Polyurethane Reactive (PUR) hot melt is a combination between a PU adhesive and a hot melt adhesive. The combination of a very fast set because of the rapid cooldown and the curing afterwards of the PU Polymers provide a strong durable, constructive bond. As a typical hot melt this adhesive is solid prior to application and dispensed with a specific PUR hotmelt system. PUR hot melt is curing by contact with moisture in the air and forms a constructive bond that is not able to not re-melt. Normally thermoplastic hot melt adhesives, such as EVA and PO, will remelt every time it is heatened. PUR hot melt adhesives are available in high and low temperature application temperatures, with very fast setting or long open time, depending on the application requirements.
Polyurethane adhesives are strong and durable, therfore it is ideal for a wide variety of applications. Hotmelt PUR is used in woodworking, furniture production, building material assembly and many other applications that would require a constructive bond with afast set time, reducing production time needed in factories. Most PUR hot melt adhesives set within five seconds and have to cure for 24 tot 72 hours afterwards.
Finish Carpentry, trim/crown molding, building materials, wooden frames, stone, clay, drawer assembly, shoe repair, profile wrapping, carpet tack strips, laminate counter tops, windowframes, ceramic lawn ornaments, peeling wallpaper, paneling.
FREQUENTLY ASKED QUESTIONS ABOUT POLYURETHANE REACTIVE HOT MELTS
Question: Are PUR hot melt adhesives more durable than traditional thermoplastic hot melts?
Polyurethane hot melts are able to provide a stronger bond than traditional hot melt adhesives. PUR hot melt cures after making a strong initial bond. This curing process is also know as cross linking. The cross linking process makes bonds internally (cohesion) and strong bonds to the substrate (adhesion).
Question: Where does PUR hotmelt get’s the moisture from for curing?
Moisture is in the air and the object being glued. Normally there is plenty of moisture in the air to continue curing PUR hot melt, however, seasonal influences may fasten or slow down the curing process.
Question: Is it possible to prolong the shelf life of the PUR Hot melt adhesive?
PUR hot melt adhesives are packed in a foil pouch, this packaging should be stored in a cool, dry location. Do not expose PUR hot melt to rain, do not store outside and prevent contact with moisture. When shutting down for the day, it may be necessary to flush the system or seal the outside of the nozzle or extruder. CAUTION: Do not touch the nozzle, extruder, coater or applicator when at maximum temperature. Always wear heat protective gloves.