Multi-response optimization of the mechanical properties of pultruded glass fiber composite using optimized hybrid filler composition by the gray relation grade analysis

Abstract

Nowadays research is aiming to develop new composites having maximum strength to weight ratio with best mechanical characteristics by using varied combinations of fibers and fillers in the polymer matrix. Usually, fillers are added to the polymer matrix to improve surface finish and dimensional stability of the composite material. The composite surfaces without fillers could become coarse leading to a decrease in mechanical properties. So, the effect of fillers must be analyzed, and its composition should be optimized. In the present work, the hybrid filler composition containing three different fillers-- bagasse fiber (BF), carbon black (CB) and calcium carbonate (CaCO3)—is formulated to obtain optimum tensile strength, flexural strength, hardness and cross-sectional shrinkage of pultruded glass fiber reinforced polymer (PGFRP) composite. The single and multi-response optimization is carried out using Taguchi and Gray Relation Grade Analysis (GRGA) approach. Multi-response optimization shows that the optimum hybrid filler composition for PGFRP composite is 35 g BF, 15 g CB and 75 g CaCO3 when 15% of the resin weight of hybrid filler is added to the polyester resin matrix. The compression of PGFRP composite with and without hybrid filler shows improvement in flexural strength (FS), hardness and % cross-sectional shrinkage (CSS) by 8.25%, 9.33%, and 77.08% respectively while a reduction of 7.06% in tensile strength (TS).