US Patent 10266334 Barrier package aerosol container and piston for the same

A barrier package aerosol container includes a can, valve, and piston disposed in the interior volume of the can. The piston is movable toward a top end of the can to facilitate dispensing of flowable material in the can. Opposing surfaces of the piston and the can and the valve define an interstitial space of the interior volume in which the flowable product is receivable. The piston is contacts at least one of the interior surface of the can at its top end and the valve, to define a piston interface when the piston is at the top end of the can during use. At least one of the piston, the can, and the valve defines one or more flow passages at the piston interface to allow flowable material in the interstitial space to flow through the piston interface toward the valve inlet during use.