The issue of decreasing air quality index due to supply chain transportation is one of the problems that must be addressed by the manufacturing sector. Green supply chain management (GSCM) can be a solution to address environmental issues... more
The issue of decreasing air quality index due to supply chain transportation is one of the problems that must be addressed by the manufacturing sector. Green supply chain management (GSCM) can be a solution to address environmental issues in the supply chain. The GSCM is an integrated view that incorporates environmental considerations into the conventional supply chain, ranging from supplier selection, product design, material selection, manufacturing processes, packaging, and distribution. The correct implementation of GSCM can address both environmental and performance issues, e.g. decreasing both energy consumption and air pollution. The GSCM consists of green design, green manufacturing, green logistics, disassembly, and remanufacturing. To address the GSCM issues, the simulation is also discussed in this work. Meanwhile, this work suggests more policies for recycling, remanufacturing, and reuse of obsolete manufacturing products to support GSCM in developing nations.
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In these days, increasing consumer demand uncertainties, e.g. due to war in Europe, severe drought in west Europe or Covid pandemic, increase challenge in supply chain operation. Uncertainty and unreliable events interfere supply chain’s... more
In these days, increasing consumer demand uncertainties, e.g. due to war in Europe, severe drought in west Europe or Covid pandemic, increase challenge in supply chain operation. Uncertainty and unreliable events interfere supply chain’s operations and strategies. As a result, increasing risks in supply chain becomes vulnerable and leads to undesired circumstance. A systematic approach is therefeore required to manage the risks. Of many methods, supply chain risk management (SCRM), as a part of supply chain management (SCM), is offered in this paper to address this challenge. The SCRM increases supply chain resilience agains many uncertainties. An important key of SCRM is risk assessment as risk-impact ordering method which can deliver solution with the lowest risks. Of many methods applied for risk assessment, analytic hierarchy process (AHP) provides several advantages, e.g. it can be used as multi-criteria decision making, it can be used with high flexibility and it can be used a...
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Corrosion is a material degradation due to electrochemical reactions involving electrical current. Corrosion cannot be avoided but it can be managed. This work investigated the influence of holding time and temperature variation for the... more
Corrosion is a material degradation due to electrochemical reactions involving electrical current. Corrosion cannot be avoided but it can be managed. This work investigated the influence of holding time and temperature variation for the homogenization process of Zinc (Zn) alloy. This zinc alloy is used as a sacrificial anode to decrease the corrosion rate of API 5L X65 steel. The investigation was performed with 3 varied holding times of 2, 4 and 6 hours of homogenization process while the temperature was varied at 150, 250 and 350ºC. After that, a zinc alloy with a size of 40mm x 0.44 mm x 10 mm was connected to a cathode. Together with steel, both metals formed galvanic cells in this study. The metal with lower electricity potential became the anode and corroded. On the other hand, metal with higher electrical potential became the cathode and did not corrode. The lowest corrosion rate was obtained for homogenization at 150ºC and 2 hours holding time. At this condition, the corros...
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Proses peleburan kaleng minuman hanya menggunakan 5% energi dari total energi yang diperlukan pertambangan untuk memperoleh aluminium cair. Namun ada masalah yang muncul dalam proses peleburan kaleng minuman ini, yaitu terdapat cat pada... more
Proses peleburan kaleng minuman hanya menggunakan 5% energi dari total energi yang diperlukan pertambangan untuk memperoleh aluminium cair. Namun ada masalah yang muncul dalam proses peleburan kaleng minuman ini, yaitu terdapat cat pada kaleng minuman saat dilebur yang menyebabkan aluminium loss serta perlu dilakukan analisa mengenai pemisahan peleburan bagian tutup dan badan kaleng minuman untuk mengetahui perbandingan kadar aluminiumnya. Pengujian pertama yang dilakukan adalah pengujian komposisi kaleng sprite 250 ml dengan spektroskopi dan jenis cat dengan FTIR ( Fourier Trasform Infra Red ). Proses peleburan kaleng minuman dilakukan dalam 5 kali percobaan menggunakan kaleng yang utuh maupun yang telah dipisah, dengan cat maupun tanpa cat. Dari hasil penelitian diketahui bahwa kadar aluminium pada sample peleburan kaleng utuh dengan cat, kadar aluminiumnya lebih tinggi dibandingkan sample tanpa tutup dengan cat, namun secara yield persentase nya lebih rendah dibandingkan dengan s...
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During stainless steel production in the electric arc furnace (EAF), oxygen is injected to oxidize unwanted tramp elements, mainly carbon and silicon. Unfortunately, oxygen also oxidizes precious elements such as iron and chromium which... more
During stainless steel production in the electric arc furnace (EAF), oxygen is injected to oxidize unwanted tramp elements, mainly carbon and silicon. Unfortunately, oxygen also oxidizes precious elements such as iron and chromium which causes economical loss and bad environmental impact. Off-gas analysis was performed at Deutsche Edelstahlwerke (DEW) to control the decarburization so that the elements, not only carbon, oxidation and oxygen consumption can be controlled as well. This paper presents a new strategy to control the elements oxidation as well as to increase the oxygen efficiency. For the investigated heat, the well controlled decarburization will decrease the oxygen consumption by about 10%. Work was carried out with a financial grant from the Research Fund for Coal and Steel of the European Community.
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Aluminum cans are widely used as food and beverage containers because of their properties. In practice, the consumption of canned drinks in the world and those recycled is not comparable. There are many challenges in recycling aluminum... more
Aluminum cans are widely used as food and beverage containers because of their properties. In practice, the consumption of canned drinks in the world and those recycled is not comparable. There are many challenges in recycling aluminum cans, one of which is the low yield of aluminum due to the formation of slag. From a literature study, it is known that the smelting temperature and the flux weight that added to the aluminium melt have an effect on the aluminum yield.Therefore in this research was conducted to smelt with 3 temperature variations were 720 o C, 740 o C and 760 o C and 3 flux weight variations were 0.5%; 0.75% and 1% based on weight of the aluminium can. The result show that experiment with melting temperature 760 o C and with weight flux of 1 % given highest recovery yield of 88.18% (388 grams).
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Friction welding is a solution for metal joint problems that are difficult to joint with fusion welding. The quality results of friction welding are highly dependent on process parameters such as friction pressure, friction time, forging... more
Friction welding is a solution for metal joint problems that are difficult to joint with fusion welding. The quality results of friction welding are highly dependent on process parameters such as friction pressure, friction time, forging pressure, forging time, and rotating speed. There is often excessive softening, hardening of the metal grains, and formation of an intermetallic phase at the weld interface due to too high friction temperatures and too high forging pressures on the alloy. Several studies on AA 6061 concludes artificial aging heat treatment can provide positive changes on the tensile strength and microstructure of AA 6061. The purpose of this study is to find out the effect of post artificial aging treatment toward profile and mechanical properties of AA 6061 friction welding joint. The varied parameters are forging pressure in friction welding of 325 bar, 350 bar, 375 bar and artificial aging heating temperature post-welding of 100 °C, 150 °C and 200 °C. The fixed p...
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In a manufacturing company, the quality loss is estimated by considering the number of defects. Taguchi is a method that finds strong conditions in uncontrollable environments of the field. Taguchi quantifies quality loss through a... more
In a manufacturing company, the quality loss is estimated by considering the number of defects. Taguchi is a method that finds strong conditions in uncontrollable environments of the field. Taguchi quantifies quality loss through a quality loss function. The Taguchi method particularly is focused on industrial processes. The method is actualizing quality philosophy for continuous quality improvement and cost reduction to improve manufacturing performance. The analysis is designed using Taguchi technique which is related to quality. A high-quality product has a minimal defect. The Taguchi method is used to analyze several defects of ammunition to reduce the number of ammunition defects. Ammunition consists of several parts are called projectile or bullet, cartridge case, propellant charge, and primer. Every part of its process possibly contributes to any defect. The defect type in every part of ammunition consists of critical, major, and minor defects. This paper is focused on cartri...
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Millions of canned drinks are consumed everyday globally and their wastes create an enviromental issue. Fortunately, the cans are made from aluminium (Al) so that it can be recycled. There are two main keypoints existing during the... more
Millions of canned drinks are consumed everyday globally and their wastes create an enviromental issue. Fortunately, the cans are made from aluminium (Al) so that it can be recycled. There are two main keypoints existing during the recycling process of Al cans, i.e. the aluminium loss or low Al-yield and low recycling yield. This work outlines the strategies to improve the recycling perfomance for Al beverage cans, i.e. by adding drossing flux, applying improved melting strategy, and cans decoating prior to melting. Drossing flux was added to assist the detachment of Al from the slag. Another improved melting strategy was worked out by decreasing exposure time cans to the furnace atmosphere during melting. All those above strategies result in an increase of recycle yield in a range of 4 % to 5 %.
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in a method for reducing the emission of nitrogen oxides in the exhaust gas (OG) of a furnace for the thermal treatment of materials in at least indirect presence of oxygen and nitrogen, particularly in the melting of iron-containing... more
in a method for reducing the emission of nitrogen oxides in the exhaust gas (OG) of a furnace for the thermal treatment of materials in at least indirect presence of oxygen and nitrogen, particularly in the melting of iron-containing starting materials in an electric arc furnace, and at a powered according to this method oven the exhaust gas (OG) a reducing action and / or reacting with oxygen in a reaction competing agent (a) is supplied.
Aluminium is widely used as a beverage can due to its excellence properties, i.e., good deformability; excellent corrosion resistance, high strength to weight ratio and non-toxic. The global consumption of canned drinks in 2017 was... more
Aluminium is widely used as a beverage can due to its excellence properties, i.e., good deformability; excellent corrosion resistance, high strength to weight ratio and non-toxic. The global consumption of canned drinks in 2017 was estimated at approximately 200 million pieces annually. These aluminium cans should then be recycled to minimize environmental challenges. Challenge, however, exists to optimize the recycling process. In this work, size of recycled cans, flux type, and recycling temperature were investigated to achieve higher recycling and Al yield. After various flux compositions were attempted to increase the recycling and Aluminium yield, the most suitable flux material was a mixture of chloride, fluoride, and SO4. Meanwhile, when the scrap dimension reduced to 1 cm2, the recycling and Aluminium yield showed no significant differences with the yield obtained using a scrap dimension of 4 cm2.
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Aluminium is widely used as a beverage can due to its excellence properties, i.e., good deformability; excellent corrosion resistance, high strength to weight ratio and non-toxic. The global consumption of canned drinks in 2017 was... more
Aluminium is widely used as a beverage can due to its excellence properties, i.e., good deformability; excellent corrosion resistance, high strength to weight ratio and non-toxic. The global consumption of canned drinks in 2017 was estimated at approximately 200 million pieces annually. These aluminium cans should then be recycled to minimize environmental challenges. Challenge, however, exists to optimize the recycling process. In this work, size of recycled cans, flux type, and recycling temperature were investigated to achieve higher recycling and Al yield. After various flux compositions were attempted to increase the recycling and Aluminium yield, the most suitable flux material was a mixture of chloride, fluoride, and SO4. Meanwhile, when the scrap dimension reduced to 1 cm2, the recycling and Aluminium yield showed no significant differences with the yield obtained using a scrap dimension of 4 cm2.
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Strategies to improve quality of gravity die casting for Sn-Pb alloy are outlined here by modifying the mould’s gating system, i.e. mainly the down sprue and the sprue well. Analysis based on the experimental work of 27 casting products... more
Strategies to improve quality of gravity die casting for Sn-Pb alloy are outlined here by modifying the mould’s gating system, i.e. mainly the down sprue and the sprue well. Analysis based on the experimental work of 27 casting products delivers a promising result for industrial application. Quantitative analysis of porosity defect in this work was based on density analysis. The investigation of the effect of down sprue design on the casting defects was worked out through the variation of tapered down sprue by one degree and two degrees. From the density analysis, the two degrees tapered down sprue results in then less porosity defect. Meanwhile, the highest density was identified at 50 mm, when radius of the down sprue was investigated at 0 mm, 5 mm and 100 mm. Finally, the investigation for sprue well radius of 0 mm, 50 mm, and 100 mm shows that the best sprue well radius related to the highest metal density occurs at a radius of 50 mm.
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During stainless steelmaking in an electric arc furnace (EAF), chromium concentrations at tapping should be well pre-estimated for several reasons. Both excessively low and high chromium concentrations require re-balancing procedures with... more
During stainless steelmaking in an electric arc furnace (EAF), chromium concentrations at tapping should be well pre-estimated for several reasons. Both excessively low and high chromium concentrations require re-balancing procedures with ferro-alloys which decrease liquid steel temperature and EAF energy efficiency. An innovative strategy is outlined in this paper to obtain higher energy and raw materials efficiency, higher productivity and lower production cost. The empirical model outlined in this paper can be used for a future industrial application at Level-2 and Level-3 of steel plants.
Gravity die casting merupakan salah satu proses pengecoran yang banyak dipakai terkhususnya untuk kalangan industri, selain karena untuk skala produktivitas besar tidak memerlukan biaya dan waktu yang besar dibandingkan sand casting.... more
Gravity die casting merupakan salah satu proses pengecoran yang banyak dipakai terkhususnya untuk kalangan industri, selain karena untuk skala produktivitas besar tidak memerlukan biaya dan waktu yang besar dibandingkan sand casting. Penelitian ini menggunakan material paduan timah putih sebagai bahan cor dikarenakan kalor peleburan yang rendah sehingga tidak membutuhkan energi yang terlalu besar. Sedangkan untuk variasi akan dilakukan pada radius sprue well atas dan panjang runner untuk mengetahui perbedaan waste material dan porositas masing – masing variasi. Dari studi literatur dan percobaan yang telah dilakukan didapat bahwa bentuk gating sangat mempengaruhi laju aliran logam cair, yang akhirnya akan mempengaruhi jumlah porositas dan waste material dari spesimen. Setelah penelitian selesai dilakukan, dapat dilihat porositas terkecil ada pada variasi radius 5 mm pada panjang runner 7 cm, dan yield waste terbanyak pada panjang runner 5 cm pada radius 10 mm, hal ini dikarenakan al...
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A coating is widely applied to protect base material during contact with surrounding. One important application in engineering is to protect a boat hull. The coating is applied to boat hull to prevent a decrease of mechanical properties... more
A coating is widely applied to protect base material during contact with surrounding. One important application in engineering is to protect a boat hull. The coating is applied to boat hull to prevent a decrease of mechanical properties of base materials particularly with corrosive seawater. Composite coating is applied since the composite coating provides better protection compared to paint coating. Additionally, sandblasting prior to composite coating is worked out to improve the mechanical properties of the coating. This work investigated the influence of the projection angle of the sandblasting process on the shear strength of the coated surface. The projection angle of sandblasting was varied from 30 to 90 °. The result shows that a higher projection angle decreases the strain strength of the coating surface. The experiment work showed that the shear strength of 30°, 45 °, 60 °, and 90°projection angle are 1.02, 0.66, 0.38, and 0.24 MPa, respectively.
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A conveyor belt is one type of goods transportation in technological processes, particularly in the mining industry. The belt is the important material and principal part of the conveyor belt. The overall quality of the conveyor belt as... more
A conveyor belt is one type of goods transportation in technological processes, particularly in the mining industry. The belt is the important material and principal part of the conveyor belt. The overall quality of the conveyor belt as its service life and impact loads are very important factors. Therefore, the purpose of this paper is to classify the types of impact damage that may occur in rubber-textile conveyor belts. In many works, many types of conveyor belts are tested at various levels and the type of impacting material. The level of damage occurred is investigated by using probability theory. Particularly, the evaluation of experimental test data and predictive modeling is carried out using the Naïve Bayes classification.
A356.0 aluminum-silicon alloy is a base material for car rims application. Car rims are critical components for a vehicle as they carry the load of the passengers, goods, and the weight of the vehicle itself, therefore they should be... more
A356.0 aluminum-silicon alloy is a base material for car rims application. Car rims are critical components for a vehicle as they carry the load of the passengers, goods, and the weight of the vehicle itself, therefore they should be sufficiently strong to withstand the vertical load, fatigue load, impact load, the side load and the braking force. Car rims are made by gravity die casting process. During the casting process, the inclusion of iron-content parts entering the molten Al can take place which leads to higher iron (Fe) concentration. High Fe con concentration lowers the toughness and the ductility of car rims. This study investigates the maximum value of Fe concentration that can be tolerated for acceptable mechanical properties of Al-Si alloy A356.0 for car rims application. The Fe concentration studied was 0.12 %wt, 0.16 %wt, and 0.20 %wt. Evaluation was performed on tensile and impact properties of the specimens. The test results show that increased Fe concentration decr...
Determining the complete energy balance of an electric arc furnace (EAF) provides an appropriate method to examine energy efficiency and identify energy saving potentials. However, the EAF energy balance is complex due to the combined... more
Determining the complete energy balance of an electric arc furnace (EAF) provides an appropriate method to examine energy efficiency and identify energy saving potentials. However, the EAF energy balance is complex due to the combined input of electrical energy and chemical energy resulting from natural gas (NG) combustion and oxidation reactions in the steel melt. In addition, furnace off-gas measurements and slag analysis are necessary to reliably determine energy sinks. In this paper 70 energy balances and energy efficiencies from multiple EAFs are presented, including data calculated from plant measurements and compiled from the literature. Potential errors that can be incorporated in these calculations are also highlighted. The total energy requirement of these modern EAFs analysed ranged from 510 to 880kWh/t, with energy efficiency values (η=ΔHSteel/ETotal) of between 40% and 75%. Furthermore, the focus was placed on the total energy related CO2 emissions of EAF processes comp...