Method for controlling the cell number in a polyurethane foam

摘要

PU foam is produced by mixing a polyol with an isocyanate, blowing agent and other ingredients. The number of cells is controlled by dispersing gas bubbles in one of the liquid components between the mixing head (1) and metering pump (3). Claimed process equipment comprises metering pumps (2,3) for isocyanate and polyol, low pressure mixing head (1), gas dispersion unit (5) between the mixing head (1) and one metering pump (3) and a means (6) for feeding gas to the dispersing unit (5).