Control Of Process Parameters Research Articles

Design of Double Tank Liquid Level Control System Based on Fuzzy PID

Liquid level is one of the main parameters in industrial production process control. There are many problems such as interference and delay in the dual capacity water tank. It is usually difficult to meet the strict production requirements with the conventional PID control scheme. The corresponding transfer function is firstly deduced through the material balance equation in this article. By testing, the performance of conventional PID needs to be further improved. Then build the fuzzy PID model in Matlab/simulink and carry out simulation verification. By comparing with the PID simulation effect, the results show that under fuzzy PID control, the overshoot of the system is effectively reduced and the adaptability is strong. It reflects that the control strategy has a good reference value.

Investigation of microstructure and texture as related to primary recrystallization of grain-oriented silicon steel

Grain-oriented silicon steel requires a very strong Goss {110}<001> texture and as such a comprehensive control of thermo-mechanical processing parameters is required to achieve a strict control of texture. In particular the cold rolling and decarburization annealing process parameters have a determining effect on the grain size, the grain size distribution and the crystal texture distribution. In this study, the effect of cold rolling reduction on texture distribution in cold-rolled sheet has been analyzed. Secondary recrystallization of grain-oriented silicon steel is also highly dependent on the microstructure and texture after primary recrystallization. The influence of annealing temperature and carbides on the primary recrystallization process has also been investigated by measurements of grain growth and texture following primary recrystallization. By optimizing the microstructure and the texture of primary recrystallization of grain-oriented silicon steel, it is shown that a grain-oriented silicon steel exhibiting high magnetic induction low iron loss has been developed at Shougang Steel.

Enhancing wettability of sapphire (Al2O3) substrate through laser surface texturing

Sapphire (Al2O3) has emerged as an incredibly versatile ceramic material, attracting significant interest across various fields due to its superior properties. The potential to control its wettability offers opportunities for enhancing the functionalities of sapphire-based devices. This study focuses on achieving superhydrophilic surfaces on sapphire substrates using a 355 nm nanosecond laser. The effects of the Laser Surface Texturing (LST) parameters on the morphology and wettability of the samples were examined through a Taguchi L16 experimental design. The results showed that the repetition rate and scanning speed influenced the Contact Angle (CA) and Surface Roughness (Ra) of the laser-textured sapphire. Lower repetition rates and higher scanning speeds resulted in rougher surfaces and smaller contact angles. The minimum CA of 4.5° was obtained at a repetition rate of 50 kHz and a scanning speed of 1100 mm/s. The study highlights the importance of controlling processing parameters to achieve desired wetting properties for superhydrophilic surfaces. The findings of this research provide insights into the application of LST for achieving superhydrophilic surfaces on sapphire substrates.

Enhancing Textile Wastewater Treatment Performance: Optimization and Troubleshooting (Decision Support) via GPS-X Model

Textile factory water consumption could be optimized to minimize the generation of wastewater, reduce treatment costs, and promote resource recovery. However, downstream plant operation and management is a prime concern in the textile industry, particularly bringing treated wastewater effluent to an acceptable discharge limit. The aim of the study was to optimize key process control parameters to the observed operational challenges of existing processes and suggest an operational guide to the operators and decision makers to enhance the treatment performance in GPS-X. The formulated troubleshooting and decision support strategy, and the optimization results of waste-activated sludge in the primary and secondary clarifiers, was within the range of 15 ± 5 m3/d and 83 ± 7 m3/d, respectively, with a recycle-activated sludge flow of 150 ± 10 m3/d. The sludge retention time was 5 ± 1 d and 6.7 ± 0.5 d in the secondary and primary clarifiers, respectively. The addition of a carbon source in the form of molasses had a flow of 0.5 ± 0.05 m3/d, and the variation in the influent due to wastewater characteristics and rainfall was optimized to 600 ± 50 m3/d. The optimum air flow into the aeration tank was 550 ± 5 m3/hr and saved 91.5% of energy in the optimized process. Thus, the study is indispensable for the effective and efficient operation of the plant and serves as a good guide to the plant operators and decision makers for the best course of action.

Power of Parametric: Methods to Validate Ethylene Oxide Sterilization Parametric Release.

When approaching an ethylene oxide (EO) sterilization validation, medical device manufacturers traditionally have two choices. They can use biological indicators (BIs) to monitor each production run or establish a parametric release process in which sterile release is based on the monitoring and control of physical process parameters that ensure process specifications are met. In ISO 11135:2014, parametric release was brought to the forefront as an acceptable release method; however, a perception exists that implementing parametric release is challenging and time consuming. This article will demonstrate that the opposite is true. It presents a streamlined approach in which parametric release is addressed through the various stages of validation: product definition, process definition, performance qualification, routine release, and process control. Considerations for establishing specifications directly from validation versus "run and record" and trending critical process parameters (e.g., relative humidity, temperature, EO concentration) are discussed. In addition, the benefits of parametric release (active monitoring) over BI release (passive monitoring), including improvements to turnaround time, process control, risk mitigation, reduction of resource investment, and elimination of microbiological release testing, are highlighted. With multiple benefits, parametric release should be the gold standard for EO sterilization processes. It is not novel and has been widely accepted by regulatory agencies globally and notified bodies. The article further describes how the data collection and process capability that is central to process control and parametric release is more powerful than the information provided by a BI, which is merely a catastrophic indicator when used in routine processing.

The effects of nozzle diameter and length on the resulting strand properties for shotcrete 3D printing

Additive manufacturing in construction (AMC) enables new design methods and strategies within the construction industry. In particular, Shotcrete 3D Printing (SC3DP) offers a high degree of design freedom by enabling the deposition of concrete at variable layer orientation based on a wet-mix shotcrete process. However, the mechanical properties and geometry of the printed layers are dependent on the material and process parameters used. In this context, the effects of air and concrete flow rates, path planning parameters, and material parameters have been investigated in previous research. The presented study investigates the influence of the nozzle geometry on the resulting strand properties, e.g. strand geometry, layer bond strength, and compressive strength, to evaluate nozzle diameter and length as control parameters for the SC3DP process. Experimental investigations were performed with fixed nozzle diameters between 10 and 30 mm and nozzle lengths ranging from 100 to 200 mm. The results show a significant influence of the nozzle diameter on the resulting strand geometry as well as the mechanical properties. Finally, concepts for a nozzle with a controllable outlet diameter were developed and evaluated.

An Experimental Approach to Determining the Average Diffusion Coefficient of Volatile Components in Polymer Waste Materials

One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of which often depends on the diffusion coefficient—a measure of the mass transport of volatile components in polymeric phases. The aim of this study was to develop a practically feasible experimental approach using thermogravimetric analysis (TGA) to determine the average diffusion coefficient of volatile components in polymer waste materials. First, the TGA method was validated with a pressure decay apparatus (PDA) using predefined binary material mixtures: Thin sheets were pressed from virgin high-density polyethylene (HDPE) and polypropylene (PP) and deliberately saturated with toluene in a sorption experiment. These saturated samples were then used in TGA and PDA desorption experiments at 60 °C, 80 °C and 100 °C, which yielded similar results with an average difference of 7.4% for the HDPE-toluene system and 14.7% for the PP-toluene system. When validated, TGA was employed to determine the diffusion coefficient of volatile components in post-industrial plastic waste melt at a temperature of 220 °C. The proposed method contributes to the understanding of diffusion-based mass transport in polymer waste materials and provides a key parameter for model-based process control and optimization. In practice, the diffusion coefficient results can be used to predict the degassing performance of an extrusion process in the mechanical recycling of plastic waste.

Optimization of Abrasive Waterjet Cutting by Using the CODAS Method with Regard to Interdependent Processing Parameters

The paper shows performance optimization effects of steel machining by abrasive water jet (AWJ). An innovative combinative distance-based assessment method (CODAS) is implemented for the optimization of cutting parameters like pump pressure, feed rate, and abrasive flow rate over cutting depth, and cut kerf surface roughness. The CODAS algorithm is among those based on measuring the distance between a scenario (in this case processing parameters in terms of performance and quality indicators) - and a certain benchmark. A benchmark is a specific hypothetical set of processing parameters devised or determined from available data. To determine the best set of process control parameters, a CODAS approach was performed with some weighting determinations. To set the initial parameters of the weights, it was proposed to calculate based on entropy weight method (EWM), that measures output value dispersion in cutting process. This technique simplifies multiple compound responses by preserving a single response.

An Application of Injection Molding to Semisolid Processing of Metallic Alloys: A Role of SIMA in Feedstock Transformation

Injection molding has proven for over 150 years to be the efficient mass manufacturing technology of net-shape components from plastics, however, its application to metallic alloys, despite four decades of commercialization, still creates challenges. Although early designs assumed a direct replacement of plastic with magnesium, subsequent research revealed essential differences in machinery and processing requirements, imposed by metallic alloys. The key discovery revealed that the dendrite-to-globule transformation during coarse particulate melting is caused by strain induced melt activation (SIMA) due to feedstock deformation imposed at their manufacturing stage, not due to the injection screw shearing during processing. As a result, the process control parameters and the screw and barrel design can be optimized with a focus on other screw functions. That discovery also led to the simplified machinery designs, eliminating the complex injection screw, and replacing it with a simple plunger.

Fabrication of Anion-Exchanged Electrodeposited Zn-Al Layered Double Hydroxides (LDHs) Coating on ZX21 Mg Alloy

Because of their low density and high specific strength, Mg alloys are considered promising lightweight alloys for various applications. However, due to the high electrochemical activity and poor corrosion resistance, surface modifications of Mg alloys are needed to increase the service life. Hence, an active layered double hydroxides (LDHs) coating was investigated in this study. Owing to the brucite-like layered structure, the weakly bonded interlayer anions can be easily exchanged with other anions in the environment. With the unique anion-exchange mechanism, LDHs coating provides dual protection to the Mg alloy substrate. It can not only act as a physical barrier but also absorb aggressive anions such as Cl- and release corrosion inhibitors to the environment.Compared to the commonly used hydrothermal method to fabricate LDHs coating, which requires high temperature and long process time, electrochemical deposition has the advantages of high deposition rates, simple experimental setup, and highly controllable process parameters. Therefore, in this study, a three-electrode electrochemical setup was used to fabricate Zn-Al LDHs coatings on a ZX21 Mg alloy. Moreover, different anions are intercalated into the interlayer galleries of the prepared Zn-Al LDHs coating through post anion-exchange processes.Through electrochemical analysis in a 3.5 wt% NaCl solution, the prepared anion-exchanged electrodeposited Zn-Al LDHs coating improved the corrosion resistance of ZX21 Mg alloy. Electrochemical impedance spectroscopy (EIS) showed that corrosion impedance increases, while potentiodynamic polarization curves revealed that the corrosion current density (i corr) of the coated sample was an order of magnitude lower than the ZX21 Mg alloy substrate. Besides the improvement of corrosion resistance, the formation mechanism of Zn-Al LDHs coating by electrodeposition was also investigated by electrochemical analysis and in situ optical microscopic (OM) observations. The corrosion behavior and microstructure of Zn-Al LDHs coating and the roles played by different intercalated anions will be discussed based on electrochemical analysis and microstructure characterizations. Figure 1

A novel structural design of cellulose-based conductive composite fibers for wearable e-textiles

Cellulose-based conductive composite fibers hold great promise in smart wearable applications, given cellulose's desirable properties for textiles. Blending conductive fillers with cellulose is the most common means of fiber production. Incorporating a high content of conductive fillers is demanded to achieve desirable conductivity. However, a high filler load deteriorates the processability and mechanical properties of the fibers. Here, developing wet-spun cellulose-based fibers with a unique side-by-side (SBS) structure via sustainable processing is reported. Sustainable sources (cotton linter and post-consumer cotton waste) and a biocompatible intrinsically conductive polymer (i.e., polyaniline, PANI) were engineered into fibers containing two co-continuous phases arranged side-by-side. One phase was neat cellulose serving as the substrate and providing good mechanical properties; another phase was a PANI-rich cellulose blend (50 wt%) affording electrical conductivity. Additionally, an eco-friendly LiOH/urea solvent system was adopted for the fiber spinning process. With the proper control of processing parameters, the SBS fibers demonstrated high conductivity and improved mechanical properties compared to single-phase cellulose and PANI blended fibers. The SBS fibers demonstrated great potential for wearable e-textile applications.

Online Correction of Laser Head Nozzle Position for Laser Metal Deposition Using a Chromatic Confocal Displacement System.

The stability and repeatability of laser metal deposition is particularly important when processing multiple layers or depositing material on complex component surfaces, and requires the use of process parameter control including the stand-off distance between the laser head and the substrate. The system proposed in this paper for correcting the stand-off parameter is based on a chromatic confocal sensor integrated into a laser head. Then, the spectral signal acquired from the measurement system is processed by using the developed application to compensate for the movement of an additional axis of the kinematic system. This study used an independent verification system based on the digital image correlation method. The validation tests were carried out using the system for correcting the stand-off parameter with different control algorithms and given motion trajectories and substrate materials. The results demonstrate that the developed system can be useful for laser metal deposition.

Improving cold sprayed Ti-6Al-4V coatings controlling processing parameters: Effect on microstructure and scratch behaviour

In this work, the local wear properties of cold-sprayed (CS) Ti-6Al-4V coatings were studied to evaluate their application for aeronautical components repair. Two different CS conditions were used, and one condition was also heat-treated. A thorough microstructural study was first done to correlate the microstructure with the wear properties. Then, microscratch tests were performed. The wear rates were calculated analytically, and this method was validated with confocal microscopy. Similar wear rates to that of the material to be repaired (substrate) were obtained for the CS coating sprayed at higher temperatures and for the heat-treated one. The wear resistance was related to the ability of the coating to plastically deform and thus, with the arrangements of different dislocations observed in the coatings.

Bioactive and antibacterial glass particles as fillers in composite bone cements: Influence of amount and size on radio-opacity, bioactivity, mechanical and antibacterial properties

In this work, a bioactive and antibacterial glass has been added to a commercial PMMA-based bone cement to promote osteointegration and simultaneously limit bacterial contamination. The influence of the amount and size of glass powders on mechanical properties, radio-opacity, bioactivity and antibacterial effect of the composite cements has been estimated. The obtained results suggested that both filler's amount and size can affect the bending strength of the samples. The composites radio-opacity can be modulated by varying the amounts of glass and radio-opaque agent usually present in the commercial composition. The bioactive and antibacterial properties evaluation evidenced that introducing 10 wt.% of glass conferred a bioactive behaviour to the PMMA-based matrix and limited the bacterial contamination. Finally, an approach to technological transfer with controlled process parameters has been proposed.

Research on Performance Control of Intercalated Melt-blown Nonwoven Materials

This paper focuses on enhancing the performance of intercalated melt-blown nonwoven materials through performance control. The study explores whether the structural variables (thickness, porosity, and compression resilience ratio) and performance indicators (filtration resistance and efficiency) of intercalated products undergo significant changes, using analysis of variance (ANOVA). The experimental results indicate that intercalation significantly alters the product’s thickness, porosity, compression resilience ratio, and filtration efficiency. The study also establishes a decision tree regression model between process parameters (acceptable distance and hot air velocity) and structural variables, and a K-nearest neighbor regression model between structural variables and product performance indicators to investigate the relationship between process parameters and product performance during intercalation. Finally, the study determines the optimal performance indicators by controlling process parameters using the simulated annealing algorithm.

High-speed manufacturing-driven strength-ductility improvement of H13 tool steel fabricated by selective laser melting

ABSTRACT H13 tool steel was additively manufactured by selective laser melting (SLM). The sample printed at a higher laser scan speed exhibited higher strength and ductility than those of the sample printed at a lower speed. The samples were repeatedly exposed to a massive heat input during the SLM. The in-situ tempering effect was applied to the sample; the phase fraction is changed by varying the heat input by controlling the laser scan speed. The microstructure analysis showed that the sample printed at a higher scan speed had a higher fraction of retained austenite than at a lower speed. The former was affected by deformation-induced martensitic transformation with enhanced strain-hardening ability. This study entailed the control of process parameters to improve the mechanical properties and the productivity of SLM-printed H13 tool steel. It investigated the relationship between the laser scan speed and the phase fraction, whose effect on the mechanical properties was confirmed.

Failure Mode Effect Analysis of Composites Prepreg Manufacturing Process for Airworthiness Certification - A Case Study

Airworthiness certification of aircraft structures requires a holistic approach ranging from material manufacturing process to design evaluation of airframe components. Present day airframe structures find greater applications of composite materials owing to their extraordinary mechanical properties on pro rata weight basis. In case of polymer based composites, the prepreg form of material is preferred for several applications due to matrix efficiency (high fiber-to-volume ratio) and ease of application. As part of composite material certification, the design audit of composite prepreg manufacturing process is carried out to assess the possible failure scenarios. Manufacturing Process Design and Control plays a significant role in satisfactory realization of composite parts right from raw material stage. Process variability/ scatter can lead to large variation in performance of the final product and thus stringent control of process parameters is essential to achieve aero-grade composite structures. This study provides basic understanding of composite prepreg manufacturing process and application of FMEA as a process design tool to detect and assess potential failures with an aim to devise preventive measures for improved process control. The complete process of manufacturing prepregs is divided into three stages viz.: Fabric weaving, Resin formulation and Prepregging operation. FMEA principles are used to identify the predominantly vulnerable operations and to quantify the inherent risk associated. Risk Priority Numbers (RPN) are evaluated for various operations in these three stages. Based on process technology and engineering expertise, suitable corrective and preventive measures are offered according to the potential risk factors and failure types. Emphasis is to prioritize the efforts and attention towards major preventive measures by targeting the least number of factors causing the maximum impact for failures (Pareto principle). Present study substantiates the significance of trained personnel, proper documentation of operating procedures and work instructions along with contamination control as critical factors in eliminating failures in composite prepreg manufacturing process.

Operational process parameters of underground coal gasification technique and its control

Underground coal gasification (UCG) is a complex process as it depends on many factors such as geological and geo-hydrological analysis of strata, physical and chemical properties of coal, operational process parameters, seismic events, analysis of produced gases in real-time. This paper mainly identifies the process parameter variations due to underground coal gasification. This scientific study could help us to choose appropriate sensors, and design and develop suitable monitoring units for the control, monitoring and precaution during coal gasification. In this article, one experimental work is carried out in laboratory scale with the help of developed system. This paper also described individual control and monitoring techniques of different operational process parameters required for successful UCG operation. This is helpful for successful operation in the actual field and reducing its complexity.

Decision support system for power cable insulation vulcanization production line management

The paper proposes a structural model of a decision support system for controlling a cable insulation continuous vulcanization line. The proposed decision support system is based on a mathematical model of the cable insulation continuous vulcanization technological process, a database, and a mode correction algorithm. The DSS will make it possible to quickly develop a new regime in case of using new materials or structures, as well as to correct the current regime in case of unplanned changes during the production process. The core of the DSS is the proposed mathematical model, which is based on conservation laws and is presented as a system of differential equations closed by boundary conditions. The vulcanization process is described taking into account the temperature-time dependence of the kinetic parameters, which made it possible to take into account the uneven heating of the cable, both in the radial direction and along the length. The numerical implementation of the differential mathematical model made it possible to carry out a systematic analysis of the nature of the processes in the vulcanization pipe and to evaluate the influence of various technological, structural and material parameters on the cable insulation vulcanization completion degree. As a result of the analysis, significant parameters were identified that significantly affect the vulcanization process completion degree. Based on the obtained numerical results, technological parameters dependence technological surfaces on the geometry of the product and the properties of the materials used were constructed, a regression mathematical model was proposed that allows determining the values of the process control parameters without resorting to the use of a differential mathematical model. Based on the results of the analysis, an algorithm for correcting the technological regime is proposed, taking into account only significant process parameters. The proposed algorithm allows you to adjust the value of the isolation rate, depending on external influences and deviations from the specified parameters. The results of the study can be used in the production of cable and wire products with vulcanizable insulation, when it is necessary to quickly select the optimal technological mode, take into account changes in the cable design, properties of the insulation material, as well as possible pressure deviations inside the vulcanization pipe.

Parametric optimization of response parameter of Nd-YAG laser drilling for basalt-PTFE coated glass fibre using genetic algorithm

Composite materials are well-recognised in the automobile and aerospace industries due to their high strength-to-weight ratios. The orientation of fibres and anisotropic properties are gaining the attention of design engineers daily in different manufacturing industries. For stipulated requirements, hybrid composite materials can be developed. Hybrid composite materials have higher variations in the material; it’s difficult to machine using conventional methods. This manuscript reports the optimization of Nd: YAG drilling on basalt and PTFE-coated glass woven fibres hybrid composite material made with hand lay-up method using a genetic algorithm. The process control parameters considered for the laser drilling were lamp current, pulse width, stand-off distance and compressed air pressure. The average values of the top- and bottom-hole diameters were recorded to evaluate and optimise the hole taper. Optimized input parameters yielded were a lamp current of 180 A, a pulse width of 3 ms, a stand-off distance of 3 mm and compressed air pressure of 8 kg/cm2. The validation test of the optimized process yielded a hole taper angle of 0.00285°.