ANALISA KEKUATAN MATERIAL KOMPOSIT CAMPURAN SERBUK TEBU, SERBUK KAYU ULIN DAN PET PLASTIK BERMATRIKS RESIN EPOXY DITINJAU DARI UJI KEKERASAN DAN STRUKTUR MAKRO

The use of organic waste and plastic as composite materials is a real effort to overcome environmental problems while creating environmentally friendly alternative materials. In this study, sugarcane powder, ironwood powder, and PET plastic were recycled into a composite with epoxy resin as the matrix. The main objective of this study was to determine the effect of knowing the variation in filler composition on the hardness value and macrostructure of the resulting composite. Seven specimens were made with varying combinations of sugarcane powder and ironwood powder, while the composition of PET plastic and resin was kept constant. Hardness testing was carried out using the Rockwell HRB Scale method, while the macrostructure was observed using a metallurgical microscope. The test results showed that the higher the ironwood powder content, the specimen hardness value increased. The highest hardness value was recorded at 83.8 HRB in specimens containing 20% ​​PET plastic, 0% sugarcane powder, and 30% ironwood powder, while the lowest value of 63.5 HRB occurred in specimens containing 30% sugarcane powder, 0% ironwood powder, and 20% PET plastic. Macro observations showed that specimens with a dominant ironwood content had a denser and more homogeneous surface. In contrast, specimens with a dominant sugarcane powder showed a more porous surface. It can be concluded that ironwood powder significantly increases the material's hardness, while sugarcane powder tends to decrease its mechanical performance. This research demonstrates that waste, previously considered worthless, can be processed into materials with good technical characteristics and has the potential for further development in engineering applications.