Pra Rancangan Pabrik Pembuatan Biji Komposit Bioplastik dari Pati Singkong dengan Proses Asetilasi Kapasitas 3.400 Ton/Tahun dan Tugas Khusus Rancangan Keteknikan Detail Screw Extruder

Abstract

Bioplastics are made from natural polymers that are environmentally friendly and can replace conventional non-renewable petroleum-based plastics. The world’s plastic production is expected to reach 6,7 million tons in 2025. Meanwhile in Indonesia there are still few producers of bioplastics. In this pre-design, bioplastics composite seeds were made from raw materials that are widely available in Indonesia. One of the materials that can be used as a raw material for the manufacture of bioplastics composite seeds is cassava starch. Based on the latest data on cassava production from the Badan Pusat Statistik (2021) in North Sumatra Province, Deli Serdang Regency is the third largest contributor of cassava with a figure of 94.929 tons out of a total of 1.045.344 tons in year 2021. Cassava has a very high starch content of 83,8% so it is very possible to use cassava as a source of starch for the manufacture of bioplastics. The pre-design factory for the manufacture of bioplastic composite seeds from cassava starch is planned to produce with a capacity of 3.400 tons/year for 330 days a year and will start operating in 2025. The process used in production is the acetylation reaction which aims to produce starch acetate by reacting cassava with acetic anhydrous reagent and sodium hydroxide as catalyst. In the manufacture of bioplastics composite, starch acetate is mixed with Na-CMC as filler and glycerol as plasticizer. The special task that was completed was the engineering design of the Screw Extruder for the extrusion process and the formation of bioplastics composite pellets. The designed Screw Extruder has the following specifications: 1. Shape : Horizontal cylinder 2. Capacity : 909,44 kg/hour 3. Material : Stainless Steel 304 4. Screw length : 1500 mm 5. Screw diameter : 199,8 mm 6. L/D ratio : 7,9 7. Screw drive motor power : 15,12 hp 8. Heating power : 11,24 hp 9. Blower power : 36,28 hp 10. Hopper capacity : 73,2 L 11. Output size : 3 mm The factory is planned to be built in Denai Lama, Pantai Labu District, Deli Serdang Regency, North Sumatera Province with an area of 19.532,65 m2. The company is a Limited Liability (PT) business entity and is led by the Board of Commissioners and requires a total of 177 employees. The results of the economic evaluation of the factory for the manufacture of bioplastics composite seeds made from cassava starch are as follows:  Total Investment Capital : Rp. 935.161.137.005  Total Production Cost : Rp. 458.436.436.697  Sales Proceeds : Rp. 690.110.518.297  Net Profit : Rp. 142.996.995.387  Profit Margin (PM) : 33,56%  Break Even Point (BEP) : 50,05%  Return on Investment (ROI) : 15,29%  Pay Out Time (POT) : 6,54 years  Return of Network (RON) : 38,23%  Internal Rate of Return (IRR) : 19,69% From the results of the economic evaluation, it can be concluded that the bioplastics composite seeds factory with a production capacity of 3.400 tons/year is feasible to build.