Bookbinding, Woodworking and Packaging Among Industries Reaping Benefits
Since hot melts are systems that consist of 100% solids, a transport agent for the sticky polymer does not have to be removed for setting, as is the case with water-based or solvent-based systems. Simple cooling is sufficient to achieve the necessary initial tack and bond strength; drying or solvent-recovery setups are not needed. Therefore, not only are maximum machine speeds faster than with many other adhesive systems, but initial investments are smaller, as well.
However, simply melting an adhesive to give it the ability to wet a surface creates some limitations. To achieve a viscosity acceptable for processing, the polymers used normally for hot melts are not as high in molecular weight as polymers in solvent- or water-based adhesives. As a result, the strength of a hot melt bond is generally poorer at high temperatures than that of other physically curing systems.