Physico-mechanical properties of Sapindus mukorossi seed

This work characterized physical and mechanical properties of Sapindus mukorossi seed to explore the mechanical behaviors of the seed during compression in a roll crusher. A new method that combines simulations and calculations with experimental data obtained using a three-dimensional optical measurement system for the measurement of the Poisson ratio and elasticity modulus of the hollow-sphere seed hull was proposed. The modulus of elasticity was derived from a mechanics formulation and verified in a computer simulation based on experimental data. Scanning electron microscopy and energy-dispersive spectrometry were conducted to reveal the mesostructure and components of the seed hull. The results revealed that the average densities of the S. mukorossi seed shell and kernel were respectively 1.49 and 1.07 × 103 kg/m3, the average Poisson’s ratio was 0.185, and Young’s modulus ranged from 1.3 to 0.3 GPa. These values had little dispersion, demonstrating both the consistency of the processing techniques and the stability of the material properties. The given properties of the S. mukorossi can be used as a theoretical basis for the optimized processing of this biomass material. The proposed method provides a new direction in the study of the mechanical properties of biomaterials.