Every polyurethane foam formulation is, at its core, a race against time between the blowing reaction (water and isocyanate generating CO2 gas) and the gelling reaction (polyol and isocyanate building the polymer network). If that timing falls out of balance, the foam either collapses before it can support itself, or gels shut before the gas has escaped, creating unwanted closed-cell defects. Controlling this reaction rhythm is exactly where the value of catalyst selection and formulation design lies.