Reactive hot melt adhesive
Reactive hot melt adhesives are based on polyurethane (PUR) and polyolefin (POR).
Sequence of the adhesive reaction
The moisture-hardening hot melt adhesives bond via a two-stage reaction:
In the first stage, the adhesive undergoes a physical setting mechanism that gives the adhesion a certain degree of hardness. This hardness is sufficient to allow further processing or transport.
In the second stage which, depending on the type of adhesive, can last over a period of hours or days, chemical crosslinking takes place. This chemical reaction depends on the supply of moisture and the access of the glue joint to moisture. After the hot melt adhesive has fully reacted, it loses its thermoplastic properties, which means that it does not soften again, even when the object to be bonded heats up. The resulting thermoset has the exceptionally good adhesion values of the polyurethane, combined with high strength, high heat resistance, good low-temperature flexibility and good solvent resistance.
Delivery forms of reactive hot melt adhesives
The range of the offered types of containers goes from 310ml cartridges for the HB 700 K / KD for manual application, up to a 200 kg drum for the HB 4000 drum melter series. The tank systems are equipped as standard with a compressed air dryer, which prevents the humidity from increasing the reaction speed of the reactive hot melt adhesive.
The tank systems, bag melters or drum melters are used in the following areas: automotive and construction industries and furniture and mattress manufacturers.