Polyurethane wear plates are steel backed, the steel is bonded with polyurethane to prevent fines penetrating behind the liner plate, thus preventing bulging of the liner which can otherwise cause liner dislodgement. These liners are a harder material compared to rubber but softer than plastic, therefore providing an excellent degree of abrasion resistance together with flow ability.
Poly liners perform very well in wet applications with fine particles and sliding wear.
Polyurethane liners are a synthesis of polyols and isocyanides chains extended or cross linked into giant molecular complexes. This material has the combined properties of rubber and plastic.