Comparison of Mathematical Surface Energy Models and Fuzzy Approach Pertaining to Surface Energy Level of Polylactic Acid and Linear Low-density Polyethylene

The usage of flexible film in the food packaging industries has been rapidly increasing over the past few years. In flexible printing process, the wettability and adhesion of polymer substrates depend on the surface composition, roughness, energy level and tension. Among all these properties, the Surface Energy Level (SEL) of polar and nonpolar polymer substrates were determined by measuring Contact Angle Values (CAV). This study focuses on experimentation based SEL measurement using corona treatment for both treated and untreated LLDPE (Linear Low-Density Poly Ethylene) and PLA (Polylactic Acid) films using MSEM (Mathematical Surface Energy Models) such as Fowkes, Owens-Wendt, and Wu based on the CAV of polymer films and further to develop a Mamdani fuzzy interface based model for predicting optimum SEL with help of experimentally generated data. The observed SEL of untreated and treated PLA and LLDPE films were 40 and 38, 48 and 44 mN/m respectively. Fuzzy-based simulations showed similar results, with treated PLA and LLDPE at 45.4 and 44. Finally, the proposed Mamdani model can predict SEL with high accuracy in comparison with experimental results and the good printability of ink adhesion was achieved in treated than the untreated films.