This study investigated the effects of rice husks and waste glass on the properties of a polyester matrix composite. The experimental samples were prepared using compression molding, and tests of their physical and mechanical properties were conducted in accordance with ASTM standards for significant properties, including density, water absorption, surface roughness, hardness, and compression strength. The result shows that a higher value of surface roughness (33.59 \(\:\mu\:\) m) was obtained with a lower polyester resin content (20 wt%) and a large particle size. The minimum roughness (1.24 \(\:\mu\:\) m) was achieved at a small particle size (250-500 \(\:\mu\:\) m) and 30 wt% resin content, which causes other properties to have better results with this combination. The Leeb hardness values ranged from 346 HL to 729 HL. The maximum compressive strength was 782.73 MPa, where the composites had higher resin concentrations of 30 wt% and a fiber size range (205–500 \(\:\mu\:m\) ). The small particle size range (250-500 \(\:\mu\:\) m) sample has the least wear rate (0.00085 mg/m) with a polyester concentration of 30 wt%. Parametric optimization was conducted using Taguchi, coupled with grey relational analysis. Particle size and concentration were identified as significant parameters, with particle concentration contributing more (64.9%) to the influence of the output response than particle size (15.6%). The objective of this optimization was to simultaneously obtain the maximum density, surface roughness, hardness, and compression strength, and minimum wear rate and water absorption of the resulting composite material for friction applications. Based on grey relational analysis, the optimal settings of the process parameters were identified, and analysis of variance indicated that both particle concentration and particle size were significant parameters. However, the particle concentration (64.9%) had a higher contribution than the particle size (15.6%) to the influence of the output response.
