Complex evaluation process on the sugarcane juice harvesting by using preparation index related to the mechanical properties: A key foundation for modeling and improved milling efficiency

Abstract

The mechanical characteristics of prepared sugarcane are essential for improving the milling process, as they contribute significantly to maximizing juice extraction efficiency while reducing the energy required. This research explored how the Preparation Index (PI) affects the mechanical response of prepared sugarcane using various tests, including uniaxial confined compression, loading-unloading compression, direct shear, and juice extraction efficiency evaluations. Experimental data reveal that the optimal PI range—92.14–95.96 %—achieves the highest juice extraction efficiency of 82 %, while maintaining mechanical stability. Bulk density increases from 460.48 kg/m³ at PI 85.95 % to 482.68 kg/m³ at PI 95.96 %, indicating improved fiber compaction. Poisson’s ratio ranges from 0.091 to 0.120, with higher PI values associated with reduced lateral deformation. Young’s modulus shows a strong correlation with PI, rising significantly from 41.62 MPa to 163.18 MPa as PI increases, especially under greater unloading forces, reflecting enhanced fiber arrangement and stiffness. Direct shear tests indicate an increase in cohesive force from 12.08 kPa to 29.15 kPa with higher PI, while the internal friction angle decreases from 30.40° to 14.43°, suggesting reduced material flowability. Juice extraction efficiency tests confirm that higher PI facilitates improved fiber breakdown, leading to greater juice release. These findings highlight PI as a key parameter in balancing juice recovery, mechanical integrity, and energy demands during sugarcane milling. The results support the potential for real-time PI monitoring and control systems that dynamically adjust preparation processes to enhance operational efficiency and reduce costs, making PI a critical metric for improving industrial sugarcane processing.