PENGARUH VARIASI CAMPURAN SERBUK PVC, BAMBU, DAN CANGKANG TELUR DENGAN RESIN EPOXY TERHADAP UJI KEKERASAN MATERIAL

This study aimed to investigate the effect of varying mixtures of PVC powder, bamboo powder, and eggshell powder on the hardness of epoxy resin-based composite materials. The powder materials were processed to 40 mesh size and mixed with epoxy resin and catalyst in seven different compositional variations. Specimens were fabricated following ASTM D785 standards and tested for hardness using the Rockwell HRB scale method with a 100 kgf load. Additionally, macrostructural observations were conducted to assess surface density and homogeneity. The results demonstrated that filler composition variations significantly influenced hardness values. The optimal composition was achieved with a mixture of 20% PVC powder, 15% bamboo powder, and 15% eggshell powder, yielding the highest hardness value of 79.33 HRB and a penetration depth of 0.1013 mm. Its macrostructure appeared most dense and homogeneous. Conversely, the bamboo-dominant composition (30%) exhibited the lowest hardness value of 76.83 HRB, with a less dense and porous structure. The study concludes that the combination of organic and inorganic waste materials in specific ratios can enhance the mechanical performance of epoxy resin-based composites. These findings reinforce the potential utilization of household waste as an alternative raw material for high-performance composite materials while supporting environmental sustainability efforts.