Finite element thermal modeling of paperboard formability using Abaqus

Abstract

Thermoformed polymer-coated paperboards are a promising solution for sustainable packaging applications. This study examines the influence of temperature on the thermoforming behavior of Polyethylene Terephthalate Glycol (PETG) coated paperboard sheets using finite element simulations in Abaqus/Standard. The composite shell model consisted of two layers: a paperboard substrate of 0.475 mm thickness and a PETG coating of 0.05 mm, modelled using composite shell elements. Composite shell models representing a substrate paperboard with PETG coating at 80 °C, 100 °C, 120 °C, and 140 °C were analyzed, while maintaining constant geometry, contact friction, and an applied pressure of 0.2 MPa. The results show that with the temperature increasing, the material stiffness and peak von Mises stress decrease gradually, and the formability increases. Within the studied ranges, a temperature of 120 °C was found to be optimal for forming, having the highest values of in-plane principal strain, highest plastic strain values, and maximum forming depth of 16.5 mm. In the comparison of the two material layers, the PETG coating exhibited consistently higher stress and plastic strain levels than the paperboard substrate. Increasing the temperature from 120 °C to 140 °C did not lead to further improvement in formability, indicating that the thermal softening effect saturates in this temperature range. The results across 80–140 °C reveal a clear trend of reducing stiffness and increasing formability, peaking at 120 °C, offering quantitative benchmarks for industrial process parameter selection and future coupled thermo-mechanical modelling.