Polyethylene Terephthalate (PET) presents unique thermodynamic and interfacial challenges for induction sealing compared to traditional polyolefins. Unlike non-polar HDPE, PET is a highly polar polyester characterized by a higher glass transition temperature ($T_g$) and a distinct surface energy profile. Therefore, the heat-sealable stratum of a PET induction wad must utilize a co-extruded polyester-based resin or highly modified, specialized hot-melt adhesives to achieve proper wetting, flow, and adhesion to the rigid container lip during the ultra-fast transient heating phase of the induction cycle.