Abstract
ABSTRACT
Snails’ shells, which are byproducts of the dining industry from restaurants, cafes, and snail vendors, represent a considerable environmental challenge with minimal commercial value. Their effective utilization could lead to substantial economic benefits. This study aims to investigate the effects of cream hardener on optimal formulation of snail shell-based auto body filler for potential industrial applications. The formulation of auto body filler was carried out using constrained D-optimal mixture experimental design. The formulation yielding the highest desirability index of 0.363comprised12%snail shell, 80% unsaturated polyester resin, 2.96% toluene, 2.22% xylene,2.82% Cobalt Naphthanate (Accelerator), and a particle size of 106.5 μm, which was also combined with cream hardener designated as samples snail shell auto body filler (SSBdfA and SSBdfB) respectively. The findings indicated that samples SSBdfB exhibited a quicker drying time of 10 minutes, while samples SSBdfA had longer curing times starting from 16 minutes and above; additionally, sample SSBdfB showed good adhesion and flexibility on metal surfaces. The physical and mechanical properties of the SSBdfA and SSBdfB samples were also evaluated. The optimal product quality characteristics revealed that SSBdfA exhibited a density of 1.03 g/cm³, a hardness of 0.7316, and a tensile strength of 0.0459 MPa, while SSBdfB demonstrated superior physical properties with a density of 1.22 g/cm³, a hardness of 0.96, and a tensile strength of 0.0931 MPa. Validation testing results for the produced samples (SSBdfA and SSBdfB) indicated optimal product quality properties with conditions of 0.97 g/cm³ density, 0.8066 hardness, and 0.0459 MPa tensile strength for SSBdfA, compared to 1.20 g/cm³ density, 0.973 hardness, and 0.0962 MPa tensile strength for SSBdfB. The research outcomes suggest that cream hardener influences the properties of snail shell auto body filler, making it suitable for industrial applications such as fillers in the automotive sector. The analysis considered a 95% confidence level, which allows for a 5% margin of error and represents 99% of the population.

Key words: Snail shell, unsaturated polyester resin, cream hardener, auto body filler, D-optimal mixture.