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

Investigation of Cryogenic Cooling of Micro EDM Drilling Process on AISI 304 Stainless Steel

In this experimental work, the cryogenic cooling of the Micro-EDM (μEDM) drilling process for improving the performance and quality of micro holes. The controllable parameters such as the current (Ip), pulse on time (Ton), Pulse off time (Toff) and gap voltage (Vg) were chosen for further investigation. The Taguchi L27 orthogonal array is preferred to achieve the best experimental runs. Case hardened AISI 304 stainless steel is selected to perform the experiments. The overall machining performances of geometrical characterization such as taper angle, Overcut, Circularity at the entry and exit and the performance evaluation such as the material removal rate and electrode wear rate are analyzed. It is found that the taper angle improved by 91%, overcut improved by 17 to 66%, Circularity improved up to 70% and 68% respectively, material removal rate increased from 9 to 70% and electrode wear rate reduced up to 76%. It is found that pulse off time plays a vital role in the quality of micro holes drilled in both conventional and cryogenic micro-EDM (CμEDM) processes.</jats:p