Mold Design of Helmet Shell from Biocomposite Banana Fiber and Polypropylene

The mold was designed for helmet shell made from biocomposite with a material composition of 10% banana fiber, 10% Maleic Anhydrite Polypropylene (MAPP) and 80% polypropylene. Based on SNI 1811-2007 Mold components are prepared with dimensions according to the SNI standards. Based on the requirements set out in the standards, the helmet shell must meet the impact and penetration tests. The design is intended to determine the thickness of the helmet shell. An impact simulation is carried out with the help of Ansys software with thickness variations from 2 to 6 mm. The simulation results show that the thickness of the shell from 4 to 6 mm meets the requirements, which is indicated by an acceleration drop that does not exceed 300 g. Furthermore, to determine the resistance of the helmet shell against the indenter weighing 3 kg, which is suspended from a height of 1.6 m. The thickness of the helmet cover that complied was 5 and 6 mm, which was shown by the thickness of the shell not being penetrated by the indenter. Next, a helmet shell mold with a thickness of 5 mm was designed, starting from the manual calculation of the required clamping force of 1367.96 kN. And with a melting temperature of 163 °C bicomposite material, the required cycle time is calculated as 129.38 s. The design is tested with the Autodesk Moldflow simulation, the required injection time of 12.43 s, with a filling confidence level of 100%, and the injection pressure is 8.789 MPa.