Definition - What does Heat Sealing mean?
Heat sealing an object refers to the process of completely isolating the interior of the object by using high temperatures and pressure to bond one or more thermoplastics to the material that requires isolation. Heat seals serve as a protective layer adhered to a corrosion prone metallic surface to prevent direct contact with corrosion causing agents such as water or other chemicals.
Corrosionpedia explains Heat Sealing
Heat sealing is performed by a direct contact method involving the use of a heated die or a sealing bar, which applies heat and welds the protective thermoplastics together. It is used to impede the free flow of energy and ions, thus keeping the base material dry and free of damage. Heat sealed jackets may be designed to protect against fire or corrosion-causing electrochemical reactions.
Heat seals are prone to certain problematic conditions that may reduce their efficiency, including radial cracking, coking, pitting, corrosion and blistering.