Heating behavior and adhesion performance of induction-heated multilayered thermoplastic polyurethane adhesive film

ABSTRACTA multilayer thermoplastic urethane (TPU) adhesive system was developed to achieve higher heat generation efficiency and adhesion by using the same amount of nickel particles in an induction heating process. The results of the present study show that a higher heat generation efficiency and peel adhesion strength were achieved with a higher density of nickel particles in the core layer, even for a constant 20 phr nickel particle content in the 200 μm film. The heat generation mechanism of the 70 nm nickel particles was confirmed as hysteresis heat loss by calculating the magnetic penetration skin depth. The results of the scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) analysis show that the observed failure mode was substrate failure in the peel adhesion test, and the nickel particles of the core layer were spread on the TPU adhesive film at the top and bottom. In conclusion, the multilayer structure, including the high-density susceptor core layer at the center of the ad...