Coating the back of a textile floor covering with a polyurethane foam

A process for coating the back of a textile floor covering with a polyurethane foam comprising:

• (a) applying a reacting foamable or reacting prefoamed mixture of a polyol and a polyisocyanate directly to the back of said textile floor covering, the NCO to OH equivalent ratio in said reacting foamable or reacting prefoamed mixture being from 1.5:1 to 3.5:1;
• (b) applying to said reacting foamable or reacting prefoamed mixture before said reacting foamable or reacting prefoamed mixture has fully reacted a second reacting foamable or reacting prefoamed mixture of a polyol and a polyisocyanate, the NCO to OH equivalent ratio in said second mixture being from 0.95:1 to 1.25:1;
• and
• (c) allowing the composite material of step (b) to harden, thereby forming said foam coating.