Integrally formed air flow valve

摘要

A region in a thin plastic sheet is formed to include a series of corrugations. These corrugations are include alternating peaks or crests and roots or valleys. The plastic sheet is to be installed on a workpiece intermediate areas or zones periodically exposed to differential air pressures. Slit areas incorporated into adjacent crests of the corrugations to extend along a longitudinal portion thereof allow air flow passage therethrough in one direction while preventing air flow in the other direction.