Alternative Manufacturing Process Research Articles

Stabilization of the pharmaceutical finished dosages form by using various techniques

The stabilization of pharmaceuticals means that the drug product is physically, chemically and microbiologically stable at the recommended storage condition throughout the predefined shelf life of the product. Pharmaceutical formulations irrespective of its physical states have been used for their efficacy and safety so for as its therapeutic activity is concern. Stability of dosage forms is the ability of drugs to remains unaffected by environmental condition viz. temperature, humidity and microbiological contamination. This research work is an attempt to stabilize the drug product at controlled room temperature for the drug product which is stable at refrigerated storage condition. Hence the aim of present study was development and stabilization of the drug product at room temperature. Investigation of alternate manufacturing processes for stabilization of the drug product at controlled room temperature was one of the objectives of the work. Keywords: Stability, shelf life, lyophilization, freeze drying

Electrochemical Performance of Dry Processed Graphite Electrode with PTFE Binder for Lithium-Ion Batteries

Both cathode and anode in Lithium-ion batteries (LIBs) are being manufactured by slurry coating process; however, currently used wet coating process has some drawbacks, including the difficulty in further increasing the electrode thickness as well as high fabrication cost mainly due to the use of facility for drying process. To address these issues, dry electrode fabrication process has been proposed and actively investigated as an alternative electrode manufacturing process. Dry electrode fabrication process with PTFE binder offers several advantages over conventionally used slurry coating process such as high manufacturing efficiency due to the non-solvent process and the ease of increasing the electrode thickness resulting from fibrillization of the PTFE binder. However, the instability of PTFE binder in dry processed graphite anodes remains a challenge, as the irreversible reaction of PTFE binder leads to the deterioration of the electrode. Furthermore, the properties of graphite materials including specific surface area, the particle size and shape can also affect the microstructure of the electrode and the electrochemical performance of graphite anode. In this work, the relationship between the properties of graphite and the electrochemical performance of dry processed graphite anode was investigated using various analytical techniques and the electrochemical characterization techniques. More detailed analyses results will be discussed in the presentation.

The Potential of High-Velocity Air-Fuel Spraying (HVAF) to Manufacture Bond Coats for Thermal Barrier Coating Systems

Driven by the search for an optimum combination of particle velocity and process temperature to achieve dense hard metal coatings at high deposition efficiencies and powder feed rates, the high-velocity air-fuel spraying process (HVAF) was developed. In terms of achievable particle velocities and temperatures, this process can be classified between high-velocity oxy-fuel spraying (HVOF) and cold gas spraying (CGS). The particular advantages of HVAF regarding moderate process temperatures, high particle velocities as well as high productivity and efficiency suggest that the application of HVAF should be also investigated for the manufacture of MCrAlY (M = Co and/or Ni) bond coats (BCs) in thermal barrier coating (TBC) systems. In this work, corresponding HVAF spray parameters were developed based on detailed process analyses. Different diagnostics were carried out to characterize the working gas jet and the particles in flight. The coatings were investigated with respect to their microstructure, surface roughness and oxygen content. The spray process was assessed for its effectiveness. Process diagnostics as well as calculations of the gas flow in the jet and the particle acceleration and heating were applied to explain the governing mechanisms on the coating characteristics. The results show that HVAF is a promising alternative manufacturing process.

COPYRIGHT PROTECTION IN ADDITIVE MANUFACTURING

Additive Manufacturing (AM) has been proven to be a significant development for production as well as become an attractive alternative manufacturing process compared with Subtractive Manufacturing (SM). This can be explained by the massive advantages of AM including mass customisation, less material wastage and ability to create prototypes. However, in order to make use of the AM process, firms, developers and designers require a virtual sharing platform, which can be used to trade designs and make the whole industry better off. This desire requires ways to protect the models and designs from digital thieves. Moreover, internal transactions of designs inside a single firm also require a significant level of security. So, this paper offers different ways of protecting both physical models and virtual designs. The solutions in this paper can be used to ensure the integrity of the physical products and virtual designs during different kinds of transactions.

Alternative Manufacturing Processes (AMP) for Wind Turbine Blade Material, in Isolated Regime Based on AHP

The newest cutting-edge technologies in Renewable Energy Sources (RES) projects provides economic benefits for project developers, especially when installing a wind power in isolated regime. The research was focused on finding technological alternatives, using an optimal composite material for wind blades structure. In this sense, the research team made a decision based on critical analysis of today existing technologies that can provide feasible solutions. The Analytic Hierarchy Process (AHP) method provides results for choosing alternative manufacturing processes, suitable for blades structure, in isolated regime

Fabrication of Chemofluidic Integrated Circuits by Multi-Material Printing

Photolithographic patterning of components and integrated circuits based on active polymers for microfluidics is challenging and not always efficient on a laboratory scale using the traditional mask-based fabrication procedures. Here, we present an alternative manufacturing process based on multi-material 3D printing that can be used to print various active polymers in microfluidic structures that act as microvalves on large-area substrates efficiently in terms of processing time and consumption of active materials with a single machine. Based on the examples of two chemofluidic valve types, hydrogel-based closing valves and PEG-based opening valves, the respective printing procedures, essential influencing variables and special features are discussed, and the components are characterized with regard to their properties and tolerances. The functionality of the concept is demonstrated by a specific chemofluidic chip which automates an analysis procedure typical of clinical chemistry and laboratory medicine. Multi-material 3D printing allows active-material devices to be produced on chip substrates with tolerances comparable to photolithography but is faster and very flexible for small quantities of up to about 50 chips.

Impact of the location of magnesium in zeolite-based shaped catalyst bodies on the methanol-to-hydrocarbons process

One of the main challenges for the chemical industries is finding new ways to produce lower olefins, such as propylene and ethylene, to satisfy the increase in demand for e.g., polymers, namely polypropylene and polyethylene. The Methanol-to-Hydrocarbons (MTH) process is an alternative manufacturing process that can help to address this increasing demand for these important chemical building blocks. It has been proposed that the addition of magnesium to zeolites, in the form of powdered catalyst materials, enhances the selectivity towards light olefins. In this work, the impact of the location of magnesium (present as Mg2+ and MgO) in zeolite-based shaped catalyst bodies on their physicochemical properties and catalytic performance in the MTH reaction has been studied. By adjusting one of the preparation steps of the overall extrusion process in which magnesium is added tuning the location of magnesium, higher interaction between magnesium and the zeolite material could be achieved. Pre-extrusion modification showed the most favorable results in terms of physicochemical properties and catalytic activity. We found that the magnesium location could be crucial for altering molecular transport, coke formation, and catalyst deactivation during the MTH reaction due to its pronounced effects on the acidity as well as porosity of the shaped catalyst bodies. These new insights can be applied to other zeolite-based extrudate materials and other acid-catalyzed reactions as it can be crucial for the design of better and more efficient catalyst materials in their industrially shaped form.

Mechanical performance and microstructure of the grade 91 stainless steel produced via Directed Energy deposition laser technique

The grade 91 ferritic/martensitic steel is considered a promising structural or cladding material for various nuclear reactor applications. Here, grade 91 was fabricated via the Directed Energy Deposition Laser technique. This alternative manufacturing process potentially enables tailoring of the mechanical properties through increased control of the product’s microstructure.Aimed at linking fabrication to performance via defining the process-structure–property relationships, the current research includes macro and up to nano-scale mechanical testing using microhardness, tensile, and in-situ nanoindentation hardness, coupled with electron diffraction-based microstructure characterization. Mapping of the product structure and properties was conducted by testing miniature-sized samples, parallel to the built direction (‘Z’ direction) and perpendicular (‘X’ direction) at constant distances.We found the majority of the microstructure consists of fine and coarsened-size lath-type martensite grains, with up to 15% δ-phase, preferentially observed at the melt pool boundaries. Most intriguing was the gradual decrease found in observed metallurgical pores alongside softening at farthest distances from the cold build platform. Here, these changes were successfully explained in terms of phase composition, ‘grain-like’ size effects of the lath-type martensite, and geometry necessary dislocation density. In finalizing this work, several competing strengthening mechanisms were addressed, and their activity was considered owing to fabrication-related mechanisms.

Manufacturing Process for Multilayer Dielectric Elastomer Transducers Based on Sheet-to-Sheet Lamination and Contactless Electrode Application

Dielectric elastomer transducers (DETs) consist of thin elastomer films and compliant conductive electrodes on each side. Several DE-based systems, e.g., DE actuators, loudspeakers or sensors, have great potential in industrial applications. Different manufacturing processes for DE-based transducers have been realized so far. An alternative manufacturing process, based on sheet-to-sheet lamination of pre-fabricated elastomer films, appears promising for the manufacturing of large numbers of DETs, as, on the one hand, the commercially available elastomer films produced are characterized by homogeneous and reproducible properties and, on the other hand, the curing time during processing can be avoided. However, the handling of thin elastomer films and a controlled film transfer onto a surface is a challenge, as pre-stretch and wrinkles can easily occur. The presented sheet-to-sheet lamination mechanism facilitates controllable film handling well, whereby a high number of DE layers can be achieved. This paper focuses on the developed, automated film lamination of pre-cut film sheets and the electrode application via a jetting system, representing core components of the corresponding overall manufacturing process of DE laminates. The process realization on a laboratory scale is presented and manufactured DET specimens investigated for validation purposes.

Closing the loop of textile: Circular building renovation with novel recycled insulations from wasted clothes

The implementation of new energy policies and standards for NZEB is expected to lead to a significant reduction of GHG emissions from building use in Europe in the next decades. On the other side, the growing pressure on insulation materials risks to significantly contribute to the exhaustion of the remaining carbon budget due to the high carbon intensity of conventional insulation for material processing. Consequently, storing carbon in construction products and promoting circular economies able to generate up-cycling processes from industrial or post-consumption waste are the key strategies to promote an effective transition toward a carbon-neutral society. Fashion & clothing is one of the manufacturing sectors which mostly contributes to waste generation and fossil GHG emission. This paper presents the main outcomes achieved from RECYdress project, which focuses on the valorisation of wasted textile collected by municipal districts to develop novel thermal insulations for building applications. Three alternative conceptual manufacturing processes were defined at lab scale based on different treatment of textile fibres, with produced specimens tested for thermal characterization. Finally, the LCA results of an ETICS application for façade renovation were compared considering as functional unit 1m2 of façade with similar thermal resistance.

Functionally graded additive manufacturing for orthopedic applications

BackgroundAdditive Manufacturing due to its benefits in developing parts with complex geometries and shapes, has evolved as an alternate manufacturing process to develop implants with desired properties. The structure of human bones being anisotropic in nature is biologically functionally graded i,e. The structure possesses different properties in different directions. Therefore, various orthopedic implants such as knee, hip and other bone plates, if functionally graded can perform better. In this context, the development of functionally graded (FG) parts for orthopedic application with tailored anisotropic properties has become easier through the use of additive manufacturing (AM). Objectivesand Rationale: The current paper aims to study the various aspects of additively manufactured FG parts for orthopedic applications. It presents the details of various orthopedic implants such as knee, hip and other bone plates in a structured manner. A systematic literature review is conducted to study the various material and functional aspects of functionally graded parts for orthopedic applications. A section is also dedicated to discuss the mechanical properties of functionally graded parts. ConclusionThe literature revealed that additive manufacturing can provide lot of opportunities for development of functionally graded orthopedic implants with improved properties and durability. Further, the effect of various FG parameters on the mechanical behavior of these implants needs to be studied in detail. Also, with the advent of various AM technologies, the functional grading can be achieved by various means e.g. density, porosity, microstructure, composition, etc. By varying the AM parameters. However, the current limitations of cost and material biocompatibility prevent the widespread exploitation of AM technologies for various orthopedic applications.

Analysis and Advances in Additive Manufacturing as a New Technology to Make Polymer Injection Molds for World-Class Production Systems.

The currently growing demand for metallic and polymeric products has undoubtedly changed the rules of manufacturing, enabling customers to more functionally define their products based on their needs. Nowadays, a new technique for rapid tooling, Additive Manufacturing (AM), can create customized products with more complex geometries and short life cycles (flexibility) in order to keep up with the new variables imposed by the manufacturing environment. In the last two decades, the migration from subtractive manufacturing to AM has materialized such products with reduced costs and cycle times. AM has been recently promoted to develop polymer molds for product manufacturing. This paper reviews the main findings in the literature concerning polymer molds created by AM compared to conventional (metal) molds obtained by subtractive manufacturing. Information about specific topics is scarce or nonexistent, for example, about the characterization of the most commonly injected materials and molds used in this type of technology, their mechanical properties (part and mold), designs for all types of geometries, and costs. These aspects are addressed in this literature review, highlighting the advantages of this alternative manufacturing process, which is considered a desirable technology worldwide.

The Influence of Size Effect to Deformation Mechanism of C5131 Bronze Structures of Negative Poisson’s Ratio

3D auxetic structures, which present negative Poisson’s ratio in the uniaxial compression deformation, is an ideal artificial material for meta-implants because of its lightweight, good material property and suitable porosity for bone recovery compared with conventional meta-biomaterials. Selective laser melting (SLM) is commonly used to produce metallic 3D auxetic structures but limited by the melting temperature and reflect rate of the material, and micro assembled (MA) structures is an alternative manufacturing process. However, the influence of size effect in 3D auxetic structures and the difference of the constitutive model of 3D auxetic structure produced by SLM and MA have not been discussed. In tandem of this, the mechanical property comparison of 3D auxetic structures produced by SLM and MA is conducted and a structural surface layer model for 3D auxetic structures is proposed. The result indicated that both SLM and MA structure can achieve auxetic effect. It is found that the Poisson’s ratio of the SLM and MA structures decrease when increasing the size factor of the structure, and the negative Poisson’s ratio effect is more obvious when the Young’s modulus is relatively small. FE simulation result of Poisson’s ratio is closer to experimental result of MA structures due to complexity of 3D auxetic structures. This paper thus provides a relatively helpful constitutive model for the prediction of the mechanical behavior of 3D auxetic structure.

Development of nano boron-doped diamond electrodes for environmental applications

• Nano-enabling silicon substrate with BDD nanoparticles as inexpensive next-generation electrocatalytic material. • BDD nanoparticles are homogeneously distributed on silicon substrate using ink-casting method. • Nano-BDD electrodes have a similar electrochemical window as macro-BDD electrodes. • The overall cost of the system decreases by more than x1000 fold. Boron doped diamond (BDD) is an outstanding electrode material with unique electrocatalytic properties and excellent stability, relevant to electrochemical advanced oxidation processes and electroanalytical techniques. From an environmental sustainability viewpoint, BDD electrodes are comprised only of earth abundant elements (carbon, boron, oxygen). However, a major drawback is the high manufacturing costs per unit surface area for BDD electrodes when fabricated using chemical vapor deposition or comparable surface deposition processes. BDD nanoparticles can provide an alternative manufacturing process that reduces costs by over 1000-fold while also improving catalytic activity. Herein, we demonstrate that nano-BDD electrodes can be fabricated by depositing BDD nanoparticles on a silicon substrate using a Nafion® ink-casting method. Scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) were used to investigate the electrode structural and morphological properties, which were compared to BDD electrodes manufactured using standard methods. Cyclic voltammetry measurements revealed similar electrochemical properties for both electrodes, with a broad “electrochemical window”, essential for effective production of ∙OH radicals without oxygen generation, providing an energy-efficient approach to degradation of pollutants in water. The electrocatalytic properties of the nano-BDD enabled electrodes were investigated using a [Fe(CN) 6 ] 3-/4- redox probe. The sensing properties of as-prepared nano-BDD electrodes was studied using Dopamine.

Effects of the Manufacturing Chain on the Surface Integrity when Machining Fir Tree Slots with Alternative Manufacturing Processes

The use of materials with increasing thermo-mechanical strengths for turbine disks and new designs inducing filigree geometries bring conventional manufacturing processes to their technical and economical limits. Investigations regarding alternative manufacturing technologies showed advantages compared to conventional broaching with high-speed steel (HSS) cutting tool material. Surface integrity is particularly crucial for the technological evaluation. However, this aspect has not been considered after downstream processes in which the machined surface integrity is modified. Therefore, the surface integrity of Inconel 718 machined by alternative manufacturing processes including wire EDM, ECM and broaching with cemented carbide is investigated after downstream processes, etching and shot peening.

Environmental and technical evaluation of additive manufacturing: Enabling process chain perspective by energy value stream mapping

Additive manufacturing (AM) currently evolves from a prototyping process to an alternative manufacturing process for end-use parts, advancing into fabrication of low to medium product volumes. Moreover, increasing awareness of environmental impacts of manufacturing lead to the necessity of holistic evaluation among traditional evaluation criteria in the technical and economic domains. However, existing evaluation approaches seldom consider a complete AM process chain and are lacking a production-oriented notation which enables comparability across technologies and support in identification of improvement potentials on technical and environmental level. To address this gap, this paper highlights the way from structured data acquisition to setup of an energy value stream map (EVSM) for AM process chains in end-use part production, augmenting methods of lean manufacturing by the energy dimension. Consequently, it contributes to a holistic and transparent process chain perspective to assess AM as a manufacturing alternative. The proposed methodology is applied to a case study covering two different process chains, a first based on powder bed fusion via Multi-jet Fusion (MJF) and a second utilizing vat-photopolymerization via Continuous Liquid Interphase Printing (CLIP). While the MJF process chain’s energetical hot spot is situated in the printing process itself, the hot spot for CLIP is found in thermal post-processing, exceeding the comparably efficient printing process by magnitudes and ultimately resulting in higher energy intensity per part compared to the MJF process chain. These results highlight the necessity of a holistic evaluation method for complete AM-based process chains and their influence on the product properties. Insights may help engineers, designers and decision makers in pre-selection of suitable manufacturing strategies with a more complete view on AM process chains.

Alternative manufacturing process of 3-dimensional interconnect device using thermoforming process

In early stages, the electronic circuits have been developed on simple printed circuit boards with multiple copper patterns and components interconnected by lead – free solder. Later on, these are converted to flexible circuits and molded interconnect devices (MID) because of high demand of complex circuit design. Laser machine is used to manufacture 3D MID circuits. An alternative manufacturing process has been introduced in this research. The method is to design functional circuits by using stretchable ink printed on a 2D substrate. Polycarbonate is selected as a substrate on the basis of its glass transition temperature (Tg). Thermoforming process is then applied to transfer 2D substrate into 3D shape. Reverse engineering technique is used to fabricate the mold through several steps. First, the dimensions of rear lighting is calculated by coordinate measuring machine (CMM), transferred to 3D drawing using SolidWorks. And finally the mold is produced using computer numerical control (CNC) machine. Screen printing technique is opted to print ink on a flat thermoplastic Polycarbonate substrate. The highly conductive circuit will be generated after heating printed ink in oven for about 30 min at 120 °C. The circuit with substrate is further transferred into 3D shape using the thermoforming process. All the light emitted diodes (LEDs) are then fixed on a circuit by dispensing conductive adhesive and cured again in an oven for 10 min at 120 °C, so strong bonds are formed at the joints. The reliability of the circuit is assessed by characterizing mechanical and electrical properties. The designed circuit is then compared with the existing design using scanning electron microscopy (SEM), universal testing, two-point probes multi-meter and spectrometer. The electrical performance of new circuit design shows promising results in terms of power consumption and luminous flux of LEDs and there is no major difference found between them. As a result, the new manufacturing process of printed circuit offers encouraging method in manufacturing the automotive lighting product.

“Un-forming” fibre-steered preforms: Towards fast and reliable production of complex composites parts

Automated Fibre Placement (AFP) allows for efficient deposition of composite prepreg materials at large scale in a reliable and reproducible way, while keeping human effort to a minimum. However, the technique is not perfectly suited to manufacturing small/medium parts with complex geometries. Deviation between as-designed and as-manufactured parts is almost inevitable, as is the occurrence of process-induced defects. In this study, an alternative design and manufacturing process is proposed. Instead of depositing composite tapes directly onto the complex mould, a flat tailored preform made from steered fibre tows is created first, and then the flat preform is subsequently formed into a 3D complex shape. The fibre path in the flat tailored preform is derived from a new virtual ‘un-forming’ process of a complex 3D part design with target fibre paths. To demonstrate the process, a small doubly curved composite part was un-formed. Fibre-steered tailored preforms were created using the continuous tow shearing (CTS) technique and then formed into the target shape using double diaphragm forming. The as-manufactured part was compared with the as-designed part as well as a part manufactured from straight fibre prepreg. The results demonstrated the feasibility of the virtual un-forming process and the potential of proposed manufacturing route.

Measuring sustainability of renewable diesel production using a multi‐criteria decision matrix

AbstractThis study presents a multi‐criteria decision matrix approach to the sustainability analysis of renewable diesel processes. The criteria include environmental, economic, technical, and fuel‐quality aspects. The main objective is to establish a comprehensive approach to the sustainability analysis of alternative manufacturing processes. A combination of an analytical hierarchy process method and an entropy method is used to obtain both subjective and objective weighting factors to achieve a more reliable and comprehensive comparison among alternatives. The technique for order of preference by similarity to ideal solution (TOPSIS) method is used to rank the alternatives based on the distance of each alternative to the ideal and non‐ideal solutions. This analysis indicates that the most sustainable processes are the process associated with Fischer–Tropsch diesel, and the catalytic hydrotreatment of vegetable oils to produce green diesel (GD I). The results determined that algae‐based green diesel (GD III) was the least favorable process. This is because GD III has the highest impact on the water scarcity footprint and unit production cost indicators. This multi‐criteria analysis with estimated weight factors can be an effective generic method for sustainability assessment of alternative manufacturing processes. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Biomimetic Approach for the Production of 3D Woven Spherical Composite Applied in Apparel Protection and Performance

Current sports bras are typically manufactured via a cut and sew process resulting in a high volume of post-production material waste. Seams derived from this cut and sew process are known to irritate the skin during exercise. This irritant discomfort seriously affects the dynamic comfort during exercise, hindering limb movement and displacement of the female breast. It implies a need for an alternative textile manufacturing process for a seamless sportswear-sports bra to combine the surface aesthetics with biomimetics together with anthropometry and ergonomic data. Tailoring the two yarn interlocking directions (0/90°) within the compound structure of a multilayer multilevel weave architecture provides a construction process to the production, the weaving, of seamless 3D woven spherical forms. Seamlessly shaped wovens in this paper are underpinned by biomimetic anthropometry and real-time data to produce variable spherical forms that mould and support a given set of 3D geometries. Upon completion of the weave generation using specialised weave software, the production parameters are completed upon transfer to the combined weaving technology, Mageba-Staubli Unival 100 (MS-100). The 2D on-loom woven fabric converts to a 3D shape upon removal and by pulling-pushing-unfolding the woven fabric (2D-to-3D). The scope of end applications within the sportswear-sports bra sector (but not limited to) enables a framework for the generic design geometries and production principles.