This article presents the concept of building a discrete event simulation model of a production system in terms of statistical and probabilistic models, which is based on a fragment of a broader production process in the furniture industry. The purpose of the study was to evaluate the efficiency of a single-shift production process during the start-up phase and to determine the impact of implementing two- and three-shift systems. The discrete event simulation model was developed using actual production data collected during a single-shift operation. Scenarios were then designed to identify and quantify the necessary process adjustments required for the successful implementation of two- and three-shift systems. The authors demonstrated that simulation modeling of production processes based on probabilistic distributions provides information that is essential for effective capacity planning. The proposed percentile grids enabled clear visualization and precise assessment of production resource utilization in various shift configurations, facilitating decision-making regarding capacity expansion based on previously assumed data.
Oana Emilia Constantin, Genica Florina Oncica, Florina Stoica
et al.
Carrots, scientifically referred to as <i>Daucus carota</i> L., are widely recognized as one of the most consumed vegetables, frequently utilized in culinary applications and juice manufacturing, both commercially and domestically. This results in significant amounts of waste, primarily from the pomace. Carrot pomace represents a promising low-cost raw material for the production of value-added ingredients for the food and feed industries. The extraction of total carotenoids (TC) and the evaluation of antioxidant activity (AA) were optimized in this study by employing environmentally friendly methods, including ultrasonication. The Central Composite Design (CCD) was utilized in order to establish a response surface approach for the purpose of evaluating the impacts of extraction duration, temperature, and the ratio of material to solvent on the recovery of TC and AA. Under optimal conditions, the TC content was 38.20 mg/g of dry weight, with an antioxidant capacity of 1522.02 μmol TE/g DW, as determined by the ABTS assay. According to the findings, the optimal parameters for extraction were a temperature of 58.9 °C, a solvent mixture ratio of 20.35 mL/g, and a duration of 51 min. The proposed ultrasound-assisted process provides a sustainable and scalable approach for carrot pomace valorization, contributing to the development of circular and resource-efficient agro-industrial processing.
Claudia Solek, Jorge Crespo-Sánchez, Sergio Fuentes del Toro
et al.
Additive manufacturing (AM) has rapidly evolved from a prototyping tool into an effective method for producing end-use components, thanks to its ability to produce complex, lightweight and customised parts. However, this technique requires a thorough understanding of the long-term behaviour and degradation mechanisms of components, especially when polymers are involved in the printing process. Unlike polymer components manufactured using traditional methods, polymers produced through AM exhibit unique microstructures, anisotropies, and interfacial characteristics due to the layer-by-layer fabrication process. These features can affect how these materials respond to thermal, mechanical and environmental stresses over time. Furthermore, technology-specific processing parameters directly govern porosity distribution, crystallinity evolution, interlayer bonding quality, and residual stress development, all of which are key factors for ensuring long-term performance. This review aims to support researchers in the development of durable additively manufactured polymer components by systematically analysing polymer degradation mechanisms, accelerated ageing and lifetime prediction methodologies. Following a PRISMA-based screening process, approximately 160 international standards relevant to polymer durability in additive manufacturing were selected from an initial corpus of about 620 documents for in-depth analysis. Processing–structure–property relationships specific to the AM processing of polymers, including the commonly used FFF (fused filament fabrication), SLA (stereolithography) and SLS (selective laser sintering), are examined in relation to crucial aspects for long-term structural integrity and degradation behaviour. Finally, limitations within the current normative framework are identified, emphasising the absence of process-aware durability assessment protocols and the need for dedicated standards tailored to additively manufactured polymer components.
César García-Hernández, Juan-Jesús Valdivia-Sánchez, Pedro Ubieto-Artur
et al.
The cutting length of milling tools must be longer than the axial distance of the material to be processed. In fact, in most cases, the cutting length far exceeds the thickness of the material to be removed. Therefore, along the entire length of the milling-tool flutes, only the area farthest from the shank wears out, leaving the rest of the tool practically without any wear, especially in the area closest to the shank. This research analyses a toolpath model to use the complete length of the milling tool flutes, in those machining operations in which it is possible, with the objective of reducing the costs associated with tool wearing and resharpening. This improves the tool performance, which clearly increases the sustainability of the milling process. For this purpose, it is necessary to transform the numerical control programme that performs a flat (2D) toolpath into a helical (3D) one by decomposing the arcs and rectilinear segments into a succession of points within a precision range. A negative aspect of this method is that it can only be applied to bottomless contours in processes of air-contour milling.
Electric discharge machining (EDM) is widely employed for machining hard, conductive materials. Tool rotation has emerged as an effective strategy to enhance debris flushing and improve stability during deep-hole EDM drilling. This study proposes a machine learning-based approach to evaluate the influence of tool rotation and predict the unstable machining conditions in EDM of ultrafine grained tungsten carbide. A structured analytical workflow, combining Taguchi–Grey optimization, regression analysis, and classification models, was designed to capture discharge dynamics across macro- and micro-timescales. Classification models trained on raw and processed electrical signal features achieved over 88% accuracy and 90% recall. SHAP analysis revealed that the relationship between key discharge events such as sparks and short circuits varied significantly across stable and unstable machining phases, underscoring the importance of phase-specific modeling. While correlation analysis showed weak global associations, phase-dependent SHAP values revealed opposing feature effects, allowing the context-informed interpretation of model behavior. Phase segmentation revealed that, compared to 1000 RPM, short circuits were reduced by about 40% during stable machining at 8000–9000 RPM. Conversely, during unstable phases, spark effectiveness dropped by nearly 45%, and secondary discharges increased throughout this range. These insights support the design of adaptive control strategies that adjust the rotation rate in response to detected phase changes, aiming to sustain machining stability. The findings support the development of dynamic control frameworks to improve EDM performance, particularly for mold fabrication using tungsten carbide.
Gerhard Poelsler, Marcel Asper, Sebastian Lülf
et al.
Intravenous infusion of human IgG (IVIG) is of vital importance for patients suffering from primary or secondary immunodeficiency syndromes, but also has been found to be clinically beneficial in other diseases with autoimmunogenic or inflammatory background. Its clinical application and therefore its demand have been continuously rising during the last decades. Besides IgG, other human antibody classes have also entered clinical applications, therefore a novel manufacturing procedure has been conceived which allows simultaneous isolation of two immunoglobulin preparations, Yimmugo™ (an IVIG) and trimodulin (an IgM concentrate). Since the only suitable source for these antibodies is human donor plasma, from which it is isolated using a series of dedicated purification steps, there is a risk of carrying over infectious human pathogens into the final preparations. We describe here validation of the measures taken to provide Yimmugo, an IVIG product, with robust margins of biological safety, free of pathogens of microbial, viral or prion origin. To this end, we spiked manufacturing process intermediates of Yimmugo with diverse pathogens and tested the capacity of the manufacturing steps to clear these from the preparation. We show that four different purification steps of the Yimmugo procedure efficiently confer clearance of viral and prion pathogens, thereby providing a safe product even in the hypothetical case that an infectious agent in the original material were present. Consequently, the novel preparation procedure yields a provably safe product and simultaneously allows production of an additional medicine from the same plasma pool.
This Special Issue on Advances in Injection Molding: Process, Materials and Applications presents a curated collection of papers highlighting the dynamic evolution of this fundamental manufacturing technology [...]
Tungsten heavy alloys (WHAs) are two-phase composites known for their exceptional density, strength, hardness, and ductility, making them ideal for radiation shielding, kinetic energy penetrators, and aerospace components. Due to their high melting point, WHAs are primarily processed via powder metallurgy, with liquid-phase sintering (LPS). Spark plasma sintering (SPS) and microwave sintering are emerging as advanced consolidation techniques. Recent research has focused on improving WHA performance through microstructural manipulation, alloying with elements like Fe, Co, Mo, and Re; rare earth oxides like Y<sub>2</sub>O<sub>3</sub>, La<sub>2</sub>O<sub>3</sub>, and Ce<sub>2</sub>O<sub>3</sub>; and employing high-entropy alloys (HEAs) as matrix phase. Additionally, additive manufacturing (AM) techniques are increasingly being used to fabricate complex WHA components. Despite their advantages, WHAs still exhibit limitations in penetration performance, primarily due to their tendency to form mushroom-like heads upon impact rather than self-sharpening. Ongoing research seeks to enhance shear localization, refine grain structure, and optimize processing methods to improve the mechanical properties and impact resistance of WHAs. Furthermore, modeling and simulation approaches are being explored to understand the mechanical behavior of WHAs. This review comprehensively overviews the above aspects and presents recent advances in WHA processing.
Christiand, Gandjar Kiswanto, Ario Sunar Baskoro
et al.
In order to avoid catastrophic events that degrade the quality of machined products, such as tool breakage, it is vital to have a prognostic system for monitoring tool wear during the micro-milling process. Despite the long history of the tool wear monitoring field, creating such a system to track, monitor, and foresee the rapid progression of tool wear still needs to be improved in the application of micro-milling. On the other hand, digital twin technology has recently become widely recognized as significant in manufacturing and, notably, within the Industry 4.0 ecosystem. Digital twin technology is considered a potential breakthrough in developing a prognostic tool wear monitoring system, as it enables the tracking, monitoring, and prediction of the dynamics of a twinned object, e.g., a CNC machine tool. However, few works have explored the digital twin technology for tool wear monitoring, particularly in the micro-milling field. This paper presents a novel tool wear monitoring system for micro-milling machining based on digital twin technology and an extended Kalman filter framework. The proposed system provides wear progression notifications to assist the user in making decisions related to the machining process. In an evaluation using four machining datasets of slot micro-milling, the proposed system achieved a maximum error mean of 0.038 mm from the actual wear value. The proposed system brings a promising opportunity to widen the utilization of digital twin technology with the extended Kalman filter framework for seamless data integration for wear monitoring service.
Anatolie Timercan, Donatien Campion, Patrick Terriault
et al.
Laser powder bed fusion allows the production of complex geometries and eases the shaping of difficult-to-transform materials, such as near-equiatomic Ti-Ni shape memory alloys. In this study, a numerical model was used to select 11 sets of printing parameters with different volumetric energy densities (VEDs) and build rates (BRs) to produce bulk Ti-50.26at%Ni alloy specimens. The manufactured specimens were studied in terms of their structural integrity, printed density, chemical composition, transformation temperatures, and crystalline phases. At high VEDs and low BRs, a significant decrease in the nickel content was observed. VED = 90 J/mm<sup>3</sup> and BR = 10 cm<sup>3</sup>/h yielded a printed density of 99.94% and an austenite finish temperature of Af = 26.3 °C. The same printing conditions were used to produce 60% porous diamond and gyroid lattice structures. After heat treatment at 500 °C for 30 min, the diamond lattices manifested larger apparent recovery strains (7 vs. 6%), higher compliance (2.9 vs. 3.4 GPa), and similar yield stresses (~48 MPa) compared to their gyroid equivalents. The numerical model predicted that at an equivalent apparent compression strain of 6%, only a ~2% volume fraction of the diamond lattice material underwent plastic deformation as compared to ~20% for its gyroid equivalent.
Viacheslav E. Bazhenov, Arseniy S. Ovsyannikov, Elena P. Kovyshkina
et al.
Investment casting is a widely utilized casting technique that offers superior dimensional accuracy and surface quality. In this method, the wax patterns are employed in the layer-by-layer formation of a shell mold. As is customary, the patterns were created through the injection of molten or semi-solid wax into the die. The quality of the final casting is affected by the quality of the wax pattern. Furthermore, the filling of the die with wax can be associated with die-filling challenges, such as the formation of weld lines and misruns. In this study, the injection filling of the fluidity probe die with RG20, S1235, and S1135 pattern waxes was simulated using ProCast software. The thermal properties of the waxes, including thermal conductivity, heat capacity, and density across a wide temperature range, were determined with the assistance of a laser flash analyzer, a differential scanning calorimeter, and a dynamic mechanical analyzer. A favorable comparison of the acquired properties with those reported in the literature was observed. The Carreau model, which corresponds to non-Newtonian flow, was employed, and the parameters in the Carreau viscosity equation were determined as functions of temperature. Utilizing the thermal data associated with the wax patterns and the simulation outcomes, the interfacial heat transfer coefficients between the wax and the die were ascertained, yielding a value of 275–475 W/m<sup>2</sup>K. A strong correlation was observed between the experimental and simulated filling percentages of the fluidity probe across a wide range of injection temperatures and pressures. The analysis of the simulated temperature, fraction solid, viscosity, and shear rate in the wax pattern revealed that viscosity is a crucial factor influencing the wax fluidity. It was demonstrated that waxes with an initial high viscosity exhibit a low shear rate, which subsequently increases the viscosity, thereby hindering the wax flow.
Abstract The CNC (computerized numerically controlled) machines are widespread in use due to their high capability of precise manufacturing in industrial production. They have a wide range of designs depending on the working capacity in manufacturing. The associated form errors in large-capacity CNC machines during production shall be identified and corrected or eliminated. This study presents an investigation of one of the main form errors that may affect the manufacturing precision of these machines. This error type is a straightness error with both two kinds of horizontal and vertical errors. The study is carried out for a vertical turning center CNC machine type. The straightness errors are measured for the X axis at different latches in the Z direction and for the Z axis at three positions in the X direction with multi-displacement steps. Different algorithms are used in the determination of straightness errors. The X-axis has minimum horizontal straightness errors at latch Nr. 3 and minimum vertical straightness errors at latch Nr. 5. For the Z axis, the minimum values for horizontal and vertical straightness errors exist when the spindle is located 1200 mm away from the machining center to the right. The displacement steps have a significant impact on the determination of straightness errors.
Susetyo Bagas Bhaskoro, Hadi Supriyanto, Syamsul Falah
Machine vision merupakan teknologi yang biasa digunakan pada industri modern untuk analisis dan inspeksi otonom berbasis citra. Machine vision membantu proses analisis dan inspeksi produk di industri lebih cepat dibandingkan dengan analisis dan inspeksi manual. Penelitian ini menerapkan machine vision pada sistem identifikasi jumlah produk berbasis pengolahan citra pada proses pengepakan industri manufaktur dengan menggunakan algoritma YOLOv4 dan evaluasi sistem confusion matrix. Hasil dari identifikasi disimpan di database dan ditampilkan pada website agar memudahkan proses monitoring. Sistem ini telah melakukan beberapa pengujian terutama pengujian fungsi utama sistem yatu perhitungan produk, dilakukan 10x percobaan. Kemudian, pengujian variasi intesitas cahaya dengan range 20 – 225lux dan variasi ketinggian dengan range 48 – 68 cm dengan masing – masing pengujian sebanyak 10x percobaan. Dari pengujian yang telah dilakukan diterapkan evaluasi confusion matrix dan menghasilkan akurasi dan presisi sebesar 100% dan error sebesar 0%. Kecepatan komputasi rata – rata dari sistem ini sebesar 6.95 FPS dengan bantuan CUDA.
Abstract This study delves into the origins of excess capacity by examining the reactions of capital, labor, and capital intensity. To achieve this, we have employed a novel three-layered production function model, estimating the elasticity of substitution between capital and labor as a nested layer, alongside capital intensity, for all industry groups. We have then selectively analyzed a few industry groups for comparative purposes, taking into account the current government policies and manufacturing plant realities. Ultimately, we recommend that policymakers address the issue of excess capacity by stimulating the expansion of manufacturing plants with cutting-edge machinery. Our findings and recommendations are intended to appeal to academics and policymakers alike. JEL Code: L6, L5.
Abstract This study delves into the origins of excess capacity by examining the reactions of capital, labor, and capital intensity. To achieve this, we have employed a novel three-layered production function model, estimating the elasticity of substitution between capital and labor as a nested layer, alongside capital intensity, for all industry groups. We have then selectively analyzed a few industry groups for comparative purposes, taking into account the current government policies and manufacturing plant realities. Ultimately, we recommend that policymakers address the issue of excess capacity by stimulating the expansion of manufacturing plants with cutting-edge machinery. Our findings and recommendations are intended to appeal to academics and policymakers alike. JEL Code: L6, L5.
Manuela Galati, Paolo Antonioni, Flaviana Calignano
et al.
Additive manufacturing (AM) technologies for metallic materials allow for the manufacturing of high-performance components optimised in weight, geometry, and mechanical properties. However, several post-processing operations are needed after production, including removing parts from the build platform. This operation is essential and must be performed rapidly, precisely, and with a good surface finishing. This work presents an experimental investigation of the wire electric discharge machining (W-EDM) process of Ti6Al4V specimens produced by AM technologies. The influence of cutting parameters is analysed compared to the material produced by conventional technology. Models of cutting speed and surface roughness obtained by a W-EDM are inferred from the collected data. Remarkably, the results show that the manufacturing process used to produce the components plays a crucial role in defining the final surface roughness and the most significant parameters affecting the machining performance.
With the continuous deepening and development of tobacco manufacturing informatization construction, tobacco manufacturing enterprises have the characteristics of strong production capacity, high degree of production automation, and advanced enterprise-level management information system. In order to cooperate with the market and brand strategy of the tobacco industry, the State Tobacco Monopoly Administration has carried out serious strategic thinking on informatization and customized the overall plan and strategic goals. In recent years, China’s informatization construction has made great progress, and both industries and enterprises have felt various benefits from the application of information technology. In the deployment and development of mobile services, it is often local and municipal mobile companies that, in order to meet the different needs of the market, immediately carry out corresponding services, resulting in one service for each municipal subsidiary in the same province or one platform for a class of services. Situation is good for quickly meeting user needs at that time. The exchange and communication of enterprise personnel information are becoming more and more frequent, and the collection of enterprise information through mobile has become a new way of enterprise information collection. The work orders, process parameters, documents, notifications, and instructions generated by the planning layer are sent to the production control layer to respond, guide, and trigger the production site events. The ultimate goal of mobile data collection is to gather the collected data into the enterprise production data center, which plays an important role in mobile devices, mobile performance, mobile planning, mobile balancing, mobile prediction, and so on. Based on the unified mobile application data collection method, this paper analyzed and analyzed the design of application architecture in the tobacco enterprise platform and further described the business functions, security performance, and system characteristics of the platform.
Héctor Rivera-Gómez, Joselito Medina-Marin, Francisca Santana-Robles
et al.
Manufacturing systems face several disturbances during production, such as sudden failures, defects, and unreliable subcontractors that reduce their production capacity. Currently, subcontracting represents an efficient alternative to support production decisions. The novelty of the study was the development of a new integrated model that properly coordinates production, subcontracting, and maintenances strategies in the context of stochastic uncertainty, quality deterioration, and random subcontracting availability. Such a set of characteristics has not been addressed before in the literature. A simulation–optimization approach was proposed to address such a stochastic model. A numerical case study was performed as an illustration of the approach and a comprehensive sensitivity analysis was performed to analyze the impact of several costs. Furthermore, the effect of the availability of the subcontractor and the producer was analyzed. The main finding of the study showed that the integrated model led to significant economic cost savings compared to other approaches that address such policies in isolation. The results also indicated that quality deterioration had a strong impact on the subcontracting rate and that the proposed joint control policy adequately coordinated these three key functions. The level of subcontracting participation was directly defined by its availability and the subcontracting cost.
Ridwan Ridwan, Maulana Hakim Swistiawan, Susetyo Bagas Bhaskoro
Bendung merupakan alat pengendali dan pemantau seluruh tata pengaturan air dan juga sebagai antisipasi banjir. Bendung tersebut digunakan untuk mengatasi besarnya debit air yang berpotensi menciptakan banjir di suatu daerah. Banjir terjadi diakbitkan oleh curah hujan yang tinggi, dengan curah yang tinggi mengakibatkan ketinggian air pada bendung terus meningkat secara drastis. Rancangan dari gambaran umum dikembangkan menjadi dua bagian yaitu sistem pemantauan berbasis internet of thing dengan menggunakan smartphone dan pengendalian debit dengan cara menggerakan pintu air. Untuk menggerakan pintu air diwujudkan menjadi sensor untuk membaca ketinggian air dan menghitung debit air yang keluar, kontroller sebagai pengendali utama untuk memisahkan data melakukan komputasi prediksi dan menjalankan algoritma pengontrolan bukaan pintu air. Arsitektur jaringan syaraf tiruan 5-8-1 yang dimana menggunakan hidden layer sebanyak delapan nodes dan satu hasil output. Metode backpropagation dapat mengklasifikasikan bukaan pintu air dengan nilai akurasi sebesar 91.78% pada proses training. Pada hasil testing menghasilkan nilai error sebesar 12.98%.
The aim of this work is to develop a die material selection criterion for aluminum hot stamping applications. The criterion has been based on the back-to-back comparison of a set of reciprocating friction and wear tests. Three representatives belonging to different stamping die material families have been selected for the study: a cold work steel, a hot work steel, and a cast iron. These tool materials have been combined with an exemplary member from two heat treatable aluminum families: 2XXX and 6XXX. Each die-material/aluminum–alloy combination has been tested at three temperatures: 40, 200, and 450 °C. The temperatures have been selected according to different stamping scenarios: long takt time press quenching, short takt time press quenching, and very short takt time hot forming without quenching, respectively. The results show that, among the three die material options available, the cold work steel turned out to be the most favorable option for high volume production and long takt time, the hot work steel fitted best for high volume production coupled with short takt time, and cast iron turned to outstand for short runs with prototype dies and for hot stamping without die quenching.