Rigid polyurethane foam is an extensively used engineering material due to its outstanding performance of low-density, high-mechanical properties and thermal insulation. It can serve as a thermal insulation material, load-bearing structure material, potting material, etc. Rigid polyurethane foam is a low-density polyurethane system often used in insulation panels and fire retardant parts. This rigid foam is used in certain formulations for shoe sole insert components and even helmet liners.