Fuel vapor adsorption filters

摘要

A fuel vapor adsorption filter for mounting within an intake air channel connected to an engine extends across the intake air channel in order to adsorb fuel vapor within the intake air channel when the engine has been stopped. The filter includes an adsorbing agent for adsorbing the fuel vapor. A holding layer is formed by a first non-woven fabric and serves to contain and hold the adsorbing agent. The first non-woven fabric is formed of thermoplastic resin fibers. A cover layer is made of a second non-woven fabric and serves to cover at least one side of the holding layer opposing the downstream side of the intake air channel. The second non-woven fabric is formed of thermoplastic resin fibers. The resin fibers forming the second non-woven fabric of the cover layer have an average diameter between 100 mum and 330 mum.