Feasibility Assessment of a PLA/PHBV Bioplastic Blend for an Industrial Thermoforming Process: Thermoforming Window and Mechanical Strength Evaluation

Abstract

The increasing demand for sustainable materials has accelerated interest in bioplastics as eco-friendly alternatives to traditional plastics. However, their adoption in industrial applications hinges on optimizing integration with established manufacturing processes. This study examined the thermoforming performance of an optimized blend of polylactic acid (PLA) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The study focused on evaluating key thermoforming parameters, including forming temperature, forming time, and pressure configuration, to determine the optimal thermoforming window that enables accurate reproduction of the mold shape while maintaining the mechanical integrity. The findings revealed that the investigated PLA/PHBV blend exhibited favorable mold conformity at a mid-range thermoforming temperature of 130–140 ℃, using only vacuum suction within 2 s forming duration. However, the compression strength of thermoformed PLA/PHBV trays was approximately 50% lower than that of commercial polyethylene terephthalate (PET) trays of greater thickness. This reduction is likely attributed to both the thinner profile and material properties of this bioplastic. Despite its limitations in mechanical strength, the blend exhibits considerable potential for lightweight, high-speed thermoforming applications, contributing to the advancement of sustainable materials in industrial manufacturing. Further optimization of the material composition could enhance its mechanical properties and broaden its range of applications.