Experimental characterization of sustainable biogenic composites reinforced with micro-scale snail shell particles for non-structural applications

This study investigates the mechanical and physical characterization of polymer composites reinforced with biogenic Achatina achatina snail shell particles. Localized snail shell flour waste was valorized as a sustainable bio-filler extender in an unsaturated polyester resin matrix. A D-optimal mixture design was utilized to evaluate the empirical distribution of filler composition and micro-scale particle sizes across 19 experimental runs. Empirical characterization tracked the variations in tensile strength, surface hardness, and bulk density across the formulated space. The tested composite formulations exhibited a tensile strength range of 0.0246 to 0.1035 MPa, bulk density from 0.95 to 1.16 g/cm³, and localized surface hardness variations. Due to the low absolute tensile strength operating envelope, which demonstrated an experimental mean of 0.0459 MPa, application of this material is limited strictly to non-structural engineering applications. These baseline results demonstrate that engineered biogenic agricultural waste can serve as a potential alternative to conventional geological mineral fillers in non-structural body filling applications, such as lightweight auto-body putties, subject to future commercial validation.