Polyurethane reactive adhesives (PUR adhesives; also known as reactive hot melt, reactive polyurethane or RPU adhesives) are one-component formulations that combine the initial speed of a hot melt adhesive with the strength of a structural adhesive. The bonding process is divided into two stages: retention strength is achieved when the adhesive cools and cures like a hot melt; then the final structural strength is achieved by a wet curing reaction over the next 24-48 hours. These adhesives are resistant to extreme temperatures and are flexible, providing resistance to vibration and impact.
PUR hotmelt adhesives are known for their strong bonds and excellent resistance to heat, cold and humidity; this makes them ideal for most difficult-to-bond, low-energy substrates, and they also perform well in extreme weather conditions.
