An Analysis of Effect of Water Hyacinth Carbonization Temperature on Fabrication and EMI Shielding Radar

The need to increase the ability of water hyacinth composites as EMI radar protection is related to the carbonization process of organic materials. This research aimed to determine the effect of water hyacinth carbonization temperature on the effectiveness of fabrication and EMI shielding radar. The research method includes the preparations such as cutting, washing, and drying the water hyacinth. The drying process is carried out using an oven with a temperature of 70 °C for 4 days. Then the water hyacinth is mashed until it reaches the 80 mesh size. Then the carbonization process is carried out, with variations in carbonization temperature ranging from 500 °C, 600 °C, 700 °C, 800 °C, 900 °C and 1,000 °C, with a heat increase speed of 3 °C/minutes. After reaching the specified temperature, a holding time is then carried out for 1 hour. Furthermore, the composite composition of 30 % water hyacinth activated carbon powder and 70 % phenol-formaldehyde (PF) resin was molded using a hot press with a pressure of 300 kg/cm2 at 180 °C for 10 minutes. The results showed that the water hyacinth composite could be used as an EMI protection material at the X-Band frequency (8–12.5 GHz). Where the electrical conductivity and EMI SE increases with increasing carbonization temperature. Water hyacinth composites at a carbonization temperature of 1,000 °C showed the highest electrical conductivity and the highest EMI SE, respectively 4.64∙10-2 S/cm and 41.15 dB (attenuation 99.99 %) at a frequency of 8 GHz. The high absorption contribution is associated with the synergy combination of KCl and the pore structure of the goitre. KCl contributes to the magnetic properties and pore structure with high electrical conductivity values.