The release of very fine gas bubbles into the reactive mix – known as nucleation – is responsible for cell formation and for the later cell structure of foamed polyurethane products. The gas charge on the polyol side is thus indispensable for certain PU applications. When producing rigid integral skin foams, this process serves to create the extremely high number of gas nuclei required for the ultra-fine cell structure of these foams. Gas-loading is also a widely used method for processing compact PU systems as in RIM and RRIM applications, for instance. During the chemical reaction, it causes a dwell pressure in the mold that prevents sinkmarks and considerably reduces trimming and finishing requirements. Moreover, this allows very high-quality surfaces to be achieved for compact systems. Hennecke offers two AEROMAT types for the different applications. The "ST" version is used for low and medium gas load rates of up to 25 percent, the "GU" option is the right choice for gas load ranges from 50 to 70 percent.