Educational

Natural rubber was once the main material for sealing devices, but silicones and polyurethanes have replaced it due to their better properties. High-density polyurethane foams are now used in automotive air filters, offering benefits like elasticity, strength, and temperature resistance. These foams contain tiny bubbles formed during production, and their manufacturing involves mixing polyols and isocyanates, with curing taking place at room temperature through an exothermic reaction.