrent Design of Composite Structure and Continuous Toolpath for Additive Manufacturing of Fiber-Reinforced Polymer Composites

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%.

Tool material selection methodology for aircraft elements design

The technology and technological equipment selection have to be substantiating for the modern materials for product the aircraft construction elements from polymer composition. The physical and technical characteristics of the material, ensuring the required accuracy of manufacturing equipment, as well as economic feasibility are the main criteria for choosing the material of technological equipment. The material equipment choosing is depends on the polymer composite construction technology manufacturing. The methodic of rigging materials selection for aircraft constriction elements production from polymer composition by vacuum infusion is considered in that paper. The results of a comparative analysis of typical materials equipment used in production are presented are considered in that paper. It is shown that the main criteria for a comparative analysis are: temperature, resistance to solvents, resistance to mechanical stress; maintainability; the value of the coefficient of linear thermal expansion; the stability of the geometry of the equipment and its tightness. It was showing that the metals and carbon fiber composite are the most appropriate for equipment manufacture that used in high temperature processes manufacturing composite components. The materials equipment algorithm choosing for polymer composite components manufacturing is considered in that paper. It is noted that the same material have to be choosing for equipment manufacturing as the carbon fiber or fiberglass polymer composite component. This allows to ensure the same CLTE, which is important in hot forming of the composite component, and to eliminate warping of the composite component during its cooling on the equipment. However, the equipment gelcoat processing has to be taking into account for specified accuracy achievement. The quantitative assessment of the economic feasibility of material equipment choosing is considered in that paper. It is shown that only a combination of technical, technological and economic factors makes it possible to substantiate the expediency of the rigging material used for the specific production of aircraft construction elements.

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.