Do you mean "hot melt adhesive"? All adhesives must be able to flow on to and "wet-out" whatever they stick to. Some adhesives are dispersed in water (Elmer's glue), and some use a solvent (Testor's model glue) to give them the ability to flow. Once they wet-out the substrate, the solvent dries, and the bond is formed. Hot melt adhesives use no solvent to help them flow. Instead, they use heat. Hot melt adhesives are solid materials at room temperature that melt when heated. They are applied while molten and the bond is formed when they cool and solidify. A big advantage that hot melt adhesives have over those that use a solvent is that cooling to form a bond is much faster than drying to form a bond and they set up more rapidly. This makes them useful for high speed bonding applications such as making diapers, gluing cereal boxes, putting labels on bottles, etc. Most hot melts are blends of plastic polymers like polyethylene and EVA, resins, and waxes. Some, like the ones used to make duct tape and packaging tape, are blends of rubber and resin.