THIN FLEXIBLE ONE-WAY VALVE, PACKAGING INCLUDING THE SAME, AND METHOD OF MAKING THE SAME

摘要

A one-way valve is mounted over a vent hole in a flexible package to enable gases to vent. The valve has a flexible base layer, a flexible cover layer and an interposed layer of oil. Each layer has an opposed pair of side edges. The cover layer is thinner than the base layer and is secured to the base layer along respective contiguous portions of the side edges to form an openable channel. The oil layer is located in the channel between the base layer and the cover layer and over the hole to form a bond holding the cover layer on the base layer until pressure within the package causes the bond to break, whereupon the cover layer to lift ups and opens the hole valve. Methods of making the package and valve are also disclosed.