Hot Melt adhesives are based on thermoplastic resins; they appear as a solid at room temperature but will become a liquid once heated. After it is heated, it can be applied and upon cooling, it will solidify, forming a bond. Because it solidifies as it cools, bonding occurs in a short time, which can improve efficiency of operations. With the exception of the solvent type, all are single component and non solvent types. There are polyester series, modified polyolefin series, and reactive type urethane series. Choosing the appropriate type depends on the materials to be bonded.
