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

Area of Science:

• Materials Science
• Polymer Engineering
• Sustainable Manufacturing

Background:

• Poly (lactic acid) (PLA) is a biodegradable thermoplastic with potential for green manufacturing.
• PLA's mechanical behavior is highly sensitive to temperature and strain rate during biaxial deformation.
• Thermoforming is a key process for creating PLA products, especially in food packaging.

Purpose of the Study:

• To optimize the thermoforming process for Poly (lactic acid) (PLA) products.
• To achieve uniform thickness distribution in thermoformed PLA items.
• To enhance the manufacturing efficiency and product quality of biodegradable packaging.

Main Methods:

• Utilized a nonlinear viscoelastic model to simulate PLA behavior.
• Employed finite element analysis (FEA) for numerical modeling.
• Developed an optimization approach to determine optimal temperature profiles using multiple heating zones.

Main Results:

• Modeled the thermoforming process, illustrating shape evolution and biaxial strain history.
• Identified an optimal temperature profile in scalloped zones for improved thickness uniformity.
• Demonstrated the sensitivity and robustness of the optimization results under perturbation.

Conclusions:

• An optimized temperature profile significantly improves thickness distribution in thermoformed PLA.
• FEA-based optimization is effective for tailoring thermoforming processes for biodegradable polymers.
• This approach contributes to sustainable manufacturing of PLA products, particularly for food packaging.