ARMATUR : Artikel Teknik Mesin & Manufaktur

Evaluasi Kinerja Cooling Tower Tipe Counter Flow Mechanical Induced Draft pada Pembangkit Listrik Tenaga Panas Bumi (Studi Kasus: PT Pertamina Geothermal Energy (Tbk), Area Ulubelu, Unit 4)

2026-06-04T10:50:10+07:00

The cooling tower is one of the vital components in a Geothermal Power Plant (PLTP) system, functioning to cool the condensate water from the condenser before it is reused. This study aims to analyze the effectiveness of a counter flow mechanical induced draft cooling tower at PLTP Unit 4, PT Pertamina Geothermal Energy (Tbk), Ulubelu Area. The data were obtained from field measurements conducted over seven days at fourtime intervals each day. The parameters analyzed include range, approach, and effectiveness, calculated using inlet water temperature, outlet water temperature, and wet bulb temperature. The results show an average effectiveness value of 70.05%, with variations influenced by changes in range and approach values. This effectiveness is close to the design standards stated in the manufacturer’s specifications, indicating that the cooling tower operates with good performance. This analysis provides an overview of the actual equipment condition and can serve as a reference for maintenance and performance optimization in the future.

Pengaruh Variasi Waktu Sputtering Terhadap Karakteristik Mekanik dan Evolusi Struktur Mikro Baja AISI 4140

2026-06-17T20:23:23+07:00

AISI 4140 steel is a high‑strength, low‑alloy material commonly used in mechanical components subjected to high load and friction. Although its bulk properties are favorable, surface modification is often required to enhance wear resistance and prolong service life. This study investigates the influence of DC sputtering Titanium Nitride (TiN) deposition time on the mechanical performance and microstructural evolution of AISI 4140 steel. The experimental procedure varied sputtering times at 30, 60, 90, 120, and 150 minutes while maintaining constant processing parameters. Characterization techniques included Vickers hardness testing, wear testing, and SEM–EDX analysis to evaluate coating morphology and coating–substrate interface quality. The results indicate that TiN deposition significantly enhances surface hardness compared to the uncoated substrate. The maximum hardness value of 186.66 VHN was achieved at 60 minutes of deposition, corresponding to a dense, uniform coating with strong adhesion. Prolonged deposition times, however, led to decreased hardness and increased wear rate, attributed to excessive coating thickness, microstructural non-uniformity, and the formation of micro-defects. SEM observations corroborate these findings by revealing notable variations in coating morphology and interface integrity across deposition durations. Overall, the study concludes that sputtering time is a critical parameter in optimizing TiN coatings to improve the surface performance of AISI 4140 steel for engineering applications.

Analisis pengaruh ketebalan dan jenis Coating terhadap kekuatan Adhesi pada Pelat Baja SA 516 Gr 70

2026-06-10T16:55:57+07:00

SA 516 Gr 70 carbon steel is often used in pressure vessels, requiring a coating system with good adhesive strength to prevent failure due to corrosion. This study analyzes the effect of coating type and thickness on the adhesive strength of SA 516 Gr 70 plates using the pull-off test method in accordance with ASTM D4541. The two coating systems tested were Interbond 2340 (UPC) and Interline 399, with variations in dry film thickness (DFT) of 75 µm, 125 µm, and 175 µm. Surface preparation was carried out through an abrasive blasting process with a cleanliness level of Sa 2½, accompanied by control of roughness profile, salt contamination, dust cleanliness, and control of application environmental conditions to maintain coating quality. Test results show that Interbond 2340 produces higher adhesion values than Interline 399 across all thickness variations, confirming the influence of coating type on coating adhesion performance. A maximum adhesion value of 17.09 MPa was obtained for Interbond 2340 with a thickness of 125 µm, indicating the optimal thickness for increasing the bond strength of the coating to the steel substrate. All specimens met the ASTM D4541 requirements, with Interbond 2340 at a thickness of 125 µm showing the most superior adhesion performance and can be used as a technical reference in selecting a coating system for pressure vessel applications.

Studi Komparatif Variasi Ketebalan Pelat Baja ASTM A36 pada Main Steel sebagai Penopang Baterai

2026-06-09T10:50:34+07:00

This simulation aims to conduct a comparative study of variations in the thickness of ASTM A36 steel plates to determine the most optimal thickness for supporting the load of batteries, which are currently a critical energy source. The analysis focuses on the values of von Mises stress, displacement, and safety factor. Battery supports are the primary focus of this study, which will compare variations in optimal thickness for batteries that typically require thicknesses of up to 3 to 4 mm; in this simulation, a thinner and optimal solution will be sought. As technology advances and the demands of manufacturing digitalization grow, production processes are increasingly utilizing simulations in Computer-Aided Engineering (CAE) software, making conventional testing more efficient. Using SolidWorks software simulation, a static analysis was conducted to evaluate each variation. ASTM A36 steel plates measuring 1400 mm in length, 70.6 mm in width, and with thicknesses of 1 mm, 2 mm, and 3 mm were selected to accommodate the battery weight. Three battery blocks, each weighing 5 kg, were used in this simulation. ASTM A36 material was selected because it has a high yield strength of 250 MPa. In addition to the parameters mentioned above, dynamic loads with variations of 1.5G and 2G will also be calculated. The optimal strength of the battery mount was determined through simulation in SolidWorks. The results of each thickness variation were then analyzed using a comparative study to determine the optimal thickness based on a comparison of von Mises stress, displacement, and safety factor. Ultimately, the optimal thickness was determined to be 3 mm, with von Mises stress reduced by 32.8% to 82 MPa. Displacement was reduced by 1.08% compared to the two previous variations, specifically 12 mm at the center of the plate. The optimal dynamic load stress occurs at a thickness of 3 mm.

Analisis Sifat Mekanik Uji Tarik Material Komposit Serat Karbon–Epoksi 1011l dengan Metode Manufaktur yang Berbeda

2026-05-05T12:02:56+07:00

Carbon fiber reinforced polymer composites are widely used in structural applications due to their high strength-to-weight ratio. Manufacturing methods significantly affect fiber impregnation quality, void content, and mechanical properties. This study investigates the effect of different manufacturing methods on the tensile properties of carbon fiber–epoxy 1011L composites with 0° fiber orientation. Three manufacturing methods were used: hand lay-up (HLU), vacuum bagging (VB), and vacuum assisted resin infusion (VARI). A total of 21 specimens were tested using a Universal Testing Machine (UTM) at the National Research and Innovation Agency (BRIN) following ASTM D3039. The results show that The VARI method showed the best mechanical performance with an average maximum point stress (MPS) of 774,31 MPa and an elastic modulus (ME) of 39.313 MPa, followed by the vacuum bagging and hand lay-up methods. The hand lay-up method produced the lowest MPS and ME values, at 507,72 MPa and 20.401 MPa, respectively. The VARI method produces the best mechanical properties compared to the hand lay-up and vacuum bagging methods.

Perancangan Ulang Produk Kruk Dengan Metode Quality Function Deployment Untuk Memenuhi Kebutuhan Penyandang Disabilitas Kaki

2026-05-12T09:17:43+07:00

The population of persons with disabilities in Indonesia is currently estimated at approximately 22.97 million individuals, representing around 8.5% of the national population. Among this group, persons with lower-limb disabilities constitute the largest proportion, accounting for roughly 38% of all individuals with disabilities. This category of disability is frequently associated with significant challenges in mobility, including difficulties in walking, ascending stairs, and performing other related movements. Consequently, lower-limb disability users commonly depend on assistive devices such as crutches to support their daily activities. However, complaints often arise when using crutches, one of which is the difficulty of using crutches when traveling, whether by motorcycle or car, due to the elongated size of the device. To address these issues, a Quality Function Deployment (QFD) approach was employed to redesign the crutch in accordance with user needs. Based on this study, improvements were made in two aspects: economic and ergonomic. The product was adjusted to ensure that the price is acceptable to users. In addition, a redesign of the crutch dimensions was carried out, resulting in an increase in height. This modification aims to enhance ergonomic comfort and prevent potential secondary health problems for the users

Analisis Hidrodinamika dan Karakteristik Pressure Drop pada Fotobioreaktor Flat-Panel Sistem Closed-Loop Menggunakan Computational Fluid Dynamics

2026-05-18T09:40:21+07:00

Hydrodynamic performance plays a crucial role in determining flow distribution and hydraulic losses inside flat-panel photobioreaktor systems. This study aims to investigate the flow characteristics and pressure drop behavior of a closed-loop flat-panel photobioreaktor using a Computational Fluid Dynamics (CFD) approach. A three-dimensional steady and incompressible laminar model was employed with water as the working fluid. Inlet velocities of 0.01 m/s, 0.03 m/s, 0.05 m/s, and 0.1 m/s were applied to evaluate their influence on velocity distribution, streamline patterns, and pressure drop. A grid independence study was conducted using three mesh densities, and the final mesh with an element size of 0.015 m showed less than 1% variation in pressure drop, confirming mesh-independent results. The simulation results indicate that increasing inlet velocity significantly increases pressure drop and maximum velocity within the reaktor due to flow acceleration near the inlet region. Streamline analysis reveals the formation of recirculation zones in the lower section of panel.

Pelapisan Antikorosi berbasis LDPE dari Limbah Kantong Plastik melalui Metode Catalytic Liquefaction

2026-06-06T07:15:13+07:00

Penelitian ini mengkaji pemanfaatan polimer LDPE yang berasal dari limbah kantong plastik sebagai inhibitor korosi pada besi. Proses pencairan LDPE dilakukan dengan menggunakan metode Catalytic Liquefaction dengan katalis ZnCl₂ pada suhu 300°C selama 30 menit. Pengujian karakteristik gugus fungsi dilakukan menggunakan spektrofotometer FTIR, sedangkan efektivitas inhibisi korosi dievaluasi melalui metode pengurangan berat (weight loss) dan Electrochemical Impedance Spectroscopy (EIS) dalam media NaCl 3%, NaCl 5%, HCl 3%, dan HCl 5%. Hasil penelitian ini menunjukkan bahwa polimer LDPE mampu secara signifikan menurunkan laju korosi besi. Efisiensi inhibisi tertinggi diperoleh sebesar 76,84% dalam larutan NaCl 5% dengan konsentrasi inhibitor 5 gram. Analisis EIS menunjukkan efektivitas LDPE ditandai dengan nilai total impedansi yang lebih tinggi dibandingkan tanpa penambahan LDPE (8,21 Ω vs. 5,29 Ω). Adsorpsi molekul LDPE pada permukaan logam mengikuti isoterm adsorpsi Langmuir. Penelitian ini menunjukkan potensi besar dalam pemanfaatan limbah plastik sebagai material antikorosi yang ramah lingkungan.

PEMANFAATAN POLIMER LDPE (LOW-DENSITY POLYETHELENE) LIMBAH PLASTIK SEBAGAI INHIBITOR KOROSI PADA MATERIAL BAJA JENIS LOW-CARBON ASTMA-53 PADA PIPA MINYAK FRAKSI BERAT

2026-06-04T09:49:23+07:00

Penelitian ini membahas permasalahan korosi pada baja karbon ASTM A53 yang banyak digunakan dalam industri minyak dan gas. Tujuan penelitian adalah menganalisis efektivitas pelapisan berbasis limbah plastik Low Density Polyethylene (LDPE) dalam menurunkan laju korosi pada media air formasi. Metode yang digunakan meliputi preparasi spesimen, sintesis larutan LDPE menggunakan pelarut toluena, proses pelapisan методом pencelupan, serta pengujian korosi menggunakan metode kehilangan massa (weight loss) dengan variasi waktu perendaman. Karakterisasi dilakukan menggunakan FTIR untuk mengidentifikasi gugus fungsi pada lapisan pelindung. Hasil penelitian menunjukkan bahwa pelapisan LDPE mampu menurunkan laju korosi secara signifikan dibandingkan baja tanpa pelapisan, di mana peningkatan massa LDPE menghasilkan perlindungan yang lebih optimal.

Pengaruh Jenis Sensor Water Level dan Variasi Tegangan Terhadap Ketinggian Air Pada Tangki Bensin Berbasis Arduino

2026-06-06T07:20:28+07:00

Cases of vehicle tank leaks throughout 2024-2025 amounted to 23,500 units. The cause of vehicle tank leaks is water vapor (condensation) because the empty space in the tank contains air. Water Level Sensor is a sensor used to detect and measure water levels. The way the Water Level Sensor works by utilizing an open conductor path that is connected when in contact with water, the Water Level Sensor used is HW 37 and HW 38. The purpose of this study is to determine the effect of the type of Water Level Sensor HW 37 and HW 38, variations in working voltage of 3V and 5V and to compare the percentage error value of water level measurements of 5, 10, 15 and 20 mm. The test method uses experiments presented in the form of tables and graphs. The independent variables are the type of sensor and voltage. The dependent variables are the accuracy of water level measurements of 5, 10, 15, and 20 mm. The test results of the Water Level Sensor HW 37 with the best accuracy occurred at a voltage of 5V with a percentage error value of 0.35%, while the Water Level Sensor HW 3 with the best accuracy occurred at a voltage of 5V with a percentage error value of 0.10%.

Waste Analysis in the Chain Wheel Gear Production Process Using the Lean Manufacturing Approach at PT Sinar Agung Selalu Sukses

2026-06-02T10:04:53+07:00

The global automotive industry faces increasing pressure to improve productivity, quality, and cost efficiency to remain competitive. Manufacturing companies are therefore required to minimize waste and optimize production processes. This study analyzes waste reduction in the Original Equipment Manufacturer (OEM) production line at PT Sinar Agung Selalu Sukses, focusing on Chain Wheel Gear (CWG). Between January and July 2025, the production line recorded 9,903 defective units, indicating significant inefficiencies. Lean Manufacturing tools—Value Stream Mapping (VSM), the Borda method, and Fishbone Diagrams—were applied to identify dominant waste and root causes. The analysis revealed a Process Cycle Efficiency (PCE) of 35.9%, below the 50% benchmark, with defect waste identified as the most critical issue. The main contributing factors include material inconsistency, unstable process methods, operator performance, and machine conditions. A 5W+1H-based improvement plan is proposed, including operator mentoring, process standardization, preventive maintenance, and stricter material control. These improvements are expected to reduce defects, shorten lead time, and enhance production efficiency, strengthening competitiveness in Indonesia’s automotive component industry.

ANALISIS PENGARUH JENIS BAHAN BAKAR B0, B30, B35, DAN B40 TERHADAP EFISIENSI THERMAL PLTD BIAK

2026-06-04T09:15:34+07:00

Diesel Power Plants (PLTD) play an important role in supplying electrical energy, particularly in island regions and remote areas such as Biak. To support the national energy transition, the government has implemented a mandatory biodiesel policy that has progressively increased from B30 and B35 to B40 in order to reduce dependence on fossil fuels. This study aims to analyze the thermal efficiency of PLTD Biak under B0, B30, B35, and B40 fuel types, as well as their effects on Specific Fuel Consumption (SFC) and heat rate. The research employed a quantitative descriptive approach using actual operational data, including fuel consumption, generator output power, and fuel heating values. The results show that increasing biodiesel content causes SFC to rise from 0.251 liter/kWh for B0 to 0.271 liter/kWh for B40, reduces thermal efficiency from 39.8% to 37.1%, and increases heat rate from 9,045 kJ/kWh to 9,704 kJ/kWh. It can be concluded that B30 provides the best balance between supporting the mandatory biodiesel policy and maintaining operational performance, while B35 and B40 require optimization of operating parameters to preserve efficiency.

Pendekatan Integratif Untuk Peningkatan Efektivitas Layanan dan Operasional Bengkel Otomotif: Systematic Literature Review

2026-06-06T06:34:31+07:00

The increasing number of motor vehicles has led to higher demand for automotive workshop services, requiring workshops to improve both service quality and operational efficiency. However, many automotive workshops still face operational problems such as long service waiting times, inefficient workflows, inconsistent service quality, and non-value-added activities. This study aims to identify and analyze various approaches used to improve service quality and operational efficiency in automotive workshops through a Systematic Literature Review (SLR). The study reviewed 15 scientific articles published between 2020 and 2025 related to automotive workshop services, operational improvement, and quality management methods. The analysis focused on approaches such as Service Quality (SERVQUAL), Importance Performance Analysis (IPA), Lean Service, Quality Function Deployment (QFD), Value Stream Mapping (VSM), Six Sigma, Service Blueprint, TRIZ, and Design Thinking. The results show that SERVQUAL is the most widely used method for identifying service quality gaps, especially in responsiveness and reliability dimensions. However, integrated approaches combining service quality methods with operational improvement methods such as Lean Service, VSM, and Six Sigma provide more comprehensive solutions for improving workshop performance. These approaches are effective in reducing operational waste, improving workflow efficiency, minimizing service variability, and enhancing service innovation. The study concludes that improving automotive workshop performance requires an integrated approach involving service quality, operational efficiency, process control, and service innovation.

Pengaruh Konsentrasi Perekat Kitosan Terhadap Sifat Fisik dan Mekanik Papan Partikel Tiga Lapis Berbahan Limbah Batang Jagung Untuk Aplikasi Meja Ramah Lingkungan

2026-06-06T07:48:41+07:00

The growing demand for eco-friendly composite materials has driven research into the use of agricultural waste as a substitute for wood-based raw materials. Conventional adhesives such as urea-formaldehyde (UF) and phenol-formaldehyde (PF) contain toxic formaldehyde compounds, making the development of natural alternatives essential. This study investigates the effect of chitosan adhesive concentration and layer arrangement on the physical and mechanical properties of particleboard made from corn stalk (Zea mays L.) waste, intended for environmentally friendly table applications. Corn stalk particles were processed using a hammer mill and bonded with chitosan adhesive at concentrations of 20%, 25%, and 30%. The boards were hot-pressed at 180°C under 30 MPa for 10 minutes and evaluated according to the Japanese Industrial Standard JIS A 5908:2003, covering density, moisture content (MC), water absorption, thickness swelling, Modulus of Elasticity (MOE), and Modulus of Rupture (MOR). Results showed that density values across all treatments (0.46–0.50 g/cm³) met the JIS standard, classifying the boards as medium density particleboard. Moisture content complied with the standard only at 20% and 25% chitosan concentrations. The 30% chitosan concentration yielded the highest mechanical performance (MOE = 654.98 N/mm²; MOR = 2.81 N/mm²), though all treatments fell below the minimum MOE threshold required by the standard. Water absorption and thickness swelling remained high across all treatments, indicating limited dimensional stability.

Rancang Bangun dan Analisis Kinerja Saluran udara pada Simulator Trainer Airbag

2026-06-10T17:02:09+07:00

Passive safety systems such as airbags are crucial for reducing the risk of fatal injuries in the event of a crash. The deployment speed of an airbag depends heavily on its mechanical design and electronic controls. This study aims to determine the effect of variations in valve channel diameter 2.5 mm, 5 mm, and 8 mm on the deployment response time of the driver-side airbag. The experimental method was conducted using an ATmega328 microcontroller-based airbag vehicle safety simulator trainer. In this test, a solenoid valve was used to regulate airflow with valve orifice diameters of 2.5 mm, 5 mm, and 8 mm. An ADXL345 sensor was used to provide the collision trigger signal to the microcontroller, while an HC-SR04 ultrasonic sensor was used to detect when the airbag began to deploy. Based on experimental analysis, it was concluded that the diameter of the valve channel significantly affects the inflation rate. The smaller the valve channel diameter, the faster the airbag response time. Conversely, the larger the channel diameter, the longer it takes for the airbag to inflate.

Analisis Sifat Mekanik Tarik Komposit Hybrid Matrik Epoxy Serat Rami (Boehmeria Nivea) Dan Serbuk Genteng.

2026-06-12T09:33:05+07:00

Ramie fiber was chosen for its superior mechanical properties and environmentally friendly characteristics as a renewable material, while roof tile powder was used as an inorganic filler to increase stiffness and utilize abundant construction waste. This study aims to analyze the effect of the composition ratio used on the tensile strength of hybrid composites based on natural ramie fiber (Boehmeria Nivea) and roof tile powder with an epoxy matrix, focusing on mechanical testing, namely tensile testing, to analyze the effect of composite material combinations. The research will be conducted using the hand lay-up method, with variations in the volume fraction of epoxy resin (75%) and ramie fiber (0%; 5%; 10%; 15%; 20%; 25%) and roof tile powder (25%; 20%; 15%; 10%; 5%; 0%). The planned mechanical test include several types of test, including tensile test to analyse the effect of composite material combination.

Pengaruh Aktivasi Termal Abu Dasar Batubara terhadap Kinerja Adsorpsi dalam Peningkatan Sifat Fisik Pelumas Bekas

2026-06-14T17:29:53+07:00

Used lubricating oil contains degradation products and contaminants that may cause environmental pollution if improperly disposed of. This study investigated the utilization of coal bottom ash as an adsorbent for used lubricating oil purification and evaluated the effect of thermal activation on its adsorption performance. Bottom ash was purified using 2 M H₂SO₄ and subsequently thermally activated at 650°C for 3 h with NaOH assistance. The chemical composition of the adsorbent was analyzed using X-ray Fluorescence (XRF), while adsorption performance was evaluated through density, kinematic viscosity, and flash point measurements of the treated oil. XRF results showed that the purification process reduced Ca content from 22.36 wt.% to 10.44 wt.% and Fe content from 29.19 wt.% to 20.61 wt.% while preserving the major silica and alumina components. The thermally activated bottom ash exhibited better adsorption performance than the non-activated adsorbent, resulting in higher density and viscosity values of the treated oil. These findings demonstrate that thermal activation improves the adsorption capability of bottom ash, indicating its potential as a low-cost and environmentally friendly adsorbent for used lubricating oil purification.

Pengembangan Filamen 3D Printing dari Strip Sampah Plastik Polyethylene Terephthalate Daur Ulang

2026-06-19T13:54:49+07:00

Polyethylene Terephthalate (PET) plastic waste is one of the most common types of waste whose volume continues to increase and poses a significant threat to the environment. This study aims to develop 3D printing filament from recycled PET bottle strips and evaluate the effect of printing parameters on the quality of printed parts produced using Fused Deposition Modeling (FDM) technology. An experimental method was employed, consisting of cleaning, drying, cutting PET bottles into strips measuring 8–12 mm, filament extrusion at a temperature of 220°C, and specimen printing using nozzle temperature variations of 255°C, 265°C, 275°C, and 285°C, combined with bed temperatures of 50°C and 70°C. The results showed that the produced filament had a diameter ranging from 1.65 to 1.80 mm, which is close to the standard diameter of commercial filament (1.75 mm). The quality of the printed parts was influenced by the combination of nozzle and bed temperatures.

Kerangka Terintegrasi Pareto–FMEA–FTA untuk Pengendalian Kualitas Berbasis Risiko pada Pemesinan Komponen Presisi: Studi Kasus Manufaktur Spinning Spinnerette

2026-06-20T13:33:12+07:00

This study aims to identify the dominant defect types, analyze potential failure modes and their associated Risk Priority Numbers, determine the root causes of primary failures, and formulate corrective action recommendations for the machining process of spinning spinnerette products at PT XYZ, Cikarang, Indonesia. A mixed-methods approach was employed, integrating Pareto Chart analysis, Failure Mode and Effect Analysis (FMEA), and Fault Tree Analysis (FTA) sequentially. Data were collected through field observation, structured interviews, FMEA questionnaires, and company documentation covering the period January–December 2025. Pareto Chart analysis revealed that rough surface defects (37.50%), non-conforming hole diameter (25.00%), and clogged holes (20.00%) collectively accounted for 82.50% of total recorded defects. FMEA yielded the highest Risk Priority Number for the rough surface failure mode (RPN = 240), while micro-crack defects recorded the highest Severity rating (S = 9), with an estimated financial loss of IDR 50,000,000.00 per unit. FTA identified that rough surface defects originate from the interaction of four primary factors: cutting tool condition, process parameters, operator competency, and production environment control. The 5W+1H-based corrective recommendations formulated in this study have the potential to reduce financial losses by up to IDR 476,000,000.00 annually and may be adopted as a risk-based quality control model applicable to analogous precision component manufacturing industries.

Analisis Penyimpangan Fasa dan Sifat Mekanik pada Baja Paduan Hasil Pengecoran Konvensional di Bengkel Tenayan Pekanbaru

2026-06-22T08:33:19+07:00

This research addresses metallurgical challenges in engineering the microstructure of as-cast products caused by the slow cooling rates and non-uniform phase distribution inherent to sand casting. This study aims to evaluate the effect of alloying elements on the microstructural and mechanical properties of as-cast steel specimens (SP1, SP2, and SP3). Characterization was performed via metallographic observation of dendritic morphology and flake graphite distribution, followed by micro-Vickers hardness and tensile elongation testing. The results reveal an inversely proportional trade-off between surface hardness and material strain capability. Specimen SP2 exhibited the highest hardness 397.77 + 9.02 HV due to a rigid, interlocking dendritic network, which heightened the internal notch sensitivity of the graphite phase and triggered premature brittle fracture with a minimum elongation of 8.1 %. Conversely, SP1 yielded the best matrix homogeneity and lowest hardness 316.00 + 1.25 HV, effectively distributing local stresses to achieve the highest elongation 17.3 %, while SP3 showed a transitional behavior. Future work recommends utilizing an induction furnace and applying post-casting heat treatment to optimize alloy toughness.

Analisis sifat fisis dan mekanis papan partikel limbah jagung berperekat kitosan sebagai kandidat material lantai bagasi mobil

2026-06-22T11:07:26+07:00

This research focused on examining the physical and mechanical characteristics of particleboard created from corn stalk byproducts and chitosan adhesive, serving as an eco-friendly alternative material, particularly for vehicle trunk flooring uses. The approach to the research included creating particleboard with different concentrations of chitosan adhesive at 20%, 25%, and 30%. The physical characteristics (moisture content, density, water absorption, and thickness swelling) and mechanical characteristics Modulus of Elasticity and Modulus of Rupture were subsequently assessed following the JIS A 5908:2003 standard. The findings indicated that the density values of the particleboard for all variations conformed to the standard, whereas the moisture content complied with the standard only at concentrations of 20% and 25%. Water absorption and thickness swelling remained quite elevated across all treatments, suggesting poor moisture resistance because of the material's hygroscopic characteristics. The maximum MOE value was reached at a concentration of 25%, whereas the peak MOR value was found at a concentration of 20%. Overall, raising the adhesive concentration doesn't consistently enhance mechanical properties, and there exists an ideal value at specific compositions.

Perancangan Inkubator Telur Puyuh Otomatis Berbasis IoT dengan Sistem Pemantauan Jarak Jauh Menggunakan Spreedsheat

2026-06-22T20:50:22+07:00

The research method used was an experimental comparative approach by comparing the performance of an IoT-based automatic incubator with a conventional incubator. The automatic incubator utilized an ESP32 microcontroller, DHT22 temperature and humidity sensor, heating lamps, exhaust fan, and automatic egg turning system using a servo motor. Monitoring data were transmitted via internet connection for real-time observation with spreadsheet. Each incubator was tested using 30 quail eggs during an incubation period of 18 days.The results showed that the IoT-based incubator was able to maintain temperature stability within the range of 37.2°C–38.2°C and humidity between 60%–68%. Meanwhile, the conventional incubator experienced larger temperature fluctuations ranging from 35.4°C to 40.0°C. The automatic incubator achieved a hatchability rate of 90% with an average hatch weight of 8.9 g, while the conventional incubator only achieved 70% hatchability with an average hatch weight of 7.8 g. Based on the results, the IoT-based automatic incubator demonstrated better performance in maintaining incubation stability and improving hatchability efficiency compared to the conventional system. The implementation of IoT technology also enabled real-time monitoring and automatic control, making the incubation process more effective and efficient.

Pengaruh Variasi Temperatur Preheating Pada Pengelasan Gas Metal Arc Welding (GMAW) Baja SM490 Terhadap Sifat Mekanik Dan Struktur Mikro

2026-06-24T16:02:52+07:00

The railway industry is a manufacturing industry engaged in the manufacture, repair, and maintenance of trains. In the train manufacturing process, one of the components of the train structure is the train bogie. Train bogies are generally made using SM490 Steel material because they have good strength, toughness, machinability, and weldability. The manufacture of bogies is generally done by welding methods. One of the commonly used welding methods is Gas Metal Arc Welding (GMAW). This study aims to determine the effect of the preheating process on the mechanical properties and microstructure of the welding results. Data obtained from tests including hardness testing, tensile testing, impact testing, and microstructure observations. Hardness testing shows a decrease in the strength value of the welding results where the highest value is obtained in untreated material of 179.53 HVN and the lowest value in material with 300˚C preheating of 172.23 HVN. Tensile test data shows an increase in tensile strength by applying the preheating process, where the highest tensile strength and elongation values were obtained in the material with 200˚C preheating, namely 536.1 MPa with an elongation of 18.9%. Impact test data shows an increase in toughness in the material with preheating treatment. Microstructural observation data shows a change in the microstructure in the weld metal area. It was also found from the microstructural observations that the ferrite phase dominates.

Kajian Penghematan Komsumsi Energi Dengan Menggunakan Energy Value Stream Mapping (EVSM) di Industri Otomotif

2026-06-26T08:25:25+07:00

Electrical waste problems often occur in the automotive industry, particularly in the vehicle painting process within the Paint Shop, which consists of Deck Cleaning Pre, Pre-Treatment & Electro Deposition (PT-ED), Dry Sanding I & UBS, Surface, Dry Sanding II, Top Coat Booth, and Paint Finishing. Estimated electrical waste occurs in PT-ED section and the oven. PT-ED comprises 9 processing tanks that often experience idle time while waiting for vehicle bodies to be processed. This situation occurs because when body 1 and body 2 are processed in PT-ED, body 1 should be in tank 4 while body 2 in tank 1. However, in implementation, body 1 is already in tank 6 while body 2 remains in tank 1, causing tanks 2 through 5 to become idle. The objective of this research is to utilize Energy Value Stream Mapping and Finite State Machine models. The results indicate that workstations in the Paint Shop still experience waste in electrical consumption. This is evidenced by the following ratios: Tva = 0.6, Tnva = 0.27, Tnva/n = 0.04, EIva = 0.55, EInva = 0.10, EInva/n = 0.35, Eva = 0.8, Enva = 0.07, Enva/n =e 0.12, Cva = 0.8, Cnva = 0.07, Cnva/n = 0.12.

Analisis Analisis Kekuatan Sambungan Angel Corner pada Alumunium Profile 2020 untuk Rangka Printer 3D Logam

2026-06-27T12:27:33+07:00

This study analyzes the structural performance of angel corner joints in aluminium profile 2020, which serve as critical connectors in the frame of a metal 3D printer based on MIG welding. The objective is to evaluate the influence of material variation on stress distribution, deformation, and safety factor using the Finite Element Method (FEM) in ANSYS. Three materials were examined: Aluminium Alloy 6061-T6, Structural Steel S355, and Stainless Steel 316L. A three-dimensional CAD model of the corner joint was developed and subjected to a static load of 150 N to represent realistic operational conditions. The results indicate that maximum von Mises stress for all materials remains below their respective yield strengths, confirming elastic behavior. Structural Steel S355 produced the smallest deformation (0.065 mm) and the highest safety factor (4.34), while Aluminium Alloy 6061-T6 exhibited larger deformation (0.145 mm) and a lower safety factor (2.59), but still within safe limits. Stainless Steel 316L demonstrated intermediate performance with a safety factor of 2.26 and deformation of 0.102 mm. These findings highlight that material selection significantly affects stiffness and safety margin of the frame. Structural Steel S355 is recommended when strength and stability are prioritized, whereas Aluminium Alloy 6061-T6 may be considered when lightweight construction is required.

OPTIMASI PROSES SAND CASTING DALAM UPAYA REDUKSI CACAT PENGECORAN LOGAM BERDASARKAN PENGARUH POURING TIME, SUHU TAPPING, DAN SUHU POURING PADA PT. X

2026-07-01T19:04:39+07:00

The sand casting process is widely used due to its flexibility in producing components with various geometries. However, casting defects remain a major issue as they reduce product quality and increase production losses. This study analyzes the effect of pouring time, tapping temperature, and pouring temperature on defect tendencies in deckdrain products produced by sand casting at PT X. A descriptive quantitative method was applied using production observation data collected during internship activities on January 12–15, 2026. The analysis included visual defect identification, defect classification, pouring time measurement, and temperature evaluation from tapping to pouring. The results showed six dominant defects: misrun, blow hole, cold shut, metal penetration, rat tail, and inclusion. The average pouring time was highest in the body part at 19.39 s, followed by grating at 11.22 s and filter at 7.14 s. Tapping temperature ranged from 1592–1673 °C, while pouring temperature ranged from 1510–1605 °C, with an average temperature drop of 52.75 °C. These results indicate that variations in pouring time and heat loss can reduce metal fluidity and increase the risk of misrun and cold shut defects. Therefore, defect reduction should focus on controlling pouring time and temperature for each

ANALISIS PENGARUH VARIASI SUDUT ELEKTRODA E7018 TERHADAP KEKUATAN TARIK SAMBUNGAN LAS SMAW PADA BAJA JIS G3101 SS400 UNTUK KOMPONEN RANGKA ATAP KOPERASI MERAH PUTIH

2026-07-24T20:57:32+07:00

This study aims to analyze the effect of E7018 electrode angle variations at 60°, 75°, and 90° on the tensile strength of SMAW welded joints on JIS G3101 SS400 steel applied as roof frame components of the Koperasi Merah Putih. SS400 steel is one of the most widely used structural materials in building construction due to its adequate mechanical properties and ease of welding. The SMAW process was selected for its flexibility and efficiency in field applications. Welding was performed using an E7018 electrode with a diameter of 3.2 mm at a constant current of 100 A, V-groove 45° joint preparation, 1G flat position, and a material thickness of 6 mm. The research method employed is a quantitative experimental approach with tensile testing conducted in accordance with the ASTM E8 standard. Each electrode angle variation used three specimens, resulting in a total of nine test specimens that were consistently prepared and tested. The test results indicate that the 75° electrode angle produced the highest tensile strength of 429.33 MPa, followed by the 90° angle at 388.00 MPa, and the lowest value recorded at the 60° angle with 370.33 MPa. These differences in tensile strength values are attributed to the influence of electrode angle on the quality of weld penetration and fusion formed during the welding process. The 75° electrode angle proved to produce the most optimal penetration and fusion, and is therefore recommended as the best welding parameter for SS400 steel roof frame components using the SMAW process.

Analisis Efisiensi Termal Sebelum dan Sesudah Overhaul Turbin Inspection Di PLTGU Blok 3 Unit 2 PT PLN Nusantara Power UP Gresik

2026-07-14T22:12:19+07:00

This study analyzes the thermal efficiency performance of a Combined Cycle Power Plant (PLTGU) at PT PLN Nusantara Power, Gresik Generation Unit, focusing on Gas Turbine GT 3.2 in Block 3 Unit 2. The objective is to compare turbine performance before and after an overhaul (Turbine Inspection/TI). The research is driven by increasing electricity demand and the gradual degradation of gas turbine components due to operating hours, such as fouling and mechanical wear, which can increase fuel consumption and reduce efficiency. Thermal efficiency, based on the Brayton cycle theory, is used as the main performance indicator and is defined as the ratio of net work output to heat input (Qin). This research applies a field study method with a comparative before–after approach using actual operational data. The analyzed parameters include temperature, pressure, fuel flow rate, and lower heating value (LHV) at loads of 100 MW and 103 MW. Data processing and calculations were performed using Microsoft Excel. The results indicate that thermal efficiency improved after the overhaul. At 100 MW, efficiency increased from 30.5450% to 31.4085%, while at 103 MW it rose from 30.7662% to 31.4256%. Turbine output power also increased by 4.7 MW (4.55%). Overall, the overhaul positively restored turbine performance and improved thermal efficiency.

Analisis Pengaruh Penambahan Material Komposit Serat Kulit Durian Terhadap kekuatan Impak Batubata

2026-07-15T09:11:50+07:00

Brick is a durable, water-resistant construction material that reduces rainwater seepage through walls and offers fire resistance, making it safer to use. This study aims to analyze the effect of adding durian husk fiber to bricks. Durian husk fiber was selected due to its high cellulose content and potential as an eco-friendly natural reinforcing agent. Fiber treatment involved cold smoking (at 35°C–45°C) for varying durations—no smoking, 5 hours, 10 hours, 15 hours, and 20 hours—to enhance surface quality and bonding with the matrix. An experimental method was employed, utilizing varying volume fractions of clay, durian husk fiber, and cassava starch: 50%:10%:40%, 50%:20%:30%, and 50%:30%:20%. Specimens were fabricated using the hand lay-up method and oven-dried for one hour at 200°C. Impact strength was assessed using the Charpy Impact Test method in accordance with ASTM D5942-96 standards. The results indicate that the highest absorbed energy value (13.096 Joules) was achieved with the 50%:30%:20% volume fraction and a 5-hour smoking treatment, while the lowest value (6.976 Joules) was observed with the 50%:20%:30% volume fraction and a 10-hour smoking treatment. Similarly, the highest impact strength value (0.163 J/mm²) was recorded for the 50%:30%:20% volume fraction with 5 hours of smoking, and the lowest (0.087 J/mm²) for the 50%:20%:30% volume fraction with 10 hours of smoking. These findings demonstrate that material composition significantly influences brick toughness, where an optimal fiber addition enhances energy absorption and inhibits crack propagation. It can be concluded that a volume fraction composition of 50%:30%:20% represents the optimum condition for enhancing the impact strength of composite bricks based on durian husk fibers and a cassava starch matrix. An excessive increase in fiber fraction tends to reduce impact strength due to diminished matrix bonding and increased material porosity.

Analisis Laju Pembakaran dan Nilai Kalor Briket Campuran Sekam Padi dan Ampas Tebu

2026-07-24T21:10:06+07:00

The purpose of this study was to investigate how variations in the composition of rice husk charcoal and sugarcane baggase charcoal affect the quality of biomass briquettes. The assessment focused on two main parameters namely burning rate and calorific value. The conversion of biomass waste into briquettes is expected to be an environmentally friendly and economically viable alternative energy source. An experimental approach was employed in this research by applying different variation ratios of rice husk charcoal and sugarcane bagasse charcoal at 4:3 (9 grams of rice husk charcoal : 7 grams of sugarcane bagasse charcoal) and 3:4 (7 grams of rice husk charcoal : 9 grams of sugarcane bagasse charcoal). The briquette manufacturing process included raw material carbonization using the pyrolysis method, charcoal pulverization, mixing with tapioca adhesive, molding, drying, as well as burning rate and calorific value testing. The testing data were then analyzed to determine the influence of feedstock composition variations regarding the characteristics observed in biomass briquettes. Burning rate analysis indicated that the 4:3 variation yielded a combustion rate reachig 0.155 g/minute and combustion time lasting 90 minutes, whereas the 3:4 variation yielded a combustion rate reachig 0.148 g/minute and combustion time lasting 94 minutes. The calorific value test results showed that the 4:3 variation produced a mean calorific value of 4752.72 cal/g, while the 3:4 variation produced a mean calorific value of 4679.59 cal/g. The findings demonstrated that the raw feedstock composition variations affected the combustion performance and energy content of the briquettes. Further more, the 4:3 variation produced the highest calorific value, whereas the 3:4 variation resulted in a longer burning time. Overall, rice husk charcoal and sugarcane bagasse charcoal have the potential to serve as feedstock in biomass briquettes production as an environmentally friendly sustainable energy resource.

Optimasi Jarak dan Sudut Pemasangan Twinshock pada Kendaraan Roda Tiga Disabilitas untuk Meningkatkan Kinerja Struktur Menggunakan Metode FEA

2026-07-29T21:58:04+07:00

Safe and independent mobility is a critical need for people with disabilities. Three-wheeled vehicles modified from conventional vehicle frames offer an economical and practical mobility solution. However, the addition of a differential axle and changes in the twin-shock rear suspension configuration may affect load distribution, stress concentration, deformation, and frame safety. This study aims to optimize the spacing and mounting angle of twin shocks to improve the structural performance of a three-wheeled vehicle frame for people with disabilities using Finite Element Analysis. A Design by Research approach was applied with numerical evaluation using Finite Element Analysis. The frame adopts a structural steel backbone chassis configuration. Two model variations were analyzed: Model V1 with a 20° twin-shock angle and initial mounting position, and Model V2 with a 30° twin-shock angle and a 30 mm rearward mounting shift. Static loads of 60 kg for the driver, 60 kg for the passenger, and 50 kg for rear cargo were applied. Based on mesh convergence, a 10 mm tetrahedral mesh was selected as the primary mesh. The results show that Model V1 produced a maximum von Mises stress of 148.17 MPa, total deformation of 0.86054 mm, and safety factor of 1.68. Model V2 produced a maximum von Mises stress of 121.02 MPa, total deformation of 0.37277 mm, and safety factor of 2.2967. Compared with Model V1, Model V2 reduced stress by 18.32% and deformation by 56.68%, while increasing the safety factor by 36.71%. Therefore, Model V2 provides better stiffness, load distribution, and structural safety.

Pengaruh Jumlah Bilah Extra Fan Terhadap Penurunan Suhu Kondensor Pada Trainer Air Conditioner Mobil

2026-07-28T22:22:57+07:00

The condenser cooling system is very important in maintaining the stability of refrigerant pressure and temperature in the car air conditioning system. The effectiveness of heat dissipation in the condenser highly depends on the airflow characteristics generated by the extra fan. This research aims to determine the effect of varying the number of blades (7, 10, and 13) and the blade tilt angles (15° and 30°) on the efficiency of condenser temperature reduction in a car AC trainer. The experimental method was conducted using a test device integrated with an Arduino Nano microcontroller as the data control center. In this experiment, thermocouple sensors were used to monitor temperature changes in real-time, while the fan blades were printed using 3D printing technology to achieve the desired angle precision. Based on experimental analysis, it was concluded that the blade geometry configuration significantly affects cooling performance. The use of a 15° blade angle results in a more stable airflow and a more optimal temperature drop compared to a 30° angle. Additionally, the number of 10 blades was found to be the most effective point in generating airflow speed capable of maximizing the temperature drop out of the condenser.

Comparative Structural Response of Spring Materials in a Spring-Loaded Jig Fixture under Variable Clamping Loads Using Static Linear Finite Element Analysis

2026-07-30T10:48:14+07:00

This study aims to evaluate the mechanical response of springs in a jig fixture system to variations in loading using a Finite Element Analysis (FEA) approach based on SolidWorks Simulation. The materials analysed include Alloy Steel, AISI 4340, and Copper, subjected to loads of 400 kgf, 800 kgf, and 1200 kgf. The parameters examined include von Mises stress, displacement, and strain to assess the stability and structural integrity. The results show that an increase in load causes an increase in stress and strain across all materials. AISI 4340 performed best, exhibiting the smallest deformation and a stable stress distribution, followed by Alloy Steel, which still demonstrated adequate performance. Conversely, Copper experienced the greatest deformation due to its low modulus of elasticity. Overall, AISI 4340 is recommended as the optimal material for jig and fixture applications requiring high stiffness and durability.

Pemodelan Stokastik Hibrida (Physics-Data Driven) menggunakan Proportional Hazards Model (PHM) untuk Prediksi Remaining Useful Life (RUL) Komponen Kritis Mesin Stamping A2

2026-08-06T09:17:27+07:00

The low availability of Stamping Machine A2 at PT XYZ, which only reaches 82% due to high accumulated downtime, necessitates a transformation of maintenance strategies from time-based to predictive maintenance. This study aims to develop a hybrid prognostic model (Grey-Box) to precisely predict the Remaining Useful Life (RUL) of the critical Piston Rod component. The methodology integrates Weibull Distribution statistical analysis and Inverse Power Law (IPL) failure mechanics into a Proportional Hazards Model (PHM) mathematical framework, solved using 100 million Monte Carlo simulation iterations. The results indicate that the Piston Rod is in the infant mortality phase (= 0,783643) and exhibits high failure rate sensitivity to operational load fluctuations with a fatigue exponent (p) of 5,60544. Sensitivity tests demonstrate that increasing the load from normal to extreme conditions drastically reduces the safe remaining life limit (P10 RUL) from 396.4 hours to 208.5 hours at the 2,000-hour observation point. This study concludes that the P10 RUL threshold should serve as the predictive maintenance schedule benchmark to ensure machine reliability remains at 90% and precisely mitigate catastrophic failure risks according to daily production load dynamic.

Perancangan Cetakan Untuk Molding Injeksi Plastik Cover Planting Arm Pada Mesin Rice Transplanter

2026-07-29T13:50:13+07:00

Injection molding merupakan proses manufaktur yang banyak digunakan untuk memproduksi komponen plastik dengan tingkat akurasi dan produktivitas yang tinggi. Namun, kualitas produk sangat dipengaruhi oleh desain cetakan dan parameter proses. Penelitian ini bertujuan untuk mengembangkan cetakan injeksi guna meningkatkan kinerja proses pencetakan. Pendekatan kuantitatif diterapkan dengan menggunakan SolidWorks 2022 untuk analisis Computer-Aided Design (CAD) dan Computer-Aided Engineering (CAE), sedangkan Autodesk Inventor 2025 digunakan untuk simulasi Computer-Aided Manufacturing (CAM) pada proses pemesinan Computer Numerical Control (CNC). Cetakan dirancang menggunakan material Aluminium 6061 pada suhu konstan 80°C, dan polipropilena (PP) diinjeksikan pada suhu leleh 200°C dan 210°C. Hasil simulasi menunjukkan waktu pengisian sebesar 1,3614 detik untuk kedua kondisi suhu tersebut tanpa adanya turbulensi serta tingkat keyakinan pengisian confidence of fill sebesar 100%, yang mengindikasikan pengisian rongga cetakan secara sempurna. Nilai maksimum weld line tercatat sebesar 149,49% dan 149,40% masing-masing untuk suhu 200°C dan 210°C. Selain itu, simulasi CAM mengonfirmasi bahwa proses pemesinan berjalan bebas dari tabrakan collision-free. Temuan ini menunjukkan bahwa desain cetakan yang diusulkan layak digunakan untuk memproduksi komponen plastik berkualitas tinggi dengan tingkat cacat minimal.

Structural Integrity Assessment and Remaining Fatigue Life Estimation of a Rotary Dryer Shell Using Finite Element and Fracture Mechanics Approaches

2026-07-30T10:18:47+07:00

Rotary dryers are widely used in fertilizer, mineral processing, and chemical industries under cyclic thermo-mechanical loading, making their shells susceptible to fatigue cracking and structural degradation during long-term service. This study evaluates the structural integrity and remaining fatigue life of a rotary dryer shell using an integrated finite element analysis (FEA) and fracture mechanics approach. A global–local finite element model was developed in ANSYS Mechanical to identify critical stress concentration regions, while submodeling was employed to improve local stress evaluation. Semi-elliptical surface cracks were introduced, and the Mode-I Stress Intensity Factor (KI) was determined using the Contour Integral method. Fatigue crack propagation and remaining fatigue life were predicted using Paris Law. The global analysis produced a maximum von Mises stress of 234.13 MPa, whereas the submodel predicted a localized stress of 874.71 MPa at the shell–riding ring welded joint. The calculated KI ranged from 203.61 to 275.72 MPa√mm, with fatigue crack growth rates between 2.67 × 10⁻⁹ and 6.63 × 10⁻⁹ m/cycle. The predicted remaining fatigue life was approximately 1.0 × 10⁷ loading cycles, equivalent to 39,682 operating hours (4.53 years). The proposed framework provides an effective basis for structural integrity assessment and condition-based maintenance planning of rotary dryer shells.

Taguchi Optimization of Friction Time and Pressure for Tensile Strength of Rotary Friction-Welded AA6061/AISI 316L Joints

2026-07-30T12:11:23+07:00

An efficient solid-state joining technique for connecting disparate materials like stainless steel 316L and aluminum 6061 is rotary friction welding (RFW). This study uses the Taguchi method to examine how friction duration and pressure affect the tensile strength of joints made of stainless steel 316L and aluminum 6061. While the rotating speed is maintained at 1800 rpm, the forging duration is 30 seconds, the forging pressure is 10 MPa, and the study variables are friction time (60, 90, and 120 seconds) and friction pressure (3, 4, and 5 MPa). Three repetitions of the Taguchi L9 orthogonal matrix were employed in the experimental design for every combination of parameters. The findings demonstrated that tensile strength rose as friction time and friction pressure increased. At a friction time of 120 seconds and a friction pressure of 5 MPa, the maximum tensile strength value of 133.05 MPa was attained. Friction duration was the most significant element influencing tensile strength, contributing 79.6%, while friction pressure contributed 18.7%, according to the Signal-to-Noise Ratio (S/N Ratio) analysis of the Larger-The-Better category. At a friction time of 120 seconds and a friction pressure of 5 MPa, the ideal set of parameters was found.

Analisis Pengaruh Variasi Temperatur Pemanasan dan Media Pendingin Quenching Terhadap Sifat Mekanik Baja AISI 1045

2026-08-04T09:33:55+07:00

This study investigates the effects of austenitizing temperature variations (850°C, 900°C, and 950°C) and different quenching media, including water, used SAE 40 oil, and SAE 10 hydraulic oil, on the microstructure and mechanical properties of AISI 1045 steel. The analysis focused on cooling rate, phase transformation, microstructure formation, and mechanical behavior using the Continuous Cooling Transformation (CCT) diagram. The results show that water quenching provides the fastest cooling rate, producing a martensitic structure with the highest hardness (527–612 BHN), Ultimate Tensile Strength (UTS) of 1986 N/mm², and very low elongation (<1%), indicating brittle behavior. Quenching with used SAE 40 oil forms a bainitic structure with balanced mechanical properties, including UTS values of 967–1776 N/mm² and elongation of 4–10%, indicating improved ductility. Meanwhile, SAE 10 hydraulic oil produces the slowest cooling rate, resulting in ferrite–pearlite structures with lower hardness (256–291 HB), lower tensile strength, and the highest elongation (16.56%). These findings confirm that quenching media strongly influence the microstructure and mechanical properties of AISI 1045 steel.

Morphology and Thermal Behavior of Natural Fiber-Reinforced Recycled HDPE Composites Using Bentonite, Fly Ash, and Rice Husk Ash Fillers

2026-08-05T09:02:37+07:00

Akumulasi limbah plastik telah menjadi masalah lingkungan yang kritis
, yang membutuhkan strategi daur ulang berkelanjutan
. Polietilen densitas tinggi daur ulang
(rHDPE) telah menarik perhatian sebagai
matriks polimer potensial karena kemampuannya untuk mengurangi
limbah plastik sambil mempertahankan
sifat material yang diinginkan. Namun, kinerja
komposit rHDPE sangat dipengaruhi oleh jenis pengisi.
Studi ini menyelidiki pengaruh
pengisi bentonit, abu terbang, dan abu sekam padi terhadap morfologi dan
kinerja tahan api komposit rHDPE yang diperkuat serat alami
. Spesimen komposit dibuat
melalui pencetakan termal dalam oven tanpa
tekanan eksternal. Karakteristik morfologi dianalisis
menggunakan Mikroskop Elektron Pemindaian (SEM), sedangkan
kinerja tahan api dievaluasi menggunakan
uji pembakaran horizontal ASTM D635 berdasarkan Waktu Penyalaan (TTI)
dan Laju Pembakaran. Hasil menunjukkan bahwa jenis pengisi
secara signifikan memengaruhi morfologi dan
kinerja tahan api komposit. Abu sekam padi menunjukkan
TTI rata-rata tertinggi sebesar 8,13 detik dan
Laju Pembakaran terendah sebesar 14,97 mm/menit. Analisis SEM
mengungkapkan bahwa abu sekam padi meningkatkan distribusi pengisi,
mengurangi pembentukan rongga dan aglomerasi partikel,
serta meningkatkan interaksi pengisi-matriks, sehingga menghasilkan
mikrostruktur yang lebih padat. Karakteristik ini mungkin
berkontribusi pada peningkatan kinerja tahan api dengan mengurangi perpindahan panas dan menunda penyalaan selama pembakaran.
Secara keseluruhan, abu sekam padi menunjukkan
potensi yang menjanjikan sebagai pengisi berkelanjutan untuk meningkatkan
mikrostruktur dan kinerja tahan api komposit rHDPE yang diperkuat serat alami.

Desain dan Simulasi Sistem Anodizing Aluminium dengan Kontrol Arus Konstan Terintegrasi

2026-08-12T14:34:36+07:00

Conventional anodizing of Aluminum 6061 typically uses manually regulated current, which is prone to fluctuation and results in non-uniform oxide layer formation. This study designs an integrated constant-current-controlled anodizing system for Aluminum 6061 using SolidWorks and analyzes Current Density distribution and oxide layer growth through COMSOL Multiphysics 5.6 simulation. The method used is quantitative design research based on numerical simulation, comprising numerical calculation, three-dimensional design, and electro-thermal simulation. The system was designed with a 28.52-liter HDPE anodizing bath, a dual lead-cathode configuration flanking the Aluminum 6061 anode at a 100 mm gap, and a galvanostatic DC power supply of 4 Ampere/12 Volt monitored by an ACS712 sensor. Numerical calculation indicated an oxide layer mass of 1.0145 grams with a power of 48 Watts. Transient simulation showed linear oxide layer growth over time, reaching 8.98 µm at the 20th minute and 17.97 µm at the 40th minute, within the Sulfuric Acid Anodizing standard range (15–25 µm). The system proved able to maintain process stability, making it feasible for laboratory-scale implementation.

Pengaruh variasi massa roller dan secondary sheave spring CVT terhadap torsi, daya dan konsumsi bahan bakar pada motor Scoopy 110 cc tahun 2023

2026-08-07T22:17:23+07:00

This study aims to determine the effect of variations in roller mass and secondary sheave spring on torque, power, and specific fuel consumption produced on a 2023 Scoopy 110 cc motorcycle. This study uses an experimental method with tools used in testing including a dynotest to measure torque and power, as well as specific fuel consumption added with a stopwatch and measuring cup. The variations in roller mass used are 11 grams, 13 grams, and 15 grams. Meanwhile, the variations in secondary sheave spring used are 1000 rpm, 1200 rpm, and 1500 rpm. Testing was carried out at an engine speed range of 4500 rpm to 7000 rpm. The results showed that the best combination to produce the highest torque was the use of an 11 gram roller with a 1200 rpm secondary sheave spring, which was able to produce a maximum torque of 8.66 N.m at an engine speed of 6500 rpm. Meanwhile, the highest power was achieved with the combination of a 15 gram roller and a 1500 rpm secondary sheave spring, which was 8.02 hp at 7000 rpm. The combination of an 11 gram roller and a 1200 rpm secondary sheave spring produced the most efficient specific fuel consumption of 0.063 kg/hp at 6500 rpm.

Perancangan Prototype Alat Elektroplating Berbasis Arduino Uno dan Validasi Kinerja Melalui Karakterisasi Pelapisan PLA

2026-08-08T15:41:51+07:00

Electroplating is a metal coating process used to improve the surface properties of materials, including corrosion resistance, hardness, wear resistance, and surface appearance, through the deposition of metal ions using direct current. The quality of the coating is strongly influenced by the stability of electrical parameters and the uniform distribution of metal ions during deposition. This study aimed to design and develop an Arduino Uno-based electroplating prototype capable of monitoring electrical parameters while improving coating uniformity through a specimen rotation mechanism. The prototype integrates an Arduino Uno, an XL4015 constant voltage/constant current (CV/CC) module, an LM2596 DC-DC converter, a voltage sensor, a digital volt-amp meter, and an MG996R servo motor. Prototype performance was validated through zinc electroplating on Polylactic Acid (PLA) specimens, followed by Charpy impact testing according to ASTM D256. The results showed that the prototype operated reliably and maintained stable electroplating conditions throughout the process. Visual observations confirmed that a uniform zinc coating was successfully deposited without significant coating defects. Impact testing revealed that the average absorbed impact energy increased from 0.1738 J to 0.1942 J, while the impact strength increased from 54.30 J/mm² to 60.70 J/mm², representing an improvement of approximately 11.8%. Therefore, the developed prototype effectively enhanced coating quality and improved the impact resistance of PLA specimens.

Performansi Komposit Sebagai Bahan Bodi Remote Control Boat dengan Menggunakan Hybrid Fiber

2026-08-13T09:44:40+07:00

This study aims to analyze the performance of hybrid composites as a material for remote control boat bodies by comparing variations in fiber types (woven, carbon, and woven-carbon hybrid), resin types (polyester and epoxy), and matrix volume fractions (40%, 50%, and 60%). An experimental method was employed through composite specimen fabrication using the hand lay-up technique, followed by impact toughness, void content, and water absorption testing. The results showed that the hybrid composite with epoxy matrix at 60% volume fraction produced the highest impact toughness value of 2.54 kg.m, outperforming single woven and carbon fibers. In void content testing, woven composite exhibited the lowest porosity (3.21%-3.98%), while the hybrid composite significantly reduced porosity compared to pure carbon. Regarding water resistance, the hybrid composite with epoxy matrix demonstrated the lowest water absorption rate (2.24%-2.90%) compared to woven and carbon. Overall, the hybrid composite with epoxy matrix provides the best performance as a remote control boat body material due to its high impact toughness, controlled porosity, and excellent water resistance.

Optimalisasi Geometri Tungku Peleburan Aluminium Untuk Meminimalisir Kehilangan Panas (Heat Loss) Berbasis CFD

2026-08-18T09:03:13+07:00

Small and medium-scale crucible-type aluminum melting furnaces commonly suffer from significant heat loss through conduction across furnace walls, reducing thermal efficiency and increasing fuel consumption. This study aims to optimize the geometry of a 5 kg gas-fired aluminum melting furnace to minimize heat loss using a Computational Fluid Dynamics (CFD) approach. Three-dimensional steady-state numerical simulations were conducted using ANSYS Fluent, incorporating three combustion chamber geometry variations (cylindrical, hexagonal, and square) and two crucible-to-bottom-wall distance variations (60 mm and 120 mm), yielding six design configurations. Simulations simultaneously considered conduction, convection, and radiation heat transfer mechanisms using SK-34 refractory brick and Salamander A10 crucible materials. Results show that design B2P2, a cylindrical geometry with a 60 mm crucible distance, consistently outperformed all other configurations, achieving a monitor temperature of 1,015.51 K, a crucible heat flux intensity of 552.16 W/m², the highest turbulence kinetic energy (TKE) of 0.217521 J/kg, and the lowest refractory wall heat loss of 2,432.11 W. Further numerical calculations yielded a thermal efficiency of 26.5% with a heat input rate of 5,539.93 W. The cylindrical geometry proved superior by eliminating dead zones, enabling hot gas flow to form a cyclonic circulation pattern that uniformly surrounds the crucible. Design B2P2 is recommended as a technical reference for developing more efficient aluminum melting furnaces in small and medium-scale foundry industries.

Pengaruh Arus Ampere Pulse On Time dan Kecepatan Potong Edm Wirecut Terhadap Kekerasan Baja Ss304

2026-08-24T21:53:15+07:00

This study aims to analyze the effect of variations in ampere current, pulse on time, and cutting speed in the Wirecut EDM process on the hardness of Stainless Steel 304. An experimental method was employed using a Fanuc Type C400iC Wirecut EDM machine. The test material was SS304 with dimensions of 30x30x50 mm, cut using a 0.25 mm brass wire. The varied parameters were current (5, 10, 15 A), pulse on time (10, 20, 30 µs), and cutting speed (2, 4, 6 mm/min). The hardness of the cut material was tested using the Rockwell method. The results showed that a low current (5 A) produced more stable and higher hardness values compared to higher currents. The best parameter combination was achieved at 5 A current, 30 µs pulse on time, and 4 mm/min cutting speed, yielding the highest hardness value. Conversely, the combination of 10 A current, 30 µs pulse on time, and 2 mm/min cutting speed resulted in the lowest hardness. The interaction between the three parameters was proven to affect machining quality, making the precise selection of parameters crucial. This research confirms that optimizing WEDM parameters can improve the hardness quality of SS304 material.

Evaluasi Kinerja Divisi Sortir Dengan Menggunakan Metode Value Stream Analysis Tools (VALSAT) (Studi Kasus: PT Sumber Barokah Polymer)

2026-08-26T16:27:21+07:00

PT Sumber Barokah Polymer, a PET plastic waste recycling company, experiences material flow inefficiency in the Sorting Division. Constraints such as the high rate of label peeling defects requiring rework and manual transportation processes cause material accumulation and swelling of production Lead Time. This study aims to identify the dominant waste and design improvement proposals using a Lean Manufacturing approach. The methods used include the 7 Wastes questionnaire, weighting with Value Stream Analysis Tools (VALSAT) where Process Activity Mapping (PAM) was the selected tool, and Fishbone Diagram analysis. The identification results showed the two highest wastes were Defect (19.44%) and Transportation (18.06%). The proposed improvement designs include the addition of Hopper 2 facility to shorten the disposal distance of reject materials, the creation of Preventive Maintenance SOPs for the Label Remover machine, and the procurement of push trolley equipment. Based on the Future State Value Stream Mapping (VSM) simulation, this improvement proposal can drastically cut pure waste time (Non-Value Added) from 96.17 minutes to 14.79 minutes. This impacts the reduction of total production Lead Time from 331.97 minutes to 208.12 minutes per trip, and significantly increases the company's Process Cycle Efficiency (PCE) from 28.19% to 44.96%.

Analisis Penambahan Nanofiller Titanium Dioksida (Tio₂) Dan Grafit (Graphite) Terhadap Kekuatan Tarik Dan Ketangguhan Impak Komposit Fiberglass–Epoxy

2026-08-27T11:07:44+07:00

The increasing demand for lightweight materials with superior mechanical properties in the automotive, aerospace, and renewable energy industries has promoted the development of fiberglass–epoxy composites reinforced with hybrid nanofillers. This study investigated the effect of Titanium Dioxide (TiO₂) and graphite hybrid nanofillers on the tensile strength and impact toughness of fiberglass–epoxy composites and determined the optimum filler composition. An experimental quantitative approach was employed using four filler variations: V0 (0 wt%), V1 (0.5 wt% TiO₂ + 0.5 wt% graphite), V2 (1 wt% TiO₂ + 1 wt% graphite), and V3 (1.5 wt% TiO₂ + 1.5 wt% graphite). Composite specimens were fabricated using the hand lay-up method and tested according to ASTM D638 for tensile properties and ASTM D6110 for Charpy impact performance. The results showed that increasing the hybrid nanofiller content enhanced the tensile strength and elastic modulus, with the highest tensile strength of 61.822 MPa and elastic modulus of 371.47 MPa obtained by specimen V3. In contrast, the average impact toughness decreased from 52.02 J/mm² for V0 to 38.40 J/mm² for V3, indicating reduced energy absorption due to particle agglomeration and brittle fracture. Specimen V2 exhibited the best balance between tensile strength and impact toughness, demonstrating that an appropriate TiO₂–graphite hybrid nanofiller composition effectively improves the overall mechanical performance of fiberglass–epoxy composites.

Efisiensi Boiler Berbasis Metode Heat Loss pada Implementasi Reliability and Efficiency Optimization Centre di PLTU Suralaya Unit 1–4

2026-08-31T20:13:08+07:00

This study evaluates the effect of the Reliability & Efficiency Optimization Centre (REOC) on boiler efficiency at PLTU Suralaya Units 1-4. A comparative quantitative design was used by analysing performance-test data before and after REOC implementation, namely January 2018 and March 2021, at 75% and 100% load. Boiler efficiency was determined with the heat loss method using fuel, flue-gas, air and operating parameters. The results show that REOC-supported monitoring, dispatch recommendation and combustion optimization contributed to efficiency improvement in most operating conditions. At 75% load, efficiency increased in Unit 1 and Unit 4, remained unchanged in Unit 2, and slightly decreased in Unit 3. At 100% load, efficiency increased in Unit 1, Unit 2 and Unit 3, while Unit 4 slightly decreased. The largest improvement occurred in Unit 1 at 100% load, from 81.49% to 85.96%. These findings indicate that REOC can support boiler-efficiency improvement, although the effect is not uniform across all units and loads.

Implementasi Sistem Interlock Pengumpanan Strength Enhancer untuk Meningkatkan Stabilitas Operasi Cement Mill Berbasis Vertical Roller Mill

2026-09-03T13:03:33+07:00

The operational stability of a Vertical Roller Mill (VRM) is strongly influenced by the continuity of the strength enhancer feeding system. Leakage in the feeding line may cause fluctuations in additive flow, increase mill vibration, and reduce production reliability. This study aimed to evaluate the effect of implementing an automatic interlock system on the operational stability of a cement mill at XYZ Plant. A case study approach was employed using operational data collected before and after the implementation of the interlock system. Root Cause Analysis (RCA) was applied to identify the primary cause of the operational disturbance, followed by the installation of an additional flow meter and the development of an automatic interlock system for leakage detection. The effectiveness of the improvement was evaluated using X̄–R control charts and process capability analysis based on cement mill vibration data. The results indicate that the implementation of the interlock system significantly improved process stability. The average vibration decreased from approximately 4.4 mm/s before implementation to 2.3–2.4 mm/s after implementation, while the average process variation (R̄) decreased from 3.2–3.8 mm/s to 0.5–0.6 mm/s. In addition, the percentage of out-of-control observations on both X̄ and R control charts decreased to 0%, and the process capability index (Cpk) increased from 0.97–1.16 to 3.28–3.60, indicating that the process became statistically stable and capable of operating within the specified limits. These findings demonstrate that the proposed interlock system effectively improves the reliability and operational stability of the cement mill and provides a practical solution for strengthening automated process control in the cement manufacturing industry.

Bahasa Indonesia ANALISIS PENGARUH JENIS ELBOW TERHADAP PERFORMA POMPA GANDER-DENVER TYPE FXD - 172 DI GATERING STATION KE MAIN GATERING STATION PERTAMINA

2026-09-07T18:19:03+07:00

This study aims to analyze the effect of elbow types on pump performance and flow rate, particularly focusing on elbow components that cause pressure losses (head loss). In the reciprocating pump Gardner-Denver Type FXD-172 used to transfer crude oil from the Gathering Station (GS) to the Main Gathering Station (MGS), elbows with different radii (Long, Medium, and Short) potentially affect the flow rate and overall pump performance. The research methodology employs a comparative quantitative approach with a case study of the FXD-172 pump piping system at PT Pertamina EP Sangatta Field. Primary data were obtained through field observations, measurements of flow rate and pressure, as well as the number and types of elbows used, while secondary data were collected from journals and technical documents. calculations include pipe cross-sectional area, flow velocity, Reynolds number, major head loss, minor head loss, static head, total head loss, pressure drop, flow rate, and pump efficiency.The results show that elbow type has a significant influence on flow losses. Short-radius elbows produce the highest head loss, followed by medium-radius elbows, while long-radius elbows result in the lowest head loss. The conclusion of this study is that the selection of elbow type greatly affects pump performance

Strategi Efisiensi Sanitasi Unloading Station Fresh Milk Melalui Penyederhanaan Sequence Cleaning in Place (CIP)

2026-09-07T23:43:00+07:00

Cleaning in Place (CIP) merupakan sistem sanitasi penting dalam industri pengolahan susu untuk menjaga kebersihan peralatan dan keamanan pangan. Penelitian ini bertujuan menganalisis efisiensi metode CIP caustic only pada unloading station fresh milk kondisi cold process melalui perbandingan waktu proses, konsumsi air, dan penggunaan bahan kimia terhadap sistem CIP full sequence. Penelitian dilakukan menggunakan metode kuantitatif eksperimental dengan membandingkan dua metode CIP. Hasil penelitian menunjukkan bahwa metode CIP caustic only mampu menurunkan waktu proses dari 37 menit menjadi 21 menit atau sebesar 43,24%, serta mengurangi konsumsi air dari 15.418 L menjadi 8.751 L. Penggunaan bahan kimia juga mengalami penurunan dari 105 L/kg menjadi 65 L/kg. Hasil uji laboratorium menunjukkan nilai mikrobiologi <100 CFU/ml, pH 7,45–7,98, turbidity 0,01–0,44 NTU, dan conductivity 78,6–98,3 µS/cm sehingga masih memenuhi standar sanitasi industri susu. Hasil visual check menunjukkan tidak terdapat residu susu maupun deposit mineral pada peralatan proses. Metode CIP caustic only dapat menjadi alternatif sistem sanitasi yang lebih efisien, ekonomis, dan ramah lingkungan tanpa menurunkan efektivitas pembersihan sistem.