Fiber Manufacturing Research Articles

Development of Porous-Polyacrylonitrile-Based Fibers Using Nanocellulose Additives as Precursor for Carbon Fiber Manufacturing.

Cellulose is a renewable and environmentally friendly raw material that has an important economic and technical impact in several applications. Recently, nanocellulose (NC) presented a promising road to support the manufacturing of functional carbon fibers (CFs), which are considered superior materials for several applications because of their outstanding properties. However, the smooth and limited effective surface areas make CFs virtually useless in some applications, such as energy storage. Therefore, strategies to increase the porosity of CFs are highly desirable to realize their potential. Within this article, we present an approach that focuses on the designing of porous CF precursors using polyacrilonitrile (PAN) and NC additives using a wet spinning method. To enhance the porosity, two jet stretching (50% and 100%) and four NC additive amounts (0 wt.%, 0.1 wt.%, 0.4 wt.% and 0.8 wt.%) have been applied and investigated. In comparison with the reference PAN fibers (without NC additives and stretching), the results showed an increase in specific surface area from 10.45 m2/g to 138.53 m2/g and in total pore volume from 0.03 cm3/g to 0.49 cm3/g. On the other hand, mechanical properties have been affected negatively by NC additives and the stretching process. Stabilization and carbonization processes could be applied in a future study to support the production of multifunctional porous CF.

Tunable Rayleigh scattering in low-loss Sr-based nanoparticle-doped optical fibers: Controlling nanoparticle features throughout preform and fiber fabrication

Alkaline earth nanoparticles in-situ grown on silica-based optical fibers are promising for distributed sensing applications. To date, only Ca-based nanoparticles have been proven to be suitable compositions for long-range distributed fiber sensing based on Rayleigh scattering enhancement. Herein, we extend this approach and demonstrate for the first time that Sr-based nanoparticles grown in-situ in silica-based optical fiber cores are suitable to fabricate low-loss Rayleigh scattering enhanced nanoparticle-doped optical fibers with tunable performance. A thorough microstructural study about the influence of preform and fiber manufacture conditions on the nanoparticle characteristics reveal their great impact, and the possibility of considerably tailoring their features throughout fabrication process. This simultaneously determines the tunability of the induced Rayleigh scattering and optical attenuation. Consequently, we improve the state-of-art trade-off between Rayleigh scattering enhancement and two-way optical losses, showing values of 26.4–43.8 dB, regarding a SMF-28, and 0.2–5.1 dB/m, respectively. This allows long-range sensing lengths from 8.6 m to 132 m. Our findings provide new insights into in-situ grown alkaline earth nanoparticles and establish solid guidelines to tailor nanoparticle features in nanoparticle-doped optical fibers, which open new prospects in optical fiber community.

Quadratic regression analysis for nonlinear heat source/sink and mathematical Fourier heat law influences on Reiner-Philippoff hybrid nanofluid flow applying Galerkin finite element method

BackgroundScientists across the world have tried to explore the effect of non-Newtonian fluids moving over a symmetric stretchable sheet with the presence of diverse influences revealed in this study due to its tremendous applications in various engineering and industrialized sectors like aerodynamics extrusion of plastic surfaces, condensation procedure of metal symmetric plate in a refrigeration immersion, and extrusion of a polymeric surface from a dye.Proposed modelReiner-Philippoff fluids flowing related to a symmetric stretch surface with the inclusion of effects like Forchheimer velocity, thermal radiative, and Cattaneo Christov heat fluxing are considered in the momentum and temperature equation. Novel tetra hybrid nanoparticles are considered to check the thermo physical behaviour of the proposed model. MethodologyThe showed PDEs are transformed into ODEs with the utilization of symmetric and self-similarity variables and further attempted numerically with the assistance of the Galerkin finite element methodology (G-FEM). The obtained findings are scrutinized in the form of figures and tables.FindingsFrom obtained outcomes, it is perceived that the heat transfer Nusselt magnifies extra in the instance of tetra hybrid nanofluids (THNFs) in disparity to tri and di hybrid nanoparticles. Darcy Forcheeimer effect Fr diminishes the fluid velocity and the temperature outline amplifies owed to amplification in thermal radiative variable Rd. The insertion of nanoparticles supports in the stabilizating of a nanofluid's flowand provides the symmetric of thestructure. Error in heat transfer Nusselt number diminishes by the virtue of magnification in Rd and the heat deliverance phenomenon magnifies as a consequence of enlargement in the thermal relaxation constraint.Practical application of the proposed modelDue to its particle use in manufacturing and engineering for shells that expand and contract, like stretchable (shrinkable) packaging, bundle wrapping, hot roll, sheet material extrusion, wire roll, glass fiber manufacturing, metallic packags, and aluminum bottles manufacturing, parabolic tough surface collectors, cooling of thermal reactors, polymer production, etc., the examination of two-dimensional flowing over an extending shallow has attracted attention. The proposed model outcomes are utilized in order the enhance heat transfer of the various liquids by utilizing tetra hybrid nanoparticles and effects like nonlinear based thermal radiation, Cattaneo-Christov heat flux and heat source/sink phenomenon.NoveltyThe effort is novel in its sagacity that no nanofluid model has been developed yet to examine the effect of tetra hybrid nanoparticles on liquid moving over any sort of surface.

Microstructured Optical Fiber Made From Biodegradable and Biocompatible Poly(D,L-Lactic Acid) (PDLLA)

We have fabricated and characterized microstructured biodegradable and biocompatible polymer optical fibers using commercially available poly(D,L-lactic acid) (PDLLA). We first report on the preparation of the preforms by means of a novel technique based on transfer molding and on the fiber manufacturing using a regular heat-drawing process. We address the influence of the polymer processing on the decrease of the molar mass of PDLLA following the preform fabrication and the fiber optic drawing process. We investigate the in vitro degradation of the fabricated fibers in phosphate buffered saline (PBS) that reveals 21, 25 and 43% molar mass loss over a period of 105 days for fibers with diameters of 400, 200 and 100 μm, respectively. Cutback measurements return an attenuation coefficient as low as 0.065 dB/cm at 898 nm for a microstructured fiber with a diameter of 219 ± 27 μm. Due to immersion in PBS at 37 °C, the optical loss increases by 0.4 dB/cm at 950 nm after 6 h and by 0.8 dB/cm after 17 h.

Influence of Process Parameters on Sheet Lamination Method-based 3D printing: A Review

Additive manufacturing of carbon fibre reinforced thermoplastic composites” provides us advantages to create lightweight structures with great strength and stiffness over traditionally developed carbon fibre manufacturing techniques, because of enhanced design freedom. This paper is a summary of scholarly sources on Additive manufacturing. This study is a summary of state-of-art techniques this study allows us to identify gaps in the existing research, and also discusses the results of the study and the conclusions derived from it.

4D optical fibers thermally drawn from shape-memory polymers

Adaptative objects based on shape-memory materials are expected to significantly impact numerous technological sectors including optics and photonics. In this work, we demonstrate the manufacturing of shape-memory optical fibers from the thermal stretching of additively manufactured preforms. First, we show how standard commercially-available thermoplastics can be used to produce long continuously-structured microfilaments with shape-memory abilities. Shape recovery as well as programmability performances of such elongated objects are assessed. Next, we open the way for light-guiding multicomponent fiber architectures that are able to switch from temporary configurations back to user-defined programmed shapes. We strongly expect that such actuatable fibers with light-guiding abilities will trigger exciting progress of unprecedented smart devices in the areas of photonics, electronics, or robotics.

Mechanistic study to reveal steric and electronic aspects involved in the formation of microstructures during Pd-catalyzed olefin/divinyl formal copolymerization: reactivity to catalyst choice.

The advancement of metal-catalyzed copolymers is a formidable challenge for achieving distinct catalytic properties to compete with existing plastic polymers in industrial commodities. Herein, we reveal the roles of electronic and steric environments in the thermodynamic preference of microstructures in ethylene/divinyl formal (DVF) co-polymerization using a Pd catalyst under mild conditions to accommodate the respective industrial applicabilities. The insertion products of DVF result in the alteration of the steric crowding, ultimately favoring the efficient formation of cyclic units having potential applications in the manufacture of high-strength fibers. More specifically, to achieve an improved yield of the end copolymer, we tuned the catalytic activity and regioselectivity through a variety of catalysts during ethylene-DVF co-polymerization. The naphthalene-bridged (P^O)PdMe catalyst was found to be promising in terms of the least hindered (buried volume of 47.8%) environment with the thermodynamic preference of 2,1-insertion with an energy of 5.1 kcal mol-1 among all the Pd-metal based catalysts. The highest activity with moderate energy barriers of the proposed catalyst will open new avenues for achieving a variety of potential applications, which is typically not possible using existing polymerization techniques.

Optimisation of the formulation of fibre incorporated reduced calorie herbal rasmalai

The present study was carried out to optimise the process of manufacturing of fibre incorporated reduced calorie herbal rasmalai. Ocimum tenuiflorum (Tulasi) extract, Withania somnifera (ashwagandha) root powder and Plantago ovata (isabgol) were the variables in the rasmalai balls studied by employing the 3-factors Central Composite Rotatable Design (CCRD). Optimisation of sucralose content in concentrated milk was carried out by Kruskal Wallis test. The formulation with tulasi extract (6.951%), ashwagandha root powder (0.423%) and isabgol (0.583%) in the rasmalai ball with 100 ppm sucralose in the sweetened concentrated milk was found highly suitable for optimisation of fibre incorporated reduced calorie herbal rasmalai. The desirability index of optimised fibre incorporated reduced calorie herbal rasmalai was 0.90.

Synthesis of optical materials based on the TlBr0.46I0.54 – AgI system and investigation of their optical properties

In order to obtain optical materials for operation in the visible, infrared and terahertz regions with high functional properties and suitable for the manufacture of optical fibers, technologies were developed and the properties of single crystals and ceramics based on the TlBr0.46I0.54 – AgI system were studied. According to the phase diagram of the system TlBr0.46I0.54 – AgI, it is possible to synthesize single crystals with a content of up to 18 mol. % AgI in TlBr0.46I0.54, as well as two-phase ceramics with a content from 18 to 43 mol. % AgI in TlBr0.46I0.54. Two compositions of each of the material types were synthesized by the directed crystallization method: single crystals of 6 and 13 mol. % composition AgI in TlBr0.46I0.54 and optical ceramics of compositions 19 and 25 mol. % AgI in TlBr0.46I0.54. It was possible to achieve an increase in the transmission range from 0.495 to 55.0 µm and to 0.504–60.0 µm with a lower refractive index: from 2.203 to 2.363 in the wavelength range of 0.5–14.0 µm, depending on the composition, by introducing AgI into the solid solution TlBr0.46I0.54. The developed materials showed resistance to ultraviolet, as well as radiation resistance under β-irradiation with doses up to 1000 kGy.

Mitsui Chemicals Inc. to scale up Microwave Chemical's innovative carbon fiber production technology Carbon-MX™.

On November 16, Mitsui Chemicals Inc. and Microwave Chemical Co., Ltd. announced that they have decided to set up a new demonstration facility within Mitsui Chemicals’ Nagoya Works. The facility will demonstrate basic technology relating to the manufacture of eco-friendly carbon fiber – an endeavor that Mitsui Chemicals and Microwave Chemical recently announced they would be looking at together.

Environmental, property and cost impact analysis of carbon fibre at increasing rates of production

The manufacture of carbon fibre is an energy intensive proprietary process which has resulted in limited detailed information on the relationship between process parameters, properties, emissions and energy consumption. This experimental study investigates the relationship between these parameters by performing an in-depth analysis of the fibre properties, composition of emitted gases and energy demand for carbon fibre produced using varying processing line speeds and increasing temperatures on a continues manufacturing line, representative of commercial production processes. The time to produce carbon fibre from a polyacrylonitrile (PAN) based precursor can be reduced by up to 33% while mechanical properties are maintained, thus describing a pathway to improved process efficiency with up to 30% less energy demand, leading to a cleaner production. Results however also show that this applies within a limited time and temperature range, while further increase in manufacturing rates leads to yield reduction and decreasing material properties. The findings from this study are scaled virtually to commercial production quantities and converted to energy and financial improvement potentials for the different process setups. This study shows pathways to significantly improve the energy demand, environmental impact and cost, achievable by optimizing the process.

Effect of electromagnetic induction on the heat transmission in engine oil-based hybrid nano and ferrofluids: A nanotechnology application

This analysis investigates the control of electromagnetic induction over the flow and heat transmission in shear-thickening hybrid nano and ferrofluids for cooling/heating applications. The stream is time-free and not turbulent. The leading equations are equipped with buoyancy, irregular heat sink/source, and thermic heat effects. The transformed, resulting equalities are resolved with the help of the bvp5c package. Twin expositions are discussed for the hybrid nano (engine oil (EO) + aluminum oxide (Al2O3) + titanium dioxide (TiO2)) and hybrid ferro (EO + iron oxide (Fe3O4) + cobalt ferrite (CoFe2O4)) cases. Numerical momentum, magnetic induction, and thermal profiles are obtained via graphical illustrations. Also, the tables present the friction factor and the measure of thermic transport. It divulges from consequences that the hybrid ferrofluids have a more conducive rate than hybrid nanoliquids, and the Nusselt number shrinks for uneven heat sink/source constraint values. Also, electromagnetic induction controls hybrid ferroliquid more than hybrid nanofluids. The prime application of the current research glimpsed in engineering practices viz. metal extrusion, synthetic fiber, microfluidics, glass fiber manufacture, etc.

Smart Fabric Textiles: Recent Advances and Challenges

Textiles have been used in our daily life since antiquity in both economies and social relationships. Nowadays, there has never been a greater desire for intelligent materials. Smart fabric textiles with high-quality and high-performance fiber manufacturing with specific functions represented by clothing and apparel brands (such as astronaut suits that can regulate temperature and control muscle vibrations) are becoming increasingly prominent. Product applications also extend from the field of life clothing to the medical/health, ecology/environmental protection, and military/aerospace fields. In this context, this review proposes to demonstrate the recent advances and challenges regarding smart fabric textiles. The possibilities of innovative smart textiles extending the overall usefulness and functionalities of standard fabrics are immense in the fields of medical devices, fashion, entertainment, and defense, considering sufficient comfort as a parameter necessary for users to accept wearable devices. Smart textile devices require a multidisciplinary approach regarding the circuit design of the development of intelligent textiles, as the knowledge of intelligent materials, microelectronics, and chemistry are integrated with a deep understanding of textile production for optimum results.

Microfluidic-assisted fiber production: Potentials, limitations, and prospects.

Besides the conventional fiber production methods, microfluidics has emerged as a promising approach for the engineered spinning of fibrous materials and offers excellent potential for fiber manufacturing in a controlled and straightforward manner. This method facilitates low-speed prototype synthesis of fibers for diverse applications while providing superior control over reaction conditions, efficient use of precursor solutions, reagent mixing, and process parameters. This article reviews recent advances in microfluidic technology for the fabrication of fibrous materials with different morphologies and a variety of properties aimed at various applications. First, the basic principles, as well as the latest developments and achievements of microfluidic-based techniques for fiber production, are introduced. Specifically, microfluidic platforms made of glass, polymers, and/or metals, including but not limited to microfluidic chips, capillary-based devices, and three-dimensional printed devices are summarized. Then, fiber production from various materials, such as alginate, gelatin, silk, collagen, and chitosan, using different microfluidic platforms with a broad range of cross-linking agents and mechanisms is described. Therefore, microfluidic spun fibers with diverse diameters ranging from submicrometer scales to hundreds of micrometers and structures, such as cylindrical, hollow, grooved, flat, core-shell, heterogeneous, helical, and peapod-like morphologies, with tunable sizes and mechanical properties are discussed in detail. Subsequently, the practical applications of microfluidic spun fibers are highlighted in sensors for biomedical or optical purposes, scaffolds for culture or encapsulation of cells in tissue engineering, and drug delivery. Finally, different limitations and challenges of the current microfluidic technologies, as well as the future perspectives and concluding remarks, are presented.

Diversity of soils in areas with the presence of Furcraea sp. in tropical ecosystems

Introduction. The fique, “cabuya” or “mecate” are the common names given to the species of the genus Furcraea that are used for the manufacture of biodegradable fibers. Their industrial and social importance in Latin American countries is significant since it is usually related to family and peasant economies. However, for this taxonomic group, the diversity of edaphic conditions in natural habitats or cultivation sites is unknown. Objective. To physicochemically characterize the soils in the productive systems and natural populations of fique, to determine the aspects and factors that best represent their variability. Materials and methods. The work was developed between 2013 and 2014, in 66 municipalities and 108 villages in 11 departments of Colombia. Passport data was recorded at the 121 sites visited, describing site conditions, including georeferencing. In each locality, soil samples were taken in the first 20 cm of depth and subsequently the following variables were determined: texture, pH, organic matter (OM), P, S, K, Mg, Ca, Al+H, CE, cations of change Ca, Mg, K, Na, cationic exchange capacity (ECEC), Ca, Mg, K, and Na. According to georeferencing, 52 agroecological zones were identified. Results. Populations located between 170 to 2,993 m.a.s.l. were found. The most significant factors were agroecological zone and soil texture. Among them, texture was the factor with the greatest capacity for group formation and represented 60.99 % of the variability of the sampled soils. The variables that most contribute to the variability of the soils were (Ca + Mg) / K, exchangeable Mg, K / Mg, exchangeable Ca, and ECEC. Conclusion. The results obtained for wild and cultivated populations indicate that the different taxa survive in diverse tropical soil conditions. It was found that the exchangeable ions had high discriminating power that could indicate diversity to the different conditions and fertility levels of Colombian soils.

Digital Manufacture of a Continuous Fiber Reinforced Thermoplastic Matrix Truss Core Structural Panel Using Off-the-Tool Consolidation

Sandwich panels are commonly used as structure, based on fiber reinforced composites, with the goal of high flexural stiffness and low mass. It is most common to separate two high performance composite facesheets with a low-density core, generally in the form of a foam or honeycomb. A recent concept has been to replace these traditional core materials with fiber reinforced truss-like structures, with the goal of further reducing mass. A system is described that can radically reduce the amount of tooling required for truss core sandwich panel manufacture. This system, which is a digital manufacturing platform for the extrusion of continuous fiber reinforced commingled glass fiber/PET tow, was developed to demonstrate the rigidization of composites both on, and off, a tool surface. Navtruss core panels were successfully manufactured using this digital manufacturing platform, without conventional tooling, and the resulting through thickness compression moduli and panel shear moduli were within 14.6% and 23% of the values baseline compression molded specimens. Thus, the results suggest that, with further development, complex truss core structures with performance approaching that of compression molded panels can be manufactured with radically reduced tooling requirements from high volume fraction, continuous fiber reinforced thermoplastic matrix composites.

Digital economy, industrial structure upgrading and green total factor productivity--Evidence in textile and apparel industry from China.

According to the standard of GB/T4754-2017 Classification of National Economic Industry and the characteristics of the textile and apparel industry, the textile and apparel industry is divided into three categories: textile industry, clothing industry and chemical fiber manufacturing industry. Based on the panel data of the textile and apparel industry from 2010 to 2019, this paper measures green total factor productivity (GTFP) by using the unexpected output super efficiency SBM model and the ML index. On this basis, this paper empirically tests the impact of digital economy on the GTFP of textile and apparel industry, and the dual intermediary effects of rationalization of industrial structure and advanced industrial structure are discussed. The results show that: (1) The GTFP of the textile and apparel industry shows a fluctuating upward trend, but it is in a state of low growth. (2) Digital economy has a significant effect on promoting the GTFP. Among them, it has a positive effect on the improvement of GTFP in textile industry, but has no obvious effect on the clothing industry, and has a restraining effect on the chemical fiber manufacturing industry. (3) In the process of the impact of digital economy on GTFP, the rationalization of industrial structure has a partial intermediary effect, and the level of effect reaches 35.81%, while the advancement of industrial structure does not necessarily have a "structural dividend", and its influence on GTFP is non-linear. This paper enriches the research on the influencing factors of GTFP, and is also an effective supplement to the research on digital economy. The conclusions provide a reliable empirical basis for digital economy to help the textile and apparel industry pollution control, and also provide policy references for giving full play to the green value of digital economy.

Atomistic modeling of tensile deformation and fracture of carbon fibers: Nanoscale stress redistribution, effect of local structural characteristics and nanovoids

The mechanisms of tensile deformation and fracture of carbon fibers are investigated in large-scale molecular dynamics simulations. The simulations performed for computational samples with different structural characteristics enable analysis of the structural sensitivity of the mechanical properties. It is found that the carbon fiber nanostructure can be represented by a fine (nanoscale) mixture of stiff and soft regions. Despite the nanoscale structural heterogeneity of the computational fibers, their fracture strain and tensile strength exceed the experimental values by almost an order of magnitude. This observation is explained by the ability of the carbon fiber nanostructure, largely consisting of curved and folded layers of turbostratic carbon, to exhibit continuous nanoscale load redistribution during the deformation. The transient, fluid nature of a percolating cluster of stress-holding structural elements prevents stress localization at the early stage of the deformation and enables the fiber nanostructure to adapt to the increasing load. Overall, the results of the simulations suggest that the design of advanced carbon fiber manufacturing and post-processing methods focused on the elimination of critical mesoscopic structural defects (internal voids, foreign inclusions, and surface flaws) can yield a substantial increase in the strength and fracture strain of carbon fibers.

Environmental Impact of Polymer Fiber Manufacture

AbstractThis review focuses on the effects on the environment due to the production of polymer‐solvent solutions and the manufacture of polymeric fibers of thicknesses from a nanometer up to a millimeter using these solutions. The most common polymeric fiber manufacture methods are reviewed based on their effects on the environment, particularly from the use of hazardous materials and energy consumption. Published literature is utilized to analyze and quantify energy consumption of the manufacturing methods electrospinning, phase separation, self‐assembly, template synthesis, drawing and pressurized gyration. The results show that during the manufacturing stage of the lifecycle of polymeric fibers, pressurized gyration is more environmentally efficient primarily due to its mass‐producing features and fast processing of polymeric solutions into fibers, it also works best with water‐based solutions. Further green alternatives are described such as the use of sustainable polymers and solvents to enhance the environmental benefit. Overall, it is shown that the most effective method of curbing the environmental impact of manufacturing polymeric fibers is the use of nontoxic, water‐soluble polymers along with the evasion of toxic solvents.

Highly Aligned Centrifugal Spun Polyacrylonitrile Nanofibers Collected and Processed with Automated Tracks

AbstractA parallel automated track collector is integrated with a rationally designed centrifugal spinning head to collect aligned polyacrylonitrile (PAN) nanofibers. Centrifugal spinning is an extremely promising nanofiber fabrication technology due to high production rates. However, continuous oriented fiber collection and processing presents challenges. Engineering solutions to these two challenges are explored in this study. A 3D‐printed head design, optimized through a computational fluid dynamics simulation approach, is utilized to limit unwanted air currents that disturb deposited nanofibers. An automated track collecting device has pulled deposited nanofibers away from the collecting area. This results in a continuous supply of individual aligned nanofibers as opposed to the densely packed nanofiber mesh ring that is deposited on conventional static post collectors. The automated track collector allows for simple integration of the postdraw processing step that is critical to polymer fiber manufacturing for enhancing macromolecular orientation and mechanical properties. Postdrawing has enhanced the mechanical properties of centrifugal spun PAN nanofibers, which have different crystalline properties compared with conventional PAN microfiber. These technological developments address key limitations of centrifugal spinning that can facilitate high production rate commercial fabrication of highly aligned, high‐performance polymer nanofibers.