Are there release agents currently available for 100% pMDI binder applications?
When pMDI first began being used in the pressing of composite wood panels, the release agents typically in use at the time generally provided good release properties. However, a drawback was that they tended to cause significant corrosion to pressing platens, considerably shortening the usable life of expensive equipment and negatively effecting mill output and utilization. As well, some of these release agents based could often be very irritating to the eyes and lungs, particularly when in mist form. They also imparted a dark color to the finished panels and had little to no “memory” (the ability to release for a period of time after the spray is interrupted).
New release agents were developed for use with pMDI binder systems. These materials give good release and have good “memory” while giving light-colored panels and exhibiting low corrosivity. However, they often suffer from a tendency to create buildup or “masking” on the pressing surfaces.
A new generation of advanced release agents for use with pMDI binder systems in the engineered wood industry is now on the market which exhibits low corrosiveness in the pressing environment and are much safer to use. They work at low application rates, have excellent memory characteristics, and give very light-colored panels without the buildup associated with some release agents.