Polyurethane (PUR) foam is a plastic formed by polyaddition of isocyanates with polyols. There are different types of foam: From soft, rather elastic foams to hard, rather brittle foams. Open-cell soft PUR foams are used, for example, for the production of filter inserts, household sponges, transport protection, upholstery in vehicle construction, seat cushions, mattresses, packaging. Closed-cell, hard PUR foams are used in the manufacture of packaging, suitcase inserts and for thermal insulation.