PROCESS FOR PREPARING POLYURETHANE FOAMS HAVING ZONES OF DIFFERING HARDNESS

摘要

A process for preparing a polyurethane foamed article comprising a hard foam encapsulated by a soft foam is provided. The process provides improved encapsulation over that described in EP 68820 by frothing the hard foam formulation, with for example carbon dioxide, before it is introduced onto the rising soft foam formulation. The hard foam formulation is frothed so that is density is between 75% and 145% of the soft foam formulation.