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Abstrak :
Food diversificatiion is one of the governmental programs to reduce rice demand. Cassava is a good sources of carbohydrate. The Objective of this research was to show the effect of composition of cassava and soybean flour in flake formula. The flake was enriched with soybean (10%,20/%, 30%, and 40%) as source of protein. Hedonic test was test was used to determine the best product. The result indicated that 10 % soybean mixing was the most accepted.

Abstrak :
Paint, salah satu jenis organic coating, merupakan zat yang dapat digunakan untuk melindungi baja dari lingkungannya sehingga dapat mencegah proses korosi. Perkembangan teknologi membuat paint dapat diaplikasikan di lingkungan air laut, seperti glass flake epoxy coating yang mengandung pigmen micro glass flake. Namun keberhasilan proteksi dari paint sangat ditentukan oleh preparasi permukaan yang baik. Sehingga diperlukan sistem pelapisan dan preparasi permukaan yang baik.

Tujuan dari penelitian ini ialah untuk mengetahui ketahanan korosi, kekuatan adesi, dan ketahanan termal dari glass flake epoxy coating pada substrat baja karbon. Preparasi permukaan dilakukan dengan pengamplasan dengan variasi grit amplas 100, 150, dan 180. Rasio pencampuran volum antara base dan activator yang digunakan ialah sebesar 2,5:1, 3,5:1, dan 4,5:1.

Ketahanan korosi dari lapisan diketahui melalui pengujian sembur garam selama 96 jam. Sedangkan kekuatan adesi lapisan dengan substrat diketahui melalui pulloff adhesion test (dengan kekuatan tarik maksimal alat sebesar 3,5 N/mm²). Untuk mengetahui ketahanan termal lapisan dilakukan pemanasan pada temperatur 150°C selama 15 menit. Pengamatan metalografi juga dilakukan untuk mengetahui struktur dari lapisan film dan juga lapisan interface antara lapisan film dan substrat baja.

Dari pengujian sembur garam didapat nilai peringkat lebar goresan pada semua sampel uji menurun dari 10 menjadi 9 dengan meningkatnya waktu pemaparan. Sedangkan dari pengujian adesi didapat hasil bahwa kekuatan adesi dari lapisan ialah lebih besar dari 3,5 N/mm² karena tidak ada lapisan film yang terangkat dari substrat baja hingga kekuatan tarik maksimal 3,5 N/mm². Secara visual, lapisan film tidak mengalami kerusakan setelah proses pemanasan.

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Paint, one type of organic coatings, is a substance can be used to protect steel from its environment so that corrosion can be prevented. Technology development makes paint can be used in marine environment, like glass flake epoxy coating containing micro glass flake pigment. However, good surface preparation has strong effect in producing successful paint protection. So, there must be a good painting system and a good surface preparation to create a good protection.

This research was conducted to evaluate corrosion resistance, adhesion strength, and thermal resistance of glass flake epoxy coating in steel substrate. Surface preparation was performed by grinding using grinding grit of 100, 150, and 180. Mix ratios of volume between base and activator used were 2,5:1, 3,5:1, and 4,5:1.

The corrosion resistance was known by salt spray test with 96 hours of exposure. The adhesion strength was acquired from pull-off adhesion test (with 3,5 N/mm² maximum tensile strength). The coating was heated in 150°C temperature for 15 minutes to get thermal resistance value of the coating. Metallographic examination was also performed to observe the structure of the coating film and interface layer between the coating film and the substrate.

From the salt spray test, the value of rating number decreased from 10 to 9 with increasing exposure time. The adhesion strength of the coatings was higher than 3,5 N/mm², because there were no failure of all film until 3,5 N/mm² maximal tensile load were applied to the coating. From visual examination, there were no film degradation after heating.

Abstrak :
Baja ASTM A36 merupakan mild carbon steel yang banyak digunakan pada sektor infrastruktur, namun demikian baja karbon memiliki ketahanan korosi yang lebih rendah dibandingkan dengan jenis baja lainnya, yang menyebabkan material ini rentan terhadap korosi dalam lingkungan atmosferik. Oleh sebab itu, untuk meningkatkan ketahanan korosinya, baja ASTM A36 dapat dilapisi dengan glass flake epoxy. Penelitian ini bertujuan untuk mempelajari pengaruh perbedaan metode surface cleaning terhadap kekuatan adhesi glass flake epoxy yang diaplikasikan pada substrat baja tersebut dan ketahanan korosi yang dihasilkannya. Dalam penelitian ini diterapkan 5 (lima) jenis metode surface cleaning yaitu: (i) solvent cleaning, (ii) hand tool cleaning, (iii) power tool cleaning, (iv) power tool to bare metal cleaning, serta (v) abrasive blast cleaning. Selanjutnya, dilakukan proses pengukuran kekasaran permukaan dari masing-masing sampel baja ASTM A36 menggunakan metode field test, sebelum diaplikasikan cat dilakukan pengecekan kondisi lingkungan terlebih dahulu (dry and wet temperature, steel temperature, dew point temperature, serta relative humidity), kemudian glass-flake epoxy diaplikasikan pada permukaan substrat baja menggunakan roller paint brush. Setelah itu, dilakukan pengukuran wet dan dry film thickness. Metode analisis data dilakukan per lima sampel dari masing-masing pengujian yang dilakukan yakni pengujian salt spray, pengujian electrochemical impedance spectroscopy, serta dua pengujian adhesi yaitu pull off adhesion dan tape test test. Hasil penelitian menunjukkan bahwa kemampuan organic coating dipengaruhi oleh perbedaan metode surface cleaning yang diterapkan. Abrasive blast cleaning memiliki ketahanan korosi yang paling baik dengan rata-rata pelebaran (creepage) korosi paling rendah yakni 0.49 mm yang termasuk ke dalam rating number 9, dan kekuatan adhesi rata-rata tertinggi yaitu 3.16 MPa. Dengan demikian dapat disimpulkan bahwa, ketahanan korosi dipengaruhi oleh tingkat kebersihan, sementara kekuatan adhesi dipengaruhi oleh tingkat kekasaran. ...... ASTM A36 steel is a mild carbon steel that is widely used in the infrastructure sector; however, carbon steel has a lower corrosion resistance compared to other types of steel, which makes this material susceptible to corrosion in atmospheric environments. Therefore, to improve its corrosion resistance, ASTM A36 steel can be coated with glass flake epoxy. This research aims to study the effect of different surface cleaning methods on the adhesion strength of glass flake epoxy applied to the steel substrate and the resulting corrosion resistance. In this research, five types of surface cleaning methods were applied, namely: (i) solvent cleaning; (ii) hand tool cleaning; (iii) power tool cleaning; (iv) power tool to bare metal cleaning; and (v) abrasive blast cleaning. Subsequently, the surface roughness measurement process for each ASTM A36 steel sample was carried out using the field test method. Prior to applying the paint, environmental conditions were checked first (dry and wet temperature, steel temperature, dew point temperature, and relative humidity), and then glass-flake epoxy was applied to the surface of the steel substrate using a roller paint brush. Afterward, wet and dry film thickness measurements were taken. The data analysis method was carried out on five samples from each test carried out, namely salt spray testing, electrochemical impedance spectroscopy testing, and two adhesion tests, namely pull-off adhesion and tape test tests. The results show that the organic coating ability is influenced by the different surface cleaning methods applied. Abrasive blast cleaning has the finest corrosion resistance with the lowest average corrosion creepage of 0.49 mm, which is included in rating number 9. In addition, the resulting average adhesion strength is also high at 3.16 MPa. It can be concluded that corrosion resistance is influenced by the degree of cleanliness, while adhesion strength is influenced by the degree of roughness.