Heat-Sealed Processes in Chañar Brea Gum Films

This work presents a comprehensive evaluation of the heat-sealability of films developed from chañar brea gum (CBG), a biopolymer with potential for packaging applications. Heat-sealability is a critical property in the packaging industry, as it directly determines the integrity and functionality of the final product. The films were prepared by the 10% casting method with the addition of glycerin and heat sealing was carried out at 140 °C using a heat sealer. The study employs a joint determination that explore fundamental properties of the films, including proximate analysis, antioxidant capacity, FTIR, DSC, TGA-DTGA, XRD, mechanical testing, water vapor permeability and sorption, and biodegradability. By integrating the results of all these determinations, the study seeks to evaluate and explain the "intimate relationships"—i.e., the complex interconnections among the molecular structure, composition, thermal behavior, mechanical properties, and barrier properties of chañar gum films—and how these fundamental properties dictate and control their heat-sealability. Thermal stability is up to 200°C with a melting point of 152.48°C for CBG. The interstrand spacing is very similar at 4.88nm for CBG and 4.66nm for CBG-H. SEM images of the heat seal show rounded shapes on the surface, while in the cross section it is homogeneous and almost without gaps. The WVP decreases from 1.7 to 0.37 for CBG and CBG-H, respectively. The Young's modulus decreases from 132MP for CBG to 96.5MPa for CBG-H. The heat sealability is 656N/m with a biodegradability of 4 days. This comprehensive approach is crucial for optimizing the sealing process and designing functional and efficient biodegradable packaging.