Existing Process Chains Research Articles

Insights Into Scalable Technologies and Process Chains for Sulfide‐Based Solid‐State Battery Production

AbstractThe successful utilization of innovative sulfide‐based solid‐state batteries in energy storage hinges on developing scalable technologies and machinery for upscaling their production. While multiple Gigafactories for lithium‐ion batteries are already operational worldwide, the upscaling of solid‐state batteries exhibiting their full potential remains to be seen in the near future. In this study, the conventional production of lithium‐ion batteries is reconsidered, and the feasibility of seamlessly integrating sulfide‐based solid‐state batteries into the existing process chains is discussed. Scalable technologies and key challenges along the process chain of sulfide‐based solid‐state batteries are accordingly addressed. Experimental investigations yield crucial insights into enabling large‐scale production of sulfide‐based battery components while highlighting remaining challenges from a production perspective. An overview of the roll‐to‐roll machinery housed in microenvironments under an inert atmosphere in the “Sulfidic Cell Production Advancement Center” at the Institute for Machine Tools and Industrial Management at the Technical University of Munich is given.

Concept for Digital Twin Based Virtual Part Inspection for Additive Manufacturing

Quality assurance is one of the main challenges for additive manufacturing. In-process quality assurance measures and, in particular, part inspection after production are time-consuming and cost-intensive. Most existing quality assurance approaches were developed for traditional manufacturing technologies like milling or turning and have been optimized over the years. Due to its unique process characteristics, these approaches will not easily translate to additive manufacturing. So, a new holistic approach for quality assurance in additive manufacturing is necessary for wider dissemination of additive manufacturing in all industry sectors.The Department of Computer Integrated Design at the TU Darmstadt sees digital twins in additive manufacturing as a promising approach to tackle these problems. This paper provides a building block for digital twin-based quality assurance by proposing a concept for a virtual part inspection. In this concept, data from product development and product manufacturing are combined to make predictions about the properties of the as-built part. The concept was developed under consideration of the digital twin architecture consisting of digital master and digital shadow and is integrated into the existing process chain for additive manufacturing.

Application of load-adapted hybrid textiles for a thermoplastic seat pass-through

The potential of a continuous non-crimp fabric (NCF) process with implemented offset technologies is demonstrated by a case study of a seat pass-through. Topology optimization with the relevant load cases and the construction of a load-adapted composite design with a weight saving of up to 18 percent is presented. Inverse draping identifies a two-dimensional development of the construction and prepares it for production based on the restrictions of textile technology. The downstream process capability of textiles produced in this way was investigated by impregnating heavy tows with polypropylene on laboratory scale and subsequent material characterization of the resulting laminates. The impregnation and consolidation of the seat pass-through is performed with load path adapted semi-finished products using novel variothermal, fluid-based pressing. This allows better control over the dynamic impregnation and unwanted fiber washing due to the large gradient of the areal weight. The final processing in injection molding tool of the reference component shows the applicability of the technology also in existing process chains and illustrates the potential of the consistent consideration of a load-adapted composite design in the development process.

Introduction to tailored forming

In recent years, the requirements for technical components have been increasing steadily. This development is intensified by the desire for products with lower weight, smaller size and extended functionality, but at the same time higher resistance against specific loads. Mono-material components manufactured according to established processes reach their limits regarding conflicting requirements. It is, for example, hardly possible to combine excellent mechanical properties with lightweight construction using mono-materials. Thus, a significant increase in production quality, lightweight design, functionality and efficiency can only be reached by combining different materials in one component. The superior aim of the Collaborative Research Centre (CRC) 1153 is to develop novel process chains for the production of hybrid solid components. In contrast to existing process chains in bulk metal forming, in which the joining process takes place during forming or at the end of the process chain, the CRC 1153 uses tailored semi-finished workpieces which are joined before the forming process. This results in a geometric and thermomechanical influence on the joining zone during the forming process which cannot be created by conventional joining techniques. The present work gives an overview of the CRC and the Tailored Forming approach including the applied joining, forming and finishing processes as well as a short summary of the accompanying design and evaluation methods.

Bottleneck reduction strategies for energy efficiency in the battery manufacturing

Regulative and social changes towards sustainability are promoting a significant growth of the electromobility sector. Lithium-ion batteries play a major role in this context; however its complex and energy-intensive process chain is responsible for a large part of cradle-to-gate impacts of electric vehicles. Therefore, this work discusses the influence of bottleneck reduction on the energy demand to foster energy efficiency in battery manufacturing. Based on data from the Battery LabFactory Braunschweig, a discrete event simulation is applied to identify bottlenecks and different scenarios for bottleneck reduction are analyzed. Next to improving existing process chain, the results may support the planning of new energy efficient installations.

Physico-Chemical Foundation of Sludge Processing Hydrometallurgical Production of Vanadium Pentoxide. Investigation of Forms of Vanadium Compounds


 
 
 To develop the physico-chemical basis of a complex technology for processing slurries hydrometallurgical production of vanadium pentoxide it is necessary to know in what form vanadium compounds are in the dump sludge and at what stage of processing they were formed, which is why vanadium is not completely extracted into the solution. This paper investigates the behavior of vanadium in the existing process chain (with the study of intermediate products of technological conversion) using a set of modern analytical methods (X-ray diffraction, SEM, X-ray diffraction, thermogravimetry).
 Keywords: vanadium, slag, sludge, vanadium pentoxide, oxidation state, phase composition, processing technology
 
 

Needle in a haystack: Mapping rare and infrequent crops using satellite imagery and data balancing methods

Most cropping systems around the world are organised around few dominant crops and a larger number of less frequent crops. While rare and infrequent crops occupy a small share of the cropped area, they produce ecological benefits on farmland, contribute to sustainability and help provide food and nutritional security. However, data about their location and extent derived from satellite imagery generally lack accuracy, largely owing to the class imbalance problem. Class imbalance occurs when only few instances of some classes are available for training classifiers, and leads to large error rates of the infrequent classes. In this study, we assessed the magnitude of the class imbalance problem in crop classification and evaluated balancing methods to combat it by creating synthetic minority observations or by removing majority observations. To that aim, we generated 18 unbalanced data sets from Sentinel-2 time series and crop type observations in Victoria, Australia. These data sets covered a wide range of complexity, number of classes, number of samples per class and spectral separability which enabled us to gather evidence about the benefits and drawbacks of balancing methods in various settings. Classification accuracy was assessed with two metrics: the Overall Accuracy (OA), which gives more weight to majority classes, and the G-Mean accuracy (GM), which is more sensitive to minority classes. Results showed that class imbalance explained near 40% of the accuracy variability. We found that balancing methods boosted GM by 0.01–0.54 but no single best solution emerged. The price for increasing the accuracy of minority classes was a drop in OA of a magnitude that was problem- and method-specific. We thus applied an algorithm selection method called the F-race to identify optimal balancing methods in a computationally economic fashion. Optimal balancing methods lead to maximum gain in GM and minimum loss in OA. We demonstrated that this approach either successfully identified optimal balancing methods or ones that were not significantly sub-optimal, while reducing the computational cost by up to 60%. It can readily be incorporated to operational crop classification systems with little disruption to the existing processing chains. This contribution paves the way for achieving a more comprehensive and detailed view of crop distribution and cropping sequences.

Manufacture of face gearing – a new production method by means of determined material pre-distribution

Research subject of this paper concerns the manufacturing of face gearing on hollow shafts. Currently, the toothing is produced by a coining process. This results in high process forces which strongly restrict the geometry of teeth in height-to-width ratio. In order to avoid these problems, a new forming process has been developed. Using determined material pre-distribution, it is possible to produce the teeth by the newly developed process of face gear coining with defined material flow.This paper describes the design and functionality of the new forming process. Furthermore, the proposed process is explained and compared with the conventional approach of coining using numerical simulations. In order to investigate the influence of preform parameters on the full filling of the teeth shape, a parameter study in design and geometry is conducted. Based on simulation results, the newly developed forming process is integrated in an already existing process chain. By means of this investigation, the potential of this innovative forming process will be indicated.

Deposition of Copper Oxide Coatings With an Atmospheric Pressure Plasma Source: I − Characterization of the Plasma

Metal oxide coatings have a variety of applications in industrial processes. As some of them have bio-sensitive properties there is growing interest for their use in medical applications as well. Thus, the development of suitable deposition techniques is of major importance for these purposes. From these techniques plasma deposition at atmospheric pressure offers a promising approach as there is no need for vacuum systems accompanied by lower costs, less process time, and easier integration into existing process chains. In order to optimize the coating process, a good knowledge of the plasma is needed. In this work, we present investigations on the plasma properties performed by systematic optical emission spectroscopy (OES) measurements.

Investigation of Simulation Parameters for Flash‐Reduced Forging of Two‐Cylinder Crankshafts

Flash‐reduced forging is a promising alternative for forging complicated high‐duty parts. With a new process chain, the ability to reduce the existing flash quota of complex high‐duty parts can make the difference in the competition and reduce the costs compared to flashless forging. The European Union is funding a research project which deals with the improvement of the forging sequence of a two‐cylinder crankshaft by using flash‐reduced forging. To increase the forecast quality of simulations using Finite‐Element‐Analysis for a future process chain design, the conventional existing process chain is simulated with FORGE3 and compared with industrial forging trials. Furthermore, a variation of simulation parameters has been used to get the significant influence parameters, fitting the results of these forging trials.

Integrating Micro-Pollutant Removal by Powdered Activated Carbon into Deep Bed Filtration

Adsorption onto powdered activated carbon (PAC) is a promising option to remove organic micro-pollutants (OMP) from drinking water sources or wastewater. Since this treatment option requires continuous PAC dosing, sufficient contact time and subsequent separation of the PAC, the integration into existing process chains is challenging. In the present investigation, the pre-loading of a deep bed filter with PAC used as fixed bed adsorber was investigated. The retention and distribution of an exemplary PAC in a pumice rapid filter were determined. Gravimetry combined with combustion of the PAC at 550 °C was applied to differentiate between PAC and filter material residues and revealed comparably high PAC immobilization in the upper third of the pumice filter. Comparative adsorption experiments in batch with suspended PAC and continuous filtration tests with immobilized PAC showed advantageous results for immobilized PAC with regard to the removal of OMP and the sum parameters dissolved organic carbon and UV light absorption at 254 nm wavelength. The results indicate that a conventional rapid filter together with PAC can be effectively utilized as fixed bed adsorption filter.

Precision Mold Manufacturing for Polymer Optics

Ophthalmic lenses, sensors, and sunglasses, among other things, are commonly made of polymer materials. Therefore, polymer optics is a growing market mainly for medium quality but also for precision optics. Polymer optics are usually produced in an injection molding process. Due to high quality requirements on the final product, the manufacturing process of the molds has to be very accurate and precise. Thus the master tool has to be fabricated to a high quality with regard to shape accuracy and roughness. The focus of this article is on the process chain for the fabrication of molds for polymer optics and the finite element simulation of this process. The typical existing process chains contain steps like nickel plating, diamond machining and manual polishing. Some of these steps are expensive and require very experienced staff. In the new process chain, an industrial robot with special tools is used for lapping and polishing. Robot polishing replaces the former nickel plating, diamond machining, and manual polishing steps. The lapping/polishing process was newly developed to achieve appropriate results. Different tool materials, polishing agents, and process parameters have been tested and compared to the finite element simulation to obtain excellent results directly on different mold materials.

Combining Landsat TM/ETM+ and ALOS AVNIR-2 Satellite Data for Tropical Forest Cover Change Detection

The European Commission funded Tropical Ecosystem Environment Observation by Satellite (TREES) project aims to assess the forest cover and its changes within the pan- tropical belt. Statistics for the monitoring target periods 1990, 2000 and 2010 are derived from analyzing a systematic sample set of satellite imagery mainly from the Landsat TM and ETM+ sensors. To reach full coverage of all sample sites for the year 2010 epoch and to ensure data continuity for possible future epochs the usage of alternative satellite data is inevitable. In this study the replacement of Landsat data with ALOS AVNIR-2 data was tested. Adaptations of the existing processing chain are presented as well as the results of an accuracy assessment. The results show that AVNIR-2 data are generally suitable to substitute Landsat data in this context.

Material Flow in Sheet-Bulk Metal Forming

Innovative trends like increasing component functionality, the demand for automotive lightweight constructions and the economic issue to optimize existing process chains, require new ways in manufacturing. Today, the traditional sheet metal and bulk metal forming processes are often reaching their limits if closely-tolerated complex functional components with variants have to be produced. A promising approach is the direct forming of high-precision shapes starting from blanks. Thus, classic sheet metal forming operations, such as deep drawing, are combined with bulk metal forming operations like extrusion of complex variants as for example teeth. This combination of sheet and bulk metal forming operations leads to a side by side situation of different tribological conditions according to the locally varying load situations within the same forming process. This new class of forming processes is defined as sheet-bulk metal forming (SBMF). The tribological conditions in sheet-bulk metal forming processes are of major importance for the process realization, its stability and for the quality of the produced part. The objective of this paper is the investigation of material flow in SBMF in general and the attempt to improve the material flow by local adapted tribological conditions. First the material flow was analyzed by FE-simulation of a model geometry that is typical for SBMF. The investigations with FE-simulation have shown, locally adapted tribological conditions are leading to an improvement in material flow and thus to an increased mould filling. As frictional conditions are directly connected to the topography of workpiece and tool, the modification of the workpiece topography is leading to an alteration in friction values. For the modification of workpiece topography grit blasting was used. The increase in friction of grit blasted surface towards untreated surface was investigates by using the laboratory friction tests. To manufacture specimens with locally adapted topographies for forming tests a masking technique has been developed. The masks are designed after the preliminary findings determined by FE-simulation.

High aspect ratio- and 3D- printing of freestanding sophisticated structures

This paper presents work towards a printing technology which provides the fabrication foundation of high aspect ratio- and 3D freestanding sophisticated structures with an aspect ratio over 150. Via connection of the printing technology and a computer aided design system a fast and cost-efficient fabrication process for prototypes manufacture and low volume production. These printing process in combination with mold and die production processes of Microsystems Engineering afford the potentiality for tool fabrication. Without the requirement of defined ambient conditions with narrow complexity this print technology can be implemented effortlessly into an operating manufacturing-plant, this provides the chance to optimize existing process chains shortly.

Coupled production in biorefineries—Combined use of biomass as a source of energy, fuels and materials

In spite of high prices for fossil raw materials the production of biomass-based products is rarely economically successful today. Depending on the location feedstock prices are currently so high that products from renewable resources are not marketable when produced in existing process chains. Apart from the higher feedstock costs one reason is that at present no optimized production systems exist in contrast to the chemical and petrochemical industry where these systems have been established over the last decades. If we succeed in developing production systems modelled on those of petroleum refineries where we can provide a flexible coupled production of energy, fuels, materials and chemicals chances are good to enable a lastingly successful production on the basis of renewable resources. Based on examples of fat-based and sugar-based concepts ideas for platform oriented biorefineries are outlined.

Influence of media on process stability in sheet metal hydroforming

The difference between sheet metal hydroforming and deep drawing is elementary: one half of the tool is substituted by hydraulic pressure. In order to guarantee an optimised forming result a tight cavity in the tool has to be created, since as soon as a leakage occurs, the forming pressure decreases rapidly and the forming operation is interrupted. The separation plane of the tool is the critical area for an occurring leakage because here a metallic sealing is often realised. Therefore, the objective of this paper is to present theoretical consideration on the leakage problematic in hydroforming. For illustration of the problem an existing process chain is presented in the beginning of this paper. Subsequently theoretical considerations are made. In the end a new strategy for defusing the leakage problem by changing the hydroforming media is presented in the outlook.

A model for the generation and evaluation of integrated manufacturing solutions for powertrain components

The vision to reduce secondary processing times dramatically has become a high priority in modern manufacturing enterprises. It is being realized that such improvements rely not only on the optimization of single processes but also on the layout optimization of the complete process chain. This is reflected in the increasing efforts by machine manufacturers to integrate multiple processing technologies into machining centres, thus shortening the process chains and reducing the overall lead-time. The purpose of the work described within is to develop a model that supports the user in identifying and evaluating potential integrated process chains. The model incorporates multicriteria analysis and net-present-value methodologies that enable assessment of the relative technological and economical advantages of the integrated manufacturing alternatives when compared to the conventional/ existing process chain. A case study undertaken that assessed whether laser hardening is a viable alternative for induction hardening for a particular powertrain component illustrates a particular instance in which the model was used.

Technologic Advance in Seismic Exploration-Its past and future-

Seismic reflection methods have been developed through several innovative steps in the history. They are : CDP (or CMP), geophone grouping, deconvolution and seismic migration methods evolved from 1960s through 1980s. Although their assumption was horizontally stratified layers, these techniques have been taken into standard acquisition and processing chain to image invisible subsurface structures such as petroleum reservoirs even for relatively complex structure where the assumption may break up.Due to the recent tendency to have their target structures in smaller scale or more complex than it used to be, new tendency is about to be brought into the existing processing chain. We may summarize the tendency as follows : a) true amplitude acquisition/processing to detect seismic signals with non-grouped geophones, i.e., mono-geophone acquisition, b) 4-C marine data acquisition (tri-component geophone and pressure gauge), c) deconvolution for deep water with vertical or deep-tow cable, d) multichannel signal processing to form seismic beams to enhance S/N, e) inclusion of anisotropy and attenuation to help quantitative processing like AVO (Amplitude Versus Offset), f) multi-resolutional imaging using measurements with different frequency signals, and g) GLI (Generalized Linear Inverse) type imaging.