Mass Production Process Research Articles

Investigation on Ultrasonic Welding Attributes of Novel Carbon/Elium® Composites.

Joining large and complex polymer–matrix composite structures is becoming increasingly important in industries such as automobiles, aerospace, sports, wind turbines, and others. Ultrasonic welding is an ultra-fast joining process and also provides excellent joint quality as a cost-effective alternative to other joining processes. This research aims at investigating the welding characteristics of novel methyl methacrylate Elium®, a liquid thermoplastic resin. Elium® is the first of its kind of thermoplastic resin, which is curable at room temperature and is suitable for mass production processes. The welding characteristics of Elium® composites were investigated by optimizing the welding parameters with specially designed integrated energy directors (ED) and manufactured using the Resin transfer molding process. The results showed a 23% higher lap shear strength for ultrasonically welded composite joints when compared to the adhesively bonded joints. The optimized welding time for the ultrasonic welded joint was found to be 1.5 s whereas it was 10 min for the adhesively bonded joint. Fractographic analysis showed the significant plastic deformation and shear cusps formation on the fractured surface, which are typical characteristics for strong interfacial bonding.

WITHDRAWN: Process/design optimization for powder injection molding of turbocharger vane by rheological & computational analysis

Powder injection molding, which is a powder-based net-shape technology, has enabled the development of a mass production process for super alloy turbocharger vanes. Here, the conditions of the nickel-based superalloy feedstock were characterized and simulated to predict possible defects and to determine the optimal process conditions. The test results show that the feedstock shows shear thinning behavior at temperatures of 170 °C, 190 °C, and 210 °C, whereas shear viscosity shows the lowest value at its highest temperature. A shear rate region could be found in the gate or thin vane regions, and this could form a bond without suitable a shape or injection speed. This research focuses on improving the quality of superalloy powder injection-molded parts, by providing information on possible defects that could occur prior to processing.

Continuous Synthesis of Double-Walled Carbon Nanotubes with Water-Assisted Floating Catalyst Chemical Vapor Deposition.

Double-walled carbon nanotubes (DWCNTs) were synthesized and continuously collected using a water-assisted floating catalyst chemical vapor deposition (FCCVD) method. Differing from the conventional water-assisted synthesis in which water vapor is one part of the carrier gas mixture, we included de-ionized water in the catalyst system, which achieved a more uniform and controlled distribution for efficient DWCNT production. Using a water-assisted FCCVD process with optimized conditions, a transition from multi- to double-walled CNTs was observed with a decrease in diameters from 19–23 nm to 10–15 nm in tandem with an elevated Raman IG/ID ratio up to 10.23, and corroborated from the decomposition peak shifts in thermogravimetric data. To characterize the mechanical and electrical improvements, the FCCVD-CNT/bismaleimide (BMI) composites with different water concentrations were manufactured, revealing high electrical conductivity of 1720 S/cm along the bundle alignment (collection) direction, and the nano-indentation tests showed an axial reduced modulus at 65 GPa. A consistent value of the anisotropic ratio at ~3 was observed comparing the longitudinal and transverse properties. The continuous capability of the presented method while maintaining high quality is expected to result in an improved DWCNT mass production process and potentially enhance the structural and electrical applications of CNT nanocomposites.

Polymer/Graphene oxide nanocomposite thin film for NO2 sensor: An in situ investigation of electronic, morphological, structural, and spectroscopic properties

The higher operating temperature of metal oxide and air instability of organic based NO2 sensor causes extremely urgent for development of a reliable low cost sensor to detect NO2 at room temperature. Therefore, we present a fabrication of large area Polymer/GO nano hybrid thin film for polymer thin film transistors (PTFTs) based NO2 sensors assisted via facile method named ‘spreading-solidifying (SS) method’, grown over air/liquid interface and successive investigation of effect of NO2 on film via several characterizations. The PTFTs sensor has demonstrated swift and high response towards low concentration of NO2 gas with air stability and provided real time non-invasive type NO2 sensor. Herein, we are reporting the nanohybrid PBTTT/GO composite based PTFT sensor with good repeatability and sensor response for low concentration NO2. The thin film grown via SS technique has reported very good adsorption/desorption of target analyte having response/recovery time of 75 s/523 s for 10 ppm concentration of NO2 gas. It has been observed that % change in drain current (sensor response) saturated with increasing concentration of NO2. The transient analysis demonstrates the fast sensor response and recovery time. Furthermore, in order to understand the insight of high performance of sensor, effect of NO2 on nanohybrid film and sensing mechanism, an in situ investigations was conducted via multiple technique viz. spectral, electronic, structural, and morphological characterization. Finally, the performance of sensor and the site of adsorption of NO2 at polymer chains were argued using schematic diagram. This work shows the simple fabrication process for mass production, low cost and room temperature operated gas sensors for monitoring the real-time environment conditions and gives an insight about the sensing mechanism adsorption site of NO2.

Calibration-based tool condition monitoring for repetitive machining operations

Reliable tool condition monitoring (TCM) system is essential for any machining process in mass production to control the part quality as well as reduce the machine tool downtime and maintenance costs. However, while various research studies have proposed their TCM systems, the complexity in setups with advanced decision-making algorithms and specificity in application to limited cutting conditions continue to complicate the implementation of these systems into practical scenarios. This study develops a very simple and flexible TCM system for repetitive machining operations. The proposed monitoring approach reduces the complexity of monitoring model by considering the important characteristic of repeatability in process which has been commonly found in the mass production scenario and implements the calibration procedure to improve the flexibility of the model application to actual machining processes with complex toolpath designs and variable cutting conditions. The selected cutting tools with specific tool conditions are used in the calibration phase to generate reference signals. In actual repetitive production, the collected signal generated by the cutting tool in each operation is compared with reference signals to identify the most similar condition of the reference tool through the proposed similarity analysis. To validate the performance, the current study demonstrates the application of proposed monitoring approach to monitor the tool wear in repetitive milling operations with complex toolpath, and the predicted tool wear progression is found to be in good agreement with experimental measurements during the machining of multiple parts over the entire tool life.

РЕЦИКЛИНГ ОТХОДОВ ТЕКСТИЛЯ В СИСТЕМЕ ОБРАЩЕНИЯ С ОТХОДАМИ ПРОИЗВОДСТВА И ПОТРЕБЛЕНИЯ

The study of methods and technologies for waste management of production and consumption allows students studying in the direction 20.03.02 nature management and water use to become highly qualified specialists in the field of rational use of natural resources and engineering protection of the environment from generated waste. Recently, legislative and executive initiatives in the field of waste management are aimed at increasing the volume of utilization of secondary material resources from production and consumption waste. But mainly these initiatives are aimed at utilization of highly liquid waste, mainly in the form of a limited range of secondary material resources, which, on average, make up no more than one third of the use of all waste. Textile waste has received little attention in the large-scale processing industry, although the textile and clothing industry is one of the largest and fastest growing sectors in the global industry, driven by an increase in population, increased consumption, a variety of textile uses and greater productivity in mass production processes. Also, the textile industry is both the largest consumer of natural resources and the generator of production and consumption waste, which is practically not utilized, but goes to disposal facilities. This article presents the main directions for the involvement of textile waste in the general domestic system of production and consumption waste management.

Experimental Investigation of Oxide Layer Formation Depending on Temperature Holding Time during Inductive Heating of Annealed 16MnCr5

Fine blanking is a highly productive process of industrial mass production of high quality components in particular for the automotive industry. The manufacturing process faces a limit at elevated tensile strengths of the materials to be processed. Consequently, high-strength steels can currently only be fine blanked to a limited extent. This can be overcome by lowering the flow stress of high-strength steels by means of inductive heating. Heating a steel sheet which is not self-passivating creates an oxide layer on the sheet surface. An oxide layer can affect a subsequent fine blanking process by changing the material properties of the processed steel sheet. In order to avoid this, the process could be carried out under protective gas atmosphere. However, to reduce cost, it would be preferable to perform the process without a protective gas atmosphere. It is thus necessary to investigate the oxide layer formation of steel sheets depending on temperature holding time during inductive heating of steel sheets prior to fine blanking. This was done for soft-annealed 16MnCr5 steel sheets using material characterization methods as well as SEM and EDX. The dependence of the oxide layer formation on the temperature holding time could be determined. In addition, the resulting oxide layer was characterized with regard to its manifestation and physical properties.

Quality Control in Injection Molding based on Norm-optimal Iterative Learning Cavity Pressure Control

Abstract Plastic injection molding is characterized by high design flexibility of the manufactured parts. Consequently, it is one of the most important processes for mass production of plastic parts. The setup of the manufacturing process is very complex due to numerous impact factors. In addition, material fluctuations or changing ambient conditions require the adaption of the setup during manufacturing to guarantee a constant product quality. In order to reduce the setup effort and to control the quality, the concept of model-based self-optimization is applied to injection molding. Therefore, a model-based Norm-Optimal Iterative Learning Controller (NOILC) is used to track a desired reference for the cavity pressure during the entire cycle. This reference is determined by the so-called pvT-optimization which considers the cooling behavior of the melt within the cavity. It is shown by experiments that the cavity pressure can be controlled with high accuracy using the presented NOILC. Furthermore, the accuracy of the quality, especially the part weight is improved by combining the NOILC with an additional pvT-optimization.

Determination of Wide Burnishing Energy-Force Parameters based on Constructing the Kinematically Admissible Velocity Field

Processing technology using productive surface plastic deformation (SPD) was developed and is known as “wide burnishing” (WB). The mechanics of new WB technology differs from classic SPD technologies (rolling or burnishing). For example, force, applied during burnishing, is equal to 150–300 N, but for WB it is equal to 2500–5000 N due to implementing this process in mass production, characterized with limited processing time (3–4 turns of the work piece). WB also has a high degree of deformation due to a multiple deformation passes. An analytical study of burnishing with the upper bound approach method energy-force parameters was carried out. Its results were compared with the results of finite elements analysis in Deform 2D and with experimental data. Field of reasonable burnishing parameters, assuring minimum surface roughness, was determined experimentally.

Facile production of natural silk nanofibers for electronic device applications

Natural silk nanofibers (SNFs) have been attracted more attentions in flexible functional devices and biomaterials. However, its mass production and complex fabrication process remains challenging. In this study, we successfully developed a new physical-chemical strategy to fabricate natural SNFs with high yield (~87%). The natural SNFs performed an excellent dispersion in aqueous solution with uniform diameter (approximately 280 nm) and 10–30 μm length. The high-flexible natural SNFs/single-wall carbon nanotube (CNTs) composite films were prepared to evaluate their potential in electronic devices. The composite films exhibited remarkable dimensional stability, chemical durability, and Young's modulus (498.7 ± 64.4 MPa). Furtherly, the composite films also presented excellent electrical heating properties and potential utilities in electronics. These natural SNFs/CNTs composite films with high-mechanical and electrical features offer new starting materials for bioelectronics devices applications, such as conductive wire, electronical heater, and capacitor.

UHMWPE molecular structure analysis after turning operations and machinability with a standard off-the-shelf carbide tool

Traditionally, ultra-high molecular weight polyethylene (UHMWPE) parts are manufactured by mass production processes, such as ram extrusion and compress moulding. However, the production of UHMWPE parts for arthroplasty is regularly unitary and performed by machining. Current literature on this material machining is scarce and there is no off-the-shelf turning tool specifically designed for polymer machining. The objective of this work was to evaluate the molecular structure of UHMWPE after turning operations and machinability with a standard off-the-shelf carbide tool through a basic experimental study. In this study, cutting force and cutting power were evaluated on face turning operations. Workpiece surface roughness measurements were taken considering the Ra parameter and the shape of the chip was observed. The degree of crystallinity was evaluated via Differential Scanning Calorimetry (DSC) and the molecular structure after machining via Fourier Transform Infrared (FTIR) spectroscopy. There were adopted one off-the-shelf carbide tool and parameters regularly recommended to metal turning. Cutting force and cutting power indicate that UHMWPE may be related to good machinability. However, the results of part surface roughness and shape of the chip lead to poor machinability. On this work, best UHMWPE machinability results was achieved for Vc = 600 m min−1, f = 0.2 mm rev−1 and ap = 1.25 mm. No significant changes were observed in the crystallinity of the chip samples according to DSC results. FTIR analysis detected hydroperoxide generation after machining with Vc = 600 m min−1 that requires further investigation.

Mass production of a S-layer protein of Bacillus thuringiensis and its toxicity to the cattle tick Rhipicephalus microplus

The most commonly used biopesticides to control agricultural, forest and insect vectors of human diseases are derived from the bacterium Bacillus thuringiensis, which begins to produce Cry and Cyt insecticidal proteins during the onset of the sporulation phase. Some B. thuringiensis strains also produce S-layer proteins that are toxic to certain pests. S-layer proteins are the most abundant proteins in bacteria and archaea. This proteins’ key trait to design high performace processes for mass production is their continuous expression during the vegetative phase, unlike Cry and Cyt, which are restricted to the sporulation phase. In this work, a S-layer protein expressed by the GP543 strain of B. thuringiensis that is toxic to the cattle tick Rhipicephalus microplus was mass produced using the batch culture fermentation technique. In addition, the spore-protein complex showed a mortality rate of 75% with a dose of 300 µg·mL−1 on adult females of R. microplus after fourteen days. The lethal concentration 50 was 69.7 µg·mL−1. The treatment also caused a decrease of 13% in the weight of the mass of oviposited eggs with 200 µg·mL−1 of the spore-protein complex and inhibition of the hatching of eggs from 80 to 92%. Therefore, this could be a good option for controlling this parasite. The advantages of S-layer protein synthesis are focused on the production of a new generation of proteins in pest control. This is the first report on the mass production of an S-layer protein that is responsible for toxicity.

Comparative study on standard decoctions of Ophiopogonis Radix and Liriopes Radix

Standard decoction is the core of the pharmacodynamics for water-soluble substance of Chinese materia medica. Its research is of great significance to the research and development of some single ingredients and the classical prescriptions,and it is the only way to transform traditional medication experience into industrial products. In this article,standard decoction research strategies were used for the comparison analysis of Ophiopogonis Radix from Zhejiang province(ZMD),Ophiopogonis Radix from Sichuan province(CMD),and Liriopes Radix(SMD). Regularities were present among different grades of CMD; potential quality markers and pH differences associated with SO2 residues were also found. Finally,the extract powder of Ophiopogonis Radix prepared by mass production process was analyzed and validated,and the results showed that the standard system could be used for the quality control of intermediates and final products. In conclusion,this study can provide reference for the clinical application of Ophiopogonis Radix medicines and provide testing method for higher quality with higher price.

Development of eco-friendly cleaning solution for industrial silicon wafer solar cell

In the cleaning process to fabricate silicon solar cell wafers, removal of stains and metal impurities on the wafer surface is important since they can affect the surface texturing of silicon solar cells. The surfactants included in a cleaning solution used for the cleaning process have a significant effect on the detergency by slightly altering the temperature, concentration, or molecular structure of the adsorbent. In this study, the eco-friendly and reusable cleaning solution have been developed to remove the generation of stains and increase the recyclability of the cleaning solution by adjusting the ratio of polyoxyethylene lauryl ether, which is a nonionic surfactant with several advantages such as, no ion pollution and strong osmosis. The stain inspection revealed that the generation rate of stains reduced from 0.35% to 0.01% when the ratio of the polyoxyethylene lauryl ether included in the cleaning solution was the highest. It was confirmed that the cleaning solution with the highest ratio of polyoxyethylene lauryl ether can be reused over 60 times by the investigation of the concentration of metal impurities, the texturing result and the reflectance values. The cleaning solution with the highest ratio of the polyoxyethylene lauryl ether is the most suitable for the mass-production process, owing to the low generation rate of stains and re-useable solution.

Surface Reinforcing Balloon Trick-Inspired Separator/Li Metal Integrated Assembly To Improve the Electrochemical Performance of Li Metal Batteries.

Li metal experiences significant morphological changes during operation, resulting in rapid electrochemical performance degradation. In this study, a traditional balloon trick is applied to the Li metal surface to release mechanical stress and hinder morphological changes during operation. Polymer separators directly attach to the Li metal surface using a polymeric adhesive to fabricate a separator/Li metal integrated assembly. The separator/Li metal assembly improves not only the electrochemical performance but also safety issues related to Li metal anodes. This approach has three main advantages: (i) Li metal surface stabilization. The separator/Li metal assembly mechanically stabilize the Li metal surface, resulting in improved rate capability and cycle performance [85.0% of initial discharge capacity (90.2 mAh g-1) at a 7C condition for rate capability and 87.6% of discharge capacity (95.5 mAh g-1) at the 220th cycle] compared with the bare Li metal without separator integration [82.6% of initial discharge capacity (84.5 mAh g-1) at a 3C condition for rate capability and 58.0% of discharge capacity (62.6 mAh g-1) at the 120th cycle]. (ii) Suitability for high energy density battery implementation. The thickness of the polymeric adhesive is less than 1 μm, which is one-tenth of the coating layer of conventional thermally stable separators, but exhibits similar thermal shrinkage characteristics (0% shrinkage at 140 °C for 30 min). By reducing the thickness of inactive components, a larger volume of active material can be loaded into the battery system to increase the energy density of the battery. (iii) Simple process for mass production. The separator/Li metal integration process ("stick" and "dry") is very simple and can be easily applicable across industries.

Surface Assembly Strategy for the Fabrication of MoS2 Thin-Film Patterns

Molybdenum disulfide (MoS2) is a novel material with remarkable properties that is widely investigated for future applications in electronics, sensors, and smart materials. In this respect, a low cost, easy process, large-area mass production process is needed to obtain diverse structures and surface patterns of MoS2. Here, we demonstrate an effective MoS2 patterning process using substrate surface modification that can solve the difficulties encountered in previous studies. This technique utilizes the sulfur vacancies introduced during chemical exfoliation of MoS2 flakes. The MoS2 patterning is performed via surface modification with thiol molecules on the substrate in pre-designed shapes. The thiol (???SH) group required to bond MoS2 to the surface-modified substrate using (3-mercaptopropyl)trimethoxysilane was confirmed by FT-IR and the patterned MoS2 was confirmed by Raman shift. Through this process, a gas sensor was fabricated and its feasibility was confirmed to show its applicability to various applications MoS2.

ANALISIS FAKTOR YANG MEMPENGARUHI MINAT KONSUMEN DALAM MEMBELI FILM BAJAKAN

he development of the Indonesian film industry is indeed unique. The rise of national films marked by the large amount of local film production and increased cinema ticket sales, on the one hand, are colored by a process of mass production that is counterproductive to the development of creativity. One of the biggest problems is the rise of film copyright infringement, especially piracy (http://bincang-media.wordpress.com, 2010).The purpose of this study was to analyze and measure the effect of price factors on the interest in buying pirated films in the people of Malang City, and the effect of quality factors on the interest in buying pirated films in the people of Malang City. This type of research is a survey research, which is a study that takes a sample from a population and uses a questionnaire as the main data collection instrument. Thus, this research is categorized as an explanatory research. The number of respondents in this study were 100 people. The research sample was taken using purposive sampling technique. The data collection method used was a questionnaire method, then the data was processed through SPSS software. The analytical tool in this study used linear regression.In this study the variables involved consisted of 2 independent variables (X) namely price, quality and the dependent variable (Y) were buying interests. From the results of the analysis showed that simultaneously the two independent variables above had a significant influence on buying interest. Partial testing gives the conclusion that price, and quality have a significant positive effect on consumer interest in the purchase of pirated films. From the Determination Test (R2), a result of 0.622 means that 62.2% changes in purchase interest can be explained by changes in all independent variables (price and quality)

Food Wastes as a Potential New Source for Edible Insect Mass Production for Food and Feed: A review

About one-third of the food produced annually worldwide ends up as waste. A minor part of this waste is used for biofuel and compost production, but most is landfilled, causing environmental damage. Mass production of edible insects for human food and livestock feed seems a sustainable solution to meet demand for animal-based protein, which is expected to increase due to rapid global population growth. The aim of this review was to compile up-to-date information on mass rearing of edible insects for food and feed based on food wastes. The use and the potential role of the fermentation process in edible insect mass production and the potential impact of this rearing process in achieving an environmentally friendly and sustainable food industry was also assessed. Food waste comprises a huge nutrient stock that could be valorized to feed nutritionally flexible edible insects. Artificial diets based on food by-products for black soldier fly, house fly, mealworm, and house cricket mass production have already been tested with promising results. The use of fermentation and fermentation by-products can contribute to this process and future research is proposed towards this direction. Part of the sustainability of the food sector could be based on the valorization of food waste for edible insect mass production. Further research on functional properties of reared edible insects, standardization of edible insects rearing techniques, safety control aspects, and life cycle assessments is needed for an insect-based food industry.

Variation Simulation and Diagnosis Model of Compliant Block Assembly Considering Welding Deformation

This article proposes a variation simulation and diagnosis model for ship block assembly processes considering the effects of welding distortion. The welding process and the deformation pattern affecting the final shape of a block assembly are diagnosed. Prior studies on welding distortion mainly focused on mitigation methodologies. In this research, welding distortion is regarded as the main cause of geometric variation in parts. In addition, how geometric variations are accumulated throughout multiple assembly processes is mathematically modeled. The variation simulation model is based on a state space equation, where variations of previous stages are propagated to the current stage. The diagnosis model predicts the quantitative effect of each variation source on the final assembly's geometrical variation, based on a normal equation and designated component analysis. The proposed model is simulated with FEM (Dassault Systèmes Americas Corp., Waltham, MA) and MATLAB (Mathworks (https://www.mathworks.com/), Massachusetts, United States) replicating a realistic block assembly process for validation. The model can effectively simulate the propagation of welding distortion and quantitatively diagnose variation patterns and welding processes. 1. Introduction Analysis, management, and variation diagnostics are some of the important aspects of the production process. These have been mainly studied in mass production processes such as in the automobile industry. Mantripragada and Whitney (1999) and Whitney (2004) proposed a tolerance analysis method for the multistage rigid body assembly using a state space equation. Huang et al. (2006a, 2007) proposed a ship block tolerance model for the single and multiple stage variation propagation of a rigid body model. Liu and Hu (1995,1997) proposed a compliant assembly model using FEM, called the method of influence coefficients (MIC). Govik et al. (2012) proved MIC using an FEM simulation. Variation propagation in a multiple stage process while considering a compliant assembly has been proposed by Camelio et al. (2003, 2002a). Variation propagation models considering the location of data such as in key control characteristics, key product characteristics, and a local coordinate system of parts were proposed by Qu et al. (2016).

Multi-objective optimization of high carbon steel (EN-31) and low carbon steel (SAE-1020) using Grey Taguchi method in rotary friction stir welding

PurposeNowadays, a rotary friction welding method is accepted in many industries, particularly for joining dissimilar materials as a mass production process. It is due to advantages like less material waste, low production time and low energy expenditure. The effect of the change in carbon contents in steel is studied experimentally in the rotary friction welding process, and a statistical model is developed. The Grey Taguchi method gives the single parameters optimization for all output responses. The paper aims to discuss these issues.Design/methodology/approachAn experimental setup was designed and produced to achieve the multi-response in single optimum parameters through Grey relational analysis. A continuous/direct drive rotary friction welding process is chosen in which transition from friction to the forging stage can be achieved automatically by applying a break. In this experimentation, high carbon and low carbon work-pieces with different carbon percentage were welded with rotary friction welding. Response tensile strength and micro-hardness of the design of the experiment are used to analyze the results.FindingsThe optimization of parameters has been performed with Grey relational analysis, and optimum parameters are friction pressure 40 kg/cm2, forging pressure 100 kg/cm2 and speed 1,120 rpm. GRA optimum parameters give 56.04 and 82.16 percent improvement in Tensile strength and micro-hardness, respectively.Practical implicationsHigh carbon steel (En-31) and low carbon steel (SAE-1020) are used in so many industrial applications. These materials are mostly used in the process like manufacturing, metallurgy, machinery, agricultural, etc. These practical applications have brought forward definite and notable economic benefits.Originality/valueIt provides a new framework to investigate the problems where multiple input machining variables and various output responses are obtained in single optimized parameters.