Hot melt adhesives are thermoplastic bonding materials applied as melts that achieve a solid state and resultant strength on cooling. These thermoplastics of 100% solid materials melt in the temperature range from 65 °C to 180 °C. Theoretically, any thermoplastic can be a hot-melt adhesive, however, preferred materials are usually solid up to 79.4 °C or higher. They melt sharply to give a low-viscosity fluid that is easily applied and is capable of wetting the substrate to be bonded, followed by rapid setting upon cooling.
https://www.sciencedirect.com/topics/materials-science/hot-melt-adhesives
