PU basically consists of two raw materials, isocyanate and polyol, which are obtained from crude oil. Mixing the two process-ready, fluid-system components – which contain various auxiliary materials such as catalysts, foaming agents or stabilisers – gives rise to a reactive compound. Depending on the formula and proportions of the mix, the properties of the polyurethane produced can be precisely regulated – hard, soft, integral, cellular (foamed) or compact.