Reactive hot melt adhesives are heated to melt and become fluid. When fluid these adhesives are applied in molten state by nozzles or rollers. When the hot melt adhesive cools down, it builds up initial strength by solidifying. After the quick cool down, water molecules from the environment trigger a chemical reaction which is also known as crosslinking. After complete crosslinking, reactive PUR hot melt adhesives provide a stronger bond than thermoplastic hot melt adhesives. These PUR adhesives provide superior resistance against moisture, heat and chemicals. PUR hotmelt also makes chemical bonds with suitable reactive partners on the substrate, which improves the adhesion to many surfaces.