Optimisation on Thermoforming of Biodegradable Poly (Lactic Acid) (PLA) by Numerical Modelling

Poly (lactic acid) (PLA) has a broad perspective for manufacturing green thermoplastic products by thermoforming for its biodegradable properties. The mechanical behaviour of PLA has been demonstrated by its strong dependence on temperature and strain rate at biaxial deformation. A nonlinear viscoelastic model by the previous study was employed in a thermoforming process used for food packaging. An optimisation approach was developed by achieving the optimal temperature profile of specimens by defining multiple heating zones based on numerical modelling with finite element analysis (FEA). The forming process of a PLA product was illustrated by modelling results on shape evolution and biaxial strain history. The optimal temperature profile was suggested in scalloped zones to achieve more even thickness distribution. The sensitivity of the optimal results was addressed by checking the robustness under perturbation.

Automated summary

The mechanical behavior of PLA in biaxial deformation is strongly dependent on temperature and strain rate, demonstrated by a nonlinear viscoelastic model used in a thermoforming process for food packaging. An optimization approach was developed by defining multiple heating zones based on numerical modeling with FEA to achieve the optimal temperature profile of specimens. The sensitivity of the optimal results was addressed by checking the robustness under perturbation.