Predicting the thermal performance of bio-based cold chain packaging system

Abstract

Cold chain logistics play a critical role in ensuring the safe transport of temperature-sensitive products such as pharmaceuticals, biologics, and perishable foods. Maintaining stable internal temperatures within insulated shipping containers (ISCs) requires an in-depth understanding of how materials, design, and environmental factors influence heat transfer. This research combines experimental and computational approaches to improve the thermal efficiency and environmental sustainability of passive cold chain packaging systems. The first phase of the study (Chapter 1) focuses on predicting the thermal performance of bio-based ISCs through finite element modeling (FEM). Material characterization was conducted using Differential Scanning Calorimetry (DSC) and Heat Flow Meter techniques to obtain the thermal properties of corrugated fiberboard, honeycomb paperboard, and phase change materials (PCMs). The FEM framework was validated through experimental data, showing strong correlation with measured results and a mean prediction deviation of less than 8% when maintaining temperatures below the critical 8 °C threshold. These findings confirm that FEM can serve as an accurate and efficient alternative to conventional performance testing while supporting the integration of renewable insulation materials in package design. The second phase (Chapter 2) examines how environmental humidity influences the thermal behavior of ISCs. Laboratory experiments were performed across relative humidity levels from 30 % to 80 % to evaluate temperature evolution and hold-time performance. The results revealed that higher humidity significantly accelerated the warming rate, particularly in fiber-based insulation systems, due to moisture absorption that increased effective thermal conductivity. In contrast, polymer-based materials such as expanded polystyrene (EPS) and polyurethane (PU) remained relatively stable. Energy-balance modeling supported these observations, confirming humidity as a major external driver of heat transfer in porous materials. Beyond performance, the study underscores the environmental benefits of fiber-based materials, which are renewable and recyclable, while emphasizing the need for design strategies that balance thermal reliability and sustainability under real-world humidity conditions.