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Pengaruh Variasi Persentase Campuran Polymer Polyester dan Vinyl Ester Terhadap Kekuatan Tegangan Lentur Nusyirwan Adnand; R Mutya; Firman Ridwan; Hairul Abral; Hendery Dahlan; Eka Satria
METAL: Jurnal Sistem Mekanik dan Termal Vol 5, No 2 (2021): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (942.586 KB) | DOI: 10.25077/metal.5.2.126-131.2021

Abstract

Polymer mixture of polyester and vinyl ester is widely used in engineering fields such as for car bumpers, boat bodies, ultra-light aircraft wings, wind turbine blades and others. One of the requirements to meet the application aspects in the engineering field is the ability of the material to withstand bending loads. For this reason, it is necessary to test the flexural stress characteristics of the mixture of the two polymers of unsaturated polyester and unsaturated vinyl ester. The aim is to find out which of the two polymer blends obtains superior flexural resistance properties from each of the polymers with respect to the blend percentage. To determine the flexural stress value of the polyester and vinyl ester mixture, a flexural stress test was carried out with reference to the standard flexural test or the bending test used based on ASTM D 790 by varying the composition of the mixture 100%: 0%, 90%: 10%, 80%: 20%, 60%:40%, and 0%:100%. From the results of the bending stress test on specimens with variations in the composition of polyester and vinyl ester with the hand lay-up method, the highest bending stress value is found in the composition of 60% polyester and 40% vinyl ester, which is 126.88 MPa ( an increase in maximum flexural strength of 255%)
Rancang Bangun Mesin Pengupas Buah Pinang Ade Hendra; Firman Ridwan
METAL: Jurnal Sistem Mekanik dan Termal Vol 1, No 2 (2017): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (582.369 KB) | DOI: 10.25077/metal.1.2.125-132.2017

Abstract

In daily life, betel nut is widely used as ingredients of medicines, cosmetic materials and even clothing. Most of rural comunities conventionally process the Betel nut, hence the quality of betel nut has become less. To overcome this, a tool which has a high selling price and save production costs was made. This study aims to develop the skin peel machine. The result shown that the machine was capable to peel 1,066 second/piece using AC motor ¼ hp as an actuator.
Rancang Bangun Mesin CNC 2 Sumbu Firman Ridwan; Arif Novriheldi
METAL: Jurnal Sistem Mekanik dan Termal Vol 1, No 2 (2017): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1007.875 KB) | DOI: 10.25077/metal.1.2.91-98.2017

Abstract

Nowadays, high accuracy and precision of products have become a major requirement by the manufacturer. It can only be achieved by using a controlled machine such as CNC machine. On the other hand, most of home industries have conventional production machines and manually operated. Unavailable precisian machines cause difficulties to achieve such products. In most cases, capability of home industries to buy high cost machines is limited. Therefore, it is then to be the backdrop of designing a simple construction and its control system for a low cost CNC plasma cutting machine. A low cost CNC plasma cutting machine was designed and expected to be realible in controlling the movement of the axis preciselly during cutting process. The result of this study showed that the machine was capable of achieving the following levels of precision up to 0.05 mm for the X-axis with a deviation of 0.04 mm. Meanwhile the Y axis was obtained up to 0.08 mm with a deviation of 0.057. The results indicate that the achieved accuracy is higher compared to the manual cutting.
Pengontrolan Kecepatan Aliran Vortex Berbasis Arduino Sebagai Metoda Pemisah Campuran Serbuk Tembaga dan Aluminium Fico Trianda Ravelli; Firman Ridwan
METAL: Jurnal Sistem Mekanik dan Termal Vol 3, No 1 (2019)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (558.316 KB) | DOI: 10.25077/metal.3.1.51-58.2019

Abstract

Several methods have been developed to separate gold from alluvial using the principle of density. Density is used as a basic concept in material separation. One of the supporting methods that can be used to utilize the vortex flow as a separation medium. With vortex flow, two materials of different density can be separated through lift force. This study aims to determine the effect of vortex flow velocity on its ability to separate two different types of density material. Aluminum and Copper powders are used as test materials with a powder size of 18-200 mesh. The tests are carried out with a variation of 10 flow rates with water as a fluid. The results showed that Aluminum and Copper can be optimally separated at the flow rate (165.25-167.77) ml/s. While for the most effective effectiveness of Al separation is the flow rate (163.22-168.87) ml / s and copper separation at the flow rate (83.5-85) ml/s.
Analisa Produk Pola Cetakan Lilin yang Diproduksi Menggunakan DIY-CNC-Endmill Firman Ridwan; Ryan Rahman
METAL: Jurnal Sistem Mekanik dan Termal Vol 2, No 2 (2018)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (679.402 KB) | DOI: 10.25077/metal.2.2.14-25.2018

Abstract

The use of technology in ring jewelry manufacturers in Indonesia is still very limited. Ring jewelers still use traditional methods in the process of forming mold patterns. This causes difficulties in producing ring jewelry that requires precision and high accuracy on each product. Unprecised wax pattern of ring jewelry can result in dimensional errors when product is manufactured so the  dimension is far from the size of the design. To avoid this, it can be overcome by using CNC machine technology. CNC machines can work consistently and precisely. For this reason, therefor, an End-Milling type CNC machines that has accuracy of up to 1/1000 mm is designed. The experiments showed that the results with high accuracy having standard deviation of repeatability of inner diameter 0.020736441, repeatability of outer diameter 0.020493902 and repeatability of thickness 0.043817805.
Pengaruh Sudut Geram dan Parameter Pemesinan Terhadap Keausan Tepi Pahat High Speed Steel (HSS) pada Proses Bubut Glass Fibre Reinforce Polymer (GFRP) Muhammad Yusra Nusa; Firman Ridwan
METAL: Jurnal Sistem Mekanik dan Termal Vol 2, No 1 (2018)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (744.26 KB) | DOI: 10.25077/metal.2.1.40-46.2018

Abstract

The high rate of tool wear is an obstacle in machining of GFRP material. This research was conducted to investigate turning behavior towards the occurrence of flank wear on HSS devices by varying machining parameters such as rake angle, spindle speed and feed rate. The GFRP of workpiece was made from resin as a matrix and the glass type Chopped Strand Mat as fiber. The rack angle of tool is varied to 5º, 10º, 15º, 20º.  Taguchi method was used to analized data experiments using orthogonal array L8. The experimental data shows that the spindle speed is the most influential parameter on flank wear with a S/N ratio of 4.10, followed by the feed rate with a S/N ratio of 3.08. Increasing rake angle can reduce wear, the smallest wear value was obtained at an angle of 20º.
Perancangan Dinamometer untuk Mengukur Gaya Potong pada Mesin Freis untuk Pemesinan Material Fiber Reinforced Polymer Firman Ridwan; Refki Harvendri
METAL: Jurnal Sistem Mekanik dan Termal Vol 4, No 1 (2020): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2814.945 KB) | DOI: 10.25077/metal.4.1.1-12.2020

Abstract

Milling machine is a machine that cuts a workpiece using a plural chisel that rotates on a freis machine. During the freis process, the material is cut because of the cutting force that occurs between the tool and the workpiece. The amount of cutting force can be known by theoretical calculations, but the theoretical calculation will produce a less accurate cutting force because of the many factors that influence the cutting force and the assumptions given in the calculation. Therefore, direct measurements are needed in order to see the magnitude of the cutting force that occurs during the freis process. The amount of cutting force obtained will be needed in analyzing machining parameters to obtain a combination of machining that is efficient and profitable. The tool used to measure the amount of cutting force on a freis machine is a dynamometer. The constituent components of the dynamometer are loadcell strain gauge, INA 125P amplifier IC, and national instrument hardware acquisition data 6212. The dynamometer is designed to be able to read 3 directions of force, namely the cutting force (Ft), axial force (Fz), and feeding force (Fy). Measuring the average cutting force (Ftm) obtained using aluminum workpieces is 97,6002 N, acrylic workpiece is 65,3338 N, GFRP (Glass Fiber reinforce polymer) chopped strand mat is 146,8845 N, and GFRP woven roving is 103.3915 N. Dimensions of the dynamometer are designed with a total length of 32 cm, width 32 cm, and height of 18 cm.
Desain Sistem Vakum untuk Mendinginkan Ruang Transformator Benny Dwika Leonanda; Yul Hizhar; Firman Ridwan; Diki Zuhury
METAL: Jurnal Sistem Mekanik dan Termal Vol 6, No 1 (2022): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1012.53 KB) | DOI: 10.25077/metal.6.1.60-68.2022

Abstract

An analysis has been carried out on designing a 60 MVA 150 kV transformer cooling chamber vacuum system. The transformer cooling chamber is vacuumed up to a pressure of 0.001 kPa. This is done to avoid the formation of gas bubbles, avoid condensation and sterilize the transformer chamber before filling the coolant. Therefore, we need a vacuum pump and other equipment called a vacuum system. The analysis of the vacuum system includes the work required by the system, vacuum time, and electrical energy. The design wllii uses a rotary pump and a root pump by varying the number of pumps with two, three, and four pumps. The results of the analysis show that the work that must be done by the design is the largest and the vacuum time is the least in the design that uses 2 pumps with a value of 2860.38 Kj and 39.31 hours. While the effective electrical energy is found in a design that uses 3 pumps. It can be concluded that an effective design is found in the design using 3 pumps. From the tests carried out in the field for the design of 3 pumps there is a difference of 5.3 hours and 38.31 kWh compared to the theoretical test.
Lignin Degradation of Kapok Fiber (Ceiba pentandra, L) with Different Times of Pulping Fransiska Angelina Rezekinta; Anwar Kasim; Edi Syafri; Irawati Chaniago; Firman Ridwan
Journal of Applied Agricultural Science and Technology Vol. 7 No. 3 (2023): Journal of Applied Agricultural Science and Technology
Publisher : Green Engineering Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55043/jaast.v7i3.186

Abstract

Lignin reduced the adhesion between the polymeric matrix and natural reinforcement in composite materials by its hydrophobic characteristic. Removal of lignin can be a solution to improve fiber function in composite use. This study aimed to determine the degradation of lignin at different times of pulping. The soda process was conducted at 60, 70, 80, 90, and 100 minutes of pulping using heat in a room atmosphere. Yields, lignin content, and lignin spectrum (FT-IR analysis) were measured.  The result showed the highest degradation of lignin was in 100 minutes of pulping with 80.34% lignin degradation and 3.57% lignin left in fibers. However, the yield of fibers decreased with increasing pulping time due to lignin removal. 100 minutes of pulping time showed the highest loss of fiber yield. This study showed the best pulping time for kapok fiber is 100 minutes with 3.57 % lignin remaining in the pulp.
The Effect of Aluminum Addition Ratio as Filling Material of PLA Toward PLA Filament Electrical Conductivity on 3D Printing Applications Firman Ridwan; Zuliantoni Zuliantoni
METAL: Jurnal Sistem Mekanik dan Termal Vol 8, No 1 (2024): Jurnal Sistem Mekanik dan Termal (METAL)
Publisher : Department of Mechanical Engineering, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/metal.8.1.1-5.2024

Abstract

 The electronic waste of daily electronic goods evokes environmental pollution because electronic waste is difficult to decompose in nature and it is also toxic to the environment and humans. The way to minimize environmental pollution from electronic waste is by making polymer composites for conductive material purposes. Polylactic acid (PLA) has the potential as a polymer matrix. PLA has a non-toxic advantage and it is easily decomposed in nature because PLA is made from organic material.The extruder machine is used to make PLA filament with aluminum filling. When made the filaments, the ratio of each mixture was varied to obtain a filament with a mixture ratio that produced the best conductivity. The four-point probe test tool is used to measure the resistivity of each specimen to find out which specimen with the mixture ratio has the best conductivity value.The electrical conductivity obtained from the ratio of 10% Al is 6.78 S/m; 20% Al is 10 S/m; 30% Al is 31.44 S/m; 40% Al is 24.15 S/m. The best electrical conductivity results was obtained in the 70% PLA and 30% Al mixture ratio with an electrical conductivity value is 31.44 S/m while the lowest electrical conductivity was obtained in the 90% PLA and 10% Al mixture ratio with an electrical conductivity value is 6.67 S/m