Polyurethane PUR Hot Melt

Polyurethane glue or PUR glue is a reactive hot melt adhesive that is heated before application to form a permanent bond. Unlike traditional hot melts, the PUR adhesive reacts with moisture in the air as it cures and changes chemically to create a powerful bond. 

Polyurethane hot melt adhesives work by attaching to the object being glued as well as themselves to form a permanent bond. Once they create an initial bond, they continue to strengthen this bond as they react with moisture in the air. This is a chemical reaction known as cross-linking.  

Because of the chemical changes that occur during the curing process, PUR adhesives are incredibly strong. While traditional hot melts are similar to a wax bond that can come apart if reheated, PUR hot melt adhesives do no such thing and can offer great strength in minutes that will continue to get stronger as they cure over 24 to 48 hours.

Due to the nature of the product and how it cures, the typical shelf life of unopened polyurethane adhesives is 12 months but proper storage will prevent premature activation. 

PUR adhesives are moisture-curing products. To prevent them from curing prematurely, keep them dry and away from water or any other moisture.

To make opened polyurethane glue last, proper storage is necessary. Extrude a one-inch bead of adhesive to remove all air from the tube and any product that has already come into contact with moisture in the air. Next, securely attach the cap and store it in a cool, dry place. If recapped and stored properly, the shelf life of an opened Infinity Bond 50-gram cartridge can be extended up to 12 months.