Fremstilling af polyurethanskum uden anvendelse af inaktive opskumningsmidler

A process for making low density and optionally low resilience, soft, flexible polyurethane slabstock foam having a substantially open cell structure without crushing, without requiring auxiliary inert blowing agents, by reacting under a condition which permits the foam to rise freely, a conventional hydroxyl-containing polyether polyol with a polyisocyanate at an isocyanate index of between about 60 and 95 in the presence of a foam processing aid comprising a low equivalent weight crosslinking agent and/or extending agent and, as needed, a cell opening agent.