All the advantages of the polyurethane binder for the foundry industry were accompanied by the serious disadvantages of the indespinsable aromatic solvents., i.e. not only the emissions during core making and moulding but paricularly those after pouring.
At the high temperatures maintaining during the pouring process the binder components are subjected to a pyrolysis process,giving rise to new stable compounds.With the presence of of aromatic hydrocarbons the pyrolysis process produces benzene, toluene and, xylene which are thermally stable.
|
