Hasil untuk "Production capacity. Manufacturing capacity"

Bruna Andrade, Aguinaldo dos Santos, Ana Cristina Broega et al.

This research raises questions regarding a systemic change in the current footwear production and consumption model, through the use of strategies oriented towards Distributed Manufacturing and Digital Fabrication of shoes components. It aims to validate such strategies for a sustainable local production, providing small companies of the sector more autonomy and involvement in the processes, towards a more distributed and hybrid (digital and artisanal) manufacturing process. It emphasizes the development of Distributed Economy solutions through the creation of value for actors in small local businesses in the sector. Through a single case study with a participatory observation, the process of redesigning a shoe was conducted in 4 main phases with a small local company in the sector in partnership with a makerspace. The project was carried out with the support of design tools to develop solutions, and as a result, a prototype of a shoe was obtained, made in collaboration between the actors, showing that the local-global capacity of the Distributed Manufacturing via Digital Fabrication strategy has the potential to provide sustainable alternatives to the complex global supply chains for footwear and a possible solution to the excessive consumption of resources in this sector.

Andjelija Mitrovic, Jelena Jovanovic, Maja Radovic et al.

This study focuses on the prediction and analysis of temperature distribution during end milling of AISI 4340 steel. The influence of cutting parameters—cutting speed, feed per tooth, and depth of cut—on temperature generation in the cutting zone was investigated using a CCD experimental plan. Temperature was measured with a thermal imaging camera, while the milling process was simulated using Third Wave AdvantEdge 7.1 FEM software. The obtained temperatures ranged from 74 °C to 200 °C, depending on the cutting conditions. A second-order regression model with three factors was developed and showed an average prediction error of 8.62%, while the alternative fitted model had an average error of 10.91%. FEM simulations using AdvantEdge 7.1 demonstrated a somewhat higher deviation, with an average error of 14.75% relative to experiments. The highest deviations for all approaches occurred at extreme cutting parameters (very low or very high depth of cut). The study demonstrates that FEM simulations are an effective tool for predicting thermal behavior in milling and optimizing cutting parameters. Accurate prediction of cutting zone temperatures can improve tool life, enhance process efficiency, and support the selection of optimal machining conditions, which is very important from an industry point of view.

Berend Denkena, Jörg Wallaschek, Henning Buhl et al.

In micro-production technology (MPT), the demand for ultra-precise machine tools has been steadily increasing. Conventional guideway systems, such as hydrostatic or aerostatic bearings, often face limitations in terms of compactness, media supply, and susceptibility to external disturbances, which restrict their applicability in next-generation precision manufacturing. In order to address these challenges, this paper presents a novel media-free, contactless, and active three-degree-of-freedom (DOF) planar positioning (guiding) system that integrates ultrasonic actuators with electromagnetic actuators. The hybrid concept combines the high load capacity and self-stabilization of double-acting ultrasonic actuators and pronounced controllability of the electromagnetic actuators. A prototype system was developed and experimentally validated. Ultrasonic actuators successfully established a stable levitation state, while electromagnetic actuators provided fine adjustment of the levitation height in the micrometer range. Load tests demonstrated that the system maintained stable levitation under an external load of 30 N. These results confirm the feasibility of the proposed approach for robust and precise positioning. The developed hybrid system therefore represents the potential for next-generation precise manufacturing machines in MPT, offering high accuracy and robustness against external disturbances.

Walid Jomaa, Monzer Daoud, Hamid Javadi et al.

This paper aims to investigate the effectiveness of cutting fluid during the high-speed face-turning of superalloy Inconel 718 using chamfered whisker-reinforced ceramic inserts. It addresses this topic by providing a comprehensive understanding of the machinability of Inconel 718 under both dry and wet conditions through analytical friction modeling and a detailed analysis of the chip formation process. Two new indexes, named the Area Function (<i data-eusoft-scrollable-element="1">AF</i>) and the Shape Function (<i data-eusoft-scrollable-element="1">SF</i>), were derived to assess the serration intensity of the chips. Particular attention was paid to the interaction between the cutting speed and the cutting fluid. The results showed that wet conditions promote uniform chip formation, more stable forces, a lower coefficient of friction, and the absence of notch wear. At low cutting speed (60 m/min) and dry machining results in high serration intensity (<i data-eusoft-scrollable-element="1">SF</i> = 0.7) and segmentation frequency (<inline-formula data-eusoft-scrollable-element="1"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline" data-eusoft-scrollable-element="1"><semantics data-eusoft-scrollable-element="1"><mrow data-eusoft-scrollable-element="1"><msub data-eusoft-scrollable-element="1"><mrow data-eusoft-scrollable-element="1"><mi data-eusoft-scrollable-element="1">f</mi></mrow><mrow data-eusoft-scrollable-element="1"><mi data-eusoft-scrollable-element="1">s</mi><mi data-eusoft-scrollable-element="1">e</mi><mi data-eusoft-scrollable-element="1">g</mi></mrow></msub></mrow></semantics></math></inline-formula> = 22.08 kHz) compared to the <i data-eusoft-scrollable-element="1">SF</i> of 0.4 and <inline-formula data-eusoft-scrollable-element="1"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline" data-eusoft-scrollable-element="1"><semantics data-eusoft-scrollable-element="1"><mrow data-eusoft-scrollable-element="1"><msub data-eusoft-scrollable-element="1"><mrow data-eusoft-scrollable-element="1"><mi data-eusoft-scrollable-element="1">f</mi></mrow><mrow data-eusoft-scrollable-element="1"><mi data-eusoft-scrollable-element="1">s</mi><mi data-eusoft-scrollable-element="1">e</mi><mi data-eusoft-scrollable-element="1">g</mi></mrow></msub></mrow></semantics></math></inline-formula> = 19.69 kHz in wet conditions. The segmentation frequency increases significantly with cutting speed, reaching 71.03 kHz and 63.32 kHz at a cutting speed of 225 m/min for dry and wet conditions, respectively. It was also found that the rate of increase in the tangential force was lower (20.49 N/s) when using cutting fluid at a high cutting speed (225 m/min) compared to dry conditions (27.37 N/s).

Hongjun Li, Yongqi Le, Hao Xu et al.

This paper designs a Dual path cold spray nozzle and studies its performance during the cold spray process through numerical simulations and optimization experiments. The gas flow field inside the nozzle and the particle acceleration process were simulated using Fluent software2020R1. The orthogonal experimental method was used to analyze the effects of five geometric parameters on the nozzle performance, determining the optimal design parameter combination. Modeling and simulation calculations based on the optimal parameter combination showed that the average particle impact velocity increased by nearly 17 m/s, the number of particles exceeding the theoretical critical velocity increased by nearly 100, and the theoretical deposition efficiency improved by 10%. Experimental results indicated that compared to the single-channel nozzle, the deposition efficiency increased from 20.22% to 28.26%, the porosity improved from 10.51% to 9.12%, and the deposition microhardness also increased. The experimental test data were in good agreement with the previous numerical simulation results, validating the accuracy of the simulation model and providing an important theoretical reference for the optimization and improvement of subsequent process parameters.

Demir, Mehmet, Hingst, Lennart, Schmidt, Matthias et al.

In the 1970s, markets changed from a seller's to a buyer's market, leading to an increasing variety of product variants. This variety confronts manufacturing companies with significant challenges, especially when integrating new product variants into existing factory systems. Decisions about new product variants are usually made by the marketing and development departments, while production and logistics, the areas most affected, are often insufficiently involved and have to deal with the resulting consequences. Therefore, identifying unprofitable product variants before production begins is crucial for preventing irreversible costs and ensuring long-term competitiveness and sustainability. This paper presents a systematic description model to evaluate the impact of new product variants on existing factory systems. For this, relevant change dimensions of new product variants are identified and an approach for an evaluation and decision model is developed to assess the effects of a new product variant before the start of production. The model serves as a decision support tool, providing a transparent view of how new product variants influence factory systems. The paper concludes with a future research outlook, emphasizing the identification of interactions between factory systems and product characteristics, as well as the definition of capacity limits in existing systems.

Alexander Watson, Masoud Rais-Rohani, John Belding et al.

Additive manufacturing of metals is limited by a fundamental tradeoff between deposition rates and manufacturability of fine-scale features. To overcome this problem, a laser-ablated bound metal deposition (laBMD) process is demonstrated in which 3D-printed green-state bound metal deposition (BMD) parts are post-processed via laser ablation prior to conventional BMD debinding and sintering. The laBMD process is experimentally characterized via a full-factorial design of experiments to determine the effect of five factors—number of laser passes (one pass, three passes), laser power (25%, 75%), scanning speed (50%, 100%), direction of laser travel (perpendicular, parallel), and laser resolution (600 dpi, 1200 dpi)—on as-sintered ablated depth, surface roughness, width, and angle between ablated and non-ablated regions. The as-sintered ablation depth/pass ranged from 3 to 122 µm/pass, the ablated surface roughness ranged from 3 to 79 µm, the angle between ablated and non-ablated regions ranged from 1° to 68°, and ablated bottom widths ranged from 729 to 1254 µm. This study provides novel insights into as-manufactured ablated geometries and surface finishes produced via laser ablation of polymer–metallic composites. The ability to inexpensively and accurately manufacture fine-scale features with tailorable geometric tolerances and surface finishes is important to a variety of applications, such as manufacturing molds for microfluidic devices.

Samuel Lisi, Antonio Rieser

We introduce a new coisotropic Hofer-Zehnder capacity and use it to prove an energy-capacity inequality for displaceable Lagrangians.

Samuel Kernan Freire, Chaofan Wang, Mina Foosherian et al.

Recent advances in natural language processing enable more intelligent ways to support knowledge sharing in factories. In manufacturing, operating production lines has become increasingly knowledge-intensive, putting strain on a factory's capacity to train and support new operators. This paper introduces a Large Language Model (LLM)-based system designed to retrieve information from the extensive knowledge contained in factory documentation and knowledge shared by expert operators. The system aims to efficiently answer queries from operators and facilitate the sharing of new knowledge. We conducted a user study at a factory to assess its potential impact and adoption, eliciting several perceived benefits, namely, enabling quicker information retrieval and more efficient resolution of issues. However, the study also highlighted a preference for learning from a human expert when such an option is available. Furthermore, we benchmarked several commercial and open-sourced LLMs for this system. The current state-of-the-art model, GPT-4, consistently outperformed its counterparts, with open-source models trailing closely, presenting an attractive option given their data privacy and customization benefits. In summary, this work offers preliminary insights and a system design for factories considering using LLM tools for knowledge management.

John D. Kechagias, Nikolaos A. Fountas, Konstantinos Ninikas et al.

This work deals with the experimental investigation and multi-objective optimization of mean kerf angle (A) and mean surface roughness (Ra) in laser cutting (LC) fused filament fabrication (FFF) 3D-printed (3DP), 4 mm-thick polylactic acid (PLA) plates by considering laser feed (F) and power (P) as the independent control parameters. A CO₂ laser apparatus was employed to conduct machining experiments on 27 rectangular workpieces. An experimental design approach was adopted to establish the runs according to full-combinatorial design with three repetitions, resulting in 27 independent experiments. A customized response surface experiment was formulated to proceed with regression equations to predict the responses and examine the solution domain continuously. After examining the impact of F and P on mean A and mean Ra, two reliable prediction models were generated to model the process. Furthermore, since LC is a highly intricate, non-conventional machining process and its control variables affect the responses in a nonlinear manner, A and Ra were also predicted using an artificial neural network (NN), while its resulting performance was compared to the predictive regression models. Finally, the regression models served as objective functions for optimizing the responses with an intelligent algorithm adopted from the literature.

Diogo Cunha, Raul Fangueiro, João Bessa et al.

Fibrous materials are often used in the manufacturing of fire protection devices such as fire curtains. Their optimization and improved performance is still a topic of interest. The present work aims to develop and test a new combination of fibers arranged in various 2D and 3D patterns with coatings. For this purpose, basalt fibers were added into a glass fiber fabric, and wires of a shape memory material (SMM) were inserted into the fabric to create air pockets induced by temperature. In fire curtains, the base structure is a 2D basket pattern, and all combinations were tested with and without a waterborne polyurethane (WPU) coating with inorganic materials. Three different tests were selected to characterize the thermal behavior: fire resistance, ignitability, and smoke production. Fiberglass proved to be the best material to provide thermal resistance in fire curtains, with the outer surface temperature of the fabric below 650 °C at the end of the tests. The SMM wires provided good protection during the initial stages of the test, but a combination of excessive deformation and reduced strength of the fabric resulted in a sudden failure of the structure. Basalt fibers contribute to a reduction of smoke production. It was observed an improvement of up to 10% in the thermal capacity between 1MIX2 (glass fibers fabric with coating, MIX2) and the best commercial curtain evaluated, Commercial3 (glass and steel fibers fabric with coating).

Bernd-Arno Behrens, Kai Brunotte, Julius Peddinghaus et al.

Due to the high specific surface area of titanium aluminide powders, significant and unavoidable surface oxidation takes place during processing. The resulting oxides disrupt the conventional powder metallurgical process route (pressing and sintering) by reducing the green strength and sintered properties. Oxide-free particle surfaces offer the potential to significantly increase particle bond strength and enable the processing of difficult-to-press material powders. In this work, the effect of milling titanium aluminide powder in a silane-doped atmosphere on the component properties after pressing and the subsequent sintering was investigated. Ball milling was used to break up the oxide layers and create bare metal surfaces on the particles. With the help of silane-doped inert gas, the oxygen partial pressure was greatly reduced during processing. It was investigated whether oxide-free surfaces could be produced and maintained by milling in silane-doped atmospheres. Furthermore, the resulting material properties after pressing and sintering were analysed using density measurements, hardness tests, EDX measurements, and micrographs. It was concluded that ball milling in a silane-doped atmosphere produces and maintains oxide-free particle surfaces. These oxide-free surfaces and smaller particle sizes improve the component properties after pressing and sintering.

Luke Osmond, Ian Cook, Tom Slatter

This work characterises the structure and mechanical properties, such as adhesion, of two different chemical vapour deposition (CVD) coatings deposited onto silicon aluminium oxynitride (Si₃N₄ + Al₂O₃ + Y₂O₃) round (RNGN) milling cutter tooling inserts. These inserts are often known by the trade abbreviation “SiAlON”. Wear was produced on the inserts using unidirectional sliding (pin-on-disc type) and scratch testing. Two coatings were investigated: a multilayer CVD coating (Coating A) with a composition of TiN + TiCN + Al₂O₃ and a bilayer coating (Coating B) with a composition of Al₂O₃ + TiN. Microstructural analysis was conducted after wear testing and Coating B demonstrated high stability when subjected to high alternating shear and tensile stresses, high abrasion resistance and very high adhesion to the SiAlON ceramic insert substrate when compared to Coating A. Coating A demonstrated a low capacity to distribute alternating shear and tensile stresses during the pin-on-disc and scratch testing, which led to failure. The scratch and pin-on-disc results from this study correlate highly with completed machining insert wear analysis that has used Coating A and Coating B SiAlON inserts to machine aged Inconel 718.

Manas K Patra

Given a unitary operator $U$ acting on a composite quantum system what is the entangling capacity of $U$? This question is investigated using a geometric approach. The entangling capacity, defined via metrics on the unitary groups, leads to a \emph{minimax} problem. The dual, a \emph{maximin} problem, is investigated in parallel and yields some familiar entanglement measures. A class of entangling operators, called generalized control operators is defined. The entangling capacities and other properties for this class of operators is studied.

Yuxiang Lu, Yuhang Yao, Syed A. Jafar

Inspired by recent work by Christensen and Popovski on secure $2$-user product computation for finite-fields of prime-order over a quantum multiple access channel, the generalization to $K$ users and arbitrary finite fields is explored. Asymptotically optimal (capacity-achieving for large alphabet) schemes are proposed. Additionally, the capacity of modulo-$d$ ($d\geq 2$) secure $K$-sum computation is shown to be $2/K$ computations/qudit, generalizing a result of Nishimura and Kawachi beyond binary, and improving upon it for odd $K$.

Aliosha I. Figueroa-Valdés, Aliosha I. Figueroa-Valdés, Aliosha I. Figueroa-Valdés et al.

Cell therapy is witnessing a notable shift toward cell-free treatments based on paracrine factors, in particular, towards small extracellular vesicles (sEV), that mimic the functional effect of the parental cells. While numerous sEV-based applications are currently in advanced preclinical stages, their promised translation depends on overcoming the manufacturing hurdles posed by the large-scale production of purified sEV. Unquestionably, the culture medium used with the parental cells plays a key role in the sEV’s secretion rate and content. An essential requisite is the use of a serum-, xeno-, and blood-free medium to meet the regulatory entity requirements of clinical-grade sEV’s production. Here, we evaluated OxiumTMEXO, a regulatory complying medium, with respect to production capacity and conservation of the EV’s characteristics and functionality and the parental cell’s phenotype and viability. A comparative study was established with standard DMEM and a commercially available culture medium developed specifically for sEV production. Under similar conditions, OxiumTMEXO displayed a three-fold increase of sEV secretion, with an enrichment of particles ranging between 51 and 200 nm. These results were obtained through direct quantification from the conditioned medium to avoid the isolation method’s interference and variability and were compared to the two culture media under evaluation. The higher yield obtained was consistent with several harvest time points (2, 4, and 6 days) and different cell sources, incluiding umbilical cord-, menstrual blood-derived mesenchymal stromal cells and fibroblasts. Additionally, the stem cell phenotype and viability of the parental cell remained unchanged. Furthermore, OxiumTMEXO-sEV showed a similar expression pattern of the vesicular markers CD63, CD9, and CD81, with respect to sEV derived from the other conditions. The in vitro internalization assays in different target cell types and the pharmacokinetic profile of intraperitoneally administered sEV in vivo indicated that the higher EV production rate did not affect the uptake kinetics or the systemic biodistribution in healthy mice. In conclusion, the OxiumTMEXO medium sustains an efficient and robust production of large quantities of sEV, conserving the classic functional properties of internalization into acceptor target cells and biodistribution in vivo, supplying the amount and quality of EVs for the development of cell-free therapies.

Petruța Blaga

Abstract In order to improve the production results, a number of techniques, methods or tools belonging to Quality Management and Human Resources Management can be applied to increase production capacity, the volume of manufactured products and the production quality. The paper aims to present the usage of quality tools and human resources management, in a company in the field of automotive production, to achieve positive results, in terms of increasing production capacity, the volume of products and therefore, their quality, through staff motivating as an effect of the usage and application of quality tools in the field of electrical and electronic equipment manufacturing for motor vehicles. The paper highlights both the Quality Management tools applied within the company and a number of aspects that focused on the motivation and active involvement of the human factor in the processes of continuous improvement in order to increase the production efficiency. Applying the tools of Quality Management and Human Resource Management in all the production departments of the company has led to the identification of the causes that affect employees’ involvement in the process of continuous improvement in production. After analyzing the identified causes, the management of the company has established to develop programs and actions involving employees in the continuous improvement process. These continuous improvement processes carried out in order to increase the production efficiency, have led to cost reductions, in the period under review, causing significant gains for the company.

Saptarshi Pal, Ayan Chatterjee, Dripto Bakshi et al.

This work addresses the problem of evaluating optimal link capacities of a packet-flow network for the objective of congestion minimization. We present a simple model of packet flow in networks and present a numerical approach to evaluate packet flow probability mass function at any arbitrary edge of the network for a given routing algorithm and traffic rate. We further discuss techniques of assigning optimal capacity at each edge for attaining desired minimized congestion and discuss related trade-offs. Our framework is built around the assumption of Poisson traffic, however the numerical approach fits for any general distribution of packet influx. Lastly, we define metrics of global performance of link capacities allocation and discuss the effect of network structure on capacity allocation and performance.

Roberto Donizeti Leme Júnior, A. O. Nunes, Luana Bonome Message Costa et al.

Abstract It is possible to create value with less environmental impact through the adoption of Lean and Green manufacturing concepts and tools. This paper proposes a Lean-Green model based on the application of the Single Minute Exchange of Die (SMED) combined with Carbon Footprint (CF) to analyze eco-efficiency of a machining center in a case study in Brazil. The novelty of this paper was the proposal of a Lean-Green model based on ecoefficiency indicators to measure performance of production systems toward a cleaner production. The developed Lean-Green model should be used by companies with low-capacity of production due to restrictions of machine availability. The case study was organized in five different scenarios by varying machine tools, workers and workpieces. First, the SMED tool was applied in the setup activities and gains of reduced idle times were up to 88%. CF results were reduced up to 81% after applying the SMED tool on each scenario. Lastly, an eco-efficiency set of indicators were used to combine results of SMED and CF, and results of eco-efficiency were 3% higher even with higher CF values after converting setup saved time into productive time. To achieve such results simple improvements were performed in the machining center, through the standardization of work and the study of time and methods for setup activities, showing that the proposed Lean-Green model could be also adopted by other companies to create value with less impact.

A. Pooya, M. Pakdaman