Nonwoven filter media for automotive air filtration

Removal of unwanted airborne contaminants entering the automotive engine and passenger compartment is the primary function of automotive engine air intake and cabin air filters. In order to meet design objectives in these applications, engine and cabin air filters must function properly and maintain their performance as well as structural integrity during exposure to specific and often severe operating environments over filter life. To meet these requirements filter media used in both applications must posses suitable performance characteristics described by pressure drop, filtration efficiency, dust capacity as well as structural properties. Nonwoven filter media have been successfully utilized in automotive oil, fuel and air filtration applications. In engine air intake filtration, the requirements regarding increased filter life, has led filter media manufacturers to develop nonwoven filter media with higher dust capacity than traditional cellulose paper. In cabin air filtration, which is one of the latest and fastest growing automotive applications, nonwoven filter media dominate. This paper provides a review of nonwoven filter media used in engine and cabin air filtration. Media structures and filtration mechanisms by which they function are described. Since the design of automotive engine and cabin air filters is based on filter performance requirements, operational conditions and packaging constraints, these issues also are discussed.