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Journal : Jurnal Polimesin

Investigation of mechanical properties and dynamic characteristics of OPEFB Fiber Composite Zuhaimi Zuhaimi; Misran Misran; Indra Mawardi; Darmein Darmein; Nurlaili Nurlaili; Zaini AK; Hanif Hanif; Amir D
Jurnal POLIMESIN Vol 21, No 4 (2023): August
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v21i4.4247

Abstract

Composite materials is increasingly experiencing an increa- sing trend, the manufacture of composites currently uses a lot of natural fiber reinforcement, Oil Palm Empty Fruit Bunches (OPEFB) fiber is a fiber that comes from oil palm empty fruit bunches waste that grows a lot in Indonesia and has the potential to be used as reinforcement in the manufacture of composites. With natural fiber reinforcement. The manufacture of composites in this study varied the fiber volume fraction by 5%, 15%, and 25%. Many previous studies on composite materials have focused on studying the physical and mechanical properties of composites. Even though damage to a structure or material is not only caused by static loads but also by dynamic loads. Vibration is a dynamic load experienced by material or structure, so it is necessary to determine the dynamic character of composite materials, one of the dynamic characteristics of materials is their natural frequency, the determination of the natural frequency in this study was carried out by using the finite element method in the ANSYS software. The results of the analysis in the form of tensile strength values and modulus of elasticity were obtained from tensile testing and dynamic characters in the form of natural frequencies and vibration modes were obtained from the analysis modal simulation process. From the results of the tensile test, it was found that the composite with a variation of 15% OPEFB fiber volume had the highest tensile strength and modulus of elasticity, as well as the results of the analysis modal simulation, a composite with 15% OPPEFB fiber, had the highest natural frequency value among the other two variations.
The Effect of Current Density on Mechanical Properties of Electroplated Thin Copper Foil Luthfi Luthfi; Yuniati Yuniati; Darmein Darmein; Sumardi Sumardi
Jurnal POLIMESIN Vol 21, No 1 (2023): February
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v21i1.3456

Abstract

Thin copper foils are commonly used in arts, crafts, and manufacturing industries. Although copper electroplating processes have been widely studied, most focused on either copper in bulk material form factor or copper in extremely thin film shape. Thin copper foils are considered neither bulk material nor thin film; thus, it is estimated that they will have unique properties. This study aims to investigate the mechanical properties of thin copper foils coated by electroplating processes. The investigations were conducted experimentally by performing electroplating at current densities of 2, 3, and 4 A/dm2. The copper foil specimen having a dimension of 10 mm wide, 0.2 mm thick, and 125 mm long were electroplated in a bath of copper sulfate, sulfate acid, chloride acid, and copper brightener mixtures for 60 minutes powered by a 30 A DC power supply. The hardness and tensile test diagrams were studied. The strain, yield stress, and ultimate tensile stress data extracted from the tensile test diagram were compared with other previous studies found in the literature and fitted with linear regression lines. The relationship of those parameters with current density has been successfully obtained. The hardness, strain, and yield stress of the electroplated copper foil increased with larger current densities used in the electroplating process except for the ultimate tensile stress, which was found to be slightly decreased with current densities. The optimum operating condition for obtaining the best results was found at a current density of 3 A/dm2.
Variasi temperatur melting polypropylene terhadap perubahan bentuk produk dengan menggunakan desain extrusi single screw Darmein Darmein
Jurnal POLIMESIN Vol 8, No 1 (2010): Februari
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jp.v8i1.1331

Abstract

Perancangan alat ekstrusi yang dilakukan dalam penelitian ini merupakan langkah awal untuk menambahkan investasi peralatan uji dan pengetahuan tentang pengolahan plastik. Dari hasil design dan manufaktur telah berhasil dibangun satu unit mesin ekstrusi single screw dan telah di operasikan. Pada penelitian ini, perubahan bentuk dan ukuran dari produk akan dianalisis dengan menggunakan variasi temperatur proses memiju titik lebur dari polypropylene. Variabel bebas adalah :170°, 180°, 190°, 200°, dan 210℃, dan kecepatan putaran screw 60 rpm digunakan sebagai tempratur proses . Produk dibuat dalam bentuk barrel dengan ukuran dies 5 mm . Hasil penelitian ini telah dibuat sebuah mesin ekstrusi tipe single screw. Dengan menggunakan bentuk dan eksirusi sebagai indikator keberhasilan, maka tempratur proses yang sesuai untuk mesin ini pada perbandingan L / D - 14 untuk 11P sampai ke 180℃Kata kunci: Plastik, Polypropylene, eksiruksi, Titik lebur
Perawatan pumping unit bukaka tipe C228 di PT. Pertamina EP Asset 1 Field Rantau-Kualasimpang Jenne Syarif; Darmein Darmein; Khaidir Fadillah
Jurnal POLIMESIN Vol 14, No 1 (2016): Februari
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v14i1.298

Abstract

Pumping unit ini adalah jenis pompa sucker rod yang menggunakan metode artificial lift yang paling baik diterapkan di sumur-sumur dangkal dan sedikit atau tidak adanya gas yang terproduksi bersama minyak. Dalam pengoperasiannya, pompa sucker rod memiliki banyak masalah yang sering timbul, diantaranya adalah tidak sesuainya laju produksi yang diinginkan dengan laju produksi sebenarnya. Gangguan- gangguan permasalahan yang sering terjadi pada pumping unit type C228 ini biasanya Terjadi keausan pada wrish pin bearing dan patahnya gigi-gigi plate clutch perawatan yang harus dilakukan pada keausan yaitu dengan menerapkan perawatan sebagai berikut: Perawatan mingguan (Pelumasan) Perawatan bulanan (Pergantian Komponen) Keadaan operasi tiap hari di amati dan di catat, setiap keadaan yang tidak normal mudah ditemukan sehingga dapat segera diatasi. Hindari semua komponen yang dapat merusak pompa, baik itu didalam pengoperasiannya ataupun perawatannya, lakukan berdasarkan prosedur yang tepat. Kerja sama dalam perawatan pumping unit ini sangat diharapkan sehingga target pengoperasian dapat tercapaiKata Kunci: Pumping Unit, Perawatan, Keausan,Pengoperasian
Gas Turbine Maintenance Optimizing using the Reliability-Centered Maintenance Method Darmein Darmein; Marzuki Marzuki; Zuhaimi Zuhaimi; Fauzi Fauzi; Nurlaili Nurlaili; Luthfi Luthfi
Jurnal POLIMESIN Vol 21, No 1 (2023): February
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v21i1.3281

Abstract

Gas Turbine is one of the important equipment in the production process in the oil and gas industry. This equipment is used as the prime mover of the compressor to the gas supply. The company has implemented preventive maintenance and condition monitoring in the context of gas turbine maintenance as well as scheduled shutdown every 52,000 hours of operation time. Along with efforts to increase production, the company's management policy has implemented a gas turbine maintenance efficiency program from 52,000 hours to 72,000 hours of operation. This policy is based on the consideration that productivity decreases over time and component replacement during MI (Major Inspection) and HGPI (Hot Gas Path inspection). This policy will certainly have an impact on the reliability, performance, and failure rate that will be experienced by gas turbines as well as their impact on maintenance costs. This study aims to recommend optimal maintenance strategies for gas turbines using the Reliability Centered Maintenance (RCM) method related to availability, reliability, maintainability, and maintenance costs. In this study, an analysis of the causes and effects of failure was carried out using the Failure Mode and Effect Analysis (FMEA) method, with the parameters of failure frequency and consequences of failure then analyzed using the RCM worksheet to determine an effective maintenance strategy.  The results of this study obtained maintenance strategy for Gas Turbine components which are Failure finding, Redesign on conditioning, and Schedule discard task. The components that are scheduled for repairs are compressors and turbines and components that receive a component replacement schedule are Air Inlet and Combustion. The application of the RCM method has been able to reduce maintenance costs by up to 30.678% along with reduced downtime rates, decreased failure rates and the number of MTTR hours
Optimization of CNC machining parameters to improve surface roughness quality of the AL6061 material using the Taguchi method Bukhari Kasim; Azwar Yunus; Ilyas Yusuf; Mawardi Mawardi; Darmein Darmein
Jurnal POLIMESIN Vol 21, No 4 (2023): August
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v21i4.4039

Abstract

Surface quality is an important variable of a milling machining process. Therefore, choosing the best machining parameters is very important to arrange so that the best surface quality can be obtained. The purpose of this research is to optimize machining parameters by using surface roughness as a performance indicator variable. This research was carried out by making 9 surface roughness test specimens through a facing process on a TU-3A CNC milling machine. Each test specimen is made with a different level of machining parameters. Machining parameters used in this research are spindle speed, feed rate, and depth of cut. Surface roughness values obtained from 9 test specimens were analyzed using the Taguchi method, signal-to- noise ratio, and ANOVA. The Taguchi approach is also used to predict the best machining parameter configurations. The results of the signal-to-noise ratio analysis show that the surface quality is affected by spindle speed, depth of cut and feed rate, respectively. The results of measurements on 9 test specimens showed the best roughness values were 0.275µm. While the results of the Taguchi analysis show that the optimal surface roughness value can be obtained at 0.267µm for machining conditions with the parameters spindle speed 1100 rpm, feed rate 85 mm/min and depth of cut 0.25 mm. Furthermore, analysis of variance (ANOVA) yielded contribution values from spindle speed, feed rate and depth of cut to the surface roughness values of 51.80%, 36.88% and 10.72%, respectively